Lathe fix. Has anyone ever had lathe gears made for replacement parts?

Oh wow, that actually is a belt drive lathe.. They don't make stuff like that much anymore (says the man who's CNC turning center is a belt drive)
I know you said it was belt drive, but I figured you saw the belt off the motor and thought "hum, belt, eh, drive --- belt drive!"

This actually is a belt drive lathe. I haven't run one of these in quite a while.

I looked at the parts list link you sent me. I'm not certain, but I think the gears involved are for driving the back gear, which is used for turning at slow speeds such as when threading. If that is the case, the lathe would be fully functional other than you wouldn't be able to run it at low speeds.

I sometimes chase threads at high speed because I am a kung-fu ninja machinist with poor "judgment skills". But you're probably not going to want to do much of that. So you'd be looking at losing threading and trouble driving drills over about 3/8". Otherwise, I think that lathe is good-to-go. Though I could be totally wrong...
 
So, with a VFD setup, low speeds and threading would still be bye-bye? The manual I have is a bit dense, but I am trying to crunch it.
If that's the case, I'll pass on it.

I'll certainly keep in mind that you could be totally wrong. You are much more likely to be right than I am, however! I'll go look at it for sure. Then I can mess with it and suss out what drives and affects what.

BTW, thanks Nathan.
 
Naw, with a VFD threading would be fine. You're probably going to want to cut threads at 100 RPM or less, which would probably be around 1/3rd the slowest speed available without back gear, which should be no problem with VFD.
 
Nathan, you the man! I can see that you are right because I just put in an hour reading the manual, and understand the back gearing scheme now. They only exist to slow the spindle. The spindle, at whatever speed it turns, back gears or no, when the lever is thrown either way, engages the change gears. The change gears then power the gear box which ultimately drives the lead screw and/or feed rod.

So, the ability to electronically control the actual motor speed would obviate the back gears without affecting threading. Whatever speed the spindle is actually turning, when the lever is engaged, power moves through the change gears so that the spindle speed, and then the gearbox, select your threading speed.

I think that in addition to shearing some gear teeth, the owner sheared or lost a bolt that connects the spindle v-belt pulley/small gear to the main spindle drive gear. The gear is keyed to the spindle. When the back gears are engaged, the bolt needs to be removed, in effect turning the v-belt pulley/small gear into an idler that drives the back gears, which then drive the main spindle drive gear.

The spindle wasn't moving because the bolt is gone or sheared and the pulley is idling on it. I wondered why he said the spindle was not moving.

I don't care if anyone followed that. I had to type it out so I can reread it and see if I'm wrong!

Now I feel much more prepared to go and monkey with this thing. It helps that I have a 2 hp. TEFC Baldor industrial motor and a VFD already... if I buy the lathe. IF. There could be other dealbreakers.

Nathan, everybody, again, thanks so much for the advice. I'll post any updates.
 
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Salem Straub said:
The spindle wasn't moving because the bolt is gone or sheared and the pulley is idling on it. I wondered why he said the spindle was not moving.


Now I feel much more prepared to go and monkey with this thing. It helps that I have a 2 hp. TEFC Baldor industrial motor and a VFD already... if I buy the lathe. IF. There could be other dealbreakers.

Nathan, everybody, again, thanks so much for the advice. I'll post any updates.
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I don't quite catch where this bolt is, not very handy if you have to pull it out to change gears.

I was able to read this manual,
On the lathes I have used and this one too, there is a pin you have to engage or disengage to use the back gears.
In this manual they call it a backgear pawl.

If that is still disengaged while trying to run it in normal forward speeds (not back gear) then there is no engagement to the spindle.
It may not run or may freewheel with no torque


It's helps to know as much as you can.
 
IMGP5036-1.jpg

Sorry for the bad picture, I had deleted the rest after I sold it.

Please take this info as just my experience with this Model lathe from Grizzly.

One of the regional high schools was downsizing their metal shop and put this lathe up for sealed bit. I was the unfortunate lucky bidder. I had looked at the lathe prior to bidding , bid $1175. The lathe was in very good cosmetic shape, with most of the tooling but was not under power.
When I got the lathe home with the help of Ken Coats and Joe Yach , I moved it in and wired it up. I discovered a broken gear for one of the quick change levers, was able to get a replacement gear from Grizzly. Nothing precision about the gears in this lathe. After getting the lathe under power I was never so disappointed in how the lathe ran. There was a funky harmonic vibration that would set up and I found it difficult to get any kind of decent finish. I have owned 3 other lathes, including a 13x40 gear head China made lathe so I am no stranger to lathes and lathe work. The divisions on the dials are all but useless. I also found that changing speeds via the belt was a pain compared to a South Bend for example.

