Making a part: Replacement gear
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- Опубликовано: 5 сен 2024
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Stefan, you have, hands down, some of the best machining content on the internet!
It is always a pleasure to watch you work!
Thank you again for sharing this stuff with us!!!! :)
Absolutely!
Agreed
No kidding. My days are instantly better if You post a new video.
Hi Sefan! Very interesting and nice result. In your drawing you have 11 teeth with a 36mm OD and 23mm root circle. This is very close to a 2.75mod gear (actually works out to 2.77) or a 9DP (9DP=2.82mod). The slight difference might be due to wear or rounding in your measurements, the original gear looks very worn apart from the broken teeth and may not have been to ideal spec. when it was new (esp. if it was cast). As you no doubt know, gears with less than 12 teeth often have the profile modified, usually by making them with a pitch circle diameter one tooth larger than the number of teeth being cut, however it doesn't look like this was done here, the OD is close to a modified 2.5 mod, but the root circle should be around 23.75mm in this case, so this appears to be an unmodified gear. Not having the profile modified probably contributed to it breaking as the teeth would have a greater undercut and less strength. (Yes I know you said it was close to a 2.75mod at the end of the video).
I'm impressed with the magnetic chuck setup, I might have to get one of those, thanks for sharing!
I was thinking the same thing. The teeth are fish-hooked from wear, so one should derive the shape from the undriven side (assuming there is an undriven side).
When I worked for UK Plant I saw a lot of gears that shape, usually teeth worn from various abrasives getting in there and changing profile. As long as things kept running, they didn't get changed (and usually compete machine was scrapped rather than try and source new parts)
Oh, wear makes sense!
Big +1 for TOS Enterprise. My favorite sci-fi space ship!
To quote Mr. Scott: "Nc-1701. No bloody A, B, C or D"
Thanks for adding the Fusion 360 modeling. I appreciate the real world description.
As a hobby machinist I've learned so much from watching your videos.
Thank you!
Gear seems to look like cycloid profile - typical this days for clockworks and very unusual in heavy machinery. Still it is a profile that fulfill law of gearing but only at nomimal distance. I was told that those gears have been known as easier to be made in "low tech workshops" . Having here a part from old drill press - maybe that is the answer to odd profile. Neverthelees great job and thank you for another fine video.
"Have been known as easier to be made in low tech workshop" - lol, and now you need a cnc for that, lol. Technology is fun)
Wow the endmills really did their job. That is truly exceptional on such a small machine.
Hi, A friend of a friend during their apprenticeship at an aerospace company needed a sprocket for their motorbike and not having the money to buy one used the old one to machine a replacement (with the supervisor's permission in his own time). He very carefully copied the old part and produced a brand new, worn out sprocket (much to the supervisor's amusement). Thanks for your great videos. John
That worked better than I expected. Really liked that high helix on the finishing pass.
"That worked better than I expected."
I say that to myself about a dozen times a day :D
I love watching many machinists on the Internet. I learn from all of them and am grateful for the efforts that they make to present fascinating material. But, when I watch Stefan I feel like I am leaving the workshop and entering the laboratory (a place I spent for more than 50 years) and what I learn is of an altogether different quality. Thanks very much for your wonderful work and videos, Stefan.
What it all combines into is a body of experience.
All these people, even the ones who fail at times, contribute to the is body of knowledge, some just contribute some really great stuff.
Yes, well put.
My grandmother had a clothes wringer in her laundry and it has gear teeth with such a lumpy shape. I’ve also seen it on an old (1890) steam paddle boat.
Stavros
I too, when I first saw the original (broken) pinion, was reminded of a 19th Century clothes wringer, or mangle, as they were known in UK.
That would be a "Wäschemangel" here :-D
Yeah, thats the kind of device I would expect a gear of that look/shape/quality
I rarely comment on your videos but had to pop a quick one down to say thanks for making them. I know when one is uploaded that I'm going to sleep well as they're very relaxing to watch as I drop off to sleep, and when I wake up I rewind and catch the second half as a soothing start to the day. This is a poorly worded compliment, I suppose I should point out that soothing/relaxing and boring are very different things for clarity.
You may be aware that in the UK, the German national stereotype is analytical, precise, efficient, boring and lacking a sense of humour. The longer I've watched your videos the more I've realised that the your (and presumably many Germans) sense of humour is very much alive, but usually far more subtle than what we Englanders are trained to pick up on. The more I tune myself into the cultural shift the more I find myself chuckling. The above is very much an assumption based on stereotypes and of course everyone is different, but assumptions are tools to work with like any other adjustment to our perception and in this case it seems to help explain a lot.
