PM1340 - the Best & Jacobs Full Custom Edition

Thanks David,
As usual, this is excellent information you have shared.

Can you tell me how you searched for and found someone to balance your lathe's drive shaft pulley? Having an idea where you started and better understanding what you asked for would be very helpful.
 
I asked around at various places to find an outfit that did precision surface grinding. Those guys have to balance their grinder tooling, and know the techniques and have the equipment. Took a while to find a path to someone willing to do it. I never got a straight answer on how far out it was and if it would have had any impact on surface finish, but they drilled a small hole that's about 1/8" diameter down about 2mm on one area of the center hub of the pulley to balance it - so it couldn't have been very far out.

There was lots of discussion about all this a year ago here, and I visited another PM1340GT owner near me (sanddan) who was the first to bring up the vibration issues. He ended up building a custom stand, and another member here (Rio) even went so far as to secure his stand to threaded rod he'd epoxied into the floor.

Here's the first thread that caught my attention: https://www.hobby-machinist.com/threads/how-are-you-mounting-your-pm1340gt-lathe.42112/
Here's another on the same topic: https://www.hobby-machinist.com/threads/1340gt-surface-finish-problem.55358/
 
I'm really looking forward to your mill project David. The lathe job was just top notch.

Regarding motors & belts & hinge plates, my Taiwan 14x40 showed some new vibration when I changed to a new belt. It was smaller circumference compared to my (obviously stretched & worn) original so I had to adjust the motor position to compensate. It didn't feel right running, I kept thinking the new one was too stiff or maybe wrong cross section for sheaves. But turns out the motor mount hinge plate needed tweaking. It wants a certain amount of belt tension, but more importantly it cannot free float like self-tensioning under its the weight. It starts to get bouncy-bouncy harmonics, you can hear it & feel it. There is a locking bolt to fix the motor plate I misinterpreted its use. I can also see this needing adjustment every so often as the belt wears.

Regarding a degrading or otherwise poor finish turning on these type lathes, I can vouch with my own experience that the power feed driveline is certainly something to look into when motors, vibrations & other issues don't seem to cure things. We live & die by the ability of the carriage to traverse smoothly & accurately for a good finish. Anything amiss in the power feed rod runout, alignment to its bearing assembly or apron gear mechanism it drives, will rear its ugly head & transfer that onto your work. My rebuild/improvements episode link below. I'm happy to report it runs much better than it ever did, even when new.
https://www.hobby-machinist.com/threads/14x40-lathe-power-feed-improvement.64907/#post-540127
 
petertha said:
I'm really looking forward to your mill project David. The lathe job was just top notch.
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Thanks. That's quite a repair you did on your lathe. I remember watching Keith straighten you feed shaft last fall. He's a super nice guy and I love his YouTube channel.
 
davidpbest said:
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It’s been several months since I took delivery of, and posted about my PM1340 lathe. It's time for an update since I’m nearing completion of what started as a straight forward VFD conversion project, and then took on a life of it’s own and led to a substantial customization of the stock PM1340 lathe.

I’m forever grateful to Mark Jacobs in particular for his thoughtful advice, council and helpful suggestions, and especially for the new electronics control package he developed to my specifications. Without Mark’s fine contribution, this project would never have taken off. I’m also grateful to this Hobby-Machinist group – I’ve received - even stolen or copied - some very interesting and useful upgrades described by other users here. Great inspiration.


In a nutshell, I started out wanting to do a VFD conversion and needed help with that aspect. I also did not like the stand offered by QMT for the 1340 because it did not offer drawer storage below the lathe. I also wanted a lathe with a chip/coolant pan that could be easily removed for cleaning. I decided to design and build my own stand, and the project evolved from there – first learning to weld, acquiring welding equipment, making a welding table, and on and on. Turns out, the stand building part of this project was one of the least time consuming aspects.


As the project evolved, I harkened back to the mid-1960’s when I did a customization of a 1957 Chevy, and the more I got into this, the deeper I dug the customization hole.


