help with lost steps??

[chrisw765]

well im running mach2 and small parts turn out great but for some resone if the file is big and runs for say 45 minutes it will ussaly skip steps and get off,its not mechanical problem, i did catch it in the act the motors where just twitching and i grabed the shaft and could spin them as if there was no power.and then bam ther where moving again off line for say 3 sec,so i thought power supply? it was a 24v switching type i pulled it out and hooked up 2 12v batterys to make 24v and what a difrance before the motors wher loud and and choppy. now they run cooler and no noise and smooth?? its even at higher volts24v vs 21v?? so i thought that was def the problem i ran a fairly larg file and it got of again??so it didnt fix it??even thought it fixed other problems, any help pls

[joecnc2006]

make sure lead screws are well lubricated, i had that problem once Doh....

Joe

[chrisw765]

thx but its not mechanical ie binding.the motor are stoping/twitching for a couple of sec??

[DieGuy]

With a Xylotex 3 things are really important. The Power supply voltage must be below 30vdc at all times including during deceleration, the vref adjustments must be set correctly for each axis and I would recomend setting them below the max ov 3.6 volts (mine are set to 3.35volts) , and if the vref voltages are set relativly high then good active cooling of the heatsinks are a must. I run 2 12vdc fans in series blowing directly down on the heatsinks.

[pminmo]

How old is the board? My understanding is the early versions had this problem before they filtered the inputs.

Phil