I seem to have found another source for advice for my shop toys.

I've lurked for quite a while now, and since i have now aquired a Pratt and Whitney Model C, to live with my K&T No.3 plain(1928), Taft Peirce No. 1(1944/45), and Sebastian 16x72. Along with some other metrology snd metallurgy toys, I feel its time to pick some brains over here.

Any one have any idea where i could economically find a set of quick change gears, and idler gear for a model c? Also a compound, machine didnt have a compound on it, just a big turret tool holder.

Another Model C (same size, similar vintage) of course, which is strictly the luck of the draw

Gears get made - "finding" them usually is an endless effort

If you are talking left end gear train, that's only several - the QC gearbox on the other hand is full of them

DJ Berg said:

I've lurked for quite a while now, and since i have now aquired a Pratt and Whitney Model C, to live with my K&T No.3 plain(1928), Taft Peirce No. 1(1944/45), and Sebastian 16x72. Along with some other metrology snd metallurgy toys, I feel its time to pick some brains over here.

Any one have any idea where i could economically find a set of quick change gears, and idler gear for a model c? Also a compound, machine didnt have a compound on it, just a big turret tool holder.

Click to expand...

DJ Berg said:

I've lurked for quite a while now, and since i have now aquired a Pratt and Whitney Model C, to live with my K&T No.3 plain(1928), Taft Peirce No. 1(1944/45), and Sebastian 16x72. Along with some other metrology snd metallurgy toys, I feel its time to pick some brains over here.

Any one have any idea where i could economically find a set of quick change gears, and idler gear for a model c? Also a compound, machine didnt have a compound on it, just a big turret tool holder.

Click to expand...

If all - or even most - of those other machine tools in your arsenal are in working order, a compound can "get made" too. Or be adapted from some other lathe of similar size.

Most weeks at one Day Job, a big 4-way was on nearly every lathe on the line, its compound five or ten feet down the chip tray waiting for the one task every few weeks that actually NEEDED it. So that part isn't a show-stopper, as-is, not even for threading.

Yes the actual quick change gears the selves and the idler gear on the quick change lever, if i had to guess, the lever was hit and knocked out of alignment, then they tried to run the machine as normal. While the gears were not meshed properly chewing up most of the teeth on the quick change set, and all of the teeth in one spot finally gave out on the idler. Originally i thought there was a problem in the x power feed clutch area, since that lever is a bit sticky, but after closer inspection, it was the shift knob.

As to replacing them, my biggest hurdle is how to internaly spline them, i have an amish buddy who would have no problem making the straight cut gears on his Cincinnati horizontal, but i would have to figure out how to broach the splines.

johnoder said:

Another Model C (same size, similar vintage) of course, which is strictly the luck of the draw

Gears get made - "finding" them usually is an endless effort

If you are talking left end gear train, that's only several - the QC gearbox on the other hand is full of them

Click to expand...

I have a line on a compound thats on some gear head oriental lathe(looked like at one time it was quite the machine), that is sitting out side of a local shop, just have not had the time to get down and talk to the guy about it. What originally grabbed my eye was a big rotary table sitting on what i thought was a big vertical mill, from the road. But once i got up to the machine infound it was actually a huge vertical shaper, and the rotary is actually part of the machine, and thats one beast of a machine, it litrerally dwarfs my k&t.

Also to do with the compound, i just found a local casting shop, if i had a pattern to the original p&w style compound i would absolutly have him make me one.

Monarchist said:

If all - or even most - of those other machine tools in your arsenal are in working order, a compound can "get made" too. Or be adapted from some other lathe of similar size.

Most weeks at one Day Job, a big 4-way was on nearly every lathe on the line, its compound five or ten feet down the chip tray waiting for the one task every few weeks that actually NEEDED it. So that part isn't a show-stopper, as-is, not even for threading.

Click to expand...

DJ Berg said:

Also to do with the compound, i just found a local casting shop, if i had a pattern to the original p&w style compound i would absolutly have him make me one.

Click to expand...

Patterns can be made - especially for something as simple as a compound

http://www.practicalmachinist.com/v...castings-look-good-255315/?highlight=castings

DJ Berg said:

What originally grabbed my eye was a big rotary table sitting on what i thought was a big vertical mill, from the road. But once i got up to the machine infound it was actually a huge vertical shaper, and the rotary is actually part of the machine, and thats one beast of a machine, it litrerally dwarfs my k&t.

Click to expand...

Any shaper CAN be used, but that vertical shaper is one of the better choices of machine to make splines for you on "onesie" sets of QCB gear-blanks.

If splines they are.

Many lathes used single or double keyways rather than splines. Those are easier. I don't know which was used for this P&W lathe.

Also to do with the compound, i just found a local casting shop, if i had a pattern to the original p&w style compound i would absolutly have him make me one.

Click to expand...

Personally, I would want to adapt one off a Lodge & Shipley or such and correct the wear in it rather than make same-same P&W new. There are far more L&S "out there", and later models had a very nice compound design.

Otherwise.. there is exactly as much precision-fit machining when working from a casting as in machining from solid bar.

The "extra" machining to get the non-bearing, non-clamping, "outer shape" is cosmetic, not tight dimension work.

Having a stout mill, not a mere Bee Bee, as you and I both have, and with exactly ONE to make, I'd do it from solid.

