Steam Locomotive Connecting Rod Bearings: Machining a “Chair” Work Holding Fixture
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- Опубликовано: 24 июл 2024
- Steam Locomotive Connecting Rod Bearings: Machining a “Chair” Work Holding Fixture
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I love that you stamped all the data on the fixture. Great Job Keith!
What a beautify drawing. I love a nice hand drawn print. That's a nice one!
This would be a great teaching video to get children to see what the trigonometry they don’t like learning is actually ised for. Great work!
Analytical response- I agree with your assessment on fixtures for machining, one poorly clamped piece shooting across the shop, one crash from a moving part jamming, the costs would surely outweigh any material and time spent by a huge factor. And the inevitable need for replacement parts on a high wear item is probable, even though it is on a limited use basis.
Happy Monday morning to you Keith! 😊
Good morning Keith. Thanks for the videos.
Great idea Keith.
You should have good repeatability between the parts.
Thanks for sharing.
Have a good week.
Always good content!
Great work
Most excellent.
Thank you for sharing.👍
Thanks for sharing
This is so cool! I love seeing what my grandpa did at work. I love this stuff. Grandpa was a tap and die maker for General Motors. ☺️
Thanks for sharing. I like watching and learning. I write down what you say. I see you do the maths pause and then do that, play you do more, I pause and I do that, … etc. I have done a set up and milled a part to see if I can replicate what you’re doing but on a smaller scale. Everything matters.
When I needed to made a new crank bearing for my miniature traction engine, I solved my angle by using a digitalinclinometer. Zeroed to the mill then tilted the bearing until the inclinometer hit 30.0 degrees
That's probably the way I'd do it too, but, after all, this is the "Vintage Machinery" channel...😉
very instructive, thank you
Wow Keith, you've got loads of cleaver mathematicians in the States. Great video again.
Nice new setup Keith. Nice job.
Thanks Keith. Good plan.
So interesting! Thanks, Keith
liking the measurements of it all!!
I think you actually made a 1 in 5.916 taper, if my memory of trigonometry holds up. Not that it really matters if the wedges are cut from the same guide (and I think it's close enough to work with a true angle anyway). The difference come down to the sine plate being a hypotenuse distance of 5 inches not a base distance.
Another way to think of this is that Keith was using a sine bar as a tangent bar. For this use, not a problem.
yes, for angles under 10 degree sin is not so far from tan. But I think if he tries to reuse old wedges, he will run into a problem and he really needs to make new ones.
@@elrond12eleven , yes, he has promised to keep the fixture that he created and has stamped it with details of where it was used. I think that I recall that he said that he was going to make new wedges.
Agreed. The gauge block stack should be sqrt(25/37) = 0.822 instead of 0.833.
And the angle is actually 9.462 degrees, not 9.426. But it doesn't matter as that number is not used here.
Awesome as Always... Love the way you explain the set up Great Vid... Season Greetings from the UK
Some good tooling that. It could help keep the loco going for 1000s of years!
Good Morning from the Pacific Northwest, Crow Oregon
Thanks for video Keith. As previously commented the stack height should have been 0.822 inches. Could you please show the correct solution in your next video. Too many machining channels ignore their mistakes and only confuse viewers who are trying to learn. Never forget you are a great teacher with a massive audience.
Great fixture Kieth! I've been really enjoying this series. Don't lose any sleep over the minor trigonometry miscalculation. Chances are you'll be the one to re make the coinciding wedge and everything will work as intended using that fixture.
0.010" Diffence in a gauge block stack over that distance only equates to around 5 minutes of a degree. Mostly everything I've seen on modern drawings is +/- 1.0 degree. I'd say you've satisfied the 1/6" taper ratio on that drawing!
I wish you all the best on your current and future projects.
Cheers from Alberta, Canada 🍻
I am a bit surprised that Keith didn’t show the verification of the angle. After the first cut or after cutting. Maybe he did it right before cutting? And he will show in the next video. Thank for showing how to use that sine bar.
