Machining a Dividing Head's Worm Wheel Replacement
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- čas přidán 22. 05. 2021
- The worm screw in my trusty Walter UTA 100E dividing head was damaged by corrosion, which in turn did wear down it's originally installed worm wheel.
In the previous episode I managed to recondition the worm by thread grinding. It's lands thereby became slightly narrower.
In this present follow-up episode, a new replacement worm wheel is made, designed specifically to fit the reground worm screw. I show how I designed and grind the necessary single point cutter and inspect it on the Nikon profile projector. The worm wheel blank is turned on my EMCO V13 lathe. The worm wheel teeth are machined on the Mikron WF-1 mill in an improvised setup, using the dividing head in question to hold the blank and my Wild-Heerbrugg T2 theodolite as an angular standard.
Finally, the accuracy of the worm wheel replacement and the reground worm screw are tested by using the theodolite.
The video ends with a discussion of the testing results.
The reconditioned worm drive is now probably as good as new and ready for another 50 years of service! - Věda a technologie
Sir, the only problem with your videos is there isn’t enough of them, Thanks
Brilliant!
I kept thinking during the video that Alex needs a set of your indexing plates with the tapered holes for that dividing head.
@@hashgeek929 That model dividing head already has direct indexing with pin in holes. Not gonna be as accurate as the theodolite for cutting precisely spaced gear teeth.
Stefan, if you feel you need to step up your "fussy German" appearance because of this guy, ... we understand 😉.
@@infoanorexic This is not a Competition.
@@StefanGotteswinter You both do wonderful videos so I declare you equally awesome
That was a lot more precision than I was expecting from a random CZcams recommendation. Excellent work and excellent explanation.
Using the theodolite is at once overkill and charmingly apt. Thank you for taking us along, and for all the trouble to get the view through the theodolite also.
NOT at all. ---- What else could he use? - Hey, a plastic protractor and a torpedo level just would not make it. The gun was a stroke of genius !!!!
For some reason, I feel inadequate when watching this video.
Awesome content as always Alex. You are way up there when it comes to engineering and machining content.
Hi Alex. You have developed an interesting simplification to the flycutting method of hobbing worm gears. The worm profile you chose was ISO 10828 Part 2 Type A flat sided profile I think. This allowed a simple conical wheel to be used to grind off the damaged worm stock at the cost of thinning the worm tooth. Bravo on your adaptation of the Emco to do that. Where I really learned something from you is your simplification of worm wheel flycutting by using a simple form tool located at the point of tangency of the 'hob' with the worm wheel bland, inclined, and just gashing to depth. Usually, this flycutting is done by gradually feeding a straight-sided form in the cutter spindle into the wheel blank in a tangential direction while the wheel is rotated on a precision rotary table slaved to the cutter spindle. A difficult CNC process to programme. I will study your simplification to compare the profile of your gashed teeth with those of theoretical Type A wheel toothing.
As for lapping. It is true that diamond lapping abrasive will try to embed into the contacting surfaces, and perhaps Timesaver would be one way to go.
I have found however in lapping hard bearing steel worms against anodised aluminium wheels using 1 um diamond paste that degreasing then powerwashing the gearing afterwards, then assembling, lubing and burnishing the gearset at the correct centre distance for some hours under reversing load and direction using an indexing servomotor produces low runout, low periodic error gearing with no evidence of embedded abrasive visible under microscopic surface exam.
There are other ways of generating precision positioning for gashing wheel teeth or indeed conventional flycutting at low cost. One, is to source a carefully-used Moore precision rotary table with a few seconds absolute error and use that to mount the worm wheel blank and to mill the bore and flycut the teeth into it.
The runout from your boring op is visible in your verification tests. If you had a way to do all the machining on your mill and remove the lathe boring op, the final runout would improve.
Another thought would be to duplicate in your flycutting fixture the same shrinkfit and radial bolting arrangement used to mount the worm wheel in the boring head, before you cut metal. The strains from this can be quite significant, as a little FEA work would show!
Thanks for the inspiration. You are a brave engineer!
Holy moly! Your the only machinist that needs TELESCOPES and mountains to create gears. Thumbs up to you sir 👍🏻
One must appreciate the effort Alex puts into these presentations. Explaining complex ideas so a average non engineer mechanic/machinist (that's me!) can understand is no small task in my book. Well done sir.
P.S. I love the theodolite targets you use. I would surmise, not the average targets used by most engineers 😁 Cheers from New Hampshire USA
Absolutely beautiful work. I love seeing your videos! I also love the humor.