For those who are inclined, the full saga of the customization, including photos and selected videos of the machine under power is documented at this link: http://tinyurl.com/m2zavnl

Here’s a summary of some of the elements that went into the Best & Jacobs Full Custom Edition:
  • Designed and fabricated a welded steel stand for the lathe that provided drawer storage below, and a removable chip/coolant pan under the lathe.
  • Upgrade of the motor to a vector-rated Baldor unit capable of high torque and HP throughout a wide speed range.
  • Working with Mark Jacobs who designed and fabricated a new control system, all the electronics in the factory-supplied lathe were replaced.
  • I like this lathe a lot, and appreciate the refinement of a Taiwanese made machine to that of mainland China. That said, one thing they haven’t mastered in Asia (to my satisfaction) is how to paint the machines with a durable finish. So I said to myself “as long as you’re replacing the electronics, might as well repaint the thing.” Wow – what a path-setting decision that was.
  • And then “as long as you’re taking it apart to paint . . .” came the decision to replace every fastener on the machine with hardened stainless steel equivalents (thank you McMaster).
  • I decided to upgrade other basic elements of the machine including incorporation of real glass and metal oil level sights, a quick and easy oil drain system for the headstock, all new front panels, new stainless steel knobs and levers, a single-point oil pumping system for the quick change gearbox, new carriage stop with micro-adjust and proximity sensor mounting, and many other minor improvements and embellishments.
  • Installed DRO-Pro’s magnetic scale system with customized mounting and drag chain to organize the cables, and a Mitutoyo scale on the tailstock. Also built a MachTach kit for the machine, came up with custom case and panel for it as well as incorporating the mounting into the structure to support the DRO display.
  • After the stand was built and the lathe installed on it, I decided to build a tool racking system and for the BXA tooling collection I was accumulating, and that evolved into a second support bracket system for the light (which I converted to LED), and a jumbo dial indicator setup for indicating-in 4 jaw fixturing, swivel tool trays for the stand, etc.
  • Added an MQL coolant delivery system from FogBuster.

Here are a few photographs that chronicle the evolution and where things stand today. Enjoy, and thanks for the inspiration and for viewing, with special thanks to Mark Jacobs for his consistent and thoughtful support throughout the project, and to Matt at QMT for his helpful and timely support throughout.

The custom lathe stand - "what do you mean, I have to learn to weld too?"

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The removable chip tray:

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VFD enclosure:

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Tear-down and preparation for stripping and painting:

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Painting:

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Replacing all the fasteners with hardened Stainless Steel:

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New controls and front panel:

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Electronic control package from Mark Jacobs:

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New Baldor motor, pulley and belt system:

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New oil level sights:

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Dorian BXA tool post:

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Single Bijur oil pump for quick change gearbox:

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New quick change gearbox oil distribution platform:

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MachTach:

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Spider and tachometer sensor mount:

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ER40 collet chuck with D1-4 mounting:

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All new stainless steel levers and knobs:

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Spindle-aligned chuck saddles:

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Tailstock DRO:

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Quick, no mess oil change system for headstock:

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Cross slide DRO:

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Carriage position DRO with drag chain for cable and coolant/compressed air plumbing:

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FogBuster coolant system:

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Flexbar LatheGuard safety shield:

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Custom mounting for DRO and MachTach display:

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Quick change gearbox oil drip pan:

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New, tool-less re-positioning and removable carriage stop with proximity sensor mounting:

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Spider run-out adjustment indicator system:

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Extensive tool rack:

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As she sits tonight:

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And there's much more here for those who are interested, including several videos in addition to four pages of photos: http://tinyurl.com/m2zavnl

Thanks for viewing, sorry for the long post, and much appreciation to you all for inspiration.
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where did you get the rpm gage?
 
Amazing what you’ve done with your lathe and stand!

Thank you for documenting your projects on Flickr, I’ve enjoyed going through them.

Thank you too for posting PDF’s of your modifications and stand, lots of great ideas there!
 
StevSmar said:
Amazing what you’ve done with your lathe and stand!

Thank you for documenting your projects on Flickr, I’ve enjoyed going through them.

Thank you too for posting PDF’s of your modifications and stand, lots of great ideas there!
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You're welcome. I extend my thanks to Mark Jacobs for the controls.
 
@davidpbest , I really like the drawings you produce for all your projects. What program are you using for these?

I’ve spent a very enjoyable year or so using AutoDesks Fusion360, so I think I’ll be following in your footsteps when I make a lathe stand.
 
I use a 2D drawing package called Visio Professional from Microsoft. I also use Fusion360 when I need a 3D modeling capability or parametric relationships during conceptual design, but the drawing output facilities of F360 are still pretty lame. I have been consulting with the F360 team for three years about drawing output enhancements, and they are getting better, but are still insufficient for my work.
 
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