That's a very conscientious thing to name the tool....really considerate of others not to mention even yourself. How often do we really remember "everything" we built "exactly"? Keep up the great work Keith!
As a person with no machine shop experience at all, I'm learning that much of the creativity is in the fixturing. Fascinating.
I am getting the same education in work holding and fixturing.
Another RUclips channel to watch on this is Joe Pie. He makes some amazing fixtures. In fact he made a precision angle block like this without the sine bar, and I would bet his angle was spot on.
He drilled and reamed two holes in his material on the mill with the appropriate offsets, then used two broken cutter bits lin the holes laid across the vice jaws to mill the angle.
Whenever the geometry gets complicated he goes to the whiteboard to explain it all first.
David Rush, ive seen that video recently as well, made my angle supports just that way, no complications and it helped in making articles for my model hobby. , but also no disrespect for Mr Rucker, he is a great machinist in his own right. This is why i watch these channels along with mr tubalcain from whom i also learned a lot and mr J Piezinski from Advanced Innovations. As for the slight oversight, im quite sure the drawings allow a tolerance?
and this particular lesson is not good. Keith made an error using sine bar.
@@elrond12eleven I've seen that discussion and acknowledge it as a possibility, but I haven't thought it through. I do think 0.011" difference over 6" only comes to about 6 min. error in the angle, which is probably within the tollerance of the part.
@@davidrush4908 It may be and may be not, but the main point is that Keith in his videos does a great deal of instructing. Now someone that credits him may find not very pleasant surprise following these instructions for precise part or greater angle (where sin is much farther from tan than in small angles).
I calculated 0.8220" for the 1" in 6" rise on a 5" sine bar 9.462°
1" up in 6" along in a triangle means the hypotenuse is the sq.rt. of 37 by Pythagoras.
Scaling the 1" down to suit a 5" hypotenuse as per the sine bar = 1 x 5 / root 37.
Answer, 0.822" , no angle calculations required.
Hi should you verify the angle to make sure it is correct before you cut that valuable part?
I dont usually defend this guy but his calculation is correct. He did make a mistake and wrote down 9.426 instead of 9.462 which is the correct angle. Even confirmed it by drawing the triangle in Fusion. 1 divided by 6 = 0.16666667. Multiply that by the length of the sine bar (5") that does equal 0.83333". He is exactly correct for what he used the sine bar for.
Yes, but the 6” in the slope is on the adjacent side of the right angle triangle and the 5” on the Sin bar is on the Hypotenuse.
@@shadowdog500 All he needed was to get the block sitting at an angle of 9.462 and he did that doing what he did. Just draw the triangle in a CAD program and you will visualize it yourself.
Look online for a sine bar calculator and calculate the stack height for a 5” sine bar at a 9.462° angle and the stack height will be 0.8220”
Wondered why you didn't just use the sine bar for the 4-bearings, but since there are wedges left and ongoing replacement parts to be made the fixture makes a lot more seance to me.
Also if there is a maintenance log on the engine, and it is kept up with the tooling used, in a hundred years when they make the parts again ---- there will be the VM fixture. ,,,,, If there is not some magical AI driven CNC machine by then, anyway. ,,,, Over the last 100, though good old manual machines STILL are the best way to get 'er done, and KR and the VM shop did exactly that. Got the job done.
So hey, Merry Christmas and/or a Happy Hanukkah as the case may be from Cleveland,,,, and keep making them chips!!
I notice youve lost weight Keith. Looking good buddy 👍
Why do you need the chair? Can't the sine bar, with the stack of shims, allow you to set the bearing on it such that it sits at the correct angle?
Why not use the sine bar under the brass block when clamping for milling?
When cutting the bearing blocks, would it be better to face it the opposite direction? When placed the direction shown the cutter force could (theoretically) push the part up the ramp making the cut deeper.