Wow, I stumbled across your channel, it didn't take long to realise that you are on a different level of precision to most! Thank you, very interesting!
Top quality! You make some awesome work and videos! You deserve more viewers!
Wow. You have every reason to be really proud of this work. I enjoy your precision adventures!
Very interesting, I like the techniques you used to aim for accuracy and calculate errors. Looking forward to the next project.
Haven’t seen anyone on You Tube use this type of equipment and be this precise since oxtoolco.
I learned a lot. Thank you for taking the time to make this video. And I love your crazy sense of humour!
Your descriptions are very good, thank you for sharing. Charles
Amazing engineering skill! Thank you for the excellent content!
Most excellent use of the theodolite. Well done in all respects.
Excellent work as usual Alex.
Fantastic project and well executed. Thanks for the great content.
Dead nuts accurate definition has just been revised. Perfect is close enough for this guy!
Very interesting. As a retired naval officer, I think I now must get out my sextant and see if I can use it to measure the runout on my mill and lathe!
Wow, that was fantastic to watch. Thanks for sharing.
Excellent job, love the innovative use of a very accurate theodolite, tool bit grinding brilliant. Your notebook is like something Leonardo Da Vinci would be proud off.
Great vlog thanks for sharing.
Best regards from the UK.
John.
Ok, shop envy and knowledge envy. But if I had your shop I'd probably be out hiking a mountain instead. So let's add location envy on top of that. But then again, it's Friday, I'm watching this in my hammock with a beer and the smell of a freshly mowed lawn in Sweden 🇸🇪. Life is good.
Hell yeah it's good, make sure to drink one beer for me too!
Well this is pretty cool. I wasn't expecting you to use a mountain to align some machinery. lol.. Thanks for sharing. I hope to see more like this. New sub.
Been a long time. Great to see a new vid.
Top quality workmanship👌
Just fascinating!!!! Top shelf work.
If you ever sell that lathe, I'm up for it! There really isn't that many Maximats available in my country. Other than that, once again top notch work. Enjoy your detailed explanations very much.
I love your videos. I learn so much. Very good explanation.
Very nice work sir
Awesome video again. Just first class as every video!
You are a true master at your craft! Not many left like you.
Thank you Sir! However I'm not sure if I can live up to that.
Really great content and video quality. Thank you.
as usual. briliant and informative. and almost like you heard my thoughts. i have for some time now bean contmplating the proses of producing such a drive. i bought a deckel kf12 and was thinking of a pair of tilting deviding heads/ indecing fixtures. then the old girl can do 3d coppy engraving in 5axis. neat idea.
Engineering design and machining at its best !
Can you post an explanation of the "screw up"?
Great content as always.
Thanks for sharing,
Cheers
Craziest setup for cutting gears!
Fabulous work.
Very nice project, excellent result!
Most channels on CZcams don't dare to be so brutally honest e.g. about final accuracy as yours.
Having worked on manufacturing inclinometers, I know how difficult it is to measure angular accuracy. Your idea to use a theodolite is brilliant!
Thank you Sir!
Your content is very through and well presented, given that I guess English is not your first language. As I am not an engineer nor machinist I couldn't follow it all and understand the terms used . I am never the less highly impressed with what you present. Keep Up the good work.
I love your CNC d-bit grinder
Interesting use for the T2 ,have a T 16 but never thought to using for this
Wow, Danke 😀👍 Hammer Video! Wieder viel gelernt
Great work sir 🤙🏼
Well done, I probably didn’t understand a quarter of it mainly the purpose of the theodolite but hey don’t reply I’ll watch it again I’m sure the picture on the wall won’t move. Excellent result.
Cheers
Peter
Great video. Inspiring.
excellent engineering :)
Wieder mal ein geniales Video 👌🏼 Grüße aus Fürstenfeld
"I wü ham noch....!"
Brilliant work. I guess you could say your worm wheel was "Peak Calibrated" :ˆ)
Wow! Thanks.
good job
Das ist Fantastisch! (wirklish)
Griasdi! Irrre was du dir antust! Respekt!
Lg Tom
Dongscheeeeee!
Wow just wow
Alex, this is a wonderful repair/reconditioning project, including your brilliant uses of your theodolite to measure the dividing head's rotation/accuracy while and after machining! I look forward to your next videos! Also, would you go into your (content creator's) settings and enable CZcams's automatic captions for those of us with poor hearing?
Hello Mr. Vines, thanks four your kind comment and for pointing out that auto generated subtitles weren't working. Seems I forgot to check the box that my videos haven't aired on US-TV. Subtitles should hopefully work in a day or two. Thanks.
