One Saturday morning I got to work and found a rough-cut titanium ring on the table with a drawing and a note: “Here’s your job for the day, don’t make a mistake, we aren’t allowed to weld on it and the blank costs $10,000.” I definitely had to sneak up on it.
Actually sometimes you can, I used to work in a fabrication shop that our parent company was a big time machine shop in Cleveland, the weldments we made were usually large and complex that took sometimes weeks to fabricate and weld up, every once in a while some machine operator or a CNC machine that went buggy when someone hit a phone pole in front of the place would make a bad cut and we'd get it back having to build up weld in an area so it could be recut, that was a bitch doing it to because there couldn't be any kind of porosity or voids anywhere inside the weld, if the shipping door of the place was open and a wind from a storm blowing in blew the shielding gas away for just an instant just go ahead and put down the welder and pick up an air arcer and gouge that spot out, because if you didn't guaranteed it'd just come back again and this time people would really be getting upset because of how hard it was to move some of those machine frames back and forth to us 3 blocks away. But that said yea, sometimes because it couldn't be welded up due to engineering and metallurgical reasons or if it wasn't worth the trouble just throw it away and start over, I know the US Navy doesn't want things like bad machine cuts welded up and recut, they were very specific about that on a set of 3 foot diameter gears we made for them, just because they were gonna spin at 10,000 RPM's on a jet engine in a destroyer, the nerve of some people.
@@dukecraig2402 tru I worked in a welding shop for a long time and if it is thick enough you can weld on extra but that takes way too much time. Especially if you are doing something like custom picket railing or fencing where you might have hundreds or thousands of pieces. To make a mistake and cut those too short it could be really costly to fix. Measure twice, cut once
@@haydenpryor2494 Yea, as I pointed out there's plenty of times it's not feasible because of cost, but when you've got press frame that's for a press rated at 1,600 tons needless to say it's more cost effective to have a guy weld up an area that'll take him a day or two as opposed to throwing the whole thing away. But like I said sometimes standards won't allow it no matter how little welding you may have to do, stuff for the military and for nuclear power plants are typically the kinds of things they don't want anything like that done to, imagine that. Someone screwing up a couple thousand feet of handrail is the kind of thing someone usually gets fired over, especially if it full blown fancy ornamental work and not handrail that's for a stairwell for a hospital or something like that. I also used to be a union ironworker, I was on raising gangs but when the kick off for a job would get pushed back they'd break up the gang and temporarily send everyone to other gangs just to keep you working until the new job kicked off, I spent some time working on ornamental gangs as a result and saw a lot of handrail and especially stairwell components that got trashed and refabbed, stair pans a lot, someone would get a stop set up on a press just an ⅛th inch off and pallets full of them wouldn't be any good, what's so amazing is the bids on some of those buildings was so big having to make a whole new set of stair pans wouldn't even get people that upset, I did jobs that were 150 to 200 million dollar buildings, something like those stair pans was a drop in the bucket for something like that, not me though, I'd always volunteer to get rid of them with my pickup truck, straight to the nearest scrap yard and directly into my pocket from there.
this is exactly why i dont machine things for other people, why i havent tried to make a living off of machining. i still take some odd jobs but only when the stock is cheap and its just a couple simple operations. appreciate all your vids, you explain things well. its really important to have this information online for people like me - who learn by doing without having a mentor
I quit machining and moved into machine repair because of the customer not understanding why we charged what we did. "Why can't you just CNC this?". I saw the end coming.
Nothing like irreplaceable tools. They deserve the upmost respect, they are quite literally a treasure. The job has to adhere to the capability of the tool and not the other way around.
That’s why when it is my antique stuff i take it to my local shop to get done because i can’t sneak up on it or fix it if i screw it up. So when it is critical i leave it to the professionals.
That’s a motto to any business involved in repairing/modifying customers goods! It doesn’t matter if it is a shoe repair, a garment adjustment, a cell phone screen replacement, a computer hard drive filled with memories (I saved a marriage once when the customer deleted pictures of his wife when she was 9 and grandpa was still alive!), or a toy from their kids, If you don’t account for the value of the object itself, you must account for sufficient insurance to care for it! AND the customer must be educated ahead of time to be in tune with any risks involved! They must understand the value you add when you expose such risks to aid their decisions when compared to other professionals who don’t! Excellent point you brought up!
Engineer: “how accurate to spec can you make the part?” Machinist: “oh, idk, within a couple of tenths.” E: “of an inch?” M: “no, ten thousandths”. E: “oh okay, well then let’s do that. I’ll need fifty of them.” M: “I don’t think you want me to do that. That’ll cost a fortune and take me months to make. Or I can just rough out 100 in about two days and tolerance check them after” Machinists can be very accurate, but often don’t have to be. Then there are times like this, where they need to be.
As an engineer I had this conversation in the first month after I graduated. I swear that we were never taught to think like that at university though. I would also add to that, considering making things from stock sizes. Engineer: "the bar needs to be 37.5mm x 46mm in section" Machinist: "you sure? The stuff on the shelf is 40mm x 40mm" Engineer: "let me change the drawing..."
The university I went to had first years lathing parts for a project in the same course that they learned 3D modelling. It was helpful to see both sides for this reason
@@johnnyt7067 the "stuff made here" channel put it really well. "The computer has this problem where you can just keep zooming in and then without thinking you have features too small to machine" or something like that. It's a real problem that engineering programs don't have tools for the students to use and learn about because half the engineering students you talk to don't know why tolerance matters. I'm closer to a machinist than an engineer and the company I'm at does it really well. All the time we have parts that could be off by a 32nd of an inch and still be totally fine but then we have a jig or something that we have to make so it has to be within some crazy degree of precision or every part made with that jig will be off. It's often the same with parts that have to be water tight too. You get a piece of crazy hard material that takes 4 hours per piece because it has to be exact
Grinding standards and gages, getting the cross hatch, parallel, half a millionths, 65 Rocwell C, lapping, micro finish, and certification, all add up to $.
I worked at a shop where many of the parts were usually +/- .005 or +.003/-.000 but one time I had to make a bearing retainer that had a tolerance of +.0000/-.0002. I made 6pcs, they were +/-.001. I shipped them to the customer. A week later, I was making 6 more…to the proper spec. I learned my lesson, luckily it wasn’t any significant material cost.
I have often thought of machinists as the surgeons of the trades. I find their work fascinating! I’m a retired civil engineer, and we work in feet & inches. If I mess up, there’s a wet spot in the lawn. When you guys mess up, stuff clangs, and spacecraft explode.
