Page 1 of 1
no Motion after tripping limit switches <resolved>
Posted: Thu Oct 10, 2019 1:11 am
by warnerr
Revised my limit switches for my allinonedc so i have seperate mechanical switches - two for each axis now. (anilam only had one per) all servers move correct, jog and count. hitting seitches triggers stop and displays correct switch. It should be noted these are old allenbradly mechanicals- they take about a quarter inch of travel in opposite direction to reset. The software sees this as no motion and trips. reversing switches software position does not solve. Was hoping to use limit switch homing....What do you recommend?

- refuses to move out of trip zone
Re: no Motion after tripping limit switches
Posted: Thu Oct 10, 2019 9:19 am
by cnckeith
please post a fresh.report.zip so we can see your settings. here is how..
viewtopic.php?f=60&t=1043
Re: no Motion after tripping limit switches
Posted: Thu Oct 10, 2019 4:03 pm
by warnerr
Re: no Motion after tripping limit switches
Posted: Thu Oct 10, 2019 9:33 pm
by cncsnw
CNC12 is unnecessarily restrictive about switch hysteresis. It will only back away from the tripped switch by one turn of the motor, or 1/4", whichever is greater. I understand the next release is at least going to increase the distance limit from 1/4" to 1/2".
A better long-term solution would be to permit the axis to back off either one turn of the motor, or back to where it was sitting when you started the homing move (whichever is farther). But that will have to wait for some more distant future release.
In the mean time you can work around the restriction by lying about your turns ratio and encoder count. E.g. if you change your Z axis revs/inch from 6.67330 to 3.33665, and change encoder counts/rev from 8000 to 16000, then CNC12 would at least be willing to back off by 0.2997" (what the control would then think is one turn). For X and Y you would have to do at least 4x adjustment, to get the apparent distance of one motor turn over 1/4".
Re: no Motion after tripping limit switches
Posted: Fri Oct 11, 2019 10:12 pm
by martyscncgarage
You have an All in One DC
I noted in your report you have two axis reversals Axis 1 X, an Axis 3 Z):
Axis Label Motor Encoder Lash Comp. Limit Home Dir Screw
revs/in counts/rev. (inches) - + - + Rev Comp
1 X 13.2247676999999992 8000 0.0000 1 2 1 2 Y N
2 Y 13.2943574000000009 8000 0.0000 3 4 3 4 N N
3 Z 6.6733018299999998 8000 0.0000 5 6 5 6 Y N
Besides just clicking Y you have to go switch the limit switch inputs and change the screen above.
Follow this tech bulletin:
https://www.centroidcnc.com/dealersuppo ... ds/137.pdf
You need to do this for X and Z Y is OK. Once you physically swap the X+ and X- limit switch inputs and the Z+ and Z- limit switch inputs on All in One DC you go into the screen above and change from 1 2 for limit and 1 2 for home to 2 1 for limit and 2 1 for home for X axis
And from 5 6 for limit and 5 6 for Home to 6 5 for Limt and 6 5 for Home
Read the tech bulletin, hopefully it makes sense. But it has to be done.
Marty
Re: no Motion after tripping limit switches
Posted: Fri Oct 11, 2019 11:49 pm
by warnerr
you are correct. i spent some time and did some reconfiguring before i got your information so i should post an updated report. System sets fine if i use ‘ jog’ and place everything centered- even the soft stops trigger properly and i can back off.
Re: no Motion after tripping limit switches
Posted: Sat Oct 12, 2019 12:43 pm
by warnerr
THANK YOU! THANK YOU! martyscncgarage - I had software flipped switches but had not moved wires- THAT IS THE SOLUTION! Might be nice to add to manual. Your a genius!