Messages

151

Brains Development / Re: ModIO THC success

« on: March 25, 2013, 08:57:48 AM »

To limit your voltage, build a simple voltage divider.  Most plasma machines have adjustable voltage divider.  Before going to too much trouble, make sure yours is not adjustable.  TD and Hypertherm are adjustable.  Older Hypertherms were preset at 50:1.  50:1 will give you what your looking for.  If your divider is not adjustable, I'd just build a 50:1 divider and connect it to your raw tip voltage.

What plasma do you have?

152

General Mach Discussion / Re: Odd problem: Z axis stalls X or Y or both

« on: March 17, 2013, 10:32:18 AM »

What are the specs on the motors?  Voltage, current and inductance? 

As steppers increase in speed, they lose torque.  Seeing as how you can fix it by slowing it down, you're probably just trying to go too fast with too small a motor and/or too little PS voltage.  Increasing voltage will increase torque at higher speeds but will cause excess heat build-up in the motors at slower speeds.  You always want to use as little voltage as you need to maintain desired performance.  Could also be that you need larger motors.  130oz/in are pretty small motors.  At higher speeds, they won't produce much torque.

The other thing that points to voltage is that 2 axes work and 3 do not.  When the third motor starts drawing current from the PS, there is less available to the other 2 axes.

153

General Mach Discussion / Re: G28.1 Z.500 (TOM) routine NOW works with G68 coord rotation in V.067

« on: March 10, 2013, 02:47:30 PM »

After some testing, I found a fairly serious issue in .067.  When cutting a large file with lots of parts, mach will skip over some of the parts.  The G-code is fine.  I load the same file on a machine running .022 and it runs fine.  When I re-load on .067, it fails.  Tried different PC's and different machines with the same results.  The failure point is random.  Every now and then it will just skip a part.  The TOM routine runs, torch fires, torch shuts off, raises and moves to next part....almost as if the linear feed code is just missing.

154

General Mach Discussion / Re: Need Help with Relays

« on: March 03, 2013, 10:46:08 AM »

Just use a mechanical relay rated for the current you need.  CNC3PC sells some good ones that can be driven from TTL 5V outputs.

155

General Mach Discussion / Re: Need Help with Relays

« on: March 03, 2013, 10:29:19 AM »

I think that's just saying that the required trigger current is 7.5ma at 12V.  At 5 V it should be less.  It sounds like you don't have enough current to trigger the relay.  find a 5V, 1A or 2A power supply and connect it to the trigger input and it will probably work.

We stopped using SSR's a while back.  They are problematic.  They don't always work.  They usually won't work with motors that have capacitive start or any sort of built in speed control or relays/solenoids with AC coils.  

156

General Mach Discussion / Re: PLASMA - "thc on" problem

« on: March 01, 2013, 10:07:50 PM »

The idea is that the THC mode pauses motion unless there is an arc.  If you want to run the machine without a good arc, just turn off THC mode.

157

General Mach Discussion / Re: File Load Speed

« on: February 27, 2013, 10:29:32 AM »

With plasma a crash is usually not painful as the torch just releases, but I do like to see the program displayed.  That atleast tells the operator that he's running the right program.

158

General Mach Discussion / File Load Speed

« on: February 26, 2013, 09:06:34 PM »

Is there a way to speed up the file load process?  When I had everything but the actual feedrate moves in macros, programs loaded fast.  Since moving al of that back to GCode, I notice that programs load very slowly.  A large program may take a few minutes to load, then if you regen the display, it does it all over again.  I tried turning off the tool path display, but that didn't make a difference.  The machine seems to run better with everything back in GCode, but we run some very large programs and the load time is an issue.  Any ideas?

Thanks

159

General Mach Discussion / Re: G31 issue

« on: February 20, 2013, 10:44:34 PM »

The parameters are not just for the TOM.  Only 3 of them are...Switch Offset, Pierce Height and Slow Zone.  The others are for feedrates, pierce delay and safe Z.  We make all of that available to the operator so it he wants to use a different material, all he has to do is change the cutting parameters on screen rather than generating a new program.  The only thing SheetCAM hard codes is the kerf width.  We could do that in Mach also, but then the operator would have to maintain a tool table.

I kind of like it all in Gcode.  RFH works fine with G28.1 in Gcode.  It seems to know not to "execute" the G28.1 when it does the simulation.

160

General Mach Discussion / Re: G28.1 Z.500 (TOM) routine NOW works with G68 coord rotation in V.067

« on: February 20, 2013, 09:21:59 PM »

Are you running 067 on a daily basis?  066 is lock down.  If 067 is still in development, I don't want to turn it loose on my customers.