Thread: A silly thing for me to offer really

That there is a generous offer Michael. I will eventually be up and running and able to cut my own, and the ones I'm missing would be nice to have but not imperative. FYI I was quoted $1.00 a tooth four years ago by a guy who had a gear cutting machine.

Once I accumulate every change gear imagineable for my lathe I am probobaly going to convert it to a servo leadscrew thus rendering all of them obsolete.

Greg

$1/tooth sounds very reasonable to me. If you got orders for a number of identical gears, could you gang them? That would at least divide the dividing time.

Mike, not for me, but for a bud, what imperial sized cutters/pressure angle do you have? I think my mate with the Rivett 608 needs something...and from memory his gears are 16DP with a 14.5 PA

Greg

My cutters are 14 1/2 degrees. Pretty sure I have 16DP.
If I got multiple requests for the same gear I was going to gang them. However, ideally they would have to have the same bore too.

Michael

Originally Posted by Bryan

$1/tooth sounds very reasonable to me. If you got orders for a number of identical gears, could you gang them? That would at least divide the dividing time.

The buck-a-tooth quote was reasonable I thought, but I ended up getting original gears out of Europe for less than 1/4 of that shipped, except the two gears that would I should have and will likely need: a 40 and a 90. I have every gear from 20 to 120 in 5 tooth steps and some primes like 37, 57, 97 and 127.

My lathe has the largest and least likely threading chart I've ever seen. I don't reckon that I'll be cutting a lot of 160 tpi threads, but you never know.

Originally Posted by Michael G

My cutters are 14 1/2 degrees. Pretty sure I have 16DP.
If I got multiple requests for the same gear I was going to gang them. However, ideally they would have to have the same bore too.

Michael

If you're doing multiples, I'd pilot-bore them and leave it to the end user to bore them to size. If they can't manage that, they probably don't really need the gear anyway.

Cast iron is nice to cut.

Greg, I've a pretty complete set of 16DP 14.5PA gear cutters as well as 12DP and some 14DP and 10DP.

PDW

I'll see what Mike G ( the Lilydale Mike G who helped with the granite) needs for his machines. I know he has two and a half Rivett 608s (glutton that he is) and several missing change gears. One of the lathes would be an ideal metric conversion given that the usual wear items all need replacing. I'm guessing that would mean a completely different set of change gears. I'll email him this thread for his input. If you are of a mind to rent out those cutters PDW I think I could make use of them for a week or so sometime down the road.

GQ, groggy from a lunch of black truffle & dead pig dumplings in Hong Kong.

As said before in another thread you could also cut the 127 with a 127 plate.

I had thought of pilot boring, but I have had occasions of angular slip where at the end of the cuts there is one slightly thinner tooth. A keyway keeps things in sync. If necessary I can make an adaptor sleeve.
Looking at the collection I can find they are all 14.5 degrees and I have 12, 16 and 32 DP.
Agreed that CI is not too bad to cut, but if a gear is only for occasional use then an engineering plastic or Al may be just as suitable and I can feed a bit faster.

Michael

PS I could also make a 127 plate

How do you hold blanks without a keyway?

Originally Posted by pipeclay

How do you hold blanks without a keyway?

With a shaft to hold the blanks, the shaft has a nut on one end to clamp the blanks together tightly up against another nut or shoulder.

But the poster stated he has trouble with them turning resulting in a thin tooth.

Hi Michael,
great offer by the way. If you needed to gang mill the blanks, Graziano idea works perfectly but I will add that if a fine thread is used on the arbor and nut(s) and a thin piece of paper between each blank, like a gasket, you will solve the problem of slippage.

Phil

Originally Posted by pipeclay

But the poster stated he has trouble with them turning resulting in a thin tooth.

There could be a lot of variables that come into play, such as feed rate, this index wheel is about 2" and is made in sets of 30+ ganged up on a shaft with nothing but a nut to hold them.



While I think of it, I bought some Myford ML7 gears from RDG in the UK that mesh well with my little Advance lathe which allowed me to complete the set as well as get a 127 tooth gear in cast iron for 15 UK pounds. I just had to drill holes for a pin drive instead of the Myford's keyway. The holes were the same diameter and they fit fine. This might help some of you with smaller lathes, I asked my friendly expert about pressure angles and he curtly replied that if you'd seen the way some change gears wobble on some lathes, the pressure angle would be the least of your worries. Anyway they work fine for my Advance with minor modification.