PM1340 lathe - motor swap to Marathon E-467, what pully to use?

Hey Guys,
Been ~1.5 yrs now, since receiving my PM1340-GT and PM30-MV. Upon receiving, worked on getting the lathe outfitted with VFD, and other "retrofits" as found on this forum. mksj helped a lot! Thanks Mark! Also, PM30-MV has been "cnc'd" since, using Centroid Acorn, DMM AC servos and drivers, and CNC kit from ProCutCNC.

Been looking at "upgrading" lathe, even more, with an "inverter grade" motor. Having "searched" this forum, time and time, reviewing everyone's questions and comments, I "pulled the plug" today and ordered a new Marathon Y551 motor, 2.5 and 3.0 pulleys from McMaster-Carr, and a GATES-BX27 belt. Let you know how this "upgrade" goes, once complete. Looking forward to it!! :)

Thanks everyone, for your Q/A's! This forum is GREAT!

Here's a "snap-shot" of my setup...

1587241601176.jpeg
 
I upgraded the motor on my 1340 to a Baldor IDNM3587T which is almost exactly the same size as the Marathon. This link shows what I did for belt and pulley. The pulley is a TB Woods BK2878 - 7/8-inch shaft to match the Baldor motor, 2.95-inch OD. The belt is a Gates BX27 Tri-Power, 21/32-inch width, 13/32-inch height, 30-inch outside circumference. Fits perfectly for this pulley setup. Good luck with the upgrade.
 
David, what was your reasoning behind for going with the Baldor motor rather than the Marathon E467 or Y551 motors?
 
Paul,

They are all excellent motors, it is more a function of what you can get and the price. Both David and I purchased Baldor IDNM 2 Hp motors, their price was dirt cheap and they were NOS. I would equate IDNM as equivalent performance wise to the Marathon Y551, both are good for about 3X their base speed and have a constant torque on the order of 1000:1. On the lathe I recommend a ~2.3-2.5" pulley and setting the maximum Hz to around 125, or around 3600 RPM. Both of these motors have a small encoder jack shaft that needs to be sawed off in order to fit on the 1340GT. If you had the room you could fit an encoder to the jack shaft and do a closed loop feedback which would be more appropriate for a mill/CNC type of operation. Using open loop sensorless vector control my speed control was usually +/- 1 RPM regardless of load. Since these motors have constant torque down to almost 0 RPM, they have a lot of low end grunt.

The Marathon E467 (145TTTN16628) is a severe duty all cast iron TENV inverter rated motor, with a maximum speed of around 100-120Hz and a constant torque on the order of 10:1. It is a great replacement for the stock PM-1340GT motor at about 1/3rd the list price of the IDNM/Y551, the street price is around $400. On the lathe using the E467 I recommend a ~3" pulley and setting the maximum Hz to around 100, or around 3000 RPM.

FYI, the motor space on many of these lathes are very tight, so standard TEFC motors will just not fit in most cases. The TENV motors are much more compact because they have no fan/shroud, so often 2-3" shorter in overall length. They are usually heavily finned and either cast iron or have aluminum finned case with cast iron end caps, they are quite heavy. You do not have the speed cooling issues seen with TEFC motors, and even under load they rarely get warm.
 
ptrotter said:
David, what was your reasoning behind for going with the Baldor motor rather than the Marathon E467 or Y551 motors?
Click to expand...
Mark is certainly the expert here, not me, but as I understood the choices at the time, the Baldor IDNM 2HP units as well as the Marathon Y551 and Y526 are rated at full HP up to 2X base speed, the E467 is rated to full Hp 1.5X base speed. Plus I was able to buy the Baldor as NOS on eBay for less than I could find a new Marathon at the time. Nothing is a drop in replacement and some modification is required. In my case, the motor mount needed new holes. Be careful with the new pulley placement that it doesn't rub the removable side cover of the machine - something you may not realize until everything is buttoned up and you try to install the cover.
 
Hey Folks! The Y551 motor arrived today! Got it hooked up to VFD and "auto-tuned" ...

1587690847390.jpeg


While here... slow speed (in reverse), a little oil, and a hack saw...

1587690964886.jpeg


Mounting will be a "bear", however!!! :)

Looks like I will have to drill holes (x4). :(

More later.

Mitch
 
Got her mounted, "purring like a kitten"! Still need to button up the wire box, however. Top speed, ~2060rpm @ 120Hz ...

1587854346010.jpeg


1587854394801.jpeg


Not much room to spare, against that "belt adjustment" bracket. Have the BK4828 fully "pushed out" flush to end of motor shaft...

1587854626386.jpeg
 
Hi All,

Now that I have completed this "upgrade" ...

1588527024545.png


... I have the "stock" 3-phase motor available to anyone wanting to "upgrade" their single-phase 1340GT, to three-phase w/VFD.
Willing to send to "buyer" for just the shipping costs, maybe $100.00 or so. Don't have exact shipping costs at this time, however.

LMK, if you are interested.

- Mitch
 
You must log in or register to reply here.
Back
Top