Machsupport Forum

Mach Discussion => Brains Development => Topic started by: Grand Master B on June 26, 2009, 09:50:10 PM

Title: I can Smell your Brain's
Post by: Grand Master B on June 26, 2009, 09:50:10 PM

Hi Everyone

I have a small problem with my retorfit, everything is working perfect except for one issue. I am using an MPG4 pendant from cnc4pc into an SS board, step mode works fine but my issue arrives in velocity mode. when press enable and rotate the mpg it works fine speeds up and slows down accordingly, but when i rotate the pendant and release the enable button at the same time the axis keeps moving at that speed without any rotation, if i press the enable button it stops. I know one solution is "dont do that" but it could be rather dangerous if left as is.  I am no way a programmer and did have a look at the brains but i think the problem is in the area on the input where it is based on the condition (ismoving) it don't seem to check if the enable triggers are still true, far as i can tell, if anyone has an idea it would be greatly appreicated.

Thanks.

Title: Re: I can Smell your Brain's
Post by: foka4 on July 02, 2009, 05:03:01 PM

I'm using the same setup and getting the same behavior.  I guess that means your experience isn't an anomoly.

I've mitigated the issue by using velocity jogging mode only in the x100 setting (for coarse positioning).  In the x1 and x10 settings, I'm using position jogging mode for exact control, and the overrunning behavior goes away.

With this configuration, I've never had the overrunning behavior cause a crash, and in fact, I've even taken advantage of it for making long, steady moves without the need for programming.  Admittedly, it does require a little technique, but it's quicker than typing a G1 move.

For what it's worth, I used keyboard jogging controls for 5 or 6 years, and now that I have the pendant, I could never live without it.

m

Title: Re: I can Smell your Brain's
Post by: foka4 on July 03, 2009, 12:18:48 PM

Here are the brains I'm using.  x100 uses Velocity, x1 and x10 use position. 

I set this up several months ago, so I don't recall what I changed in the brains to get them to work this way.

In x100, you get fast, smooth jogging for coarse positioning.  On my mill, I can zip along at max rapid feedrate, but still position to about .1" in this setting.

I seldom use x10, but it gives a nice 1" per MPG turn.  So six cranks is 6", etc.  Nice for quickly and accurately jogging the tool an exact distance just by reading the marks on the MPG wheel.

x1 is handy for accurate positioning.  I have it calibrated to the MPG dial, so one detent on the MPG is .001".  This is invaluable for precision jogging.  Note that the CNC4PC pendant has 4 encoder counts per mark on the dial, so you must calibrate accordingly.  It's kind of handy - you can actually eek out .00025" jog increments by carefully moving the MPG between detents.

m

Title: Re: I can Smell your Brain's
Post by: Grand Master B on July 04, 2009, 08:00:13 AM

Thanks,

Let play time begin.