Gear cutting and making gear cutters from scratch

[RobinHood]

You could probably even use a Dremel or a tool post grinder on the lathe to make HSS buttons. Rough them out on the bench with an angle grinder and then finish grind them to size on the lathe.

 

[Brent H]

I was planning on the same with respect to broken/old end mills etc and grind them to size on the Cincinnati No2 - I have the shaft grinder attachment and a wee 4 jaw chuck that fits it - can then do the faces to whatever desired angle

 

[PeterT]

Ah that's right, I forgot he made his with a lower stem extension. That would add lots of rigidity

 

[gerritv]

The original Balzer version (for which there is no patent) had variable tooth counts. The only etching found does not elucidate at all on how that was done. However, Taylor did describe a similar device, which is adjustable and for which there is a patent

Balzer did patent a relieving device, it was based on differential gearing. That of course assumes you can cut the gears on something first.

I built a Eureka device to make T2.5 timing belt cutter and a few others (not gears). Do not underestimate the load on your spindle and tailstock, it is substantial. For a cutter with 1" arbour I would recommend the approach of using a moving cross slide instead. Unfortunately I can't put my finger on which magazine I saw that in.

Ah, found it:
Model Engineer's Workshop, Feb 1999(#56) and April 1999(#57), issues 58,59,60 describe building a gear hobber. If I were to start cutting gears it would be with something along these lines: F. Cleff - YouTube. There is also an article coming out about using an Arduino to replace gear trains with steppers. I think that is in Digital Machinist but not sure.

Gerrit

 

[Hacker]

That’s exactly what I was wondering.

The change gear method is the traditional way - there is no possibility of getting “out of sync” because of the gear teeth. I think the modern cog belts / wheels have proven to be very reliable, just look at all the timing belts out there...

But first one needs to have a cutter...

The basic principle of the EUREKA attachment is to have a stationary tool and the work “lobes” in and out of the cut. Traditional relieving lathes are the opposite: the tool moves on the X-axis and the work rotates concentrically with the lathe’s Z-axis. The number of “reliefs” per rev is a function of the number of teeth the cutter has.

I am contemplating using the taper attachment mechanism (mostly the telescoping leadscrew) via a timed cam to move the cross slide. I would need the cam to rotate at the number of cutter teeth per one spindle rev. The cam profile would control the relief profile and the stroke length. This way, one could make cutters of various sizes & relief angles. Furthermore, if the cam drive was via a telescoping cardan shaft, one could use the lathe carriage and set up a desired Module or DP and make a gear hob. Gear hobs have straight flanks - eliminating the need to try and approximate the involute curve. And you only need one for all the gears, regardless of # of teeth.



View attachment 12953

Another thing, if the drive train to the cam was via a planetary, one could drive the ring gear “slower“ than the planet carrier and get a differential function. This would allow for helical cutters as long as the differential per rev is a function of the helix angle. (differential division is the mechanical principle behind an universal dividing head: with each rotation of the crank, the reference point moves backwards ((or forwards)) by the “differential amount” to allow the circle to be divided by a prime number, for example, without using a prime number hole circle plate [like 127]). I digress.

Maybe all this could be done on a Menziken M200? Hint, hint.... Joking aside, I think they fell victim to the CNC revolution, like so many other manufacturers of high quality manual machines.

Ok, you have me hooked. I went out to the shop this evening and pulled out the pieces that Horst and Konrad gave me for the lathe and laid it all out. I believe all the pieces are there to connect the drive mechanism to the cross slide. I will see about fitting it to the lathe tomorrow. I have the manual for this but it is in German and so I am hooped there. Would you know someone that could do some translating?

Were they bought out buy another outfit or did they just closed their doors. There seems to be quite a few in Europe yet. I guess the only reason this one is here is because of Horst.

 

[RobinHood]

I am not 100% sure what exactly happened to Menziken. Horst is from Germany and Konrad from Switzerland. I am sure that played a big part why they got the M220. I can translate the manual for you, I speak the language fluently. Maybe send me a PM and we can arrange something?

That would be great if you could get the relieving attachment going and then we can all be green with envy as we watch you make gear hobs, gear cutters, etc.

 

[Brent H]

we can all be green with envy as we watch you make gear hobs, gear cutters, etc.

I second that motion!

 

[Hacker]

Thanks for the support and encouragement. Every time I use the lathe I see that attachment on the back and wonder if I will ever figure out how to use it. I will PM the manual, I have some commitments over the next few days and have to get my auction goodies today but will try to get it to you this afternoon. If not will send it on Sunday. I have an e copy but it is in word and the file is huge so will have to make a PDF first. You can have a look at it and decide if you want to pursue this. Thanks!!