Newbie with a SB9! need motor/countershaft help

[Pevehouse]

picked this up on friday along with a truckload of tooling - my first (metal) lathe. it's a '37 9" 3ft. last run in 2001. complete from everything I can tell (if I'm missing anything in the pics, I likely have it)

first order of business is building a bench and sorting the belts and motor and countershaft.

from what I can tell, this looks like someone's home build countershaft stand - it doesnt match the stationary versions I've seen in the catalogs or other pictures at all.

I'd love to track down a better solution - either the stock adjustable version or I'm open to ideas if someone has come up with a better option. maybe a direct drive with vfd? or?

this is a very very budget build (brought it home for $250).

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Nice score

 

[woodchucker]

you are missing the lead screw support . That's important to have, you can bend the screw without the support.

 

[keen99]

The factor motor mount/counter shaft assembly is probably a very prudent way out of that situation. What's there obviously worked, but as I'm sure you know, 90 percent of the effort, and 90 percent of the functionality, is in the last ten percent of the details when you're building things off of the stock rack...

The factory back gears are long gone on that machine. Broken teeth is a common failure. (Typically from stuck chucks, poor judgement, and big hammers). I don't know as I'd run off after a factory offset bushing just yet. (But maybe, if the dimensions line up) My guess is that this "wheel" was a more convenient handle to engage/disengage the back gears, since they obviously wouldn't be needing a tension lever, as the "good enough" counter shaft was done without it. The bushings are both locked to the straight shaft, and should both turn with it. You don't need that "wheel", but that exact bushing fits, and (apparently) does it's job.
I think I might see some gold color where that wheel is joined to the bushing. If it's braised, it can be released with heat. (Torch heat, you're not gonna do that with a propane torch). Were that me, that's how I'd start off. Doing what it takes to separate that wheel from the existing excentric bushing.

It's pretty obvious that this machine had a hard life, but it looks to have been in the hands of somebody quite capable. Maybe a dedicated machine for "some" operation(s) The repairs on the backgears (quite possibly the spindle gears as well), the remade cross slide handle. "Original might be gone, but it looks to be in a condition that could be very functional, probably even proper looking, with very reasonable effort.

thanks jake - for <$20, I'll give a stock eccentric bushing a shot (measure, test fit, etc). if it works, it saves me a lot of time (just digging the big torch out, if nothing else, since my entire "temporary" engine build station is in the way with two motors in the works). if it doesnt, not a huge loss.

tore the countershaft down - it was...not as well engineered as some of the other bits. it shows a lot of history where the cone and the drive pulley spun on the shaft. the uprights seem to be someone's factory part, though. or maybe were. with nice bushings. dunno why no one put a keyway in the slot, both parts are already slotted..... and it really needed some sort of thrust arrangement.

 

[keen99]

you are missing the lead screw support . That's important to have, you can bend the screw without the support.

thanks - it's not missing, I'd just not reinstalled it when I temporarily slid the cross slide on to confirm fit and take a picture.

 

[keen99]

The repairs on the backgears (quite possibly the spindle gears as well), the remade cross slide handle.

do the spindle gears look like they were replaced? definitely the small gear shows signs of being welded in place.

 

[keen99]

looks a lot better cleaned up. (not that the parts table pics are dry - but they are dry now... )

 

[Jake M]

do the spindle gears look like they were replaced? definitely the small gear shows signs of being welded in place.

Well, I did say maybe. Or possibly. Or something like that. They don't look like mine. Slight differences. Proportions don't look the same. Maybe it's the pictures? And they'd be easier to do than the back gear assembly. Whoever did those could certainly have done the other. And usually (not always, usually), broken gears come in pairs. But your lathe is a little older than mine, so maybe they are original. As long as they engage properly (some fiddling to get all four gears lined up is to be expected, but once they're "in", they should mesh well), they should run smoothly (which with original parts is a little noisy compared to modern stuff), and all in all they get the job done, I wouldn't sweat it either way until/unless you had a failure in one, then you'd want to verify the gear profile and tooth count. Outside of that, being as this lathe is what it is, and part of that is "well used", it's probably just trivia either way. Every mechanical contrivance gets repaired over it's life, a solid, but non-standard repair repair is nothing to worry about.

thanks jake - for <$20, I'll give a stock eccentric bushing a shot (measure, test fit, etc).

