Best PM lathe for threading?

Pcmaker

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I have a PM1127. Threading is incredibly time consuming because of change gears. Such a pain to be messing around with changing gears when you have to thread a workpiece and THEN changing the gears back for feed rates.

If and when I decide to upgrade my lathe, which PM machine is easiest to work with when threading? Is there one where you don't change gears even when switching between metric and standard?
 
It seems like most of them have a change required between metric and imperial. It is just one though. It should be possible to integrate that into a gearbox, but perhaps due to the large size it doesn't make sense to do it.

I figure if the design uses metric and imperial threads on the same project, the design is wrong. Switch between projects and call it a day. :)

One thing I do wish the 1127 had is a switch between feed and threads without having to to swap gears. Perhaps not the full range, but being able to switch would be nice. I found I could avoid most of them by carefully considering order of operations and occasionally using a collet to grip finished surfaces.

There's also ELS setups, but they come with a different set of problems. I think it's worth it, but some people prefer the mechanical setups.
 
ERL-1340 will do all common metric and imperial thread pitches without having to remove/replace gears. It's not on the PM web site, but they carry it. Mark Jacobs has one.

Or you could upgrade your 1127 with an electronic lead screw.

 
I would look at the 1236T or 1340GT with a Norton gearbox, that will give you a range of imperial threads/feeds with no change gears, but one will still need to use change gears for metric. The PM-1440GS which has not been available for a long time is a mid-priced universal gearbox Chinese lathe, would be my only other recommendation in this price range if it becomes available. If you want a universal gearbox in a Taiwanese lathe (pretty much all threads except MOD/DP), then you are looking at much more expensive lathes (ERL, RML and TRL series) which are in the 10-14K cost range.

An ELS is an option as far as cost effective in the less expensive lathes w/o universal gearboxes. The Rocketronics system is one of the more advance full featured ELS designs that is more of a turnkey type, plus the ELS 4 includes positional coordinates, VFD spindle speed control, additional inputs for limit switches and E-Stop.

ERL-1340
ERL-1340 Gear Chart.jpg


PM-1340GT
PM-1340GT Gear Chart.jpg
 
I scrounged extra gears and made a couple of spare banjos, for the standard threads I use. Set one for feeds, others for threads, Its only a couple of minutes to change banjos.
 
The PM-1640TL and PM-1660TL can single point the entire range of both metric and Imperial thread pitches with NO change gears. This was one of the main selling points for me when I bought one.

I don’t mind the effort in changing gears, but I do mind the time needed to do it.

3C252255-602D-4292-A591-2EC643742F79.png
 
To do metric threads on my 1340GT I need to change one gear, according to the manual. But I've not done that yet, and may never. ;)

The Norton gearbox on my lathe was a bit sticky when it was new, but has since broken in a bit and works smoothly now. I wish it was an enclosed gearbox, but it does what I need, when I need it.
 
I would look at the 1236T or 1340GT with a Norton gearbox, that will give you a range of imperial threads/feeds with no change gears, but one will still need to use change gears for metric. The PM-1440GS which has not been available for a long time is a mid-priced universal gearbox Chinese lathe, would be my only other recommendation in this price range if it becomes available. If you want a universal gearbox in a Taiwanese lathe (pretty much all threads except MOD/DP), then you are looking at much more expensive lathes (ERL, RML and TRL series) which are in the 10-14K cost range.

An ELS is an option as far as cost effective in the less expensive lathes w/o universal gearboxes. The Rocketronics system is one of the more advance full featured ELS designs that is more of a turnkey type, plus the ELS 4 includes positional coordinates, VFD spindle speed control, additional inputs for limit switches and E-Stop.

ERL-1340
View attachment 333924

PM-1340GTView attachment 333925
I see an old friend here.
It's amazing how close the levers and lay out is to my Clausing Colchester 15X50. Cutting imperial or metric is just a flip of the levers and there is a gear change-swap to go from one back to the other. Never done it.
 

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