I don't think the way the "chair" is cut matters, just what direction it's put in the vice. The vice is what's holding the part against the cutting forces, not the chair. The notch in the chair is just to make it easy to locate the part in the vice.
Couldn't all the machining be done on the bearing using a sine plate as a fixture?
I was wondering about the same thing. I can think of two possible reasons. Having a single block means less fiddly bits. Also this probably doesn't need the precision of the sinebar, so better save the wear on them?
The 1:6 taper is 1 opposite to 6 adjacent which is 9.462°
The sin bar calculation uses the opposite and the HYPOTENUSE .
The stack under the sin bar should have been 0.8220” to get the same 9.462°angle.
A digital angle calculator would have been an easy way to verify the angle.
I agree. If he already machined all of the blocks, he may as well machine new wedges to match. If he decides to correct the machined blocks to match the factory speck he would only lose about 0.013” which is tiny compared to the size of those pieces.
@@shadowdog500 it may seem tiny, but the whole assembly would not work with old wedges.
Keith, are you goingto relieve the bottom corner of the fixture to allow for the difference in the radius of the inserts on the face mill and the corner of the actual part?
I was thinking the same thing. - I usually try to drill a small hole centered where the apex of the corner is when I make something like that.- Works good on V-Blocks too if anyone is interested. Back "in the day" it was a pain but now days with cheap DROs everywhere it's a snap to locate and drill the Apex. ,,,,, On this one, though, a couple minutes with a nice sharp 3 square file will do the trick just as good.
6:38 - And that's how you use Jo Blocks!
12:40 - You're a young man, but documentation is wise; you might note the YT vid date/link
14:56 - More time than making one part, less time than making them all.
I think it would be easier to put the material in the vise and tap it around until I got .5" of rise over 3" of indicator travel.
That would work I guess, if you have a rapid on your machine, anyway, but I do not know ANY tool and die maker that would not use a sine bar. - It's what they are made for, you know.
The grease paper on top of the gauge blocks read (upside down): Do not use with foodstuffs.
I thought that was funny.
Any news on the tally ho capstan?
Check out Dave Clark, he’s already released part 3 on the Tally Ho capstan pattern design, I imagine that after Dave’s done with the the pattern it will end up at Sandy Hill to be cast and from there back to Keith for some machining.
@@Hoaxer51 hi, thanks for the response. I’ve been enjoying watching Dave’s work with the pattern, that’s what brought me back here to ask. Obviously with the progress of the tally ho project, I’m aware that time is moving on so wanted to check the project was still with Keith
I think having Windy Hill cast these was cool, but, wouldn't you have been better off starting with billet blocks of oil impregnanted bronze ? Just woulda been done a lot quicker and probably for not any more money.
I think the application on a steam engine might be too brutal for oilitte. Any lube guys out there that can hip us up on that one?
This would've sounded so much nicer on the shaper.
He doesn’t have a shaper.
@@grntitan1 he does have fully restored metal planer.
one in six inches should be measured in the plane, not on the grade. So using a five inch sine plate won´t work.
I agree. I could see this coming. The 1 in 6 taper describes the tangent, not the sine, so Keith has set up the angle as 9.594deg rather than 9.462deg, or 1.014" per 6".
@@ThePottingShedWorkshop Well, it was so tempting to recalculate from 6 to 5 but that results in a systematic error. Unfortunately.
Who told you that, bro? There is NO angle ANY sine bar will not make. - I have 3 different sizes. Just have to make sure to use the right number that matches the bar for the hippopotamus (sic),,,,,And I do not know any toolmaker that would wold not use a sine bar to set this up,,,,,pretty much universal in the tool and die game.
@@mathewmolk2089 It´s not about the angle. You may set any angle with a sine plate. It´s about the calculation of the angle.