Absolutely. Tight tolerances affect the programming (if CNC), the fixturing, time required to measure, and time involved in sneaking up on the final dimension. It will definitely add to the cost.
Had to work on an iridium piece at a semi-conductor machine shop, worth $360,000. I was 5 years into my career and had only been at the shop for 6 months. I was sweating bullets, made a good part. 🎉
Anytime, I make something on my grandpa‘s lathe, which is almost 100 years old, I get it close to size and then walk away for a while. Later, after the piece cools down, I’ll then take very fine cuts to finish it. Works well for me.
I'm a carpenter and some materials I'll cut down five/ten times to get it just right because that's the finished product, no paint, no caulk, no cover-up, do it right or make it twice. Awesome work made interesting 🤔 Thanks 🙈🙉🙊
When I used to work as a machinist (I had to quit because of workplace allergies, a 17 year career down the drain😒) I was in charge of setting up and inspecting the first part of all our CNC machines so the "green button pushers" could take over and run the jobs and was one of 5 people in the shop out of 108 machinists and operators who was given jobs like these, for the sole reason that we had this type of mindset with expensive parts, there is simply no room for failure and it has to be meticulously planned out and ran through multiple checklists several times before anything gets cut, it absolutely costs extra money to put the higher skilled workers on jobs like that who have to take their time as well. It goes the same with expensive material, I've done jobs with billets of material that cost more than my house and one wrong tolerance will scrap the entire thing, some customers will not accept a part that is even .0001" out of tolerance and it screws the company over big time, so you have to creep up on all your numbers and meticulously inspect everything throughout the process.
@@jacobwiertsema4784 It was the cutting fluid/coolant in the machines, I'm not sure what exact component of it I was allergic to but it didn't matter what brand it was, all of the water-based coolants used in machining caused me serious issues. It started with itchy skin, then turned to rashes, then it started making me feel awful whenever I was around it. Near the end of my career I was doing everything I could to stay away from it, working as a full time inspector so I wasn't working directly with it, but even the airborne coolant that evaporates into the air was causing problems, I was getting very routine headaches that happened once every 5-8 days that were so painful they would put me in bed for an entire day with the windows blacked out due to light sensitivity. I had to file for FMLA just to keep my job, I was missing work literally one day nearly every single week because of it, and when I finally broke down and stopped working in machine shops the headaches disappeared in about two months, and I haven't had one in the three years since.
Damn 17 years and you’re bragging about only being able to troubleshoot a part😂I’m 23 and do that shit all the time and do the off hand programming on a control and do the overhaul work I made 104k this year
@@jggg202 Who said I "only" troubleshot parts? I did everything in that shop, I programmed, I made tooling, I fixed everyone else's fuckups (many of them by a lot of 20-something yr old hotshots who thought they were king shit like someone I've just been introduced to), I ran and programmed CMMs, Romer Arms, a Lieca laser tracker and scanner, did Solidworks stress analysis, and much, much more. I think you might want to increase your reading comprehension before jumping the gun like that and making yourself look like a tool.
Being a Machinist.... probably the world's most respected professions and skill a person can possess. I applaud your craft 👏. Humbled by your experience and expertise.
Props to Austin for standing there to share this lesson with the rest of us. Mistakes aren't some reflection of our worth as a person, which seems to be the trend nowadays and people will fight against him taking credit for any misstep. Training new people is really hard because some people take it so personally regardless of how minute the mistake was. Glad to see there's still human beings out there. I've never seen anyone do something worth doing that doesn't have a large collection of mistakes along the way. Happy to see a business not just get angry and let the employee learn as well and a results in that great investment for the company and for the employee.
Great advise to anyone whose doing irreplaceable work for customers or their selves and it never hurts to slow down sometimes if the process isn’t working exactly the right way
This is the knowledge and wisdom that can only be learnt with years of time served! Great video guys! I wish I could find a machine shop in my area like yours, they have all gone!
So many people will get mad when you tell them that you've got to charge them through the roof or that you need a disclaimer. People just don't understand the undertaking and the potential costs when trying to mod Irreplaceable parts
People don't realize that you need to also be consistent. You want to hit 2 tenths on a part, you can't just cut a tenth at a time (with conventional tools like a lathe). Just recutting at the same dimension will result in undersize. So it's important to cut to a known consistent operation: rough...rough, then semi-finish, semi-finish, then take 1 or more finish passes (first pass will tell you how the second pass should react). I'm not telling you anything you don't already know, but to the average joe it's not as simple as "dial in the number and click the lever". Heck, CNC machines need more care!
I made a cast iron bushing for old unique hydraulic motor pump. I pressed it in, and out several times, until it was sized to fit the shaft. Sweating that I would oversize the bore.
As a maintenance manager, if this situation occurs, I fully understand and appreciate the shop doing the right thing, and ima pay ya. My local shop operates in same manner
i was lucky to have a shop teacher like you, I see myself in that bearded gentleman in the background. Absolutely filled with knowledge gathered through actual experience, and with the will to teach it to the next generation. This stuff will always be essential knowledge, no amount of evolution will take us past mills and lathes, welders and fabricators
I worked in a machine shop. I did not hurt I did not walk quickly to the bathroom I did not change the tooling quickly. I put my vice on my Bridgeport with three bolts. I think this is the best message for anybody just cut everything close and then fit and measure for the exact part. I like each step to be a calculated part at the last of the machining for a finish pass.
Respectfully most people are lost in many of these videos this man makes because they do not understand how technical and precise these items need to be fabricated. Many people in todays modern society believe robots do this work and can not appreciate the level of skill and experience it takes to fabricate or modify these parts, especially one offs. Its great you make these videos atleast you demonstrate the technical level and the need you and your worker bring to society.
We knew a guy who made hydraulic scraper rings for the landing gear on military aircraft. We needed some basic machining done for our business and he offered to help. In comparison to his stuff, ours was completely elementary. What we spent a few hours scratching our heads over he was able to figure out and complete in mere moments. Such a great (and completely professional) guy. RIP Mr Schultz.