Ta,
J James.
"I... suspect mine might be a little higher quality..."
Hah, brilliant! Your work is amazing, I always enjoy the detail you get into.
I am in awe of your ingenuity and ability as well as the excellent way you present your work.. well done Stefan!
As my Dear Old Dad use to say, “Good enough for who it’s for”!
👍🏻
Flat bed scanners are underrated in manufacturing. Beats a photo
Mighty impressive. I once watched a CNC machinist neck down a 6mm end mill with a cordless drill and a bench grinder. He looked a bit embarrassed doing it but I had to admit that I'd do the same.
Thats a absolutely viable option - I prefer a machine guided approach, since I do it a lot on endmills smaller than 2mm :D
For such replicas, which are based on very old stuff that has a lot of wear, i like the normalization method, the Gauss method as i like to call it... You do what you did, take the photo or a scan of the thing, and in this case, overlap the photo 11 times, indexing by one tooth per rotation, granting you the normalization of the wear and form pattern remaining... Sure, its not the do all end all method, but doing that gives you one or more teeth in this case which were there, and are now overlapped by their brethren teeth and can be studied for better match or replication... In your case with cnc, it would involve extruding that one best tooth found after 11 overlaps and rotary projecting the tooth as you did...
Warmest regards,
Steuss
Thats a brilliant trick! Makes absolutely sense, thanks for the idea.
@@StefanGotteswinter I am most glad! All the best!
Axial load is the physics behind the geometry that achieves surface finishes in tight corners. You sold me on the cheap mag plates. Now I'm thinking of die sinking some relief in them. You know why! Cheers from Vancouver Island.
I have just stepped down four steps on the ladder to being able to do stuff. Yup, I am on the bottom step. Excellent work.
I laughed at the complete inability to go to the other room for a bolt to bolt it to the table. I'm with some of the others, it looks like a cycloidal gear. Nice work as always. Thanks for the insight.
Nice to see these "oddball" jobs, and the measurement methods ... I used the "just clearing" method to get the center of a pulley to drill a set screw hole...
Yes.. as Elan Jacobs mentioned in another message below, it looks to be 14.5 degree PA. It doesn't appear to have much (or even any) enlargement, so a large portion of the profile/flank will be undercut. With a 20 degree pressure angle, I recall the minimum number of teeth where undercut is not an issue is 17 teeth. At 14.5 degree PA, that minimum number of teeth will be even greater, so at 11 teeth... there really is no good solution. (or at least no good solution without redesigning this gear *and* its mate).
However, you made the best solution there was -- simply copy what was still working before it broke! Your part turned out beautiful. I need to get my hands on a few of those very high helix, small diameter cutters!
You are truly a master of improvisation.
As always Stefan, you really nailed this tricky problem and that’s what makes you videos so compelling. Excellent video, thanks for sharing this.
Oustanding lesson in problem-solving. Superb! Thank you!
One of your most informative videos. Thank you.
Beautiful part. I am impressed what you are able to create. Thank you for taking the time to make videos; they teach us a lot!
A great feeling of satisfaction was had by all. Thanks for demonstrating your approach.
Looking good! Didn't expect a router to do such a good job on steel
I'm amazed that a router can machine 4140 so well. I'm more amazed that the magnetic chuck can hold the part! I learn something new in every video you post. Cheers.
Your work and videos are always top notch
Another fine job Stefan. Your methods are always where they need to be and then some. Thanks for sharing and take care!
Stefan, this video was perfect in all ways.
Nicely done Stefan!
ATB Robin
Thank you, Robin!
Nicely done I learned something from today's video. The high or low helix angle creating less radial load and transfers the cutting force to more of an axial load I understood before today's video. However I have never used that style of cutter on steel at such a high rpm and I have to say I was very surprised at the result. A very nice surface finish and the tool seems to have stood up very well. I am guessing the most important ingredient is a high quality tool to start with. Thanks for sharing as always a very interesting video.
Fantastic Stefan. Amazed at the finish on that gear from such a skinny end mill and done on a gantry style mill. Impressive!
An enterprising approach to making the replacement gear... thank you.
Stefan the Precisionator will be back!
Loved the video! Thank you for great content Stefan!
Excellent. I was surprised how well such a long slender tool performed. Thanks Stefan.
Excellent vid, Stephan. I use the flatbed scanner to get all my real world stuff into the cad. I put a coin in the scan and create a circle in the cad to verify the scan size. I love your English, we'd say root and tip for the gear rather than foot and head. Foot would imply a mounting or standing feature. I have a German friend who once told me she'd left her children in the child garden, which is quite funny in English, despite being a literal translation.
