Power feed gear

[sk1nner]

The whole story on the lathe is that one of my works customers was using it in there shop. My boss was contacted buy them wanting to know if he wanted the lathe, they said it needed some work. He got it from them for a good price (I think it was "what ever you want to give us, or just scrap it"). When he got the lathe home he had his father in law (former machine repair guy) do some work on it. Years later I buy the lathe from my boss ($200), but he couldn't find the manual on it. A year or so later I come to work to find the manual on my work table. Along with the manual was the P.O.s from the parts they had to order (from a company called Machine Tools Direct). I never really looked at the P.O.s, until a few minutes ago. Turns out they had to replace the worm gear and worm wheel!!!!! I'm going to email MTD and see if they still have the part in stock. Looks like they paid about $80 for it back in 2001.

[sk1nner]

E-mail fail...

[spro]

Well I made you count your teeth again and little else. So yours is different enough. Hopeful Dave shared good advice about making a wheel and pinning. We have keys on the wheel and in my case, it was the weak link. The worm didn't show damage. Probably should have a shear pin where the feed shaft connects to the gear box. Can't say about the worm.

[Hopefuldave]

Definitely replace those roll pins with something softer, roll pins are actually pretty tough! Soft brass or aluminium would be perfect, shame it doesn't have the ball/spring over-torque clutch but manufacturers can save a whole quid by not fitting those... It WILL limit the torque and hence cutting forces available on the feeds, but replacing a sheared piece of rod will be a lot better than replacing expensive / hard-to-make parts on a regular basis (and screw-ups are sadly frequent for me...)

To be honest, I've broken more than one wormwheel in similar circumstances on a lathe with the over-torque clutch, when someone had screwed the grubscrews behind the springs right in until they were solid! Only way it would have let go is if the tailstock end bracket bent or the lathe bed stretched about 1/8"...

My current lathe doesn't need them, it's designed to run to a solid stop then the carriage stops and then ramps on the feed worms trip the individual feeds... Dave-proof! Comes to a halt within the accuracy of my cheapo Asian DTI, too, so less than half a thou", probably closer to a couple of tenths, of variation in the stops - handy!

It's really handy on those half-hour 2-foot finish cuts at 0.8 thou"/turn, I can trust it while I get a coffee and a smoke (then the phone rings...) to stop the feed at the end of the cut and wait for me to get back!
Damn good for repeat parts too in combination with a collet stop in the spindle and DIY "length blocks" or Jo-blocks in the gauge trays to set all the lengths/depths of cut (one of many tricks learnt from my late granddad, toolmaker before, during and after WW2, although his lathe didn't have the feed trips, had to be wound to the stop by hand). I've seen some very neat microswitch stops that cut the motor at the end of a cut, so I suppose something similar could be added to most lathes?

If you can't get the wormwheel as a spare part, definitely consider making one - it's not a horrible job, you've got the worm to measure and copy so you're halfway there already - and you don't NEED a mill to make the hob flutes (as MyfordBoy did in the video), in a real pinch I've managed by jigging up a grinder or dremelloid in the toolpost and running the carriage along the flutes, for a 3 or 4 flute a Suitable Stick between the lathe bed and a chuck jaw will index well enough for government work

[John Evans]

Well I stopped by the tool dealer today and he did not have any 17 tooth gears in the box. Sorry.

[sk1nner]

Thanks for stopping by John, I really appreciate you going out if your way to have a look. when it goes back together I'm defiantly replacing the roll pins, I think aluminum will be best. The soft sheer pins may lower the heavy cutting ability of my lathe, but its also not the most robust machine so i probably shouldn't be taking cuts that hard any way.

[sk1nner]

John you go me thinking.... Wholesale Tools is only about 10 minutes from me. I took my broken gear in and they just happened to have one!!!! $40, I couldn't pass on that. So now I have the parts needed to fix my auto feed. Thank you every one for the advice on making one, and thank you again John Evans.

[ken572]

Your post got me curious. That company is Taiwanese. Rumor: they are no longer in business. They may have made some machines for Jet, so if you could find the Jet model #, that might get you somewhere. Also Enco.

http://www.taiwantrade.com.tw/MAIN/en_f ... y_id=95140

Good Morning Steve

Thanks for sharing that Trade Show/Info LINK

Very useful site..

Ken.

[pdfox1]

sk1nner, I am in need of the same worm gear. Do happen to have any reference info from Wholesale Tool?
I am try to source is from CP Machine Tools as well. Any help would be appreciated. Thanks