I have been a Machinist in the trade going on 46 years welcome to my world it's not just how to set up something and hope it doesn't hurt you in the process but it's about Time & Materials and most importantly Fit, Finish, Function , as an end result
When I was fresh out of school (18), I worked at a machine shop as a helper/apprentice. I had no machining experience whatsoever. They put me to machining dipole connecters for satellite navigation antenna (on a forerunner of GPS). The tolerances were +.005/ -.000 and I was expected to maintain that on a lathe that was pre-WWII vintage and had more backlash than a critique of your wife's family, cooking, romantic prowess. They put me at the lathe with a washing machine box full of about 3500 of these things and told me to have at it. The only instruction they gave me was when I got within 5 thousandths of spec, do not move the tool, that the push-off of the previous cut should get me within my tolerance. Out of 3500, I think I missed my smallest tolerance by about 1 - 3 thousandth under on about 280, which I thought wasn't bad with no experience and a worn out lathe (I know what you say about it's not the machine). We assembled the bases and the number killed came down considerably but we still lost around 100. 43 years later, I'm not a professional Machinist, but now when I get to do any machining, I'm better on maintaining my tolerances but the stuff I have done since I've had newer tighter machines to work on.
Sometimes we got the jobs, even without the lowest bid. We had tight tolerances, finish, sharp edges broken, holes chamfered, in other words, quality. Take apart a 500 and 870, 12 gauge. The edges are left on the 500, and can cause wear, or injury. The 870 is built with quality.
Do a check pass slightly undersize before you shoot to size. Also helps to use a bore mic or dial bore gage instead of telescoping gage when holding a tight dimension.
As a gunsmithing student I was assigned a .357 S&W revolver with the customer requesting I install a 3" barrel after removing the factory 5". I suck at math. They probably should have charged extra. With much help from my instructor a TX Instruments calculator and tons of formula out of a cheat sheet book I got a new short barrel indexed and everyone was happy😊
I remember machining a whole bunch of parts for my dad and when I measured them they were still warm and hot and when he went to ship them out they were cooler and the tolerances were all off
Yep. I've made a bearing-fit for parts on one day, then came in the next morning to find them to be too tight. That's what happens when you don't have heat in a machine shop in winter.
That's why we had a controlled atmosphere quality control room. 68°F and 50% humidity year round. You bring a part in, clean it, set it on the CMM, and let it acclimate to the ambient temperature. Run through the tests, print the results and then follow whatever in process checks are required. I ran a job that had 8 hour cycle times, the material was very expensive, it required specific expensive tooling, and the tolerances were extremely tight. It's stressful as hell. You are swapping inserts multiple times per run too. So much opportunity for error.
@Chris P. Bacon Completely depends on the metal, what temp it was while being machined, how well your coolant works, where it's checked etc. You could see .01" if everything is going against you. (That's a huge difference in this trade)
We had a tool man that would come into our old shop and try to sell us saw blades. My boss got sick of him coming in and tired of telling him no we couldn't use them. The seller swore by his product. My boss finally went ahead and told him, "if you can cut this piece of metal in this vise we will buy them all." Totally trolled the tool man for minutes while he vigorously tried like hell to cut this material. Once the teeth started breaking and he realized he wasn't making a scratch. My boss told him, now you see what the problem is. Son, that is Hastloy. Still one of the funniest things I've ever seen until this day. 😂😂😂
Completely agree, when the piece is valuable and has to be "perfect" you inch toward that. You can always take more material, but you can't put that material back once it's milled off.
I never did it in the field, but i spent 3 semesters in college doing Auto Machinist and I understand how tough that job is. I don't see myself argueing with a Machinist.
I have never, ever heard of this fee. I used to make parts for the old German automatic pistols and aerospace parts and I always made certain that I made the correct drawings before I machined the parts and I always used the metric system so tenths to me is 0.10 mm.😊😊 For one thing I studied machining under the care of Germans from "Operation Paperclip" and all parts came out to specifications. I'm hearing this attitude on machining and it really, really sounds "wack."
I worked for a guy who did not understand that. To be fair, his background was fabricating and welding, and he had a successful business, but he wanted to do machining. And he underbid jobs because he didn’t understand that tighter tolerances required more time. Also, he’s miss surface finish callouts and grinding tolerances. He quoted jobs on more than one occasion for machine time only, and we had to send it out for grinding and heat treatment 😬
Oh boy then there’s my dad who designed a “2 ton” jack… long story short they were a huge hit, people come back STILL 20 YEARS LATER ASKING “please fix this jack it’s THEE BEST I have used” the dude lifted his SEMI with it.
I had to bore out three bearing fits for a planetary gear box. After each cut, I kept a record of what was the actual dimension verses what I set the cutter to. This way, if the bore went oversize (which did not happen) I could show my methodology and how I was accounting for tool pressure. Slow but steady. I hit sizes on all three bores.
Precision is part of everyfay life for a toolmaker. Believe it or not it becomes second nature and just another job. I go for a few .0001" and polish to size. Looks like ground finish and spot on every time at 15deg C 😊 never forget the temperature of the job.
Literally all you got to do is divide your cut into 2 cuts, both equal. Take the first cut and use the equivalency formula to figure out intended/actual cut made. Then offset the machine to compensate for the error. The next cut will be within tenths, if you followed the steps correctly and your machine is repeatable. If the machine is inaccurate and non-repeatable, obviously you shouldn't be using it for precision work. Edit: you can use this to find out your tool pressure and rigidity. It will work for any cutting tool, any setup.
No matter how good You are more time is needed if the part is of higher value, not just double checking everything, but rather 12X checking everything. This video I did some time ago Echos Your point, as to obtaining a good size: ruclips.net/user/shortsFsuQgCGDSyI
@@HOWEES I worked machining platinum on swiss automatics making cardiovascular implants. .068" stock o.d. 15 operations 2 spindles boring milling drilling. Holding sub tenth tolerances measured optically and digitally (mitutoyo ELF) You can factor in oil temp and guide bushing preload on a sliding headstock, but on yours all it is a simple backlash measurement and compensation since you're only looking for .001 accuracy, or .0007 if you're really tight. Anything else, you're using the wrong tool for the job. Now if your bearings are worn, just say that. I appreciate what you're getting at, but it only applies on small frame manuals or very worn machines. I love your content, but I just think that a distinction should be made. Both things are very good to know. People often have to work with what they have, and for that audience you shine. I think you would do better showing the process instead of talking about it is what I'm getting at. Show what makes your process work for a worn machine or a hobby machine. You have a platform, go in and show how to make sand plugs, or hone it or however you make due with what you have. Show it. Thats the special bit, ya know?
I have also worked with every other style cutting tool there is. I stand by what I said. Cross multiplying then dividing to get the cut/cut intended then applying it to one decision forward resulting in an insignificant math error, not a human one.
