Southwest Industries Prototrak DPM conversion

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CRM
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System Serial Number: A900171

Southwest Industries Prototrak DPM conversion

Post by CRM » Wed Jan 05, 2011 7:08 pm

I'm interested in replacing the Prototrak MX2/MX3 control on my 1996 Trak DPM Bed Mill.
Trak DPM.JPG
Trak DPM
I see in the machine retrofit gallery that a SWI Prototrak has been done already; I've searched all nine pages of the forum but there's nothing on a machine like mine.
I am wondering what hardware (besides the All-In-One DC board, PC and Mach3 software) would be needed to do a conversion. Specifically, I'd like to know if the servo motors can be reused. It appears that SWI used Magnetek DC servomotors, with the drive card enclosed in an aluminum housing attached to the end of the motor housing in order to make the drive and motor modular and serviceable as a unit. The label for the motor faces the drive housing and therefore I can't read all of the part number and some of the other specs. Is anyone familiar with this motor and/or drive? I've attached photos.
servo encoder.JPG
encoder?
servo end view.JPG
servomotor end view
servo drive.JPG
drive board
I'm assuming it is possible to separate the servo motor from the drive board housing. If the motors are similar to the ones used in SWI's retrofit kit, they should have a rating of 17.5 in-lbs. and therefore would be within the limits for the All-In-One board. There appears to be an encoder on the motor shaft (see picture) but the wiring is not labeled. Does anyone know the functions of the wires by their color, and can these encoders interface with the All-In-One board? If not, plan B would be to buy encoders and fit them to the servos, correct? I have determined that the ballscrews are 5 rev/inch and are tooth belt driven from the servomotors at a 2.75 : 1 ratio.

The spindle electrics have already been retrofitted by me to utilize a Hitachi SJ200 drive so the entire machine can run on single phase power. It is my understanding that I will be able to program and control spindle speed/direction with this setup, correct?

The physical machine is in excellent shape, but I do mostly off-line programming with GibbsCAM and the current control doesn't interface well because it is conversational-based programming. I'd like to be able to program in g-code. Since the machine is currently operational, I don't want to dig into the servos too deeply until I commit to the conversion, so I'd be very grateful for any info from anyone who has done a SWI Prototrak conversion. If I have to replace the servomotors it will significantly increase the cost of the conversion, to the point where it may not be practical; so I'd like to make every effort to reuse the ones I have.
Last edited by CRM on Thu Dec 29, 2016 1:05 pm, edited 1 time in total.
Dean Jahnz
Cannon River Machine

cncsnw
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Re: Southwest Industries Prototrak DPM conversion

Post by cncsnw » Wed Jan 05, 2011 11:51 pm

The machine should be a fairly easy retrofit, well within the capability of the All-in-one unit.

If I am interpreting your encoder picture correctly, it appears that the encoders only have about 100 cycles per revolution (maybe 125 or 128?). That is too low for good servo control, so you should plan to put new encoders on.

It is likely that the motors themselves are suitable. If the original drives incorporated the AC-to-DC rectifier in each drive unit (with an AC supply running from the cabinet out to each drive) then you will need a suitable rectifier in the cabinet. It will need enough capacity for all three axes, to supply DC to the All-in-one.

See if you can either find Volts, Amps, Torque, and/or RPM data on the motors. Barring that look for model numbers and see if you can find data online. Barring that, see if you can tell what AC supply voltage or DC bus voltage the original servo drives use.

diycncscott
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Re: Southwest Industries Prototrak DPM conversion

Post by diycncscott » Thu Jan 06, 2011 9:28 am

Hello Dean,

As Marc mentioned, the motors should not be a problem. The encoders will need to be replaced however (8000ppr encoders are $155.00ea.).

I'd like to see if we can work something out. I've had many people with old Prototrak controls with the same question that you asked.

How can I re-use my motors and or amplifiers? I haven't really been able to give a definitive answer because when calling SWI or AO Smith to ask for specs and information, I'm told only that the information is proprietary. I've been told that existing customers also receive the same reply. In the interest of providing a complete retrofit solution, I'd like to see if we could work together to come up with an easy to use retrofit package for the MX2/MX3 based machine.

If you would send us your motors/drives and cables, we will do what we can to engineer a solution for your retrofit.

If you are interested, please give me a call at 814-353-9218 to discuss the details.

Best regards,

Scott

CRM
Posts: 40
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System Serial Number: A900171

Re: Southwest Industries Prototrak DPM conversion

Post by CRM » Thu Jan 06, 2011 8:09 pm

Thanks for the reply Scott (and Marc).
I am interested to see what we can work out. I too was given the "proprietary" runaround with SWI. :roll: I'm not suprised you've had many other inquires for a conversion, it's a well built, stout piece of iron paticularly suited to the "garage machinist" due to the fact that with a 3 hp spindle, it's possible to run single phase thru an inverter and save the hassle of a phase convertor.

Even though I have access to my Fadal 4020 (not much to brag about) at work for the home projects, I am a little concerned about laying up the Prototrak for an extended period of time. Would you need all the drives/motors, or would one suffice? (the X axis is pretty easy to remove, but the Y and Z are a little tougher) Even without the X axis, I believe I could still use the mill manually. The ram can only be moved via the Z axis servo. I'm not even sure what I showed in the picture was an encoder--could it possibly be a tach? My machine has "Trak" sensors which are essentially the equivalent of glass scales. They use a small micro-knurled contact wheel to read table movement directly. The quill on my machine uses one (in a slightly different housing) along with the ones that read table and saddle movement. I have attached a picture if the innards from the quill position encoder:
quill scale.JPG
quill position encoder ("Trak" sensor)
The ram does not use a Trak sensor, but I haven't gone up top poking around to see how that servo differs from the X & Y units yet. I believe I read in the manual that that axis does use a rotary position encoder. That brings up another question: even in a worst case scenario, if I have to fit standard encoders to these drive motors and a glass scale to the quill; can Mach3 be configured to evaluate both the quill scale and the ram encoder to keep track of the actual Z position? (The quill movement would be strictly manual and locked into the retracted position when running under program control) The operation would be similar to a horizontal boring mill where the quill is defined as the z axis, but the table movement toward and away from the spindle is defined as the W axis. I wouldn't need (or want) a seperate W axis, I would simply like the Z axis position to be the sum of two encoders (if you move the quill positive one inch and the ram negative one inch the Z position would be the same as before the moves) This behavior would have excelent utility when it comes to setting tool lengths and touching off Z on the part.

