Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: Waynec on January 14, 2009, 10:55:17 AM

Title: Gantry Jerk at Reset
Post by: Waynec on January 14, 2009, 10:55:17 AM

I'm doing so well with Mach 3 now- learning Screen 4, getting things dialed in- its good!

Today's little issue is a problem when I shut down the machine or click the reset button to take it offline.  I get a half inch or so of jerk on the X axis.  It doesn't seem to happen on Y or Z axis.    I can't tell if the DRO is showing the change in position, but I suspect not.  Its just a sort of one time jerk when I release the gantry from motor control.  There is no similar jerk when I turn the Reset ON. Only when I switch if OFF.

I'm sure I read something about this, but I can't seem to find it now.    I'm using Gecko controllers on a crudely modified ShopBot if that makes a dif.

Thanks to all.

Wayne C

Title: Anyone? Bueller?
Post by: Waynec on January 17, 2009, 12:19:46 PM

I'm trying to see if anyone has an idea why my gantry jerks when I click the reset button.  Only when I turn it off, not on.  Its about a half inch lurch.

Should I be looking at mechanical or control box or Gecko issues? 

Anyone? 

Thanks
Wayne C

Title: Re: Gantry Jerk at Reset
Post by: Hood on January 17, 2009, 12:38:27 PM

Can you attach your xml, also what hardware do you have?
Hood

Title: Re: Gantry Jerk at Reset
Post by: Chip on January 17, 2009, 11:42:07 PM

Hi, Wayne

Your gantry is twisting. It can be allot of issues, Steps Per settings different on one side, Homing issues, Home  SW's settings issues, Lost step's on one side, ...........

Give us the details as Hood stated, Have a overhead gantry water jet hear, Been down this road myself.

Chip

Title: Re: Gantry Jerk at Reset
Post by: AJF on March 15, 2009, 02:13:02 PM

I'm having the same problem. It started 2 days ago and I've checked to see if any settings have changed and I haven't found anything. I've been running various versions of Mach over several years on the same machine and this is the first time I've encountered this problem. Has anyone found the cause and the solution to it.
It happens several seconds after after I shut down down the computer but while the controller is still powered on. Only happens on the x axis and is about a 1/4" of movement in the positive direction.