Generally yes, sometimes there is no other method of machining something. 30 years ago I ran a gun drill. EVERY piece ran was a setup piece. Gun drill bits had to be sharpened EVERY part ran. Granted machines were 30 years old but kept up to top specs. I spent several months with an engineer checking every possible variable. IE speeds, feeds, oil pressure, bushing size, etc. We finally settled on 5 pieces per sharpening to hold a hole about 2" deep with concentricity of .0005" TOTAL. Used air spindles with ring gages to set the high/low tolerance zone. That one feature cost $500 EACH! Now this was production items to keep craft in the air. I now restore antique tractors. Same as for cars, motorcycles, whatever. Sometimes the ONLY piece you have was dug out of a river bank after 90 years being there. It doesn't matter if you have a MILLION DOLLAR MILL you STILL sneak up. One tractor I have is the oldest in existence and 11th made. I've had to buy 6 other tractors to get specific items that are unobtainable otherwise. But once done this machine will ONLY have factory made components with ONLY items new replacements being tires, oil, filter, gaskets, rings, and bearings. IT WILL BE PIECE ALL OTHERS WILL BE COMPARED TO!
Undershoot, check and creep up on it so you don’t overshoot. When something is too big it can still be worked with, when you try to hit the mark but go over the piece is done. When working on a one off and things can’t be replaced there is a different set of rules to play by so you don’t screw yourself and the customer
The company I work for (I do the engineering side) repairs high speed pumps. Our manual machinists are some of the best there is. They may not be the fastest but they do excellent work as messing up a diffuser for a boiler feed pump could be $10k-100k in costs to undo and up to a month in time. Even worse if it has to be scrapped. So taking the time to ensure the parts are damn near perfect when they leave and to question engineering if something feels even slightly off are immensly valuable qualities for a mchinist to have simply because we cannot afford to make big mistakes.
Better to sneak up than blow the size on roughing passes. I just make sure I can take atleast 2 finish passes with a TPMR 01 radius with .015 per pass. Check taper after the first pass, mark accordingly , attach dial indicator to saddle to read X, dial out taper in second pass.
Sometimes with Stainless or TI alloy you have to watch sneaking up on the final dimensions. If you have a .002” thick work hardened skin on the part from the previous pass and try to take that .002 or so off you end up taking .004 off. Something you won’t learn until you physically see do it.
well that explains a lot. even if it's a $2000 part that's still a big headache, and even if it's a $200 part it's a hassle... so it makes sense that people have been less and less willing to do that sort of thing over time.
I worked as a process inspector and often had to ask the engineers, "Is that really the tolerance you want? " The print would show + or - 50 millionths and in reality + .005 - .000 would suffice.
I am a maintenance mechanic in NASA's Jpl. I see the guys working to tenths daily. I see the old school machinists do this on 60 year old Bridgeport and Hardinge machines. All the younger guys cannot do this without 500k machines. There are no young guys coming up in the trade that can do this on manual machines
Really suck when you make a whoops on a Mold base that the previous machinist spent 2 weeks working on. We can usually weld up a whoops on a part though, usually anyway.
Depends what it is what it's doing why it needs to be that size ect ect if you're making the mating part then if you screw up on the bore you can just usually compensate on the shaft
This is where it helps to know your process capability. “Sure I can hit the target within 0.0005” turns into “you don’t understand all the complexity and such and such” real quick- and thats because as an engineer, you went off some guys gut feeling about accuracy instead of measuring the process outputs. If your CPK is less than 1.3 for the process, then prepare to slow it down and have a guy sweating bullets trying to make sure he doesn’t blow past the target because the process is out of control. Thats just how it works. When people talk about “sneaking up on the dimensions” that means they understand their normal process is not capable, and so they have a secondary, much slower process which in fact is capable. Study that, or you will lose a lot of money!
yes absolutely you need to account for extra time the tighter the tolerances. The number of managers that think you can keep a +/- 0.0005 one shot with a CNC. While CNC is more accurate it is still a slower process to ensure a 0.001 total tol
One Saturday morning I got to work and found a rough-cut titanium ring on the table with a drawing and a note: “Here’s your job for the day, don’t make a mistake, we aren’t allowed to weld on it and the blank costs $10,000.” I definitely had to sneak up on it.
How big was the ring?
That was my life as an Air Force Machinist.
@@matter9 big ass finger.
Oh, wait, I don't think he's talking about jewelry
reminds me of high tech ceramic stuff, 1 little piece ends up costing $10k
What kind of blank like that can cost 10,000 dollars though? Did it have platinum or something in it?
General rule: You can always cut more off. But you can't really add more to it
I cut another piece off and it's still too short.
When I first started working in a machine shop, the machinist used to remind me that every time I would hand him drawings and dimensions.
Actually sometimes you can, I used to work in a fabrication shop that our parent company was a big time machine shop in Cleveland, the weldments we made were usually large and complex that took sometimes weeks to fabricate and weld up, every once in a while some machine operator or a CNC machine that went buggy when someone hit a phone pole in front of the place would make a bad cut and we'd get it back having to build up weld in an area so it could be recut, that was a bitch doing it to because there couldn't be any kind of porosity or voids anywhere inside the weld, if the shipping door of the place was open and a wind from a storm blowing in blew the shielding gas away for just an instant just go ahead and put down the welder and pick up an air arcer and gouge that spot out, because if you didn't guaranteed it'd just come back again and this time people would really be getting upset because of how hard it was to move some of those machine frames back and forth to us 3 blocks away.
But that said yea, sometimes because it couldn't be welded up due to engineering and metallurgical reasons or if it wasn't worth the trouble just throw it away and start over, I know the US Navy doesn't want things like bad machine cuts welded up and recut, they were very specific about that on a set of 3 foot diameter gears we made for them, just because they were gonna spin at 10,000 RPM's on a jet engine in a destroyer, the nerve of some people.
@@dukecraig2402 tru I worked in a welding shop for a long time and if it is thick enough you can weld on extra but that takes way too much time. Especially if you are doing something like custom picket railing or fencing where you might have hundreds or thousands of pieces. To make a mistake and cut those too short it could be really costly to fix. Measure twice, cut once
@@haydenpryor2494
Yea, as I pointed out there's plenty of times it's not feasible because of cost, but when you've got press frame that's for a press rated at 1,600 tons needless to say it's more cost effective to have a guy weld up an area that'll take him a day or two as opposed to throwing the whole thing away.
But like I said sometimes standards won't allow it no matter how little welding you may have to do, stuff for the military and for nuclear power plants are typically the kinds of things they don't want anything like that done to, imagine that.