Back to those destroyed gears:

IF, and I knoweth not, P&W used a readily available pitch, THEN, stock blanks with the TEETH already cut would be relatively easier to start with, needing only the bore with splines or keyway done. Maintaining precise concentricity, tooth circle to bore, is very important, but there is otherwise not a lot of rocket-insemination involved. Only tedium.

You might have to accept softer gears, and of lesser precision than P&W shipped, but they would still be eminently serviceable for all the non-abusive loading you are likely to place on them, going forward.

Thank you, that just triggered a great idea, it may be easier just to build the whole assembly, shaft and gears over to a single or double key way, that shaft is only 8" maybe 10" long, and that would eliminate the whole need of figuring out the internal spline scenario, and i would assume the idler gear is sitting on a bearing (donno why i haven't looked to see what size that bearing is in the parts catalog, guess thats too easy).

As to the compound, i would like to stay with the p&w look, i like the angled wheel look.

What about monarch k or ck lathe compounds, my amish buddy has a 14x30 that would probably be the easiest to "borrow" to use as a pattern.

DJ Berg said:

But once i got up to the machine infound it was actually a huge vertical shaper, and the rotary is actually part of the machine, and thats one beast of a machine, it litrerally dwarfs my k&t.

Click to expand...

That machine is the answer to your question about splining the ID of your gears. Depending on the machine, you may be able to cut your gear teeth as well.

got any pics of your Sebastian 16x72? I have done a deal on one. I need to get it moved but like everyone else I need some space to put it. It makes a fair amount of noise in in particular speed but I forget which speed it was now. Mine is a 1948 if I remember correctly. The cross slide nut is toast as well so I'll be making a new one of those soon.

58-66cadilac said:

got any pics of your Sebastian 16x72? I have done a deal on one. I need to get it moved but like everyone else I need some space to put it. It makes a fair amount of noise in in particular speed but I forget which speed it was now. Mine is a 1948 if I remember correctly. The cross slide nut is toast as well so I'll be making a new one of those soon.

Click to expand...

Cant seem to post pics here yet, so look at this thread of mine on

New shop toy, finally! Been wanting a lathe for half a dozen years. - Old Woodworking Machines

Monarchist said:

You might have to accept softer gears, and of lesser precision than P&W shipped, but they would still be eminently serviceable for all the non-abusive loading you are likely to place on them, going forward.

Click to expand...

Yeah, I went around to find a shop that could i.d. the dp and pa, my educated guess said 14dp, and i was right, but couldnt figure out the 20deg pressure angle, but the big kicker, was its as hard as a coffin nail, 63c to be exact. I thought it was cast iron from the cracked off teeth and large grain structure, but not so much. The shop owner said he could make one out of 81something and it would be a couple hundred bucks, of in reality seems pretty cheap for what all would be needed to make it, and the 1.0625" i.d.(which doesnt really matter it seems that 13/16" i.d. roller bearings are cheapand easily attainable as long as the o.d. is in .0625" increments).

Elsewise, what O-1 maybe since it is known to hold tolerance during heat treating? Not sure of anything steelwise else, that i could have machined and hardened, anything else would need ground afterwards, and i dont think i could dress a 14dp weird radius(looked into it, cant wrap head around what ive read so far, let alone doing it symetrically to a grinding wheel), or the ability to i.d. grind that accurately.

Some guys on facebook say boston gear is a good place to look, maybe ill try calling on tuesday, but will most likely just have the local guy cut it.

I would attatch pics, but that doesnt seem like an option on here, and dont remember any of my flickr passwords to embed.

The other option i could just run it, it has half its teeth, but the good side of the q.c. gears(they were soft enough to touch up with files), are the side of the gear that lost teeth(pretty much if you split the gear perpendicular to the teeth, one side is fine, the other side is broke off, or when the gear was half on the q.c. gear to the right where it should have been for that selection, the other half were in and out of mesh with the tips of the teeth of the gear to the left). Or i could grind the stick out of the i.d. section of the gear(one side is proud .125") and make a spacer to flip the gear around and run it good tooth side to good tooth side.

So thats where im at at the moment, and a side note, they sure loved loose roller bearings back then.

58-66cadilac said:

got any pics of your Sebastian 16x72? I have done a deal on one. I need to get it moved but like everyone else I need some space to put it. It makes a fair amount of noise in in particular speed but I forget which speed it was now. Mine is a 1948 if I remember correctly. The cross slide nut is toast as well so I'll be making a new one of those soon.

Click to expand...

Dont know how to attatch pics on here sorry, maybe not a mobile version capability(still new to this forum), but if you google owwm dot org sebastian lathe DJ Berg, you should find my thread overthere with pics.

Have you seen the Mr Pete youtube video on 3D printer and change gears? You can google it, I dunno how durable they are but he is running some on his atlas, I know is a light weight hobbyist type machine. Just throwing it out there.

I did, and even pointed him towards fusion 360 for other gears, god has cad changed since i was in middle school. Just a couple of clicks as long as you know the gears specs, there it is. Doing anything else with it... boy do i have alot to learn.

But for the time being, i am going knock the offset bushing side of the gear down, make another bushing to go on the oposite side and run the gear in the opposite orientation.

Then build a wire edm and cut a new gear, may not be the most efficient way to go about it, but ill learn something, and have another tool in the end.