Loved your drafting of the cutter form.
2 questions...
What was the spacing used when rotating the tooth profile device around the pitch dia (or is it arbitrary)?
And could the same simple approach work for generating spur gear Tooth patterns and cutters?
Great video, thanks much
Hi Alex,
thanks for this video.
I am impressed by your coordinate grinding of the tool, my german-made copy of an S0 is not robust enough to allow for accurate work using the dials, I end up creeping to dimension and testing.
Also, thanks for confirming that accurate worm-wheel cutting is possible without a hob.
Last, wondering why you didn't use the dividing head's dividing features and had to resort to the theodolite :D:D
Thanks again
Thanos
ps. If I may, technically, this is not a single-point cutter... :) Single point is to distinguish from form cutters in the lathe. This is, to be strict, a single tooth form tool ;P
Short of a hobbing machine, that was very nice work. Many thanks for an interesting video.
Amazing video. Is there a particular reason you use cutting oil on bronze? Shouldnt this stuff be self lubricating?
Grate video and grate work , Wie immer. Alles gutte.
Sehr Geil, Endlich mal kontent aus Österreich :D
Bekomme zwar schon Kopfschmerzen von den Berechnungen aber scheint ja Sinn zu ergeben haha
Great content as usual! Please continue with many more videos :) Can you please give a link to the oiler can you use when milling?
Thanks, the oiler can I use is made by Reilang in Switzerland.
So, where did you screw up ? Inquiring minds need to know 8-)BTW would lapping the worm and pinion together improve the accuracy? (Remove peak errors -the ones on the teeth not the mountain ;-))
I have considered lapping the worm and wheel in my small dividing head with Timesaver lapping compound. Timesaver is non embedding and breaks down to non abrasive action in use.
Would mounting theodolite on the other side of the dividing head spindle cut down in cutting vibrations going into the theodolite and give more room for cutting tools. Would it decrease accuracy? Love your channel great ideas. Thank you
Beautiful. I think the error was snow melting off your rock formation.
Stunning. What went wrong with the first one?
As always a very impressive and well thought out video. And it shows just how unbelievable the "guaranteed" inspection sheet is for both my Vertex rotary table and universal dividing head. Whatever features I've been able to accurately check such as the spindle run out and table flatness certainly don't agree with what the numbers are on there so called certificates of accuracy. So both there worms and wheels stated dividing accuracy are also highly suspect.
I'm certainly no expert, but one nagging question I've had since your first video while using your high accuracy theodolite is the optical effects of mirage randomly displacing the target at long distances. I've done just enough precision shooting with high power optics to know it's a real and definite issue where the target due to that mirage with fluctuations in air currents, temperatures and humidity levels isn't optically always in the exact same position. How do you compensate for those effects?
One of the causes of the degradation of your original worm wheel and worm might have been created by the previous owner from using the incorrect high sulfur content lubricating oil by mistake. It's a fairly common additive used in high pressure gear lubrication such as older automotive ring and pinion gears. Yes you also had rust on the steel worm, but that may also have been helped to start due to the bronze reaction as well as initiating galvanic corrosion. Some bronze alloys but not all have an adverse reaction towards that type of oil. Our issue is you can't know what you have unless there's a problem and by then it's too late.
Thank you for your interesting comment, Sir!
Is that TV or just music in the background? I heard a song from the movie "Oh Brother, Where Art Thou" but definitely other stuff too, so I'm guessing radio or music playlist.
Your original video with the theodolite inspired me to pick one up too. I got a Wild T3000. Prior to your video I hadn't been aware of these, so thanks for the introduction!
And great videos BTW, I particularly enjoyed the sets on welding distortion and these on the dividing head reconditioning. Keep up the good work!
Thanks a lot, and yes, you won this video's movie quiz!
By the chip I see the blank is being made from Aluminum Bronze
Nice job by the way.
what do you use to plot the graphs? just wondering why you don't include the axis labels there (and perhaps a trend line)
Wonderful job! It's a pity I don't have a steady view of a mountain or other high object in sight for using a theodolite for achieving above standard results. I like your approach "I have to know everything involved and have to improve or at least match the factory standard. I own a Walter dividing head as you are and it's in better condition as the one you started with. I'm quite happy with engaging the worm quite tight for full engagement of the worm drive system and it served me well for 25+ years now. Of course I watch the oil level, which never leaked since I started using it. By doing so the steel worm is the master of movement and the bronze worm wheel, more or less worn has to follow. I decided that the wear should be uniform because of the not so uniform use it had for the last 50 (?) years. I made hundreds of precise parts this way and it never let me down. So, no nagging here, is it necessary to use a theodolite for obtaining the accuracy needed for this trustworthy Walter dividing head? I'm curious (and like to have a reason for buying a theodolite too ;-p) about your "general" thoughts on the matter. For now I recognize I can be really, realy, accurate and therefore I like to do so (accompanied by using such sweet equipment). Curious about your answer, thank you for uploading all your inspirational work and all the best, Job PS; an optical edge/center finder would be a nice addition to your shop for finding a ridge on a chamfered corner on a tilted surface or a hole under an angle too.