Someone screwing up a couple thousand feet of handrail is the kind of thing someone usually gets fired over, especially if it full blown fancy ornamental work and not handrail that's for a stairwell for a hospital or something like that.
I also used to be a union ironworker, I was on raising gangs but when the kick off for a job would get pushed back they'd break up the gang and temporarily send everyone to other gangs just to keep you working until the new job kicked off, I spent some time working on ornamental gangs as a result and saw a lot of handrail and especially stairwell components that got trashed and refabbed, stair pans a lot, someone would get a stop set up on a press just an ⅛th inch off and pallets full of them wouldn't be any good, what's so amazing is the bids on some of those buildings was so big having to make a whole new set of stair pans wouldn't even get people that upset, I did jobs that were 150 to 200 million dollar buildings, something like those stair pans was a drop in the bucket for something like that, not me though, I'd always volunteer to get rid of them with my pickup truck, straight to the nearest scrap yard and directly into my pocket from there.
this is exactly why i dont machine things for other people, why i havent tried to make a living off of machining. i still take some odd jobs but only when the stock is cheap and its just a couple simple operations.
appreciate all your vids, you explain things well. its really important to have this information online for people like me - who learn by doing without having a mentor
I quit machining and moved into machine repair because of the customer not understanding why we charged what we did. "Why can't you just CNC this?". I saw the end coming.
It's called; "sneaking up on the dimensions"!👍😃👍
Didn't leave enough for the finish cut and deflection fucked him. lol
Nothing like irreplaceable tools. They deserve the upmost respect, they are quite literally a treasure. The job has to adhere to the capability of the tool and not the other way around.
That’s why when it is my antique stuff i take it to my local shop to get done because i can’t sneak up on it or fix it if i screw it up. So when it is critical i leave it to the professionals.
Well no. Screw that… I don’t want to be responsible for ruining your antique stuff… too much liability.
There's lots of professionals that would be happy to destroy your stuff for a fee.
Ill do it. For the right price. Have cofidence in your abilities, machinists out there 😉😎
That’s a motto to any business involved in repairing/modifying customers goods! It doesn’t matter if it is a shoe repair, a garment adjustment, a cell phone screen replacement, a computer hard drive filled with memories (I saved a marriage once when the customer deleted pictures of his wife when she was 9 and grandpa was still alive!), or a toy from their kids, If you don’t account for the value of the object itself, you must account for sufficient insurance to care for it! AND the customer must be educated ahead of time to be in tune with any risks involved! They must understand the value you add when you expose such risks to aid their decisions when compared to other professionals who don’t!
Excellent point you brought up!
Engineer: “how accurate to spec can you make the part?”
Machinist: “oh, idk, within a couple of tenths.”
E: “of an inch?”
M: “no, ten thousandths”.
E: “oh okay, well then let’s do that. I’ll need fifty of them.”
M: “I don’t think you want me to do that. That’ll cost a fortune and take me months to make. Or I can just rough out 100 in about two days and tolerance check them after”
Machinists can be very accurate, but often don’t have to be. Then there are times like this, where they need to be.
As an engineer I had this conversation in the first month after I graduated. I swear that we were never taught to think like that at university though.
I would also add to that, considering making things from stock sizes.
Engineer: "the bar needs to be 37.5mm x 46mm in section"
Machinist: "you sure? The stuff on the shelf is 40mm x 40mm"
Engineer: "let me change the drawing..."
The university I went to had first years lathing parts for a project in the same course that they learned 3D modelling. It was helpful to see both sides for this reason
@@johnnyt7067 we did a whole module about design for manufacture, etc. So useful!
@@johnnyt7067 the "stuff made here" channel put it really well. "The computer has this problem where you can just keep zooming in and then without thinking you have features too small to machine" or something like that. It's a real problem that engineering programs don't have tools for the students to use and learn about because half the engineering students you talk to don't know why tolerance matters. I'm closer to a machinist than an engineer and the company I'm at does it really well. All the time we have parts that could be off by a 32nd of an inch and still be totally fine but then we have a jig or something that we have to make so it has to be within some crazy degree of precision or every part made with that jig will be off. It's often the same with parts that have to be water tight too. You get a piece of crazy hard material that takes 4 hours per piece because it has to be exact
Grinding standards and gages, getting the cross hatch, parallel, half a millionths, 65 Rocwell C, lapping, micro finish, and certification, all add up to $.
I worked at a shop where many of the parts were usually +/- .005 or +.003/-.000 but one time I had to make a bearing retainer that had a tolerance of +.0000/-.0002. I made 6pcs, they were +/-.001. I shipped them to the customer. A week later, I was making 6 more…to the proper spec. I learned my lesson, luckily it wasn’t any significant material cost.
I have often thought of machinists as the surgeons of the trades. I find their work fascinating! I’m a retired civil engineer, and we work in feet & inches. If I mess up, there’s a wet spot in the lawn. When you guys mess up, stuff clangs, and spacecraft explode.
The farther the decimal place goes to the left on tolerances, the farther it goes to the right on pricing.
Absolutely. Tight tolerances affect the programming (if CNC), the fixturing, time required to measure, and time involved in sneaking up on the final dimension. It will definitely add to the cost.
Had to work on an iridium piece at a semi-conductor machine shop, worth $360,000. I was 5 years into my career and had only been at the shop for 6 months. I was sweating bullets, made a good part. 🎉
Anytime, I make something on my grandpa‘s lathe, which is almost 100 years old, I get it close to size and then walk away for a while. Later, after the piece cools down, I’ll then take very fine cuts to finish it. Works well for me.
I'm a carpenter and some materials I'll cut down five/ten times to get it just right because that's the finished product, no paint, no caulk, no cover-up, do it right or make it twice.
Awesome work made interesting 🤔
Thanks 🙈🙉🙊
As a tool maker. My hats off to you. Have you ever met an old school pattern maker?
When I used to work as a machinist (I had to quit because of workplace allergies, a 17 year career down the drain😒) I was in charge of setting up and inspecting the first part of all our CNC machines so the "green button pushers" could take over and run the jobs and was one of 5 people in the shop out of 108 machinists and operators who was given jobs like these, for the sole reason that we had this type of mindset with expensive parts, there is simply no room for failure and it has to be meticulously planned out and ran through multiple checklists several times before anything gets cut, it absolutely costs extra money to put the higher skilled workers on jobs like that who have to take their time as well. It goes the same with expensive material, I've done jobs with billets of material that cost more than my house and one wrong tolerance will scrap the entire thing, some customers will not accept a part that is even .0001" out of tolerance and it screws the company over big time, so you have to creep up on all your numbers and meticulously inspect everything throughout the process.
