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[Robert ProctorParticipant @robertproctor10223]

Hello there, I haven't delved much yet into model making although I have an interest, I opted to become a clock repairer 18 months ago as a hobby joining the BHI & doing several of their short courses. I tried to find part time college courses in my area for work shop disciplines but non were available all I was hearing was computers! There was a clock training college in Manchester but it closed long ago & the BHI courses are so expensive I am a qualified electrician so I briefly did a little turning, welding etc in my first years apprenticeship but that was in the early 70's so meanwhile I have been trying to learn as much as I can by what ever means available.

I note there are similarities in the tools, machinery & processes between model making and clocks, I have a Myford ML7 with various add ons including a recently acquired dividing head & I have made the adapter to hold it in the rear of the chuck spindle, a pedestal drill, a Quorn precision grinder & the usual bits & pieces.

I am trying to cut cycloidal wheels & I have the specifications on paper, I have tried to make a cutter but my problem is replicating the curve of the cutter to produce the correct shaped teeth on the wheel. I think I need to make form tools to do this with the correct radius?

I have made several cutter blanks from Gauge plate after making the holder to make the cutter blanks in the first place of course. I just need to finish them off now

Perhaps there is someone close to me to who lend me a hand & I would of course share my workshop which may be of help to someone.

I am in Bury Lancs.

Thankyou

Robert

[Robert ProctorParticipant @robertproctor10223]

[Brian WoodParticipant @brianwood45127]

Hello Robert,

I live on the opposite side of the country to you at Thirsk in North Yorkshire, so I can't be of direct help.

You may already have the book but Gears and Gear Cutting by Ivan Law [#17 in the Workshop Practice Series ISBN 0 85242 911 B] is a good starting point for making gear cutters. He concentrates on involute cutters but I think you would find much of interest in the book. Try Tee Publishing or ArcEuroTrade

There are alternatives to the use of form tools to both relieve and shape gear cutter blanks which use the side cutting teeth on end milling cutters to shave down the side of individual teeth, first on one side, and then offset onto the other side to complete the job.

It is not a method I have tried but I can see no good reason why it would not work. The ones I have made were for 20 DP 20 degrees PA and both were button tools The method requires the use of a good vertical mill to keep the cutter engaged while cutting, ie one that has minimum slop in the slideways and a well supported spindle.

Your study of the gear specifications will help in choosing the diameter of the cutters that best approximate the curves needed.

I think you will find the book full of good practical advice, it also draws attention to the compromises from true gear tooth shape that are necessary without having to revert to generating methods such as gear hobbing to cut gear teeth to the truly correct form.

Regards

Brian

[Neil WyattModerator @neilwyatt]

Hello Robert,

+1 for Ivan Law's book.

Neil

[Robert ProctorParticipant @robertproctor10223]

Thanks Brian & Neil for replying yes I have the Ivan Law book gear cutting & J Malcolm Wilds gear cutting to, but unfortunately not got a milling machine yet. I do have an Adept hand shaper which I was going to off load I can’t see it being of any use for cutting wheels & it seems to heavy to sit on my little Myford but I could be wrong!
I have actually cut 1 wheel using a tool post adaptor but i believe it’s not the best way because trueing the work piece in the chuck then moving it to the tool post adaptor loses concentricity apparently something I hadn’t thought about when I bought it.
I have found 2 small cutters with numbers on but my search doesn’t find anything I’m not entirely sure if there cycloidal.
I have been reading about escapements in an attempt to get into the reading mode again I must persue that more.
Thx guys
Robert

[roy entwistleParticipant @royentwistle24699]

Robert Can you post Photos of the cutters or give us the numbers. Clock wheels and pinions are usually cut with Module size cutters

Roy

[Martin KyteParticipant @martinkyte99762]

Making wheel cutters for fly cutting is simple. The technique is to turn the form on a piece of silver steel and then file to half the diameter. The correct radius is obtained either by grinding a radius on the end of the cutting tool testing against a guage made by drilling a hole in a piece of sheet material or turning a button from silver steel and silver soldering this to a shank and turning the cutter with this. The cutter is then hardened and tempered and finally sharpened on a slip stone and polished.

Multi point cutters are more complex animals and can be made in the home workshop but require more effort and generally more equipment.

Pinions in steel cannot really be cut with fly cutters. Generally home clock makers either buy pinion cutters (and you require a specific cutter according to the modul and the number of leaves on the pinion) or make lantern pinions.

You could do worse than getting hold of a couple of John Wildings books, specifially How to Make an 8 day wall clock and The Construction of an Elegant Scroll Clock. The first of these books descibes a clock made using lantern pinions throughout and shows the process to make the cytters for the wheels and the ratchet wheels.

regards Martin

[BazyleParticipant @bazyle]

I take it you have seen the youtube videos by Clickspring.

Hang on to the shaper which is great for wheel cutting. Make a standard clockmakers cutting spindle (the sort that looks like a g-clamp) to put in the tool holder and mount your dividing head on the table. A sewing machine motor provides power for the cutter.

I may be wrong but I didn't think the curved bit on the top of the wheel teeth did anything apart from stop the corner scratching the pinion tooth. The working face of a large diameter cycloidal approximates to a straight line so the only requirement of the cutter is to make both flanks of the space radial (ie a slitting saw isn't quite right) and round off the top nicely. Most of the cutter making instructions in the books using button form tools tend to be for involute gears.

Edited By Bazyle on 24/09/2018 14:43:40

[Robert ProctorParticipant @robertproctor10223]

Hi bazyle, thanks for replying, I was going to have the Myford dividing head on the rear if the chuck spindle driven by a stepper motor which in turn is powered by a division master that then automates the jogging of the work piece for truing & tooth cutting. This is not how Myford suggest to do it they have the d head on the cross slide. I have already made the adaptor with the MT2 taper & split shaft on the other end & the draw bar with the tapered nut to spread it locking it into the internal dia of the chuck spindle.
I of course need a potts or homemade spindle & a power source for tbe cutter. I did have an incling that the shaper might be able to be adapted to cut wheels so I’ll hang onto it as you suggest.
I have seen the click spring video & doesn’t he make it look easy he has of course all the tooling.
I’m not sure what the clock makers spindle in the shape of a g clamp looks like.
Thx

[Robert ProctorParticipant @robertproctor10223]

Hi Martin, thx for replying I have heard of fly cutters & I was aware that maybe this would be easier to do rather than a 6 toothed cutter which I have attempted to make after I made the mushroom holder to make the cutter in the first place.
Also I have a 10 inch Regal le blond lathe which was sent here from the US in about 1940 under some loan scheme during WW2. It has wear to the cross slide & as I don’t know how to refurbish it myself I was considering off loading it because it’s not economically viable to pay someone ?25 an hour to do it.
I have just bought John Wildings book how to make a weight driven 8 day wall clock it was in an Oxfam charity shop it arrived a couple of day’s ago.
Thx

[BazyleParticipant @bazyle]

Cutting frame – that's the phrase for I couldn't remember earlier. There are a couple of pics further down this page. Probably a picture in the Wild(ing) books. Surprisingly few for google to find.

[Robert ProctorParticipant @robertproctor10223]

I have created an album & put photo’s in of the 2 cutters, a minute hand I made from an old click main spring & the adaptor i made for securing the myford dividing head to the rear of the chuck spindle.
Thx

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