At 20 bucks for a cam bushing (offset bushing)... I didn't look, I figured you'd get hit for 2 or 3 times that. No argument from me on that one.

tore the countershaft down - it was...not as well engineered as some of the other bits. it shows a lot of history where the cone and the drive pulley spun on the shaft. the uprights seem to be someone's factory part, though. or maybe were. with nice bushings. dunno why no one put a keyway in the slot, both parts are already slotted..... and it really needed some sort of thrust arrangement.

This clearly has a machine number on it, which puts it in a commercial environment. The "somebody else's factory part" notion plays into what I'm thinking- And only thinking. I'm thinking the machine did "some" thing, but not everything. Perhaps as an example (and I'm making this up, it could have been anything, I have no idea), perhaps one belt setting was fine, the machine drilled a hole in back gear, then bored said hole in direct drive. Or maybe a "second op" machine that did an inside and outside chamfer on a semi-finished part that required flipping the back gear. Making the convenience of the back gear lever a much higher priority than the convenience of a belt tension lever. So the repair brought the machine back to full production status, (possibly better than) verses OE functionality standard. As I said, the repairs that you've showed us do show that somebody quite capable was doing the work. I suspect that the partial functionality was not a lack of ability, but a matter of what was prudent at the time.

Old machines always have a lot of stories. We never get to know them all, and what we do know, we seldom have complete certainty.

 

[keen99]

ran today for the first time under it's own power since 2001 (per the PO's report that it was in parts since they moved it from his shop after he died).

I made the possibly controversial decision to flip the motor drive to the inside, instead of the outside - that allowed for a full 5 inches of depth to be recovered. (making room for the pulley to clear the gear door pushes it back to 15" from the rear bed bolt, this is at 10". I could have shaved 2 more if I'd used a 1/3 or 1/2 motor and didnt use the adjustable plate).

between the ebay score dual speed 3/4hp 3 phase motor ($38 shipped and taxed) and my current favorite 120>240 VFD (at5-2200) and the 56 frame adjustable base I'm under $100 for the motor.

the 1/2hp motor that came with the lathe was smoked, and the 1/3hp motor worked, but it didnt line up with _anything_ of the 4 bolt sets that had been drilled in the countershaft base previously.

the countershaft assembly was a lot more (more than the entire lathe cost me). and the dual size motor pulley it came with was broken and undisclosed by the seller. ah well.

I milled the countershaft housing flat on the other side - the factory casting is rough, they only flatted the side they planned for the pulley to ride on.

need to measure bearing clearances (we determined in another thread that this 415-y has had bronze bearings added to it), it runs tight (it'll lock up at around 120-125 degrees on the big bearing cap after a few minutes at ~700rpm).

oh, and figured out the back gears were, from what I can tell, replaced with a larger gear set. large enough that the engagement handle doesnt rotate toward the operator as far as stock, so the backlash adjustment bolt is useless. before I go modifying the handle, I'll just run it as-is and see how it does.

 

[Jake M]

I made the possibly controversial decision to flip the motor drive to the inside, instead of the outside ...

Hmmm. I'm not sure I like that. On the other hand, I'm not sure that I don't like it. It sure does get everything tucked in there very nicely.

I wonder if chips in the belt is gonna be an issue. I wonder if that could be alleviated with a simple "L" shaped guard over the belt. That swarf would only be coming from one direction. Or if it's even a problem that I just made up. Hmmm...

I have a new bench that's gonna for mine somewhere in the foreseeable future. Given that the small savings in depth would go back into the main traffic path from my door to my wood stove... That could be huge with an arm load of firewood...

Hmmm.....

Good, Bad, or indifferent, I like your thinking there. You won't get any controversy from me.

 

[keen99]

I wonder if chips in the belt is gonna be an issue. I wonder if that could be alleviated with a simple "L" shaped guard over the belt.

that's my only real worry - and yeah, I'll just make a cover for it.