I have purchased a Pratt Whitney 12x30 B and having a problem getting the thread selector going into the bottom to feed selections 5 and 41/2 position

[cabbott]

I have purchased a Pratt Whitney 12x30 B and having a problem getting the thread selector going into the bottom two feed selections 5 and 41/2 position. I have attached a few pictures of problem. I don't know if I'm not doing something properly for this gearing selection or there is something wrong with the lathe. Any help would be greatly appreciated. Picture 1 shows gear selector engaging in #3 position and picture 2 will not completely engage.

 

[johnoder]

I have purchased a Pratt Whitney 12x30 B and having a problem getting the thread selector going into the bottom two feed selections 5 and 41/2 position. I have attached a few pictures of problem. I don't know if I'm not doing something properly for this gearing selection or there is something wrong with the lathe. Any help would be greatly appreciated. Picture 1 shows gear selector engaging in #3 position and picture 2 will not completely engage.

Been welded on?

 

[kwfiggatt]

Definitely a bronze hue to the casting. Here's a pic of mine in the last position.

The handle is a bit askew on mine. I don't think it's supposed to be that way, but everything works. Maybe an encounter with a forklift in the past?

I'd think the OP may have to dig into his and determine why it won't go in the last positions.. They definitely weren't designed and built that way, but a lot can happen in the 70-80 years since they have been produced..

 

[HWooldridge]

When I got my Hardinge, it had a few gears in the train that were stuck together. I sprayed them with penetrating oil and let everything soak for a few days then started wiggling each one. After a couple of weeks of the same routine, I was able to break all of them loose without any disassembly.

 

[cabbott]

Been welded on?

View attachment 428086

It has not been welded on. I used a bore scope and looked at the gears, they look good. The selector handle goes in all the other positions just fine.

Been welded on?

View attachment 428086

Been welded on?

View attachment 428086

It has not been welded on. I used a bore scope and checked the gears and they look good. Will go in all the other positions just fine. Thanks for the response.

 

[cabbott]

It has not been welded on. I used a bore scope and checked the gears and selector rod they look good. Will go in all other positions just fine. Thanks for the response.

 

[cabbott]

Definitely a bronze hue to the casting. Here's a pic of mine in the last position.

The handle is a bit askew on mine. I don't think it's supposed to be that way, but everything works. Maybe an encounter with a forklift in the past?

I'd think the OP may have to dig into his and determine why it won't go in the last positions.. They definitely weren't designed and built that way, but a lot can happen in the 70-80 years since they have been produced..

Thanks for the response.

 

[Clive603]

May be a thing with these lathes. Mine has its moments of not wanting to simply engage and seat the handle properly at the bottom end of slot. As with HWooldridge I've anointed directly with oil and sprayed lubricant around the area. Which sometimes seems to work.

These days I just slide it back into a position it will engage in, spin the machine up briefly and try again. Sometimes it takes a couple of goes but it always works. Eventually.

My Smart & Brown 1024 VSL occasionally has attacks of the same problem. But on that machine I can simply disengage the drive using the neutral position between direct drive back gear an turn the chuck by hand until things engage properly.

Not figured out how to do the same sort of thing with the Model B. After the first couple of failures I just accepted that the single tooth drive clutch won't allow this turn the gearbox by hand solution. But I've never made a more serious investigation as a quick spin under power seems to sort the issue reliably enough.

Clive

 

[cabbott]

Thanks for the response.

May be a thing with these lathes. Mine has its moments of not wanting to simply engage and seat the handle properly at the bottom end of slot. As with HWooldridge I've anointed directly with oil and sprayed lubricant around the area. Which sometimes seems to work.

These days I just slide it back into a position it will engage in, spin the machine up briefly and try again. Sometimes it takes a couple of goes but it always works. Eventually.

My Smart & Brown 1024 VSL occasionally has attacks of the same problem. But on that machine I can simply disengage the drive using the neutral position between direct drive back gear an turn the chuck by hand until things engage properly.

Not figured out how to do the same sort of thing with the Model B. After the first couple of failures I just accepted that the single tooth drive clutch won't allow this turn the gearbox by hand solution. But I've never made a more serious investigation as a quick spin under power seems to sort the issue reliably enough.

Clive

Thanks for the response

 

[Clive603]

Whilst waiting for the shaper to finish a job I had another look at the P&W B to see if it were possible to move the gearbox innards by hand turning the chuck to fiddle things into alignment.

Turns out its easy.

With the lever on top of the headstock in the back gear position and the lever below the chuck in the direct drive (lower) position the chuck and main shaft easily turn by hand. Engage the single tooth clutch using the alloy lever on the right of the apron and the whole gear train turns as you move the chuck. So it's easy to get things aligned.

Works with the feed - screw cutting selector too which I find more regularly balky than the screw cutting box.

Doh!!

Only taken 15 years or so to figure that out!

Will never know why I didn't twig when I first got the lathe. Given that I get a gearbox balk about once or twice a year at most and the feed-screw cutting sector balk maybe twice as often I guess there was no motivation.

Clive

 

[cabbott]

May be a thing with these lathes. Mine has its moments of not wanting to simply engage and seat the handle properly at the bottom end of slot. As with HWooldridge I've anointed directly with oil and sprayed lubricant around the area. Which sometimes seems to work.

