PM 1340GT max spindle RPM with VFD

One other point. Another user here asked how I fabricated the swing-away/ lift-off convenience trays, so I put up additional photos of that aspect at this link that illustrates that design. Details on the tool racks and everything else can be found at this link. Let me know if you have any questions.
 
David,

Thank you for the detailed writeup. I do like your design? How would you modify the design to get the center height down to 43 inches from the finished floor? I am just barely 5' 6" the center height on the PM1440TV is perfect for me. Rough scaling it is about 43 off the floor.

Another question, with the tool boxes and their contents, what would be your best guess of the weight of the stand?

I am on the plan to replace my ACER 1236 with a 1236T, I am thinking about finding a local guy to clone your design, scaled to the 1236.


nez
 
To get the spindle CL down to 43" off the floor, you'd have to employ less tall drawer cabinets and just shorten the legs. I spent a lot of time trying to figure a way to get all drawer storage without having the spindle height too high. So I recommend you start your activity by finding the tool chests you'll use and design around that. For a 43" spindle height, you'd want a tool chest that is no taller than 17". You could start with something like this and cut that flip-up top section off the chest. I do not recommend you lighten up on the C-channel height or thickness to lower the spindle height - that HR C-channel is 10" wide, 2 1/2" tall with 1/4" webs and is very effective in dampening harmonics and keeping the lathe bed aligned.

As for the weight of the unit, I'm guessing here, but the stand itself is about 200 pounds, the tool chests are another 200 or so, and as the lathe with all the tooling sits in my shop, I'm guessing the total weight is just over 2,200 pounds. I have a lot of gear in those drawers and that collection of BXA tool holders is also quite heavy. The center leveling feet are important supports for all that load, so don't eliminate them.

Attached is the complete set of dimentioned plans for the lathe stand FYI. What's posted on my Flickr site is a subset of the attached. Hope this helps.
 

Attachments

  • PM1340 Lathe Stand - David Best.pdf
    346.4 KB · Views: 179
Last edited:
David,

Thank you for the help.


Nez
 
I am close to selling my 1127 and getting a 1340GT. I can't figure out what frequency to normally keep the VFD at. I understand that people sometimes use a knob to vary the freq to reduce rpm lower than 90rpm for threading, but what is the default recommended frequency?
 
60Hz, plus/minus 30Hz for the factory supplied motor. I can run my 1340 at 24RPM in lowest geared setting with the VFD turned down to 30Hz, and well over 3K RPM at highest gear setting (well beyond the specs of the bearings). Click on THIS LINK to see my 1340 in lowest gear combination with the VFD running from 30 to 100HZ. I replaced the factory supplied motor with a vector-rated Baldor which provides better torque at the lower speed ranges and widens the possible frequency choices to ~20-120Hz.
 
Thanks a lot.

I will be ordering a WJ200-015SF outside PM as they are out of stock. I see that it is rated as 2HP for constant torque and 3HP for variable torque. Is it something we can choose when wiring?

Sent from my ONEPLUS A5010 using Tapatalk
 
I believe the difference between "constant" and "variable" torque has to do with vector-drive motors only. The PM1340 from PM does not come with a vector-drive motor. Tread carefully here - this is not something to gloss over. You might tune in with Mark Jacobs on this topic - he's the resident WJ200 guru here. He goes by mksj here on H-M.
 
Variable torque is for driving pumps, constant torque is used for machinery. There are also ratings based on normal duty and heavy duty load, as well as various deratings. There are various programming parameters that need to be adjusted based on the application and function, what is important is to look at the rated output amps of the VFD for your motor and application. The WJ200-015SF will work well with the PM-1340GT stock motor, or a replacement motor of the same size. Vector motors allow a wider range of constant torque, typically form almost 0 Hz to 60 Hz, and constant Hp above their base speed to the maximum rated RPM which is typically 5-6K RPM. A vector motor can either use a shaft encoder if absolute position is required, or typically w/o an encoder but run in sensorless vector mode which gives around 0.1% speed regulation. Vector motors can only be used with a VFD, the standard 1340GT 3 phase motor runs well in the 15-90 Hz range. There are many vendors for the Hitachi WJ200, as well as other VFDs. The WJ200-015SF has been very reliable and works well with the 1340GT, the recommend programming parameters have been posted and/or are available from QMT.

Recommended vendors are below that also provide warranty and technical assistance, there are other on-line vendors. Please beware that there are many VFD models that may be very close but are not the same, some models lack a fan and require mounting to a heat sink. A 3 phase input VFD cannot be run on single phase without a significant derating and often require other components to function properly. A braking resistor is required for quicker stopping times.
www.driveswarehouse.com

WJ200-015SF

www.driveswarehouse.com www.driveswarehouse.com
www.wolfautomation.com

WJ200-015SF

WJ200-015SF quick delivery, authorized Hitachi Drives distributor. Offers complete line of AC Drives . Easy online ordering, rewards program, and great pricing.
www.wolfautomation.com www.wolfautomation.com
Mark
 
Thanks a lot Mark, this is very helpful.

Sent from my ONEPLUS A5010 using Tapatalk
 
You must log in or register to reply here.
Back
Top