1950 Standard Modern 12 x48 Utilathe, headstock rebuild question

[Glenn Brooks]

Looking for proper procedure to remove the spindle and gearing on a 1950 S-M 12x48 'Utilathe'.

My lower speed gears are really worn and making a lot noise, so am considering replacing the gears.

However, previously, when pulling the bearings, i could not see any apparent method to extract the spindle, back gear shaft and gears. No room to remove everything as an assembly, and no apparent method to pull the gears inside the headstock casting.

Anybody know The correct method to disassemble?

Thanks
Glenn

 

[Garwood]

Where is the compound on that thing?

The lathe spindles I have pulled come out once the the bearing nuts are backed off. I found the easiest way is to leave a chuck on it and chuck on the tailstock quill (with something to protect quill from jaws in there). Use tailstock to slide spindle right out and back in.

 

[johnoder]

so am considering replacing the gears.

Way before I ever took it apart I would know where from and how much on the replacements

Assuming parts are reasonable or even existent on a 67 year old is probably a mistake

 

[Monarchist]

Looking for proper procedure to remove the spindle and gearing on a 1950 S-M 12x48 'Utilathe'.

My lower speed gears are really worn and making a lot noise, so am considering replacing the gears.

However, previously, when pulling the bearings, i could not see any apparent method to extract the spindle, back gear shaft and gears. No room to remove everything as an assembly, and no apparent method to pull the gears inside the headstock casting.

Anybody know The correct method to disassemble?

Thanks
Glenn

View attachment 193132

You can do this.. but.. might you be time and money ahead to just put a VFD to driving the motor, add a few carbide tools, then just reduce/avoid outright the very use of those badly worn ratios?

It ain't a Herringbone Sidney, after all.

 

[Jim Christie]

I don't have time to look to far into this but there are some parts manuals for that lathe on line here Resources & Support | Standard Modern™ Lathes.
There are likely bearing caps on either end of the shaft that have to be taken out to remove the shaft.
There maybe a socket head caps screw or a set screw inside the headstock holding the cap /bearing housing on the head stock end as on the newer models .
Check the parts breakdown .
If these gears are worn you may also be looking at wear on the shaft they are riding on .
If new parts are available they will likely not be inexpensive so you may have to look at patching the ones you have or making your own if that option works for you.
More S.M. links here.
Google

Regards,
Jim

 

[Glenn Brooks]

Thanks guys for your replies. Compound? What's that?? Oddly it came with no compound. Nobody knows why. I have one but have't fitted it yet. Had to make a new bottom mounting plate.

Yep, Iam aware parts are worth more than gold. Thinking about making the gears I need.

A VFD for carbide bits might work. I see prices on VFDs have come down substantially in the last year or so. This lathe has a 3Phase 3/2 HP motor, which may require a 5HP VFD. Initially VFDs were over $1500, now I see them as low as $250.

The bed also needs grinding and the saddle and tailstock built back up. So not a trivial deal. Right now, just sizing up whether it's worthwhile to recondition and keep the old girl over the long haul. It would be a phenomenal machine if brought back to new condition.

Thanks
Glenn

 

[johnoder]

Thinking about making the gears I need.

Your complaint was noise.

Think about the noise the not quite right shop built ones will make

I.E., not hobbed or otherwise GENERATED for true involute profiles

A VFD for carbide bits might work

Faster just makes more noise

 

[Monarchist]

It would be a phenomenal machine if brought back to new condition.

Well, no, actually it would not be "phenomenal". S-M are rather decent, but also rather ORDINARY medium-grade lathes.

Better to get the nostalgia and emotions well-distanced from an 'economics' decision.
IF .... one is to go to all the trouble and expense to refurbi-shit, better it had at least left the factory as one of the Grand Olds that truly WERE "phenomenal" and stood a half-vast chance of being made so again. A S-M never was one of those exalted Olympians. Wishing, fishing, and hand-scraping ain't about to change that cast-in legacy, either.

 

[Mike C.]

I would expect a set of new gears and all the other repairs you speak of to end up costing several thousand dollars, at least. As said, in the end you would have a nearly new decent lathe, but nothing super special. I'd try running it, as-is, and see what it does in terms of accuracy and finish (given worn gears). If it doesn't have ridiculous amounts of taper and doesn't pattern the work like a tractor tire, use it. If it has gobs of taper and the gears are leaving divots in the work, block out those speeds and make do, or use it for a polishing lathe. You could buy two or three good used lathes of that brand or even higher quality for less than this one will require to fix.

As John O says, a set of home made gears are probably not going to be an improvement over the worn ones, and will wear a LOT faster, unless you have the capacity to get them hardened. Lathe headstock gears should be viewed the same as automotive transmission gears. They must be VERY precisely made, must be hardened and then ground and polished or they will be short lived and noisy. None of these operations are practical for one off repair parts. If it was leadscrew gearing, then yes, go for it. Not internal spindle drive gears.

 

[Glenn Brooks]

Well, it's not worth the cost of grinding and $2k for gearing, that's for sure. Might try a VFD with carbide with the higher speeds. The hi end speeds have hardly been used and are in excellent shape. A VFD might give enuf speed range control to be useful... thanks

Gpb

 

[Monarchist]

Well, it's not worth the cost of grinding and $2k for gearing, that's for sure. Might try a VFD with carbide with the higher speeds. The hi end speeds have hardly been used and are in excellent shape. A VFD might give enuf speed range control to be useful... thanks

Gpb

If you need to cover missing 'usable' gearing in the HIGHER RPM band end, go VFD.

If they are LOW end .. AND you actually USE that range, which you might not, much, what with modern carbides, then a 90 or 180 VDC motor and KB-Penta DC Drive controller will give you good LOW end torque.

CAVEAT.. that can then also stress the NEXT higher set of gears being used, and decrease their lives, much as the others have already seen, and at an even faster rate of decline. Stall a DC motor, be prepared for the hammer-blow of anywhere between two and nine times its nameplated torque if the DC drive doesn't trip-out fast enough to save you from that. Or there is at least one belt in the drivetrain that can slip.

IOW .. probably wisest to just work around these noisy gears and spend nada until you have some sort of compelling need - or fortuitous accident - to find another lathe in better condition.

 

[Mike C.]

"Well, it's not worth the cost of grinding and $2k for gearing, that's for sure."

I doubt $2000 will get you even two hardened and ground gears. Last time I priced custom gears, it was a pair of large bevel gears for a radial drill I was restoring. They were similar size, but different tooth counts. I was quoted $1000 each, and those weren't even hardened or ground. I would expect $4000 or more to make a matching pair of hardened and ground gears.

Call and see what Standard Modern wants for a new set. You see, they don't stock any parts like these. When you call for parts like this, they pull a drawing and send it out to whatever shops they use to make you a new part. You might can get a 10-20% discount by shopping the work out yourself, but it is not going to be significantly less than what they quote you for new gears.

If this machine is that beat, start looking for a replacement. Don't get too sentimentally attached to it. I hate to see machines scrapped or put to a terminal service, but when they get too far gone, it's just not worth trying to salvage them when there are so many machines left out there with lots of life remaining. You could find a good condition late model 14 or 16" Pacemaker for $3000 and come out WAAAAYYYY ahead.

 

[rj1939]

I've got a SB with noisy gearing..................STP is a cheap patch, bottle will last a long time