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1

General Mach Discussion / How to fight noise

« on: July 15, 2015, 02:43:00 PM »

I'm having a heck of a time getting the last of my noise out of my plasma build, need some ideas.

First the specs;
scratch build table with ac servos and drives from DMM tech (Dyn4 drives)
Hypertherm Pmax85 with cpc and serial port
CandCnc Mp3500 DTHCiV EtherCut

Next the issues;
My arc volts on the Mach3 screen is floating between 1-10 volts with no arc fire.
My Z motor has a jerky downward drift to it.

Things I've found;
When I had full 3 phase power to the drives the arc volt reading was 2-18 or so volts, so taking the generated 3rd leg (Phase perfect digital converter for the shop) off cut the phantom volts in half.
If I only power up the Z motor and drive the motor is stable and quiet with no drift
Power up any other drive and the Z starts drifting.
Using an O-scope I can see noise on the Step/dir connections on the MTA board when the drives are powered up, drives off, no noise. Any drive on, all step and dir connections have noise.
If I unplug the MTA card from the Mp3500, Z drift stops.
I have tried switching Z motors, drives, cables, but the drift always stays with whatever is plugged into the Z step/dir connections.
I've tried putting a EMI noise filter ont he PC and Mp3500 supply lines, no change
I have made sure the ground plugs from the Pc and Mp3500 are not in continuity to the table ground. I have a PC ground that goes back to the electrical cabinet on the wall, and a table ground that goes to a ground rod next to machine. The PC ground currently has the PC, Mp3500, seros and drives connected to it, while the table ground has the pmax ground and gantry ground connected to it.
I even tried noise filtering line magnets on the db25 cables going to each drive with no change.

I really need to get this thing running and making parts, but it is kicking me. I've been emailing tech support at both Candcnc and Dmm tech, but have only managed to narrow down where the noise is coming from. I'm going to try moving the PC, Mp3500 and mta card outside of the electrical cabinet on the machine to see if that helps next.

2

General Mach Discussion / Path Generation not working

« on: June 14, 2015, 01:15:44 PM »

OK, I need help on a new build

I had a simple point to point G code program working yesterday, now today when I load the Gcode it freezes on path generation. I did a fresh install of Mach3 and still the same problem. I cut the program down to one line just a G0 X80. Y100. and still it brings up the "Please Wait...Path Generating" and will not finish.

I'm using CandCNC hardware and their screens etc, not sure what is going on.

3

General Mach Discussion / Help with wiring DMM drives step and direction signal

« on: June 12, 2015, 06:45:32 PM »

If this is in wrong section please move.

I am trying to get my plasma cutter moving and have run into a wall.

Specs;
DMM Ac servos and Dyn 4 drives
CandCNC MP3500 torch ht controller.

I can get the motors to run through the DMM software, but I can not get mach3 to move them. The DRo in Mach moves but motor does not.  Any help would be greatly appreciated, as Candcnc is gone today and all weekend, and DMM doesn't seem to answer phone or email.

I have tried wiring it as the DMM manual shows for open collector internal power supply and no luck. I was assured when I bought the drives and motors that they would work togther.

4

General Mach Discussion / Mach3 for press brake controller?

« on: May 30, 2015, 10:37:29 PM »

Hi all, new here. Long first post but hoping I can get some help here  

I got a cnc press brake that needs a new control system and am wondering how hard it would be or if its even possible to use Mach 3 to run it. Some of the specs.

-Has (well will have) Y1, Y2 hydraulic ram axis's with servo valves and linear encoders. Valves will require a +/- 10vdc signal, encoders have to be bought yet so whatever works here. Need the control to close the loop.

-Has 2 servo motor axis for back gage (X and R) control that I will probably upgrade with DMM tech servos and drives that could be run on a step and direction and closed loop at the drive.

- Has an ac gear motor with brake for a crowning axis adjustment with encoder feedback. Assuming I can control this with a VFD with a Fwd/Rev signal and let the VFD operate the brake and have a set ramp to it. Optionally could convert this to a servo motor setup with closed loop at the servo drive. As is I need the control to close the loop from the encoder feedback.

- Has adjustable pressure via a Nachi valve, the driver for this requires a 0-10vdc analog signal. Currently is no feedback on this, I would like to put in an electronic pressure sensor and atleast have a readout of the pressure though, but that should just be a 0-10vdc input.

-Also have a dual pedal foot control that I would want to use to step through the program.

I'm assuming I would need to run a Galil card or something of the like to do the closed loop stuff correct?

Now onto the controller questions. I need Y1 and Y2 to be slaved together but yet be adjustable some times for tilt adjustment, is it possible for mach to do this with like a button on the screen to bump like the left side of the ram down "x" amount?

The machine has a fast approach speed of the ram that is achieved by activating a pair of solenoid valves that switches the high pressure oil to a smaller inner cylinder (inside the large ones) and letting the large ones suck oil direct from the tank, Is it possible for Mach to run this? I'm thinking one would have a rapid speed move to a clearance ht above the material, then maybe the ram has to pause for a split second while these solenoids switch back to putting the high pressure oil to both the large and small cylinders for pressing speeds. Would be good for it stop above the work anyway so operator can make sure sheet is up against the stops.

Would it be possible to prgram this by means of a table of sorts that let you fill in stuf like bend 1 angle, bend1 tab length, bend 1 ht offset, and then bend2 and bend 3 etc? Maybe a way to set up tool offsets for the different punches and dies I might have, say lower dies are work offsets and punches are tool ht offsets. Lower die offsets would affect the ht of the back gage stops (R axis).

Can Mach do bend angles from a stored table that I can fill in from test bends or past work? I mean like with this punch and die, with this material and this thickness, Y has to go this far into the metal to get 90 deg bend or 45 deg bend?

I know its alot of questions, and thanks in advance for any help. I see some guys here have made some neat tubing benders on Mach3 and it looks like my project should be doable, but I have to figure out the details. I have seen Bigtoy's cnc press brake build on dynomotion with Mach 3 and like it as well, but I believe he programs it with G code, and I'm hoping I could do something like a fill in the blank thing to program or it will wind up too complicated for anyone but me to run the thing, not that that is all bad, but it would be nice if it was pretty easy to teach someone the basics of operating and doing a simple new program on it.