Hello Job, many thanks for your interesting comment. I agree, an optical centering device would be very helpful. But as you know, SK30 taper is not so very common with these devices.
About the accuracy and the averaging wear I agree with what you write. My case was different with the corroded worm screw that severely damaged the worm wheel with every turn on the crank. So consequently I had to go the repair-route I took.
The worm wheel made with the theodolite would be even more precise if it wasn't for the drifting spindle clamp on the Walter. But other than that, I am really glad I have the Walter. As I say in the video, I believe I use it more frequently than my machinist vice.
ATB, Alex
@@anengineersfindings For the optical center finder; they are more common with a straight shank for use in a collet. I always adjust the center when mounted in the spindle on a sharp edge (vice) and turn 90 degrees to find the center. Mine has 4 setscrews for aligning the optical center with the edge. Real simple. Takes two minutes max. A lot of them have a removable shank too so you can adapt e.g. a SK30 weldon holder for this purpose too. They're pretty cheap to do so. Thank you for your answer. Be safe and happy, best, Job
Hi Alex
Good job 👍.
What is brand of your milling machine ?
Unbelievable
Thank you again.
Could some of the error be down to having to use the dividing head with the original worn gear to manufacture the new gear?
Effing brilliant though.
The dividing head is only use as work holding, the actual division was done using the theodolite.
Can you maybe post a short vid on your tool grinder vacuum scoop? I 3d printed mine, but I like your better. Even just pics would be cool.
I'll try to when I find the time. Thanks.
Great video, heads up though, at 3:30 you say broaching, that's actually called trepanning.
Uhm, pretty sure you forgot to account for the snow melting at your target and how this would affect the precision of your part... but nice try I guess.
And the surface of the earth bending as traffic goes by. Overkill statement forsure but if Scotland can be shown to bend as the tide goes in and out.......
Brilliant! Unfortunately there are no rocks at my workshop. Are you watching TV while machining?
TV or Radio in the background is essential for precision machining :)
Oh Brother Where art thou?
I'm pretty sure that's an anular cutter in the beginning not a broach. A broach is like a thick saw you shove through a hole with a guide in it. The teeth get bigger as it goes to broach a keyway into something. Maybe I'm wrong, maybe it's an ac/dc and it goes both ways...
Ok now that I'm done with my broach bitch, wow I'm going to have to watch this again like 3 or 5 times! There is just so much to digest. This is not the thing I do there's just so much... Good job!
What’s the song you used for your intro ? I love your videos. I have a dividing head just like yours. Just not as nice paint.
Frankly I don't recall the song's name, it is a hard rock sting from the youtube audio library. ;-)
Comment for the algorithm
It's most controversial engineering material I've ever met. It's little too much informative and instructive.
3:30 If I understand correctly, the proper English name for what you call "broaching" is "trepanning".
Yes and kind of no, since the tool used is known as a rota broach :)
Excellent craftsmanship, it's a shame about the loud TV playing in the background, it's very distracting.
Using a mountain for a precision measurement is risky. Mountains _move_ you know. It’s how they got there in the first place. Probably the actual explanation for the wild (ha!) variation in accuracy.
It is more likely that the workshop's foundation moves (orders of magnitude more) than the peak of the mountain in the short time-scale. Even more likely that the radiated body-heat causes localized thermal effects in the metal-parts even more severe than the moving foundation. On a universal time-scale, everything moves.
@@AdityaMehendale I just assumed he’d taken into account all the mundane I-always-stand-in-the-place-so-the-shop-foundation-flexes-the-same-way stuff. Oh, and I was also kidding. :-)
@@hashgeek929 I missed that last part ;)
@@AdityaMehendale dont forget to add in lorries on the roads between Alex and the mountain.
@@chrisstephens6673 ;) Gravitational-lensing due to the mass of the lorries? :o hadn't thought about that.
Brilliant video & explanations - unfortunately, the radio in the background distracts from and obliterates much of your vocal commentary ! - Just turn it off please.