Messages

241

General Mach Discussion / Re: New machine arrives tomorrow, first project advice sought

« on: May 10, 2012, 06:07:47 PM »

Lazycam is part of Mach3.  It imports DXF files and creates GCode.  You still need to draw the part though.   Is this a hobby for you or will you be working the machine in a production environment?  It matters.  In production, time is money.  Cheap or free software can end up costing you WAY more than it's worth.  We use plasma machines and use Rhino3D to draw and SheetCAM to generate GCode.  We've tried just about everything over the years from free to crazy expensive and this combo has proven the most efficient. 

242

General Mach Discussion / Re: New machine arrives tomorrow, first project advice sought

« on: May 10, 2012, 01:55:56 PM »

What are you using for CAD and CAM?  Basically, you draw the part in CAD then run it through CAM to get GCode.  The machine manufacturer should have some recommendations for CAM and have posts available for their machine.

243

General Mach Discussion / Re: Mach3 EStop Fault

« on: May 09, 2012, 06:35:33 PM »

We've had issues with the parallel cable between the BOB and the PC picking up noise.  Tried going all the way to 10000 on debounce with no effect at all.  The only solution was to fix the problem causing the noise.  We ended up grounding the PC chassis to the star ground, which is connected to an earth ground rod.

244

General Mach Discussion / Re: New...And very odd issue

« on: May 02, 2012, 04:50:16 PM »

Tried that first thing.  It didn't help.

245

General Mach Discussion / New...And very odd issue

« on: May 02, 2012, 04:11:10 PM »

In 10+ years of working with Mach on numerous machines, I've never seen this one.  When you zero the X axis, then G0X50, it moves 50".  If you G0X0 it moves back 48.75".  The error accumulates consistently as the length of travel increases.  50" will always produce an error of 1.25".  96" of travel will always produce the same error of about 2".  The closer to zero the travel gets, the smaller the error.  We know it's not a mechanical issue and to make it even more perplexing, if we zero on the other end of the table and G0X-50 followed by G0X0, it returns properly to zero.

Has anyone heard of such a thing?  We're re-installing Mach3 since everything else has been checked OK.   It's almost as if Mach is using different steps per settings for X- vs X+ motion.  If it were something loose or random missed steps, I wouldn't expect a consistent error.

Thanks

246

General Mach Discussion / Re: Pause Mach3 with miss fire?

« on: April 29, 2012, 08:07:52 PM »

Our THC just compares set voltage to tip voltage and if tip voltage exceeds set voltage + 10%, it goes into anti-dive mode and suspends Z motion.  This all happens inside the THC and has nothing to do with Mach or feedrate.  If the speed slows, the lerf gets wider and the tip voltage increases.  If it increases to 10% greater that set voltage, anti-dive goes active and prevents the torch from crashing.  If the tip voltage comes back within range inside of 5 seconds anti-dive turns off and Z motion resumes.  If not, it shuts the torch down.  Aside from the fact that your speed slows without reducing cutting current, which may not produce the best cut, the system does do a good job of preventing a torch crash.

I'm guessing that by saying that his THC is "local" that means he  built it himself.  If that's the case, he should be able to make a few mods to the THC and get it working properly.  The problem is really a THC issue, not a Mach3 issue.   IMO, you shouldn't be turning off THC mode in Mach at all.   If you pierce with THC mode off, you stand a good chance of beginning motion before you have a good arc transfer.

247

General Mach Discussion / Re: Pause Mach3 with miss fire?

« on: April 29, 2012, 12:47:22 PM »

In cases like that, we either turn on anti-dive or in most cases just put the THC in manual mode. In manual mode, you contol the Z with a remote pendant. Mach THC is still active so no arc will pause motion. The difference is that in manual mode, once the torch pierces and moves to cit height, you control the Z. Works great for fine detail where the feedrate slows way down.

Anti-dive works also, but I prefer the added control with manual mode.

248

General Mach Discussion / Re: Pause Mach3 with miss fire?

« on: April 29, 2012, 10:22:31 AM »

Why do you disable the THC on small holes?  We burn holes as small as 1/8" with the THC enabled with no problem.

249

General Mach Discussion / Re: Bad cuts

« on: April 08, 2012, 06:27:21 PM »

Velocity in Mach3 has no effect during a program run...other than possibly limiting your feedrate to the velocity setting.  With velocity set to 60IPM, your machine will rapid at 60IPM.  Feedrate during a program run is set by the gcode program.  F30 would set the feedrate to 30IPM.

250

General Mach Discussion / Re: Bad cuts

« on: April 08, 2012, 10:00:39 AM »

Chattering usually means you're cutting too much too fast.  Reduce your depth of cut per pass and as Tweakie suggested, reduce the step over distance.  The rigidity of the machine has a lot to do with how much you can cut in a pass and how fast.  Also, 3/4" is a lot of bit for the Bosch Colt router...especially working with hardwoods.