What were the allergies?
@@jacobwiertsema4784 It was the cutting fluid/coolant in the machines, I'm not sure what exact component of it I was allergic to but it didn't matter what brand it was, all of the water-based coolants used in machining caused me serious issues. It started with itchy skin, then turned to rashes, then it started making me feel awful whenever I was around it. Near the end of my career I was doing everything I could to stay away from it, working as a full time inspector so I wasn't working directly with it, but even the airborne coolant that evaporates into the air was causing problems, I was getting very routine headaches that happened once every 5-8 days that were so painful they would put me in bed for an entire day with the windows blacked out due to light sensitivity. I had to file for FMLA just to keep my job, I was missing work literally one day nearly every single week because of it, and when I finally broke down and stopped working in machine shops the headaches disappeared in about two months, and I haven't had one in the three years since.
Damn 17 years and you’re bragging about only being able to troubleshoot a part😂I’m 23 and do that shit all the time and do the off hand programming on a control and do the overhaul work I made 104k this year
@@TheExplosiveGuy I’m glad you were able to make the change. I wonder why that doesn’t happen to more people. That coolant can be nasty stuff.
@@jggg202 Who said I "only" troubleshot parts? I did everything in that shop, I programmed, I made tooling, I fixed everyone else's fuckups (many of them by a lot of 20-something yr old hotshots who thought they were king shit like someone I've just been introduced to), I ran and programmed CMMs, Romer Arms, a Lieca laser tracker and scanner, did Solidworks stress analysis, and much, much more. I think you might want to increase your reading comprehension before jumping the gun like that and making yourself look like a tool.
Being a Machinist.... probably the world's most respected professions and skill a person can possess. I applaud your craft 👏. Humbled by your experience and expertise.
... and my English sucks too.
Props to Austin for standing there to share this lesson with the rest of us. Mistakes aren't some reflection of our worth as a person, which seems to be the trend nowadays and people will fight against him taking credit for any misstep. Training new people is really hard because some people take it so personally regardless of how minute the mistake was. Glad to see there's still human beings out there. I've never seen anyone do something worth doing that doesn't have a large collection of mistakes along the way. Happy to see a business not just get angry and let the employee learn as well and a results in that great investment for the company and for the employee.
Well.your a.carpenter no one exspects.you to.get math right 😅. Sorry needed to.jab you.
Great advise to anyone whose doing irreplaceable work for customers or their selves and it never hurts to slow down sometimes if the process isn’t working exactly the right way
This is the knowledge and wisdom that can only be learnt with years of time served! Great video guys! I wish I could find a machine shop in my area like yours, they have all gone!
So many people will get mad when you tell them that you've got to charge them through the roof or that you need a disclaimer. People just don't understand the undertaking and the potential costs when trying to mod Irreplaceable parts
I call it, Knowing what you can get away with. Different for everyone.
People don't realize that you need to also be consistent. You want to hit 2 tenths on a part, you can't just cut a tenth at a time (with conventional tools like a lathe). Just recutting at the same dimension will result in undersize. So it's important to cut to a known consistent operation: rough...rough, then semi-finish, semi-finish, then take 1 or more finish passes (first pass will tell you how the second pass should react). I'm not telling you anything you don't already know, but to the average joe it's not as simple as "dial in the number and click the lever". Heck, CNC machines need more care!
I made a cast iron bushing for old unique hydraulic motor pump. I pressed it in, and out several times, until it was sized to fit the shaft. Sweating that I would oversize the bore.
Absolutely correct.
People do not understand that.
Happy New Year.
Take care, Ed.
As a maintenance manager, if this situation occurs, I fully understand and appreciate the shop doing the right thing, and ima pay ya. My local shop operates in same manner
i was lucky to have a shop teacher like you, I see myself in that bearded gentleman in the background.
Absolutely filled with knowledge gathered through actual experience, and with the will to teach it to the next generation. This stuff will always be essential knowledge, no amount of evolution will take us past mills and lathes, welders and fabricators
Exactly my thoughts, keep as much of the original material as you can when repairing/modifying
Its nice to see ppl that know what we do and how we do it.
Love this guy. I’ve been a machinist since 1974. Learned CNC last 10 years. Brand new game.
I worked in a machine shop. I did not hurt I did not walk quickly to the bathroom I did not change the tooling quickly. I put my vice on my Bridgeport with three bolts. I think this is the best message for anybody just cut everything close and then fit and measure for the exact part. I like each step to be a calculated part at the last of the machining for a finish pass.
Respectfully most people are lost in many of these videos this man makes because they do not understand how technical and precise these items need to be fabricated. Many people in todays modern society believe robots do this work and can not appreciate the level of skill and experience it takes to fabricate or modify these parts, especially one offs. Its great you make these videos atleast you demonstrate the technical level and the need you and your worker bring to society.
We knew a guy who made hydraulic scraper rings for the landing gear on military aircraft. We needed some basic machining done for our business and he offered to help. In comparison to his stuff, ours was completely elementary. What we spent a few hours scratching our heads over he was able to figure out and complete in mere moments. Such a great (and completely professional) guy. RIP Mr Schultz.
I have been a Machinist in the trade going on 46 years welcome to my world it's not just how to set up something and hope it doesn't hurt you in the process but it's about Time & Materials and most importantly Fit, Finish, Function , as an end result
When I was fresh out of school (18), I worked at a machine shop as a helper/apprentice. I had no machining experience whatsoever. They put me to machining dipole connecters for satellite navigation antenna (on a forerunner of GPS). The tolerances were +.005/ -.000 and I was expected to maintain that on a lathe that was pre-WWII vintage and had more backlash than a critique of your wife's family, cooking, romantic prowess.
They put me at the lathe with a washing machine box full of about 3500 of these things and told me to have at it. The only instruction they gave me was when I got within 5 thousandths of spec, do not move the tool, that the push-off of the previous cut should get me within my tolerance.
Out of 3500, I think I missed my smallest tolerance by about 1 - 3 thousandth under on about 280, which I thought wasn't bad with no experience and a worn out lathe (I know what you say about it's not the machine).
We assembled the bases and the number killed came down considerably but we still lost around 100. 43 years later, I'm not a professional Machinist, but now when I get to do any machining, I'm better on maintaining my tolerances but the stuff I have done since I've had newer tighter machines to work on.
