Search found 26 matches

by David2011
Fri May 17, 2019 4:01 pm
Forum: Lathes
Topic: Jet GHB 1340 thread\ half nut issues - beginner
Replies: 20
Views: 4306

Re: Jet GHB 1340 thread\ half nut issues - beginner

Another thought: Do you have the same "hiccup" near the headstock, in the middle of the travel and at the right end of the travel? If the lead screw is bent I would expect the amount of drag to vary as the carriage is repositioned. If the lathe is working correctly there should not be any perceived ...
by David2011
Fri May 17, 2019 3:47 pm
Forum: Lathes
Topic: Jet GHB 1340 thread\ half nut issues - beginner
Replies: 20
Views: 4306

Re: Jet GHB 1340 thread\ half nut issues - beginner

Feed rod works fine, I misspoke. I threaded some pvc today and the threads are perfect, but I can still see and feel a little hiccup when the half nuts are engaged. The hiccup didn’t seem to effect the threading capabilities. Should I simply not worry about it? If I owned this lathe I would be look...
by David2011
Tue Apr 30, 2019 1:15 pm
Forum: Lathes
Topic: Soft Start for Lathe?
Replies: 54
Views: 10938

Re: Soft Start for Lathe?

soft starts can be very handy on a flat belt lathe with a big heavy part / chuck....assuming you have a 3 phase motor. My 16" south bend, on the higher speeds, often slips the flat drive belt off when powering up (did so for 40 years). It has a very big / heavy 12" chuck on it that I take off every...
by David2011
Mon Apr 29, 2019 8:28 pm
Forum: Lathes
Topic: Soft Start for Lathe?
Replies: 54
Views: 10938

Re: Soft Start for Lathe?

Love those old South Bends. We had about 8 of the 14" model in the gunsmithing class but seldom spun anything heavier than a rifle barrel.
by David2011
Mon Apr 29, 2019 6:25 pm
Forum: Milling Machines
Topic: New to me Bridgeport clone!
Replies: 24
Views: 5969

Re: New to me Bridgeport clone!

A tip I read somewhere worked out well for moving a mill once you have it off the trailer. Many mills have holes in the corners of the base. Those holes are often the perfect size to be tapped with a 3/4" NC tap. I did that and made lifting bolts from 3/4" threaded rod cut into 9" pieces and pinned ...
by David2011
Mon Apr 29, 2019 6:10 pm
Forum: Lathes
Topic: Soft Start for Lathe?
Replies: 54
Views: 10938

Re: Soft Start for Lathe?

It feels right. Better than at any time since I bought it. I'll just have to use it for a while and see how it goes. I hope to be moving the heavy equipment in about a month. I'm very grateful for the contributions from all the participants. They all helped me narrow down the areas to evaluate. David
by David2011
Mon Apr 29, 2019 3:32 pm
Forum: Lathes
Topic: Soft Start for Lathe?
Replies: 54
Views: 10938

Re: Soft Start for Lathe?

Glenn and all, Couldn't help myself and had to poke around a little more. After removing the bearing cap behind the chuck I found a hard shoulder on the chuck end of the tapered bearing so clearly shimming would not reduce the preload. Clean oil ran out so the bearing has been running well lubed. So...
by David2011
Mon Apr 29, 2019 1:57 pm
Forum: Lathes
Topic: Soft Start for Lathe?
Replies: 54
Views: 10938

Re: Soft Start for Lathe?

Also, remember that this is AC. The capacitors don't charge up and stay charged while the motor is running. They charge, discharge, and charge to the opposite polarity 60 times a second. I'm more familiar with DC capacitors, particularly in electronic flash units as I was a professional photographe...
by David2011
Mon Apr 29, 2019 1:46 pm
Forum: Lathes
Topic: Soft Start for Lathe?
Replies: 54
Views: 10938

Re: Soft Start for Lathe?

Thanks for the info. It's a little tight between the motor and the wall so I'll look for a second capacitor when I pull the lathe out. Sounds promising. Particularly the bearing caps. That suggests you might have split bearings- solid yellow metal spherical castings, split in half. If so, similar/id...
by David2011
Sat Apr 27, 2019 10:29 pm
Forum: Lathes
Topic: Soft Start for Lathe?
Replies: 54
Views: 10938

Re: Soft Start for Lathe?

Ah, that makes sense. That's different from an air conditioning motor or other capacitor start motors that don't have starter windings. So much I have learned about other similar stuff is different with this motor. I didn't think about the switch discharging the cap. Thanks!
by David2011
Sat Apr 27, 2019 6:28 pm
Forum: Lathes
Topic: Soft Start for Lathe?
Replies: 54
Views: 10938

Re: Soft Start for Lathe?

Steve, I know you're right about a cap having to charge up before it can dump but if a motor is being started and stopped repeatedly the cap should still have a charge from the last time the lathe was running. OTOH, maybe at its age it isn't holding a charge for very long. Not gonna stick my tongue ...
by David2011
Sat Apr 27, 2019 4:59 pm
Forum: Lathes
Topic: Soft Start for Lathe?
Replies: 54
Views: 10938

Re: Soft Start for Lathe?

I'll check the spindle play. The bearings are conventional tapered roller bearings held in place with end caps. No split bearings. I've run the lathe at its highest speed a few more times today and it hasn't tripped the breaker yet so even if the belts were not the entire problem they were certainly...