1989 Thermwood Ressurection Project?


Good day,

New here...but long on the planet.

We have a project that we am hoping you can assist us with. We have a 1989 Thermwood Cartesian 5 router. 3 x5 table. Pretty much all original including the 5.25" floppy drive. It all works and I have run some programs from old floppies that came with it. I can also manually input co-ordinates with the handheld controller to make it draw lines, arcs, circles, etc. as they did "back in the day". I can control the spindle speed via the control on the cabinet.

BUT... that's all I can do. How can I get control of it? Will Masso work?

Here are some specs:

The axis motors are original Baldor Servo motors Model MT-4090-FL-5A.

The Driver Cards are Baldor Model FLD7151C-02.

The Spindle is a Perske 12HP, 17,830 RPM,

Spindle Control is Delta VFD-B Model VFD 110B43A,

Input 3ph 380/480v 50/60 hz 25A

Output 3ph 0-48v 24A 18.3kvA 15HP

Freq. Range 0.1 to 400 Hz. Version 04-22

Open Collector Shaft Encoder Dynamic research #152-020-625-48CJ 625 Step.

I have much of the original documentation and wiring diagrams if there are other details needed.

The goal is to get the machine under control with as many original parts as possible. This is a non-profit project for educational purposes in a sign shop environment and not a high production manufacturing facility.

Thank you in advance for your insight and advice.


Staff member

The main thing to look at is the drivers, do they accept S & D signals, differential is best but single sided referenced to -ve or +ve will work as well.

And can the spindle speed be controlled with a 0-10v signal or PWM and switchable FWD & REV.

Then MASSO can be used.




Thank you for the info. This may actually work.

How can I determine if the drivers accept S&D signals? please clarify.

Also, PWM?



Staff member

I had checked your VFD after my earlier reply and that can be controlled by MASSO. Your VFD can be wired as per this model Delta VFD-M allowing for different terminal naming.

My googling for your drivers only finds places that can repair them but no manuals. You mentioned in your first message that you have much of the original documentation, can you copy that and post it we might be able to work out the driver connections from that.




Good Day,

Sorry for the slow reply. I have scanned a section of the wiring diagram for the axis motor connections. It is hard to read but hopefully will offer some clues. I have also included a few pages from the manual dealing with the same topic.

Note that the documentation refers to the "Westamp" Drive Units. These were replaced in 2005 with the Baldor ones specs in my earlier post. All connections seem to be the same though.

Thank you for your attention to this and any advice or insight you may have.


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The servo amplifier documentation mentions +/-10V, so they seem to be analog.

Assuming that's the case, you could either use LinuxCNC with a Mesa card combo that outputs +/-10v like a 5i25 & 7i77 combo (this would be very tinkery, steep learning curve with LinuxCNC, complicated setup etc), plug in something to convert from analog to step/dir (still a bit tinkery from the looks of it, your mileage may vary), or replace the drives and motors with AC servos or closed loop steppers (probably what I would do but it will cost a bit).

The following article describes your situation with some helpful graphics showing how a step/dir controller can be integrated. Most of the solutions mentioned are no longer available but it is a helpful read:

I have found this though. I can't vouch for it but it might work. $90 per axis isn't exactly cheap either, but cheaper than replacing with AC servos:

YAPSC mentioned in the first link:


Thank you for the links and info. Very helpful.

The machine actually functions fully and completely as it did in 1989. My issue is I can not input G-coe in to it. I have a couple of 5.25 floppies that came with it. They have some G-code files that will run the machine. But I can't read the floppies to see the Post Processor details and code formatting. No luck (yet) with a post that works. If I could crack that I might put in a floppy emulator so I could input via thumbdrive.

It has a pendant and using the info in the manual I am able to write "programs" in to the memory and execute them but this is a painfully slow blast from the past. I can save these "programs" to floppy and use them again later.

The motherboard of the machine has an RS232 input that is supposed to accept the program files but I have not succeeded in getting communication established.

There is info in the manual relating to the post formatting etc. if anyone has skills in this dept. I could scan and post those.

It was in the absence of a solution to the above that I am considering the Masso or other controller options.

It should be noted again that this is an educational restoration project and not intended to be a high production machine.

Open to all suggestions and thanx again.


When you say you can t read the floppies, is that because they are formatted with a proprietary file system or because you don t have a PC with a floppy drive?


I actually tracked down a floppy drive and installed it in an older windows machine but could not read the disks.

Also... I believe they may be formatted with Thermwood proprietary software. Perhaps someone has some vintage Thermwood program that might work to run this?

again.... thanx


I am NOT certain of that. I was getting down a whole different rabbit hole of having to study up on antique floppy drives, disks. firmware, and software. It was becoming a whole other project that seemed more effort than exploring other controller options. .... but I may have to revisit those issues.

So here I am. I was hoping to gain some insight via the old floppies that might help develop a functioning post p. to by-pass the floppy via the RS232 or perhaps a floppy emulator.

I have been exploring the Kflop/Kanalog option you mentioned. This may be the path.

Always open to ideas.


I have just ordered a set of those step2linear units to convert analog to digital to use on my cincinatti mill The drives and motors are to good to throw in scrap bin will be interesting to see how they go there are many older machines with good quality hardware out there that could be retrofitted



Good afternoon here is the link to the step2linear analog to digital converter for older analog drives to convert to step and direction input that masso requires .

I am hoping i can get these to work will make my retrofit way cheaper than replacing motors and drives

Cheers Trevor