Newbie Problem 9" Model A

driftpin · Dec 11, 2014

Howdy All,

Name is Kevin, got a South Bend lathe from a guy who said he had restored it, just got it set up and have run into an issue.

It's a horizontal drive and when I engage the motor with the spindle unlocked the lathe runs fine except for the occasional belt walking off but when I lock the spindle then it bogs down so hard to the point where I dont think I could machine anything. In fact if I engage the lead screw, it pops the reset on the motor. That is without a chuck on the spindle. The back gears arent engaged either (it wont even turn with back gear are engaged.) So I'm kind of perplexed as to whats going on. I can turn the bull gear by hand but its difficult. How freely should it spin? Any help would be appreciated. Thanks.

kitno455 · Dec 11, 2014

It should spin freely. Is there oil in it?

allan

iwananew10K · Dec 11, 2014

hi Kevin,

when you say it runs fine with it unlocked is that with the bullgear pin pulled out and the backgears not engaged? is the spindle itself turning?

with the belt loose the bullgear(along with the spindle) should turn easily if not in backgear.

driftpin · Dec 11, 2014

Yea I topped it off with the oil it called for in the manual but still with the back gears disengaged and the bullgear pin in, it spins the spindle but it bogs down so far that i think it would stop if I started to even take a light pass across a piece of brass. with the pin disengaged, it spins great. is it possible that the guy who restored it cranked down on the front bearing to much? I took a video of it for my dad to see and I'll upload it to you tube and put it in a reply. I put a chuck on it and with the pin that locks the bullgear to the spindle pushed in, it is hard to turn by hand. I may also chuck up a torque 1/2" socket and throw a torque wrench on there so I can give you a little bit more accurate description that "hard to turn".

Is there any kind of spindle lock on these machines that could possibly be on causing it to drag?

Also when I bought it, it came with a 115V motor (harbor freight) that says it only draws like 7.8 amps. Is that enough to drive one of these lathes? I tried plugging it into where I have my compressor plugged into (which I had upgraded because my compressor kept blowing fuses, I believe it has a larger breaker 30 amp I think) and it seemed to run faster than one of my other outlets with a 15A breaker. Is it possible that the motor is just inadequate for it? I'm not much of an electrician so sorry for not using the correct nomenclature.

iwananew10K · Dec 11, 2014

stop running it, it sounds like the bearing are too tight.

unplug it, then loosen up the bearing cap bolts.
spin it by hand, it`ll probably start spinning freely.

leave it unplugged , it`s not the motor.

bet you need some shims in there.

driftpin · Dec 11, 2014

Yea. That's what I thought too but I was a bit leary of breaking loose that bearing on the bull gear end without knowing more about it. I've rebuilt a couple car engines and transmissions so I'm not a novice in that area but new to machining. Mostly done small fabrication jobs. You don't happen to know the torque specs for the bearings caps do you? Or if there is a certain sequence to torquing them?

Here is the video I made for my father. I apologize in advance for it sounding very novicey but both of us don't know much about lathes. We're kind of learning on the go. He comes from a carpentry background so....anyways here's the video. http://youtu.be/EVFqtwbUBco

packrat2 · Dec 11, 2014

driftpin said:
Yea I topped it off with the oil it called for in the manual but still with the back gears disengaged and the bullgear pin in, it spins the spindle but it bogs down so far that i think it would stop if I started to even take a light pass across a piece of brass. with the pin disengaged, it spins great. is it possible that the guy who restored it cranked down on the front bearing to much? I took a video of it for my dad to see and I'll upload it to you tube and put it in a reply. I put a chuck on it and with the pin that locks the bullgear to the spindle pushed in, it is hard to turn by hand. I may also chuck up a torque 1/2" socket and throw a torque wrench on there so I can give you a little bit more accurate description that "hard to turn".

Is there any kind of spindle lock on these machines that could possibly be on causing it to drag?

Also when I bought it, it came with a 115V motor (harbor freight) that says it only draws like 7.8 amps. Is that enough to drive one of these lathes? I tried plugging it into where I have my compressor plugged into (which I had upgraded because my compressor kept blowing fuses, I believe it has a larger breaker 30 amp I think) and it seemed to run faster than one of my other outlets with a 15A breaker. Is it possible that the motor is just inadequate for it? I'm not much of an electrician so sorry for not using the correct nomenclature.

a 15 amp breaker would be for a 115 volt circuit, a 30 amp two breakers would be for 220 volt circuit { two hots }. I assume you do not have three phase. {three hot wires}

iwananew10K · Dec 11, 2014

says the vid is private.

each bearing should only have one bolt in the front and the cap doesn`t come off, it`s part of the headstock casting(if it`s a 9A)- no real torque spec I know of - just nice and snug- not really a crush factor like a car bearing. the clearance is just from the shim packs.

driftpin · Dec 11, 2014

Sorry bout that. I'm kind of new with the whole YouTube thing. I think it should be unlocked now.