Nice job Stefan, will be looking for one of those hi-helix cutters asap...great choice. To quote Scotty; "I'm giving her all she's got Captain"
Thanks for another interesting vieeo Stefan. It is always nice to watch a master at his trade.
Fascinating use of the software! Imagine the fun you are going to have when you have a metal 3d printer.
Very impressed by the surface finish with that kind of stick out.....great video and awesome job.
Excellent step my step views through the project And then bits and Meg Chuck and did a fantastic job A gear look awesome Thanks for the video
Very interesting, I enjoyed seeing how you found a solution to getting the teeth shape perfect.
Interesting method, and a great result!
Looks like a pinion to mate with a rack, they have funky looking tooth module like that.
Clever solutions and excellent final product-Very well done ✅👍
Excellent machining, very interesting on the 55 degree helix 4 flute end mill, I've used images inserted in CAD, works very well, as long as its scaled correctly 😀.
Thanks for sharing.
Ingenious! Very interesting and some great tips too. You must be extremely satisfied with the result.
Cheers
Andrew
Great video 👍A repair for the home machinest,so glad the gear work's with a rack as I thought you would have to make the other gear it mesh's with 😊
We will have to review after fifty or so years of using and see how well it works. Is there no end of your versatility? You continue to amaze me with your depth of experience. Another well explained design, and the surface was a work of art!
Love the confidence. Keep the videos coming!
Superb as always
Awesome Stefan!
Hey Stefan, safety weenie here. What particulate size do you expect from grinding carbide, and what kind of filter is in your shopvac?
If the filter is not appropriate, you may be making the problem worse by distributing the particles evenly around the shop.
I state this from personal experience, (cheap craftsman shop vac filter), and the desire to continue watching your videos for many more years. ;-))
Prost!
Thats a Class M vacuum and a pre-seperator that keeps already most of the carbide in it.
On a very sceptical day I will wear a P3R respirator :)
keep that gear profile!
you will need it when the customer tears up the cast iron rack with the steel gear.
:o)
Superb .. as always. Consistent quality to be proud of
I agree, when you are too lazy to get into the other room you spent hours to create tools to avoid that. 😄 Thank you!
Now the gear is so strong, it will probably break the rack next.
Interesting info about the cutters.
Great videos to watch in the evening. Keep on!
I guess you don't only work with metal, you also listen to it 😉🤟🏼
I'm so impressed that you able to cut steel so good on your router, I would thought that is a job for much bigger and heavier cnc, can you share what model that is maybe?
Sorry, already found in one of shoptalks xD
Really enjoyed this project!
Nicht schlecht, Herr Specht. Solche Einzelfaelle sind immer interessant.
Ist eine schöne Abwechslung von Kleinserien :-)
very good job stefan..thanks for your time
Really interesting part. Looks a bit like like a chainwheel or a clock wheel in profile. Very interesting video again.
Your prototype gear might have been somewhere around 9 DP, if it is old enough to use that system.
Enjoyed….excellent video production/discussion/build
Nice replacement gear Stefan👍
They're definitely involute gears, they just have a rather deep well.
I am a simple man, I see a Stefan Gotteswinter video -- I smash the like button.
I ordered a replacement button, the old one has been smashed. Any idea how that happened?
@@StefanGotteswinter I... err... uhm... yeah that was me.
I always watch 2 or 3 times (often with the volume off) just to increase the view time for the algorithm.
OHOHHOO GTWR CONTENT ....ALWAYS APRECIATE THE NICE VIDEOS STEFAN ! WEITER SO !
Good morning Stefan! Class is in, again, and I appreciate it!
I will not be so bold to comment how cleaver and genius you are because that would require me to be as well, but I’m always impressed and like your style. 👍
Thank you :-)
Naaaaah. You don't have to be clever or genius to recognize it. I'm not a great craftsman, but I know great craftsmanship when I see it!
I enjoy your videos more and more. This was a fun part to make. I don't like the choice of material. In the past, they made simple parts from material that broke faster than the larger parts that were more difficult to make. So the cheap part broke and not the expensive one.
I think the material choise on the original was primarily for ease of manufacture - At the time a casting and a minimum of machining was cheaper and easier than cutting it from bar stock. These days its the other way round.
And agreed, the gear is now stronger than the rack, but the original gear was not damaged in normal use, it seems to have been a transport damage.
You make everything look so easy Stefan., a true engineer!!
Interessting to see that one of your Chrome Tabs is WhatsApp the other one Netflix :D
Nice problem solving, and impressive results with the skinny end mills!