I poked around in the "computer module" as SWI calls it and from what I can tell is they are using a standard computer motherboard that boots from a floppy (no hard drive :shock: ) and loads the operating system to "ram disk". The motherboard has a 386 processor and a seperate video card. two of the full length PCI slots hold what appear to be the custom SWI motion control cards and two big (40 pin?) ribbon cables transfer all signals off the board to another board who's only function seems to be to serve as a mount for all the various plugs and connectors going to the drives, position encoders, CRT display and keypad. If you are thinking along my thought lines, there ought to be a way to utilize your MPU11 to drive my discrete servo drives without needing the DC3IO. Or is that required to handle spindle speed control via the VFD? Also, the prototrak does not have any limit switches and does not "home". If the table reaches the end of it's travel, it just thumps hard into the hard stops and faults out after about a second with an axis fault/overtravel warning (crappy system if you ask me).

Scott, I will try to make contact with you via phone Friday 1-7-11, the complication is that I do not have long distance privileges on my phone at work, I don't have long distance service on my home phone (which wouldn't be during business hours anyway), and my cell phone has lousy reception in both locations. :cry: Email is the best communication method for me until I need quick back and forth rapport.
Dean Jahnz
Cannon River Machine

diycncscott
Posts: 522
Joined: Thu Mar 04, 2010 4:03 pm

Re: Southwest Industries Prototrak DPM conversion

Post by diycncscott » Sun Jan 09, 2011 6:52 pm

Dean,

Please check you PM (private messages)

CRM
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Re: Southwest Industries Prototrak DPM conversion

Post by CRM » Mon Jan 10, 2011 7:25 pm

Scott,
I can't PM you back, I get this message:
We are sorry, but you are not authorised to use this feature. You may have just registered here and may need to participate more to be able to use this feature.

Apparently I don't participate enough :roll:

I left another message on your cell phone with a number and times I can be reached at.

I checked two things in the meantime:
1)unplugging the cable to the X-axis drive board/servo will cause a fault when I try to jog the axis under CNC control. If the control is placed in the DRO mode, and I crank the table by hand, the readout will update. That tells me that position information is not taken at the servo motor, and that the pics I showed were either a tach for the servo or a lower resolution encoder.

2)pulled the cover and checked some things on the Z-axis (ram, not quill). There is no seperate "Trak" encoder for the Z axis, unlike the X & Y axes. The servo motor APPEARS to be the same as the X & Y but I haven't unbolted it and pulled it out of the column for a good look yet. However, it is belted to the ballscrew at a different ratio--30 tooth at the servo, 44 at the ballscrew (1.466:1) but the ballscrew is still the same .200" per rev unit that the other axes use. When I removed the belt and turned the ballscrew by hand, there was no movement indicated on the readout, if I spun the shaft of the servomotor it did register movement in the Z-axis. That indicates that there IS an encoder used on the servomotor for Z-axis position feedback.

I hope this info helps some, and that we can connect soon.

--Dean
Dean Jahnz
Cannon River Machine

diycncscott
Posts: 522
Joined: Thu Mar 04, 2010 4:03 pm

Re: Southwest Industries Prototrak DPM conversion

Post by diycncscott » Tue Jan 11, 2011 7:15 am

Hi Dean,

I apologize for the inconvenience regarding the PM system. There shouldn't be any "participation" threshold
and, as far as I know, nobody has ever had a problem sending PM before. I'll look into it.

I'll call you later this morning to discuss your retrofit.

Regards

Scott

CRM
Posts: 40
Joined: Mon Jan 03, 2011 11:54 pm
Allin1DC CNC Controller: Yes
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CNC11: Yes
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System Serial Number: A900171

Re: Southwest Industries Prototrak DPM conversion

Post by CRM » Thu Jan 24, 2013 2:33 pm

1/24/13 Update:
This thread isn't dead, I am still going to do the conversion. Scott held up his end of the bargain and reworked my servos and shipped them back with the All-In-One board, remote pendant and a couple other things. I disassembled the mill and was about to start laying out the components in the cabinet when I wound up being in a 4x4 accident that found me barrel rolling my Toyota 6 times down a cliff. :cry: The broken shoulder that resulted put the brakes on the conversion, and 2 other projects had to cut ahead in line. I hope to be back on this project this spring, sometime in late May. I'm getting antsy to post up my success story!
Dean Jahnz
Cannon River Machine

diycncscott
Posts: 522
Joined: Thu Mar 04, 2010 4:03 pm

Re: Southwest Industries Prototrak DPM conversion

Post by diycncscott » Mon Jan 28, 2013 11:16 am

Hi Dean,

Sorry to hear about your accident. I hope you are fully recovered and keep us posted on your progress.

Scott

joe7sch
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Re: Southwest Industries Prototrak DPM conversion

Post by joe7sch » Mon Jul 15, 2013 11:31 am

Greetings,

How is the healing going? Would love to hear how your project is coming along!

_J

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