Long story short the lathe turned into a expensive belt storage rack until a new owner was found.
 
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Thanks, Ken for taking the trouble to post that. It helps me to remember to consider the rest of the machine other than the obvious problems.

Count, there is the back gear pawl, but when the back gears are engaged, there is a pin or "bolt" that the manual states needs to be taken out that connects the spindle pulley to the main spindle drive gear right beside it. If that bolt is gone, and the back gears are not engaged, the spindle won't spin with the belts running.
 
Salem Straub said:
Thanks, Ken for taking the trouble to post that. It helps me to remember to consider the rest of the machine other than the obvious problems.
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No problem! Here is a picture of my 13 x 40 gear head lathe purchased new in 1994, sold in 2002 and reclaimed (long story) this last summer. This lathe is badged Enco but I can honestly say it is 5 times the lathe that G1003 Grizzly was.

Good luck with what ever way you decide to go!
DSC02045.jpg
 
Well, I went up and looked at it- ended up buying it and hauling it home. I'll post some details tomorrow, after setting it up again and running it a bit.
 
Salem -- don't fret about the missing gears. Get a copy of Machinerys Handbook, and in it there will be every. single. thing. you will ever need to know about gears (and a whole buttload of other stuff you might need to know, such as speeds and feeds for turning different metals, lathe tool shapes, how to calculate surface feet per minute, etc. -- it's a good investment, even a used copy)

Once you figure out the "PCD" (Pitch Circle Diameter) of your existing gears, there is a good possibility that you can locate a PAIR of straight-cut gears that will be an easy-to-fit replacement for the pair of helical-cut gears. It won't run as smooth, but it will run.

Or, a replacement that requires a little work.

For example - if you can find a gear pair that are almost right, but the gear centers need to be closer together, you can make an offset bushing that you pin to the shaft (assuming one of the shafts is stationary), or you can fill a shaft hole and re-bore at the correct center. There are a number of solutions.
 
Thanks, Al. I will ultimately probably investigate some of those avenues. It appears as if retrofitting my 3 phase motor in won't be a problem, other than having the motor pulley bored from 3/4" up to 7/8" to fit.

I was correct in thinking that the set pin/bolt being out was causing the spindle not to run... so what I have is a lathe that will run at all speeds non-back gear. After the VFD, it should be all good.

This thing is big and heavy. I had a chancy moment with the last 10 inches of getting it from the tailgate through the door onto support, barely balanced. Past that now, just have to swing it onto the stand. I put my anvil on the back of the cherry picker as an additional counter balance so the wheels wouldn't float during that sketchy bit...:eek: but it worked. Why do I do this stuff alone?!?

I'll post more updates as I install it and run it a bit. We'll see if this machine is actually "a pile of garbage shaped like a lathe" as one owner put it so eloquently somewhere on the interwebz... hey, it's my first one. Some other folks have said that theirs was decent.
 
Alright, Numbers, I'll give ya the numbers.

$650. (Ducking.)

F'er dug in his heels. Not that I'm a master bargainer...

But, whatever. I sold one of my three belt grinders to afford it, the one that I was given. So I feel OK about it. (So far...)
 
Salem Straub said:
Alright, Numbers, I'll give ya the numbers.

$650. (Ducking.)

F'er dug in his heels. Not that I'm a master bargainer...

But, whatever. I sold one of my three belt grinders to afford it, the one that I was given. So I feel OK about it. (So far...)
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That's not as low as we had hoped for a "broken" machine but I can't criticize it.
It's still half price.

Last time I bought a machine I think I paid $3-400 for shipping alone (power tailgate truck )
 
Put a bunch of work in today. Got the machine in place, wired and running. Took the spindle out to repair the sheared back gear lock bolt, put back together, runs OK. Lots of scrubbing grime off, did some light facing on a 1-1/4 mild bar and with re-sharpened HSS cutter got a fairish finish.

Carriage and cross slide power feed, forward and reverse, threading dial, lead screw gears all seem OK so far. One thing I don't like is some play in the rack gear. I'll be investigating that soon.

I'll start a new thread about it when I've installed the VFD. Just have to get the motor pulley bored out to 7/8" for my Baldor motor.

Thanks for going easy on me, Sam!
 
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