Messages

1

General Mach Discussion / Re: Fast Jog but it skips on G-Code

« on: February 11, 2008, 08:58:57 AM »

One last post (I hope).  Thank you all for your help.  After a lot of experimenting I have come to the conclusion that the problem isn't all Mach3.

Just a note for those who use the HobbyCNC package.  Set your board to 1/4 stepping.  Doesn't make sense but it works.  Using a 1/4-20 rod you end up with 16000 steps per inch.

Then I changed my motor tunings to 45 ipm and acc. of 10.  When I changed my settings to this it seems to work.

I have cut 3 complicated pieces and it never skipped.  Changed my feed rate from 30 to 16 and it still never skipped.  So thanks a lot everyone for your help.

Thanks,
Clint

2

General Mach Discussion / Re: Fast Jog but it skips on G-Code

« on: February 07, 2008, 11:35:56 AM »

First off, thank you all for your help.  It is appreciated.  Here is the latest data I have.  Some things are better and some things are stranger.

Chip,  your advice helped a bunch.  The feed rate was set to 6 and the percentage to +5% or something like that.  I changed both of them to 100.  It ran better but it still wanted to skip.  I set it to 50 ipm on all axises and, here is the strange part, I had to set the acc. for Z to 1, Y to 2 and X to 3.  Then I set the feed rate in my g-code to 50.  It worked beautifully.  It was fast but the quality suffered a little.  Now when I change the feed rate to anything else than 50 it skips again.

Anyone have any more ideas.

Thanks
Clint

3

General Mach Discussion / Re: Fast Jog but it skips on G-Code

« on: February 06, 2008, 07:13:54 PM »

What happens is this.  When I set the motor tunings to 50ipm and acc. of 4 ( and I think 5 or whatever) I am able to use the jog controls without missing steps.  But when the computer runs the g-code, that is when it misses steps.  If you are able to jog at a given rate, why can't the computer run g-code at that rate, especially when there is no load on the steppers?

I guess that is my question.  When I set it to 45 (or 50) ipm and the feed rate to 16 ipm it seems to work, but I would like to cut faster than 16 ipm.

Thanks for your help.
Clint

4

General Mach Discussion / Re: Fast Jog but it skips on G-Code

« on: February 06, 2008, 01:08:43 PM »

Just an update.  I set the acc. from 1 to 50 and it didn't seem to make any difference.  I set the ipm down to 45, the acc to 5 and the feed rate to 16.  I managed to run it without a skip for a couple of times.  Sure wish there was a way to up the feed rate.  Anyone have any suggestions.

Later,
Clint

5

General Mach Discussion / Re: Fast Jog but it skips on G-Code

« on: February 05, 2008, 05:52:11 PM »

Thanks, will do.

Clint

6

General Mach Discussion / Re: Fast Jog but it skips on G-Code

« on: February 05, 2008, 03:55:53 PM »

Thanks for your reply.  What is a good acceleration number?  I noticed that mine is set to 4.  My power supply is producing 33.4v to my steppers which are rated 3v 3A.  I was told that that was a good number.  I have HobbyCNC's 208 oz-in steppers.

Thanks,
Clint

7

General Mach Discussion / Fast Jog but it skips on G-Code

« on: February 05, 2008, 12:52:08 PM »

???I have my motor tuning set to 50 ipm and it runs fine with the jog controls.  But when you run G-Code and the computer takes over, it skips steps on anything greater than 16 ipm.  There basically is no load on my router.  I'm just using a V-bit to carve in wood and only going 1/16" deep.  What is even more strange is that when I change my motor tuning to anything less than 50 ipm it skips when you jog.

Is there any way to get a faster cut speed?  I'd like to go up to at least 25 ipm.  I'm using HobbyCNC kit that includes the driver board and motors.

Thanks,
Clint