Messages

1731

General Mach Discussion / Re: Engraving around outside of a tube

« on: December 21, 2009, 04:37:58 AM »

If replacing Y with A in the code doesn't work because Mach doesn't like doing G2/G3 in the "XA" plane then just swap the settings in ports n pins so that the rotary axis is Y. As far as aspect ratio is concerned - that's what I meant above by get the steps per right.

Cheers

Ian

1732

General Mach Discussion / Re: Engraving around outside of a tube

« on: December 20, 2009, 11:44:55 AM »

why is "special" software needed for wrapping engraving gcode round a cylinder? just swap the Y code to the A code and as long as the steps per are set right - job done. Isn't it?

1733

General Mach Discussion / Re: Plasma torch height control, ??

« on: December 14, 2009, 09:31:31 AM »

you may want to read this http://www.machsupport.com/forum/index.php/topic,10339.0.html and there are others. Also a ton of info on cnczone. Look also at section 12.2 in "Using Mach2 Mill" in the docs downloads.

Cheers

Ian

1734

General Mach Discussion / Re: How to use the Run From Here option.

« on: December 11, 2009, 09:31:47 AM »

sorry if I missed the answer here but when I had first time ever cause to use "run from here" yesterday it didn't behave as I expected.

2.5D job. zeroed Z on top surface. max cutting depth of job = -8mm. I'm at 3rd out of 4 passes at Z= -6mm. Bit brakes. I hit feedhold and change bit. I set next line to just before where the bit broke. I hit run from here and I get the prep moves diialog. X and Y cool. But Z set to -8 !!! - I don't think so. I edit the file removing all lines that have been done and just run it as a new program - works a treat.

Why would it set the prep Z to -8mm i.e. the max depth of the final pass when currently it's only at -6mm?

Cheers

Ian

1735

General Mach Discussion / Re: router tips burning

« on: December 11, 2009, 07:00:14 AM »

Hi Gerry

I wonder how your PS V to motor V ratio compares to roly's.

Ian

1736

General Mach Discussion / Re: router tips burning

« on: December 11, 2009, 05:02:16 AM »

rolyjm - Sorry - I may have misled you by wording my previous post poorly. Reducing your microsteps to full steps is not going to help with your speed problem - I shouldn't have mixed that with my comment about increasing lead. Put them back to 10 or 8 or whatever's near 10 on your setup. I was just saying that above 10 microsteps is pointless.

My suggestion above re: increasing lead would give you more linear speed for the same stall speed of your 6 revs/sec. Alternatively you can up your present stall speed by increasing your PS voltage. You don't say what your motor's rated V is but I'm guessing your PS to motor V ratio is not very high.

1737

General Mach Discussion / Re: second parallel port

« on: December 08, 2009, 01:29:20 PM »

Hi Hood

Just to say I received your card today. Thankyou very much, really appreciate it. I'll let you know how the THC goes - when I receive it.

Cheers

Ian

1738

General Mach Discussion / Re: router tips burning

« on: December 08, 2009, 05:30:25 AM »

pretty much all been covered, but I'd just add this: Up your screws to (say) 10mm lead and cut your microsteps to 10 max (more than 10 microsteps is (generally speaking) not only pointless, it's counter productive). This will get your max feedrate waaaaaaay up at your motor's stall speed of 6 revs/sec without loosing any *real* resolution. There's no way you're going to get your current theoretical res of 0.000390625mm/microstep anyway with a dremmel's runout - not to mention your rig would need to be made of granite etc. etc. 

Ian

1739

General Mach Discussion / Re: Toggle Outputs with No Interuption to Motion

« on: December 07, 2009, 07:11:17 AM »

After a few similar problems recently reported on the forum - I took a look at this and other issues concerning the speed of M calls and switching outputs. Hood's suggestion is a pefectly reasonable one but what actually happens is the same as if you code the M1000 between the X10 and X12 i.e. the blending fails to cross the M call just as described in the OP. I'm in two minds as to whether this is a bug or not. In this particular case however, would a lead-in and lead-out not solve the problem?

1740

General Mach Discussion / Re: second parallel port

« on: December 04, 2009, 01:16:28 PM »

Hi Hood - thanks very much - have PM'd you.
Hi melee - thanks also - unfortunately all UK stockists I've been able to come up with register it as discontinued.

Cheers both

Ian