I half expected you to unleash the pantograph but that would no doubt be much more work :)
I thank you for waking up my brain cells. I have two 12dp. gears to make for my own use. Once the hay is in the barn, this will make a good evening project. Over fifty years of tool room work, I have never cut a gear from a blank. It will be interesting, either way it goes. :-) :-(
Again, another thank you for the plan and a chance to learn a new skill.
Hey Stephan , thank you for the upload great advice as usual, have a great weekend
I get more impressed with that Sorotec every time I see you using it. I'm seriously tempted to get one as I can manage without auto tool change and most of the material is dielectric plastic, aluminium, copper and brass - and now you have it running 42 chromoly! Wow. Did you choose a watercooled spindle motor? I thought there was a list of machines on your website but I can't find it now. Never was any good with computers...
Thanks for sharing 👍
Stefan, wenn du mit dem Fräser zwischen die Zähne fährst, hast du daran gedacht, dass die Fräsgeschwindigkeit im Bogenlauf zwar auf die Fräserrmitte bezogen konstant ist, aber nicht an der Kontaktfläche zum Frässtück. Beispiel: x mm/min Fräsgeschwindigkeit bei einem Bogenradius von 2 mm (bezogen auf Mitte Fräser) bedeuten bei einem Fräserdurchmesser von 6mm (r= 3mm), dass der Fräser mit (2+3)/2= 250% der Fräsgeschwindigkeit das Frässtück fräst.
Vor allem wenn man spiralförmig Löcher fräsen will, stimmen die Geschwindigkeiten bei Fusion360 dann ganz und gar nicht.
Im Video bei 19:10 hört man gut, wie der Fräser durch die engen Bögen zwischen den Zähnen rauscht.
Sehr richtig - Nein hab ich nicht beachtet/berücksichtigt :D
Fusion kann leider nicht die Vorschubsgeschwindigkeit anhand der Außenbahn berechnen, nur auf die Mittelpunktsbahn. Creo z.b. hat die Option.
Bei sowas kreisch ich dann halt durch, ist ja nur ein Teil :D
On my Haas VM-2, this would have been a great application for a plunge milling rough operation. I’m not sure of the rigidity of your router in Z. I’ve also had to do much larger parts, not a gear, but a pipe flange that had open lobes where I drilled a bolt hole pattern, roughed out the waste on the bandsaw, and then finished it back on the mill in a rotary table. Great video! I liked seeing a little more CAD / CAM stuff. I’ve been using SolidCam, but it is not great for some things. I got a seat for Fusion 360 but I haven’t had time to use it much.
I tried plunge milling on the Datron M10 at work - It helps in some cases, but the machine is also not exactly VMC-Rigid ;)
I have thousands of hours experience in proEngineer/Creo Cam, but very limited experience in Fusion Cam. But I have to say, fusions cam is stupid easy to learn and far more powerful in most regards.
Compared to the early days of CAM, things are so much better now. I’ve worked thru the evolution of the industry and there was definitely a trend where both software and machine controls evolved so rapidly that it was impossible to keep up with ever increasing levels of complexity. I’ve seen literally dozens of machines that were either never used or not used to their full potential because only the people who designed the controls could understand them.
Good video.Thank you.
Always enjoy your content.
The tooth form looks cycloidal to me....but its hard to tell on video of course. Thanks for another excellent video. I always learn something. I have no cnc equipment so I'd probably have to resort to drilling some holes at the root and dress a grinding wheel.
I gotta get that coffee cup
Thank you for your time
Excellent work, as always! Hope you are doing well, sir. - Tom Z
Thanks Tom! Yep, all going well here :)
Another fascinating episode - thanks Stefan. 👍👍😎👍👍
Such clever stuff, so far away from my machining experience, impressive to see how things have progressed.
Nice work Stefan.
Almost looks like a gear tooth used in old clock movements.
Excellent machining and programming skills as always understated by Stefan!
The blank audio cut out towards the end, I wonder if that might have been something like: The bad part about using a magnetic chuck for this job is you must DE-MAGNITIZE everything on the chuck?
Yes, but since I also have a surface grinder with a magnetic chuck, a de-magnetizer is an absolute must for my shop.
I'm impressed by the great advance in technology for one-off gear making, since that broken gear was made. When was that?
Good question - I guess that gear is a good 80...100 years old.
Probably what you did but didn't call it out in the video, Once you add the image as canvas you need to click on "Calibrate" select two points on the image and provide the accurate caliper measurements. Thus Fusion can scale the image accurately and rest of the drawing can just follow the canvas. Nice video BTW!
Very correct! Thats what I did (And forgot to show :D )