Powermatic model 90 - new setup with vfd question

[Bill Summerlin]

I am newly registered, but have been reading threads for some time. I just returned from North Carolina with a powermatic model 90 of undetermined age, came with a rotary phase converter, I would like to convert to vfd for speed control and simplicity. I would like to maintain the use of the headstock micro switch for turning the lathe on and off. Does anyone have a schematic of how to hook this up. The lathe has an arrow hart contactor, but no on/off switch. Any help would be appreciated. Have a teco fm 50 on the way, thanks

[Doug Ladendorf]

Welcome Bill. The switch will need to be connected to the VFD. There is a video on this for you unit on YouTube (mobile so can't grab link). You also might consider mounting it lower right for safety, so if you have something fly apart you don't have to cross the shrapnel zone to turn it off.

[Bill Summerlin]

Thanks Doug, I will check out the video first chance I get.

[Harry Robinette]

Bill I just put a 3ph motor and VFD on my General 160. If I can help let me know.

[Mike Cruz]

Bill, click on my name, go to my page, and search through my threads for titles with PM90 in them. I restored a 1980 (81?) PM90. I put riser blocks on it, 2 hp motor, VFD, the works. I sold the lathe earlier this year. But what I did and all I would remember anyway would be in those threads.

I completely second the idea of having your switch(s) to the right, not to the left (under the headstock) in case you need to turn it off quickly.

Another thread of mine to look at would be the one pertaining to the Nicol-Cruz lathe. On that lathe, I made a remote box with the on/off / fwd/rev, potentiometer (you don't want to have to change the speeds on the VFD...that would be a pain), and E-STOP buttons. I absolutely LOVE it. Wish I had done that with my PM90.

[Bill Summerlin]

Thanks Doug, looked for video, did not see it, how is it listed?

[Steve Fulgoni]

Hi Bill, Like Mike above, I too converted my PM90 into a hot rod (well almost). I strongly suggest against using the micro switch in the headstock. It will drive you nuts. You will have to turn the speed dial every time you want to start and stop the lathe. Most turners start and stop the lathe constantly. The micro switch in the headstock was designed as a safety feature for school programs so that students could only start the lathe at slow speed. Most VFDs can have low voltage digital controls so you can easily bring out forward / reverse and start /stop to toggle switches that you mount in a radio shack project box. Add a potentiometer and you have your speed control. Together with the Reeves drive you have the best of all worlds. Use the Reeves drive to get you belt ratio in the right range for max torque and then use the VFD for speed variation within that range. I can send a photo of mine to you. Steve

[Doug Ladendorf]

Sorry Bill, here it is.

http://www.youtube.com/watch?v=jrLdNmAIkso

Temco has a whole series of videos you might want to check out, including one on adding a potentiometer for speed adjustment.

http://www.temcoindustrialpower.com/product_selection.html?p=CFW10_Product_Selection

[Bill Summerlin]

Thanks Steve, a picture would be great. My vfd will arrive Friday, but I am still looking for parts for the control box. I have picked up a couple of toggles, but I would prefer to have the heavier duty switches that I have seen on this site. Sources for these switches around jackson, ms are non-existent, so will have to find other sources. Still pondering over the schematics I have run across. New to site, so trying to figure out how to add pics.

[Roy Turbett]

Search my name and you will find a link to a 1955 Powermatic 90 I rebuilt. I mounted the VFD on a piece of aluminum channel above the headstock and added a remote starter box with a magnet in it so I can move it to either side of the lathe. OWWM.org and Vintagemachinery.org have alot of infomation on the Powermatic 90 as its a very popular lathe to rebuild.262869262870262871

[Mike Cruz]

This thread is pulling out all the PM90 guys!

[Bill Summerlin]

Thanks Roy, the pic looks great, don't plan to restore mine for now, just want to get up and going with the vfd. I take it that you are not concerned with dust mounting it so close to the bed, is there some reason you did not mount it remotely that would make it more functional?

