Newb Needs Help Getting Starting!!!

[Dick Strauss]

I've got a friend that is trying to set up a CNC type of operation for his mill. He plans to use a PC running both BobCad v24 and Mach3 to output to servo drives. He will be ordering a new PC to run everything with my assistance (he is not real computer literate).

Do I understand correctly that the post processing information is then sent to a servo controller via a computer connection? If so, what types of connections are typically used for the computer to servo connection...it looks like some use ethernet?

When we order the computer (we're leaning toward a Dell Inspiron 580 with i5-650 3.2Ghz proc, 6GB memory, and dedicated 1024MB graphics card), do I need to make sure there is an open slot for anything else?

Thanks in advance,
Dick

[Gerry Grzadzinski]

If you're using mach3, it needs to have a parallel port, and a 32bit version of windows.

BobCAD outputs g-code.
Mach3 reads the g-code, and sends step and direction signals to the servo drives through the parallel port (usually via a breakout board).
You can also use an external motion controller like a Smoothstepper to generate the step/dir signals. That will allow you to use a USB port and 64bit OS, but it's another $150

This assumes that the servo drives can accept step/dir signals. If they accept anaolg ±10V signals, then you'll need an analog motion controller to drive them, like a DSPMC (~$1K) or Galil card.

I recommend you do some more research before ordering anything, so you don't purchase something that won't work.

[Dick Strauss]

Gerry,
Thanks for getting me pointed in the right direction.

Take care,
Dick

[Dick Strauss]

A little more info and more questions...

My buddy has several Slo-Syn M092-FF-402E (325in oz, 200 steps) and M093-FC11C3A (450 in oz, 200 steps) motors. He also has several Slo-syn 3180-PT125 (125 micro-steps) translator drives. He plans to use some of them for basic cnc operations.

The translators have D-15 (two row, not 3 like VGA) connectors. What is the best way to connect these to the PC for ease of use? I'd prefer to use a USB connections on the PC side but have read that is not the best idea and that installing a serial card is a better idea. The problem is finding a DB15 serial card. I could use a D25 or D9 serial card and hand wire an adapter to make the right connections but I'd prefer not to have this extra step.

Pins assignments are as follows: 1-AWO, 2-Dir, 3-Pulse, 4-Reduce Current, 5-Reset, 6-Boost current, 7-NC, 8-NC, 9-Half/Full, 10-NC, 11-Opto Supply In, 12-NC 13-Drive Fault+, 14-Drive Fault-, 15-NC. If I understand correctly, I only need to be able to control pins 1, 2, 3 with the rest being optional.

Thanks in advance,
Dick

[John McClanahan]

Those specs sound like stepper motors and drives. You will probably want to set the drives for half steps. The motors will run a bit smoother. The "reduce current" is used when a stepper is "holding". It helps reduce motor heating. Try to utilize this feature if possible. The drive connector may be optically isolated, and the "opto in" may need to be connected somehow to make the drive work.

John

[Dick Strauss]

John,
You are right on the money...they are definitely stepper motors even though my original post said otherwise. I didn't know what he had at the time of my first posting. Thanks for explaining the reduce current feature. I think you are right about the opto-in...the manual states that it should have between 4.5-6V and 14-20mA. I'll have to figure out how to supply this power separate from the computer power supply.

I think the half/full step feature is only for use on the 3180-PT translators that have both full and half-step options according to the manual that covers three models. There is also a 3180-PT10 (10 microsteps) and 3180-PT125 (125 microsteps...the model my friend has) that can only be used in microstep mode. This should allow the steppers to move very smoothly if I understand correctly.

Thanks,
Dick

[John McClanahan]

For a separate 5v supply, consider a cell phone charger. Be sure to test the voltage with a meter first. Some adapters produce more than their labeled voltage without a load.

Yes, 10 micro steps will be smoother than half steps at low and mid speeds. 125 micro steps sounds like a lot Check if the number of micro steps can be adjusted. When setting up Mach, remember to enter 2000 (or your number of micro steps) steps per turn. That's 200 motor steps times 10 micro steps.

John

[Dick Strauss]

John and company,
I happen to have an extra charger that can be re-purposed for the opto-in 5v supply per your suggestion.

I bought a PCI card with two 9 pin serial ports and a 25 pin parallel port. I've got it installed okay I think. The serial ports work fine with an old computer mouse so I assume everything is fine with the card.

