Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: dwrightny2266 on October 18, 2015, 08:17:53 AM

Title: Random Direction
Post by: dwrightny2266 on October 18, 2015, 08:17:53 AM
Hopefully a newbie problem :) But when i try to move either the X or Z, it will change direction randomly.  So if i were to be at the center of the table, and push right arrow, to move in that direction, it may go right (+) or left (-), and the same goes for the Z axis.  Any thoughts?

Title: Re: Random Direction
Post by: Tweakie.CNC on October 18, 2015, 08:25:49 AM
Just a shot in the dark...

If you are using the Parallel Port for communication then it is possible that your PC output voltage is to the 3.3Volt TTL specification and your controller requires a 5Volt TTL signal for correct operation.

Tweakie.
Title: Re: Random Direction
Post by: dwrightny2266 on October 18, 2015, 09:58:05 AM
Worth a shot to look into it.  Sent the seller/OEM a message to see what their thoughts are.  Much appreciate the feed back.
Title: Re: Random Direction
Post by: dwrightny2266 on October 18, 2015, 10:09:29 AM
And yes it's a parallel port connection. 
Title: Re: Random Direction
Post by: Tweakie.CNC on October 18, 2015, 10:30:15 AM
You could check by identifying an axis direction pin, then connecting a voltmeter, jogging that axis in one direction should show (approx.) 5 Volts and jogging in the other direction should show (approx.) 0 Volts.
If the maximum voltage shown is only 3.3 Volts then you could perhaps consider fitting your PC with a PCI Parallel Port card which has 5 Volt TTL output.

Tweakie.
Title: Re: Random Direction
Post by: BR549 on October 18, 2015, 02:25:47 PM
Or there are LPT cards that take either  a 3 or < 5v signal lower voltage signal and BOOSTs it up to a clean 5v signal.

(;-0 TP
Title: Re: Random Direction
Post by: dwrightny2266 on October 18, 2015, 02:33:28 PM
Thanks a bunch!!  I have a buddy who may have one and looking to see if it will fit.  If not, there only $10-$15 on ebay, and can have it by Tuesday.  Then its off to the races lol :) Thanks again!!