Denford Software & Machines

got some issues with the x axis, every few months it snaps the belt.

please watch these videos closely

here my holding the stepper by hand trying to keep it as straight as possible, you can clearly see the stepper jumping.

https://www.youtube.com/watch?v=zIy6T6yE9jY

so now to try narrow down if its the stepper of x axis

you can clearly see the drill here jumping

https://www.youtube.com/watch?v=lp-cu9Hml1s

very wobbly drill

https://www.youtube.com/watch?v=nsxI3tgn-xE


anything got any thoughts?

Have you got the correct belt, you may have a metric belt on an imperial pulley.

The current belt I got off ebay

Is this the correct belt?

http://uk.rs-online.com/web/p/timing-belts/4749434/

Looks like the right one, how about the grub screws holding the pulley on could it be proud of the pulley surface.

I'm having an issue with my x axis on my triac also. it machines circular parts with steps as if the datum point shifts. no matter what speeds i use it always shifts
I've bought a new stepper motor for it that was supposed to be the correct one. but it has 8 wires instead of 4. looks exactly the same as the one in your video.

check the x and y gibs and drive end bearings

toby1995 wrote:I'm having an issue with my x axis on my triac also. it machines circular parts with steps as if the datum point shifts. no matter what speeds i use it always shifts
I've bought a new stepper motor for it that was supposed to be the correct one. but it has 8 wires instead of 4. looks exactly the same as the one in your video.

when you removed the original stepper from your triac how many wires were being used?

i haven't removed the original motor but it has 4 wires, i bought a replacement just like in the video and it has 8 wires.

toby1995 wrote:i haven't removed the original motor but it has 4 wires, i bought a replacement just like in the video and it has 8 wires.

I bet if you strip the wire leading to the original stepper there is actually 8 in there

turns out it was 8 wires but was just using 4 like you suggested.i accidentally shorted the extra wires and had to replace the fuse on the axis "0" drive board. I've just wired up my new motor and ill do some accuracy tests when done to see if it can machine circles accurately now.
the new motor takes a lot more torque to rotate it when no power is present. the old one was smooth and i think it may have been knackered as their should be some resistance to being rotated but there was almost none

all sorted! accurate little machine now. thanks for the advice

the issue was the stepper?

its appears to be. it must have been worn somehow. i have no issues when machining now. is this problem with steppers uncommon?