Machining a Dividing Head's Worm Wheel Replacement 

Sir, the only problem with your videos is there isn’t enough of them, Thanks

Brilliant!

That was a lot more precision than I was expecting from a random RU-vid recommendation. Excellent work and excellent explanation.

Holy moly! Your the only machinist that needs TELESCOPES and mountains to create gears. Thumbs up to you sir 👍🏻

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.

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!

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.

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

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.

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!

Haven’t seen anyone on You Tube use this type of equipment and be this precise since oxtoolco.

Absolutely beautiful work. I love seeing your videos! I also love the humor.

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!

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.

Your descriptions are very good, thank you for sharing. Charles

Excellent work as usual Alex.

Dead nuts accurate definition has just been revised. Perfect is close enough for this guy!

Amazing engineering skill! Thank you for the excellent content!

Fantastic project and well executed. Thanks for the great content.

Wow, that was fantastic to watch. Thanks for sharing.

Wow. You have every reason to be really proud of this work. I enjoy your precision adventures!

Top quality! You make some awesome work and videos! You deserve more viewers!

Most excellent use of the theodolite. Well done in all respects.

I learned a lot. Thank you for taking the time to make this video. And I love your crazy sense of humour!

Top quality workmanship👌

Very interesting, I like the techniques you used to aim for accuracy and calculate errors. Looking forward to the next project.

Been a long time. Great to see a new vid.

Just fascinating!!!! Top shelf work.

I love your videos. I learn so much. Very good explanation.

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.

Awesome video again. Just first class as every video!

Fabulous work.

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.

You are a true master at your craft! Not many left like you.

Really great content and video quality. Thank you.

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.

Great work sir 🤙🏼

Engineering design and machining at its best !

Craziest setup for cutting gears!

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.

I love your CNC d-bit grinder

Very nice project, excellent result! Most channels on RU-vid 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!

Wow, Danke 😀👍 Hammer Video! Wieder viel gelernt

Great video. Inspiring.

excellent engineering :)

Brilliant work. I guess you could say your worm wheel was "Peak Calibrated" :ˆ)

Can you post an explanation of the "screw up"? Great content as always. Thanks for sharing, Cheers

Interesting use for the T2 ,have a T 16 but never thought to using for this

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

Wieder mal ein geniales Video 👌🏼 Grüße aus Fürstenfeld

good job

Das ist Fantastisch! (wirklish)

Griasdi! Irrre was du dir antust! Respekt! Lg Tom

Wow! Thanks.

Wow just wow

Short of a hobbing machine, that was very nice work. Many thanks for an interesting video.

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 RU-vid's automatic captions for those of us with poor hearing?

Sehr Geil, Endlich mal kontent aus Österreich :D Bekomme zwar schon Kopfschmerzen von den Berechnungen aber scheint ja Sinn zu ergeben haha

Grate video and grate work , Wie immer. Alles gutte.

Stunning. What went wrong with the first one?

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

Great content as usual! Please continue with many more videos :) Can you please give a link to the oiler can you use when milling?

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

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

Amazing video. Is there a particular reason you use cutting oil on bronze? Shouldnt this stuff be self lubricating?

what do you use to plot the graphs? just wondering why you don't include the axis labels there (and perhaps a trend line)

Beautiful. I think the error was snow melting off your rock formation.

By the chip I see the blank is being made from Aluminum Bronze Nice job by the way.

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!

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.

Hi Alex Good job 👍. What is brand of your milling machine ?

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 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.

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 ;-))

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.

Unbelievable

Great video, heads up though, at 3:30 you say broaching, that's actually called trepanning.

Brilliant! Unfortunately there are no rocks at my workshop. Are you watching TV while machining?

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.

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!

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.

3:30 If I understand correctly, the proper English name for what you call "broaching" is "trepanning".

Comment for the algorithm

It's most controversial engineering material I've ever met. It's little too much informative and instructive.

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.

Brilliant video & explanations - unfortunately, the radio in the background distracts from and obliterates much of your vocal commentary ! - Just turn it off please.