Sometimes we got the jobs, even without the lowest bid. We had tight tolerances, finish, sharp edges broken, holes chamfered, in other words, quality. Take apart a 500 and 870, 12 gauge. The edges are left on the 500, and can cause wear, or injury. The 870 is built with quality.
We should probably get Austin a new pair of jeans haha
Same thing in the trim Carpenter world cut it over size and shave it several times to ensure fitment versus losing an expensive piece of millwork.
Do a check pass slightly undersize before you shoot to size. Also helps to use a bore mic or dial bore gage instead of telescoping gage when holding a tight dimension.
As a gunsmithing student I was assigned a .357 S&W revolver with the customer requesting I install a 3" barrel after removing the factory 5". I suck at math. They probably should have charged extra. With much help from my instructor a TX Instruments calculator and tons of formula out of a cheat sheet book I got a new short barrel indexed and everyone was happy😊
I remember machining a whole bunch of parts for my dad and when I measured them they were still warm and hot and when he went to ship them out they were cooler and the tolerances were all off
Yep. I've made a bearing-fit for parts on one day, then came in the next morning to find them to be too tight.
That's what happens when you don't have heat in a machine shop in winter.
That's why we had a controlled atmosphere quality control room. 68°F and 50% humidity year round. You bring a part in, clean it, set it on the CMM, and let it acclimate to the ambient temperature. Run through the tests, print the results and then follow whatever in process checks are required.
I ran a job that had 8 hour cycle times, the material was very expensive, it required specific expensive tooling, and the tolerances were extremely tight. It's stressful as hell. You are swapping inserts multiple times per run too. So much opportunity for error.
Not a machinist here, just curious. How much difference can the expansion be from the heat generated from machining?
@Chris P. Bacon Completely depends on the metal, what temp it was while being machined, how well your coolant works, where it's checked etc. You could see .01" if everything is going against you. (That's a huge difference in this trade)
We had a tool man that would come into our old shop and try to sell us saw blades.
My boss got sick of him coming in and tired of telling him no we couldn't use them. The seller swore by his product. My boss finally went ahead and told him, "if you can cut this piece of metal in this vise we will buy them all."
Totally trolled the tool man for minutes while he vigorously tried like hell to cut this material.
Once the teeth started breaking and he realized he wasn't making a scratch.
My boss told him, now you see what the problem is. Son, that is Hastloy.
Still one of the funniest things I've ever seen until this day. 😂😂😂
I made a mistake once, over bore a ring. I learned my lesson the hard way.
Remember don't get owies at HOWEE'S
I can relate I was a machinist/ tool maker for 45 years
Completely agree, when the piece is valuable and has to be "perfect" you inch toward that. You can always take more material, but you can't put that material back once it's milled off.
You got it that is what we called it back in the 60s sneaking up on it
Luckily I'm an apprentice in metal manufacturing, I am allowed to learn all of these lessons now before a rejected piece reflects badly on me 😅
You think professionals don't fuck up constantly? Lmao 😂
I never did it in the field, but i spent 3 semesters in college doing Auto Machinist and I understand how tough that job is. I don't see myself argueing with a Machinist.
Well said no kidding I really am impressed with how you seem to think and run your shop just wish you were down in the lower 48 lol
You have to "creep up" on those tight tolerances!!
I wish I could've had a teacher like this, unfortunately nobody wants to teach anymore, they just want to toot their own horn.
People should be removed from Earth.
Sneaking up on a final size is usually a good idea when working with expensive materials.
I had a similar experience once. I was to machine Myron Kinley's personal tools used to fight oil well fires. It was successful.
I hadn’t thought of it that way.
There is an equation for how much addl time it takes for every .001 or .0001 of tolerance is required.
I love this channel
Love this guy i wish i leanerd under him on the machining side i had a really good teacher but he wasn't really interested as he was near retirement
I call this "sneaking up on it"
It's when you really really gotta have your head screwed on tight.
I've tried to explain this to engineers. The larger the tolerance is, the cheaper and faster I can make a part.
I have never, ever heard of this fee. I used to make parts for the old German automatic pistols and aerospace parts and I always made certain that I made the correct drawings before I machined the parts and I always used the metric system so tenths to me is 0.10 mm.😊😊
For one thing I studied machining under the care of Germans from "Operation Paperclip" and all parts came out to specifications. I'm hearing this attitude on machining and it really, really sounds "wack."
I worked for a guy who did not understand that. To be fair, his background was fabricating and welding, and he had a successful business, but he wanted to do machining. And he underbid jobs because he didn’t understand that tighter tolerances required more time. Also, he’s miss surface finish callouts and grinding tolerances. He quoted jobs on more than one occasion for machine time only, and we had to send it out for grinding and heat treatment 😬
Oh boy then there’s my dad who designed a “2 ton” jack… long story short they were a huge hit, people come back STILL 20 YEARS LATER ASKING “please fix this jack it’s THEE BEST I have used” the dude lifted his SEMI with it.
I had to bore out three bearing fits for a planetary gear box.
After each cut, I kept a record of what was the actual dimension verses what I set the cutter to.
This way, if the bore went oversize (which did not happen) I could show my methodology and how I was accounting for tool pressure.
Slow but steady.
I hit sizes on all three bores.
Precision is art
Precision is part of everyfay life for a toolmaker. Believe it or not it becomes second nature and just another job. I go for a few .0001" and polish to size. Looks like ground finish and spot on every time at 15deg C 😊 never forget the temperature of the job.
Literally all you got to do is divide your cut into 2 cuts, both equal. Take the first cut and use the equivalency formula to figure out intended/actual cut made. Then offset the machine to compensate for the error. The next cut will be within tenths, if you followed the steps correctly and your machine is repeatable.
If the machine is inaccurate and non-repeatable, obviously you shouldn't be using it for precision work.
Edit: you can use this to find out your tool pressure and rigidity. It will work for any cutting tool, any setup.
No matter how good You are more time is needed if the part is of higher value, not just double checking everything, but rather 12X checking everything. This video I did some time ago Echos Your point, as to obtaining a good size:
ruclips.net/user/shortsFsuQgCGDSyI
@@HOWEES I worked machining platinum on swiss automatics making cardiovascular implants. .068" stock o.d. 15 operations 2 spindles boring milling drilling. Holding sub tenth tolerances measured optically and digitally (mitutoyo ELF) You can factor in oil temp and guide bushing preload on a sliding headstock, but on yours all it is a simple backlash measurement and compensation since you're only looking for .001 accuracy, or .0007 if you're really tight. Anything else, you're using the wrong tool for the job. Now if your bearings are worn, just say that. I appreciate what you're getting at, but it only applies on small frame manuals or very worn machines. I love your content, but I just think that a distinction should be made. Both things are very good to know. People often have to work with what they have, and for that audience you shine. I think you would do better showing the process instead of talking about it is what I'm getting at. Show what makes your process work for a worn machine or a hobby machine. You have a platform, go in and show how to make sand plugs, or hone it or however you make due with what you have. Show it. Thats the special bit, ya know?