Keith, I think you made a mistake in your calculation for the gauge block height. In your calculation you have taken 5" as the base of your triangle - it should be the hypotenuse of the triangle. The calculation should be: angle = arctan (1/6), gauge block height = 5 x sin of the angle calculated. I calculate 0.822" (not 0.833").
I disagree. Another mathematical approach is to simply compare the fractional ratios: 1/6 is to ?/5. Cross multiply 1×5÷6=0.833.
I was about to point that out to Keith but I see that you already did so.
I wonder why he didn't use the angle found by the arctan function to achieve the sin height? So close to being there but I suppose it was just an oversight, either way, he's off by 0.0113" too high on the stack and 0.164° too steep.
Well done! 🙂
PS, I just noticed that the angle he wrote down is 9.426°, it should be 9.462° Bad math day?
Of course it's pointless to mention this stuff here because Keith never reads these comments. 😞
@@azenginerd9498 The slope is defined by a right angle triangle where the base is 6" and the height is 1". A triangle with a 5" base would have a height of 0.833" as you and Keith calculated, but 5" is not the base! The 5" side is the hypotenuse of the triangle, not the base!
@@azenginerd9498the slope is 1 opposite over 6 adjacent. The sin bar is x opposite over 5 HYPOTENUSE.
In my non-machinist mind, if you were to complete the machining using this fixture, a level would show you whether the fixture was correct, no?
Let me just order that from McMaster-Keith.
This is interesting, but I have a dumb question. Why make a fixture when you could just set the brass piece up on the sine plate directly?
Keith explains that near the end. He's going to do 4 of these now, another 4 some time in the future and many matching wedges. Making the fixture means not having to do the sine plate setup multiple times.
@@artkaufman595 I think the sine plate setup was pretty fast. This took longer than 4 sine plate setups and cost material.
How do you tell beryllium bronze from regular bronze?
. I have some old, old scraps and don’t want to get exposed to Berrylium.
Aluminum bronze is more likely than beryllium. Beryllium bronze is non-magnetic, aluminum bronze is slightly magnetic, if that helps. Both are non-spark types.
Kieth, did you ever have a mustache?
Awhile back, a couple years maybe, he grew a beard for a few months. I guess he didn’t care for it (or his wife didn’t) because it hasn’t been back. Lol
Hehehe will it WORK? As is. Way above my pay grade.
There are lots of ways to get jobs done and I am not skilled in any kind of metal work so I ask this from a point of ignorance. Before using your cutter to mill this piece, why wouldn't you first cut most of the metal out using a bandsaw? Is that just not a thing among machinists?
Ditto. We have a CNC Burning machine and I would have no problem with a burn-out from a plate. Leave .075 machining stock on a side. -
Metal removal choices Joe Pie. ---- SAW, Drill, Mill and Grind.,,,,, I'll add burn to the top of the list with Casting and forging as things to consider.
I would have just clamped it to an angle plate.
Oh, well. What makes even less of a difference than the sin vs. tan vs angle in radians mix up: The angle should be 9.462°, not the 9.426° on the paper. Oh no! An angle off by 1/27th of a Degree! Put another way, what’s 90 - 80.538 again?
I've watched 4 episodes of these bearings and you keep referring to them as "brass or bronze". They are different alloys, so maybe you should ask Clark over at Windy Hill Foundry what they are.
They're bronze. You can watch Clark on his channel pouring these.
You look pretty snug. Is it cold in your shop?
Bronze!
i hate insert facemills that bloody noise,
We got plenty of these at work and they don't sound like this...
They are not loud on bigger machines. I used to run 12 inch Kennametal face mills on a big Cincinatti machine where I worked. Keith has a smaller mill kind of like a Bridgeport and they don't have the mass of the bigger machines plus he is only running maybe a four or six insert tool which also lends itself to chatter. The more inserts you have the smoother the cut and less chatter.@@FireGodSpeed
Too bad you didn’t have a metric sine bar. 6 to 1 would be easier to do without odd fractions.