Proto Trak MX3 Retrofit - Which Boards Mesa?

Hi, everyone.

I've been very busy in last days. I've not shared my progress because, I've not any progress yet .
Because in my country is very difficult to purchase electronics things like MESA products and other stuff like that.
So, after do a some research , here in my city , one friend helps to me to order the 5i25 + 7185s for my project. They have cost around 200 bucks.

So, here I have



So afert they (the parts) arrived to me, I made some moves.
The first one was on the mill machine. This is:



It's an old Bridgeport machine and came with Prototrak controller that never worked.



Some tech snuff:



So, I've decided to extract all electronics in the blackbox and replace it with a PC with previously installed LinuxCNC on it. And Mesa 5i25 too.





So, here I'm , I'm still working with the setup, I need to machining some parts, connect some cables, design a monitor stand and machining it too, connect the "brain" with the motor drivers and encoders together , do some research about the configurations of Mesa cards and what HAL means?, and how to use mesaflash?, and then configurate the 7i85s to allow antiphase PWM in 15 Mhz frecuency.

In resume and basically all things that I need to put this baby on the way.

List of the things that i have.

1.- The Bridgeport with its motors and its drivers and encoders.
2.- PC with LinuxCNC installed on it.
3.- Mesa i525+7i85s.
4.- Cables and other stuff.


I was thinking about install Vmware player on Debian and run Windows 7 at the same time with two monitors and use Mastercam on it, but first thing's first.

Where can I start?
How can I configure the MESA 5i25 to work with anti phase PWM?
How can I connect the 7i85s in order to the previous diagrams uploaded?
Jrjones's configuration works for me?
I installed the 5i25, now what?

I really really appreciate your previous help. Just for information, I'm an engineering student and I started this project , because I like to learn more and this project will be implemented in my work and if it works fine, then one machine on my school.

Thank you in advance. specially to PCW and andypugh for they valuable assistance.

Regards and Gracias!!.

vsidon wrote: How can I configure the MESA 5i25 to work with anti phase PWM?

When you say "anti-phase PWM" do you mean pne PWM channel for FWD and one for REV, or do you want a PWM channel and its complement?

You might just need to set output-type to 2 on the PWM channels: linuxcnc.org/docs/2.7/html/man/man9/hostmot2.9.html#pwmgen

The Prototrack drives use a locked antiphase signal that use a single 15KHz PWM channel with differential (complementary)
outputs. Its actually a clever way to use a single signal for direction and magnitude. They also disable the drive when the PWM is not present so they don't start up at full scale output.

50% duty cycle is 0 drive so you use a standard PWMgen but offset the PID output 1/2 way up

vsidon, you should probably beg techrat for his the hal and ini files as a config starting point
since its a rather unusual setup

PCW wrote: Its probably differential PWM in locked antiphase mode (50% = 0 drive),
and I think these drives are disabled by shutting off the PWM

Probably drivable with a 5I25 and a 7I85S with maybe a 7I84 added for GPIO

Hi andypugh.
It's just like PCW says previously "differential PWM in locked antiphase mode" .

According with the schematics by jardomi :


and I can see in the servo driver, it have 2 input signals -pwm and +pwm running at 15Khz (No 15 Mhz sorry for that).And it have 3 more input pins and they're marked like LS (Limit Switch I guess), 5v (circuit power supply) and the inputs for the motor.

So, I suppose that techrat or jrjone have that kind of configuration. I guess that I need some files to "upload" to the MESA 5i25.

Thank you for you quickly response.

Hi everyone.

Recently, I've working again with this project. I talked with Jeff about his configuration files, setups and other stuff, but he say me that he still working on the documentation, So I have to wait .

At this moment I have the computer running LinuxCNC with 5i25 and 7i85s (not connected yet) . But I was thinking that my servo amps (original prototrak) maybe work or maybe not.

So, this is the question.
What is the best option (performance/price) for new servo drives?

Is the Gecko 320x an option?



Is the Advanced Motion Controls servo drive an option?



If I buy one of those drivers, they will work with my current combination 5i25 +7i85s?

Things to considering.
I don't know if the servo motors are BRUSHLESS or BRUSHED. I think that they are BRUSHLESS.
I don't know the Voltage for the motor.

I still learning of LinuxCNC by reading notes and manuals.
Guys your help is a very valuable for my.

Thank you.

The G320X is for brushed servo motors, and takes step-dir inputs. If the motors are brushless it won't work.

The AMC drive is for three-phase brushless, and could work, but you would need to commutate in software and provide the 2 PWM phases (just like the existing drives).

There are alternative drives from AMC that take different command types, some of which commutate in the drive, relying on Hall sensors in the motor.

Do you know what outputs your motors have?

Hi andypugh.

My motors has 2 output wires with attached encoder.
Like this:


So, they're brushed motors, isn't it?

If you take apart the cover that supports the encoder interface you'll find this:



The encoder attached on the shaft of the motor. and the two output wires.

Thank you for you support.

Whats the black wire? I see red, white and black?

The encoder seems to be one of these: uk.farnell.com/broadcom-limited/heds-900...00ppr-2ch/dp/1654866 or very similar.

If it really is 2-channel without an index then I think that the motor _must_ be DC.

The black wire is a set of cables that go to the servo amp.

The motor wires are red and white.

Yes that is the encoder HEDS 9000.

So, you think that the combination of Mesa 5i25+7i85s+Gecko320X is an option?

This is an accurate schematics for the servo system by jardomi

vsidon wrote: So, you think that the combination of Mesa 5i25+7i85s+Gecko320X is an option?

It's an option, if you are happy with step/dir control for the servo drive.

I have a (not very rational) preference for +/-10V servo amp control.

In fact: Why not skip the G520X and retain the original servo drives?