Lathe parts

All discussion about lathes including but not limited to: South Bend, Hardinge, Logan, Monarch, Clausing and other HSM lathes, including imports

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Hammer989
Posts: 6
Joined: Tue Mar 06, 2018 12:11 am
Location: Silverton,OR

Lathe parts

Post by Hammer989 »

Hello

New to a great forum!!
I am looking for a replacement gear for my Jet 12-36 lathe. (the brass gear in picture) Appears it is not made and no one has a copy.
Would anyone on the forum be able to make one for me? Or another solution?

I also bent the pinion gear. I think that's what its called? when I hit the headstock under power.
How is the best way to straighten it?

Thanks

Rod
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John Evans
Posts: 2366
Joined: Tue Jan 20, 2009 9:33 pm
Location: Phoenix ,AZ

Re: Lathe parts

Post by John Evans »

I know where some of those style gears are but, I need to know how many teeth-bore ID-OD. As far a straightening that shaft a press is about the best way.But you can't use those V blocks as they are too long. Heat straightening is another way but you need a Oxy/Act torch. See Keith Fenner on Youtube re heat straightening. And putting in your location in your profile would be helpful ,city is fine.
www.chaski.com
pete
Posts: 2518
Joined: Tue Feb 10, 2009 6:04 am

Re: Lathe parts

Post by pete »

Boston gear might have something off the shelf that could be modified to correctly fit. Almost for sure those would be metric gears and made from bronze not brass if it was done properly imo. Appears to be a serious lack of lubrication in that area for a long time that I'd be sure to address for the new parts. Some of these lathes are poorly designed in that respect and there's no way provided to get lube into some areas on some lathes. Drilling more oil passages to direct oil into where it's needed might be a good idea unless it was a previous owner that just neglected it.
spro
Posts: 8016
Joined: Mon Feb 20, 2006 11:04 pm
Location: mid atlantic

Re: Lathe parts

Post by spro »

I counted 20 teeth on the worm gear. Some fellow ordered one from Griz but hasn't come back to say how it worked. There are button oilers on the saddle and a larger removable screw plug above the apron. The lubricant doesn't go straight down for the handwheel can be lubed from outside. This oiler runs down a cast ramp to the worm and wheel area. The new OP can tell if his is the same because he has it apart.
Hammer989
Posts: 6
Joined: Tue Mar 06, 2018 12:11 am
Location: Silverton,OR

Re: Lathe parts

Post by Hammer989 »

John Evans wrote: Wed Mar 07, 2018 5:20 pm I know where some of those style gears are but, I need to know how many teeth-bore ID-OD. As far a straightening that shaft a press is about the best way.But you can't use those V blocks as they are too long. Heat straightening is another way but you need a Oxy/Act torch. See Keith Fenner on Youtube re heat straightening. And putting in your location in your profile would be helpful ,city is fine.
19 teeth, How would I get the diameter? So worn
Hammer989
Posts: 6
Joined: Tue Mar 06, 2018 12:11 am
Location: Silverton,OR

Re: Lathe parts

Post by Hammer989 »

spro wrote: Wed Mar 07, 2018 7:52 pm I counted 20 teeth on the worm gear. Some fellow ordered one from Griz but hasn't come back to say how it worked. There are button oilers on the saddle and a larger removable screw plug above the apron. The lubricant doesn't go straight down for the handwheel can be lubed from outside. This oiler runs down a cast ramp to the worm and wheel area. The new OP can tell if his is the same because he has it apart.
Yes, you are dead on. The ramp was plugged part way down. Appear like no place to oil gear if I am seeing this correctly
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John Evans
Posts: 2366
Joined: Tue Jan 20, 2009 9:33 pm
Location: Phoenix ,AZ

Re: Lathe parts

Post by John Evans »

19 teeth, How would I get the diameter? So worn
You measure what is there ,close with number of teeth will get you close enough to have a good idea of the gear pitch [tooth size]. But ,I also counted 19 teeth and looked in the gear stash I know about and no joy ! Was not a 19 tooth gear there > :( That gear is called a worm wheel and teeth are cut at a slight angle and the top face has a radius cut into it. People put grease on that gear big NO NO oil only. I just give mine a squirt of oil from oil can ever time I use the lathe along with the ways etc. Have you contacted JET about a gear?
Most lathes of this class/style that I have seen do not have a oil feed to that worm & gear ,so you and your oil can is all that it gets.
www.chaski.com
Hammer989
Posts: 6
Joined: Tue Mar 06, 2018 12:11 am
Location: Silverton,OR

Re: Lathe parts

Post by Hammer989 »

Thanks John!
Yes, jet says no joy. Tried Former gearworks out of Seattle. Made them at one time, but couldn’t find prints, not in the system they said. Probably to small of an order.
Hopefully someone else will chime in.

Thanks
spro
Posts: 8016
Joined: Mon Feb 20, 2006 11:04 pm
Location: mid atlantic

Re: Lathe parts

Post by spro »

Thanks, John. This has been informative, in that the worm and wheel needs outside lube (from the right side of the apron). I think we are talking about the same type apron with the yellow paint. The gear is 19 teeth. It was difficult to discern between 19 and 20 but now I see it. There is a part #of the Enco wheel around here. Before finding that # , Your wheel doesn't appear to be "sheared" nor the worm damaged. That bent pinion is the major problem. I had reason to disassemble my apron because the interlock didn't lock and the wheel got buzzed- but not sheared. IIRC I found that there was some adjustment among those components to tighten things up.
Hammer989
Posts: 6
Joined: Tue Mar 06, 2018 12:11 am
Location: Silverton,OR

Re: Lathe parts

Post by Hammer989 »

spro wrote: Thu Mar 08, 2018 6:59 pm Thanks, John. This has been informative, in that the worm and wheel needs outside lube (from the right side of the apron). I think we are talking about the same type apron with the yellow paint. The gear is 19 teeth. It was difficult to discern between 19 and 20 but now I see it. There is a part #of the Enco wheel around here. Before finding that # , Your wheel doesn't appear to be "sheared" nor the worm damaged. That bent pinion is the major problem. I had reason to disassemble my apron because the interlock didn't lock and the wheel got buzzed- but not sheared. IIRC I found that there was some adjustment among those components to tighten things up.
Spro
Yes, gear works fine. lotssss of slop in handwheel. pinion seems to be bent at through pin location, .010 to .015
Going to try 2 indicators with a press. Would a hammer hit at center point work? bushing slid over od of pinion, between two v's, then strike?
spro
Posts: 8016
Joined: Mon Feb 20, 2006 11:04 pm
Location: mid atlantic

Re: Lathe parts

Post by spro »

No, man. A strike is too dicey unless it is already configured. A screw press where you can tap within a tight limit while under tension... There is an art to this. If we look at old bench vises, big old vises, there are strike marks at the handle end of the clamping screw. All this has been done before. The heavy screw has play to a limit.
I edited my reply because yours was different and you are on the right track with sleeve support and vee type blocks.
spro
Posts: 8016
Joined: Mon Feb 20, 2006 11:04 pm
Location: mid atlantic

Re: Lathe parts

Post by spro »

It is too easy to bend something back without proper support. You end up with a "dog leg" which then requires further pounding. The crash induced some damage to the original bushings but those can be replaced/ reamed straight. That original pinion shaft has actually bent? Keep us informed about that because we are with you.
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