[Bill Summerlin]

By the way, what kind of conductor did you use going to your remote?

[Roy Turbett]

Thanks Roy, the pic looks great, don't plan to restore mine for now, just want to get up and going with the vfd. I take it that you are not concerned with dust mounting it so close to the bed, is there some reason you did not mount it remotely that would make it more functional?

The MDF hood over the vfd provides adequate protection from dust and also allows for ventilation. I mounted it where I did so I could access the pot dial on the vfd to control the motor speed. I always start the lathe with the pot turned all the way down to the minimum. I chose 20 Hz because any lower the motor would strain under load. I also set the parameters on the vfd so that it takes 5 seconds for the motor to accelerate to full speed and 5 seconds to decelerate to zero. This lets you see how a piece is spinning and provides enough time to turn the lathe off if you see something you don't like. This provides plenty of safety and I removed the micro switch. Since I don't have to worry about 8th graders doing "slam" stops, I also removed the spindle lock safety pin so I can engage the spindle lock regardless of the speed dial setting.

The remote box has off, on, fwd/rev buttons and is connected with a 4 strand 14 ga. rubber cord. I know that most vfd's say to used shielded wire, but the experts at OWWM advised it wasn't necessary. The shielded wire is only needed where the vfd is mounted in close proximity to other devices that could emit electrical interference. If you look close at the photo of the speed dial you can see numbers in green and in red. I used an inexpensive tach to record the spindle speed at 20 Hz and at 60 Hz at various points and use it to take maximum mechanical advantage from the reeves drive. At 20 Hz, my minimum speed is 220 RPM. At 60 Hz, my maximum speed is over 4000 RPM.

[Bill Summerlin]

Began electrical connections in preparation for vfd arrival. Pic include the following steps: hookup to 220 pen phase from power panel, from there to a double pole switch for cutting power to the vfd, then on to the box which will house the vfd, from there, four conductor cable to lathe to the contactor box (contactor removed) and grounded and hooked to the three motor leads.

[Lee Alkureishi]

Ok, I can't miss out on this party!

I'm just one more guy who restored a pm90 (1970), added risers (thanks to Roy!) and a VFD, and upped the motor to 2hp. It turned out great, and it was just last year so everything's fresh. Happy to help out with any advice, but I fear Mike and Roy are the "horses mouth" - they pretty much taught me everything I needed to know :)

http://www.sawmillcreek.org/showthread.php?190195-Restored-Powermatic-90-and-first-bowl-complete!&highlight=

Next project: PM90 bowl lathe!

Lee

[Roy Turbett]

This is a picture of the back side of my vfd setup. I used a double pole switch to shut off power to the vfd and the two electrical outlets. The outlet in this picture is for the lights. I mounted a second outlet in the front of the cabinet for my sander.

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[Mike Cruz]

I have to admit...I miss my baby...

[Bill Summerlin]

Vfd installed this a.m. And tested. Works good and so now on to setting up my remote station. Hope to hook that up today with on off switch, speed control and forward-reverse switch. I think I will be happy with that for awhile.

[Mike Cruz]

Bill, if you haven't already bought the controls, you can get a FWD/off/REV switch, the pot, and the third one can be an E-STOP. That E-STOP is very handy. Especially when your hands are tied up and you want to turn off the lathe...all you have to do is hip check it. You can also hit that a LOT faster than reaching for an on/off switch in an emergency.

[Bill Summerlin]

I used a 10 k pot from radio shack, also a high/ low as a forward reverse switch, seems to work well, now have speed and direction control at the lathe, would still be interested in pics of how others are wiring their remote, including hooking up a stop button for the hip check you mentioned. Again, thanks for all of the input.

[Bill Summerlin]

Remote box completed and lathe now has variable speed, forward off reverse switch on remote, turned a coca bola pen and a bowl today, pm 90 working well with vfd. Thanks to all who helped with setup.


http://youtu.be/HaUA_yFKp00