I have also worked with every other style cutting tool there is. I stand by what I said. Cross multiplying then dividing to get the cut/cut intended then applying it to one decision forward resulting in an insignificant math error, not a human one.
@@TlD-dg6ug damn, I've only ever set foot in a machine shop once in my life but I can tell you know your shit lol. Good job
Generally yes, sometimes there is no other method of machining something. 30 years ago I ran a gun drill. EVERY piece ran was a setup piece. Gun drill bits had to be sharpened EVERY part ran. Granted machines were 30 years old but kept up to top specs. I spent several months with an engineer checking every possible variable. IE speeds, feeds, oil pressure, bushing size, etc. We finally settled on 5 pieces per sharpening to hold a hole about 2" deep with concentricity of .0005" TOTAL. Used air spindles with ring gages to set the high/low tolerance zone. That one feature cost $500 EACH!
Now this was production items to keep craft in the air.
I now restore antique tractors. Same as for cars, motorcycles, whatever. Sometimes the ONLY piece you have was dug out of a river bank after 90 years being there. It doesn't matter if you have a MILLION DOLLAR MILL you STILL sneak up.
One tractor I have is the oldest in existence and 11th made. I've had to buy 6 other tractors to get specific items that are unobtainable otherwise. But once done this machine will ONLY have factory made components with ONLY items new replacements being tires, oil, filter, gaskets, rings, and bearings. IT WILL BE PIECE ALL OTHERS WILL BE COMPARED TO!
Undershoot, check and creep up on it so you don’t overshoot. When something is too big it can still be worked with, when you try to hit the mark but go over the piece is done. When working on a one off and things can’t be replaced there is a different set of rules to play by so you don’t screw yourself and the customer
The company I work for (I do the engineering side) repairs high speed pumps. Our manual machinists are some of the best there is. They may not be the fastest but they do excellent work as messing up a diffuser for a boiler feed pump could be $10k-100k in costs to undo and up to a month in time. Even worse if it has to be scrapped. So taking the time to ensure the parts are damn near perfect when they leave and to question engineering if something feels even slightly off are immensly valuable qualities for a mchinist to have simply because we cannot afford to make big mistakes.
That what I simply refer to as
" Sneaking up on it" .
Yes, ya gotta get it right the first time.
Because failure IS ALWAYS an option.
Better to sneak up than blow the size on roughing passes. I just make sure I can take atleast 2 finish passes with a TPMR 01 radius with .015 per pass. Check taper after the first pass, mark accordingly , attach dial indicator to saddle to read X, dial out taper in second pass.
I unscribed after another youtube shop did a motorcycle brake drum hub resurfacing. It had so much run out that i was done with that channel forever.
Sometimes with Stainless or TI alloy you have to watch sneaking up on the final dimensions. If you have a .002” thick work hardened skin on the part from the previous pass and try to take that .002 or so off you end up taking .004 off. Something you won’t learn until you physically see do it.
I’d love a good discussion on the art and science of flatness and accuracy vs precision.
Agreed, you can’t replace material after its gone on something where welding is not allowed to build it up.
As a metal shop teacher said to a student when he said took too much material off..." What do you want me to do? ..get a putterbackeronera??" lol
Pay attention to your machine, know the deflection of your equipment. Sneaking up on cast iron is way different than sneaking up on Ti.
well that explains a lot. even if it's a $2000 part that's still a big headache, and even if it's a $200 part it's a hassle... so it makes sense that people have been less and less willing to do that sort of thing over time.
I worked as a process inspector and often had to ask the engineers, "Is that really the tolerance you want? " The print would show + or - 50 millionths and in reality + .005 - .000 would suffice.
That is what a tolerance is for!
The fact that you do the same work as my neighbor and could 100% be his twin brother is pretty awesome. Any relatives from western mass? Haha
How western
I am a maintenance mechanic in NASA's Jpl.
I see the guys working to tenths daily.
I see the old school machinists do this on 60 year old Bridgeport and Hardinge machines.
All the younger guys cannot do this without 500k machines.
There are no young guys coming up in the trade that can do this on manual machines
The more digits to the right of the decimal, the longer it takes.
very true I use to save 2 to 4 thou for sand and polish to get to my number
I never miss,
I always shoot to the correct size 🏀
Really suck when you make a whoops on a Mold base that the previous machinist spent 2 weeks working on. We can usually weld up a whoops on a part though, usually anyway.
A lot of my old work as a gauge maker was tied up to boxed tolerance.
True.. here in spain ..metal has trebled in price in 1 year...
Ditto
Depends what it is what it's doing why it needs to be that size ect ect if you're making the mating part then if you screw up on the bore you can just usually compensate on the shaft
That's why complete job shops have grinders.
I'd like to learn from this guy.
This is where it helps to know your process capability. “Sure I can hit the target within 0.0005” turns into “you don’t understand all the complexity and such and such” real quick- and thats because as an engineer, you went off some guys gut feeling about accuracy instead of measuring the process outputs.
If your CPK is less than 1.3 for the process, then prepare to slow it down and have a guy sweating bullets trying to make sure he doesn’t blow past the target because the process is out of control.
Thats just how it works. When people talk about “sneaking up on the dimensions” that means they understand their normal process is not capable, and so they have a secondary, much slower process which in fact is capable. Study that, or you will lose a lot of money!
What?! That's crazy! Nah, makes total sense. :D
I ran into a situation similar a couple of months ago working on some parts for a 1912 Thor motorcycle
This guy's a good boss. He's like me I'm a good boss...that's how I can tell hahaha😊
That makes perfect sense to me
Agree a rough cut then a finish pass hopefully .001 undersize then a final pass to bring to size within .0005 that's what I like to do!
Totally understand the older something is the more likely your are to break it trying to modify it 👌
I use the term ( sneak up on it) . I understand what you are saying.
yes absolutely you need to account for extra time the tighter the tolerances. The number of managers that think you can keep a +/- 0.0005 one shot with a CNC. While CNC is more accurate it is still a slower process to ensure a 0.001 total tol
I machined titanium alloy turbine cases and they never failed to tell you if a $30K part you made was scrapped.