These days I just slide it back into a position it will engage in, spin the machine up briefly and try again. Sometimes it takes a couple of goes but it always works. Eventually.

My Smart & Brown 1024 VSL occasionally has attacks of the same problem. But on that machine I can simply disengage the drive using the neutral position between direct drive back gear an turn the chuck by hand until things engage properly.

Not figured out how to do the same sort of thing with the Model B. After the first couple of failures I just accepted that the single tooth drive clutch won't allow this turn the gearbox by hand solution. But I've never made a more serious investigation as a quick spin under power seems to sort the issue reliably enough.

Clive

Thanks for the reply, still working the problem

 

[cabbott]

Whilst waiting for the shaper to finish a job I had another look at the P&W B to see if it were possible to move the gearbox innards by hand turning the chuck to fiddle things into alignment.

Turns out its easy.

With the lever on top of the headstock in the back gear position and the lever below the chuck in the direct drive (lower) position the chuck and main shaft easily turn by hand. Engage the single tooth clutch using the alloy lever on the right of the apron and the whole gear train turns as you move the chuck. So it's easy to get things aligned.

Works with the feed - screw cutting selector too which I find more regularly balky than the screw cutting box.

Doh!!

Only taken 15 years or so to figure that out!

Will never know why I didn't twig when I first got the lathe. Given that I get a gearbox balk about once or twice a year at most and the feed-screw cutting sector balk maybe twice as often I guess there was no motivation.

Clive

Thanks for the reply, still working the problem.

 

[cabbott]

Thanks for the reply, still working the problem.

Clive, I have a question about back gear position. As best as I can figure when utilizing the feed / back gear shift selector it should change speed of the head. When I shift my machine into back gear the chuck has no power, it will turn but I can stop the chuck with my hand. I don't think this normal? I have not had this quality of lathe before. I guess what I'm saying is I don't fully understand the complete operation of the Model B because I can not find any definitive operations manual. I have the PW operator's Instruction book. I also have a 12" Craftsman Model 101.28990 which was made by Atlas and has served me well for my efforts. I tried your recommendation on getting the lower two threading positions to lock in and it did not work. Any information you can provide would be greatly apricated. Thanks Chester

 

[Clive603]

Chester
Back gear selection on the P&W isn't obvious until you spot that there are two levers involved.

The one on top behind the head pulls the spindle out of direct gear, so it spins freely. Same effect as the sliding pin locking back gear to cone pulleys on lighter machines such as SouthBends and, presumably, your Atlas.

Raising the lever poking out towards you underneath the spindle turns an eccentric to lift the back gear shaft bringing the back gears into engagement. Again same principle as lighter machines where the back gear shaft is eccentric.

Most larger and modern gear head lathes do both the disengagement of direct drive on one lever. Usually with a neutral position between direct and back gears where the spindle turns freely.

There is a pdf copy of the earlier 20" plain bearing model B parts manual floating around the internet. Have you found it? I think John sent me mine. Probably the best resource out there for whats what and what goes where.

The 12 x 30 with anti-friction (roller) bearing headstock is essentially identical except for the obvious differences in the bearing area.

Wonderfully drawn in an old fashioned style that doesn't take kindly to being reduced to A4 size.

If I ever decide to treat mine to a well earned and justly deserved go through and re-decoration I shall do an A3 size print out. The headstock drawing is particularly lovely but takes a deal of squinting to figure out what is going on where. Bent sections where not everything is on the same plane may be diagrammatically cleaner but brain engagement is essential. Not completely in love with how the part numbers are tabulated either.

Clive

 

[cabbott]

Chester
Back gear selection on the P&W isn't obvious until you spot that there are two levers involved.

The one on top behind the head pulls the spindle out of direct gear, so it spins freely. Same effect as the sliding pin locking back gear to cone pulleys on lighter machines such as SouthBends and, presumably, your Atlas.

Raising the lever poking out towards you underneath the spindle turns an eccentric to lift the back gear shaft bringing the back gears into engagement. Again same principle as lighter machines where the back gear shaft is eccentric.

Most larger and modern gear head lathes do both the disengagement of direct drive on one lever. Usually with a neutral position between direct and back gears where the spindle turns freely.

There is a pdf copy of the earlier 20" plain bearing model B parts manual floating around the internet. Have you found it? I think John sent me mine. Probably the best resource out there for whats what and what goes where.

The 12 x 30 with anti-friction (roller) bearing headstock is essentially identical except for the obvious differences in the bearing area.

Wonderfully drawn in an old fashioned style that doesn't take kindly to being reduced to A4 size.

If I ever decide to treat mine to a well earned and justly deserved go through and re-decoration I shall do an A3 size print out. The headstock drawing is particularly lovely but takes a deal of squinting to figure out what is going on where. Bent sections where not everything is on the same plane may be diagrammatically cleaner but brain engagement is essential. Not completely in love with how the part numbers are tabulated either.

Clive

Thanks Clive, I have not found the 20" manual except 1 place that wanted 45 lbs for it. Don't know if that is the one your referring to. Still looking looking, if you can send me a copy of yours would appreciate it. My e-mail is [email protected]
Thanks for all your help.
Chester