I have a few of the old connectors (before the whole shooting match was taken apart). The old computer used a 25-pin serial interface to connect to the 15-pin translator interface. Supposedly the system was working when it was taken apart but I wasn't there so I con't confirm. The original connections were as follows as far as I can tell by the cut cables:

DB25 to DB15
Tx to Pulse in
Rx to All Wind Off
Gnd to Opto-in

This makes no sense to me. How would you wire it utilizing the AWO, CW/CCW, and Pulse connections (assuming that the Opto-In is powered separately by the phone charger)?

Thanks in advance,
Dick

[John McClanahan]

Dick,
Did you find the manual for the drivers? If not, it is here http://www.kollmorgen.com/uploadedFi....213710026.pdf It explains the connections at the 15 pin connector. As soon as I get a chance, I will read thru it. I assume the opto-isolator needs 5v to energize it. Then it will pass signals from the printer port to the driver.

The step, direction and AWO are controlled from the printer port. I will read up and post more later.

John

[John McClanahan]

Page 12 of the manual explains the connections. most of the pins could be left unconnected. You will need pins 2, 3 & 11. The common (-) must be the connector shell, as there is no pin for it.

The AWO could be controlled with Mach3, as the "motor enable", but I haven't found a good need for it on my DIY router, so I never hooked it up. If you move an axis by hand, the DRO will need to be re-zeroed.

The "Boost Current" could be connected with the step (Pulse in), and the motor amps set lower with the DIP switches so the motors don't get too hot. That would give extra amps (extra power) during stepping with reduced current (reduced heat) for holding. I can't think of a good way to use for the "Reduce Current" with Mach3.

If the motor current DIP switches are set correctly and there is sufficient cooling for the drive, the "Drive Fault" should never be a problem.

Your drives are micro-stepping, so the "Half-Full" (pin 9) isn't used. You will need a fairly fast computer and have the kernel speed set higher than the default 25000 mhz in Mach3 to produce the high pulse rate needed as a result of the 125 micro-stepping.

Be sure your parallel port shows up in Device Manager and is set for LPT1 and an ECP port type.

I would bench test a drive/motor with the computer first, before mounting anything.

John

[Dick Strauss]

John,
I've got the manual for the connections. For some reason I thought the translator was looking for a serial connection based on the connectors. I suspect that the previous owner used a 25-pin parallel port to run the translator even though it has a 25-pin female serial connector (since the port is usually male for serial). They must have been using some sort of 25-pin male to male connector. It would make more sense that they were using parallel pins 2, 3, and 7 (all data outputs from the PC) to drive the 1-AWO, 2-CW/CCW, 3-Pulse, 11-Opto-In inputs....

Does Mach3 work with serial ports? I can't really find any details for serial and it seems like parallel is easier to set up having lots of outputs...?
Does supplying the 5V signal from the data outs on the parallel interface really work to isolate the motor from the computer or am I better off using a separate power supply?

Thanks,
Dick

[Mike Heidrick]

You guys are using drives and a breakout board between the parallel port and the stepper motors? For example a Gecko G540?
http://www.geckodrive.com/g540-p-39.html


Mach3 works with parallel ports. You can also use a USB connected smooth stepper beween the pc and the breakout board.

[John McClanahan]

Even though the translators (drives) are optically isolated, you may want a breakout board to make the connecting easier. Maybe someone else could chime in on properly connecting the opto-isolaters. Logic level electronics pushes my electronics knowledge limit.

I'm 99% sure the drives can be controlled thru the parallel port. I have a serial based drive and the control inputs don't have any references to step or direction. Not much use to me.

I doubt the parallel port has enough power to supply the isolators. I used a seperate supply.

As far as the AWO, while the machine is on, the motors need to have the windings on (energized) so the axises will not move, resulting in a loss of positioning. That's where the holding torque spec. of the motors come into play. It is most important on the Z axis.

John

[Mike Heidrick]

Even if it could theoretically do, it the wires in a parallel port would not be sized large enough to hold the amperage requirements a stepper motor. This whole thread has me scratching my head.

[John McClanahan]

Mike, the drives have built-in opto-isolators at the inputs. There is some confusion on how to properly connect the power to isolators. The manual indicates 5 volts, but there is no return ( negative or ground) pin in the connector. I think Dick was asking if one of the parallel port pins could supply the 5 volts needed to power the opto-isolators directly. Due to the type of connectors used on the translators (stepper drives), there was some question if these were serial or parallel devises.

John