Is there any set clearance rates on the bearing? Can I use plastigage to figure out the correct size shims? I noticed earlier the cap wasn't really a cap. It must be a real PITA to change a belt out on these little buggers.

Derek Smalls · Dec 11, 2014

I just watched the video. DO NOT RUN THE SPINDLE ANYMORE! You are going to seriously damage things if you haven't already. I would pull the spindle out of the headstock to check the journals and bearings. Hopefully they are not completely wiped out yet. Check that there are wicks installed to get oil to the spindle and infact there is oil present. If the journals and bearings are not gauled up, reassemble and correctly adjust bearings. It's real easy to remove spindle. Remove nut on the gear train end from spindle, and slide spindle out towards tailstock. The bull gear is I think a light press fit, It's been years since I've had one of these apart, so you may need to tap spindle out until it clears the bull gear. If the guy you got this from says he restored it, you may need to speak to him about getting your money back if things are damaged.

martik777 · Dec 11, 2014

Spindle re/re and bearing adjustments:

https://www.youtube.com/watch?v=U1agcVkQ63U

https://www.youtube.com/watch?v=oS0DQusUR0w

If the wicks and springs are in decent shape, you can clean them with solvent and reuse.

driftpin · Dec 11, 2014

Yea. That's what I was afraid of. Unfortunately It was a craigslist deal and a refund isn't in the cards. I bought it too far back and took quite a bit of time to get it set up. I haven't had it running very long but I know it doesn't take much. I'll dig into it tomorrow and check things out. Thanks for the help.

iwananew10K · Dec 11, 2014

yes, for now unplug it, take off the belt tension, loosen the bearing caps, and see how it feels by just turning it by hand.

if it sat for quite a while after you bought it could just be gummed up oil- did you run it when you bought it?

regardless, don`t panic, these things are almost indestructable.

Derek Smalls · Dec 11, 2014

Don't loose hope! Asking questions here is a great first step. Lots of guys here with tons of experience with SB. When I got mine, spindle and bearings weren't in great shape, this can be repaired to some degree with out costing a fortune. Keep us updated!

driftpin · Dec 12, 2014

I didn't get to try the lathe before I bought it. The owner met me half way but seemed very trust worthy. I have no problem sinking some money into it if need be. You can tell the machine was made right, back when our country made machinery.

I'll post anything I find out. Thanks a million for the help so far. Seems like a good place to learn with a good group of guys!!

driftpin · Dec 12, 2014

Well I just went out and loosened that bolt on the, for lack of a better word, bearing cap on the bull gear end and it wasn't very tight at all so I just broke it loose and took the slack back up but didn't tighten it. I could feel the bull gear was "easier" to turn by hand. I hooked up the belt and ran it for about 30secs and it was considerably faster than before but still seems like it's struggling. So I'm going to move on to pulling the spindle out to have a peek at the bearings. It may take me a bit to figure out how to get it out but I'll keep posting with any questions I may have.

paulsomlo · Dec 12, 2014

Before you pull the spindle, try loosening the bearing cap bolts on both sides, not just on the bull gear side. If you still need to pull the spindle, here's what the apparatus looks like:

Paul

driftpin · Dec 12, 2014

Well I got the spindle removed and the bearings aren't galled. As soon as I loosened that threaded collar the whole unit spun freely. The bearings aren't perfect though. They have some markings on them but can't be felt by touch. I think I'm going lube it up and put it back together. I have a feeling the person who had it before had that collar wound on way too hard. I had to use a brass punch to get it broke free. Looks like he may have tightened it with a screwdriver. Anyways I took another video and would like any suggestions.

http://youtu.be/EodVdUsvIag

janvanruth · Dec 12, 2014

No problem relax!!!
You found ou tthe problem but didnt know it.
You stated that when you loosened the threaded collar at the end things spun freely.
That was the problem.
The collar adjusts the endplay.
If too tight it will stop the spindle .
It was way too tight.
Your bearings look fine.
Reassemble the headstock.
Take care the wicks are held down when installing the spindle.
Insert a needle in the hole above the oiler, holding the wick down and pull the needle out as the spindle is installed.
The collar is adjusted in small increments, a little to tight will bind up the spindle.
The video shows the belt is rather tight, it may want some readjusting a little slack in the beginning will keep small things from getting nasty.

have fun and stay safe

iwananew10K · Dec 12, 2014

bearings look great.

it looks like the wicks are just about flush with the spring. they are cheap on ebay.

nice job!

Newbie Problem 9" Model A

Plastic

Titanium

Diamond

Plastic

Diamond

Plastic

Hot Rolled

Diamond

Plastic

Stainless

Aluminum

Plastic

Diamond

Stainless

Plastic

Plastic

Stainless

Plastic

Titanium

Diamond

Similar threads