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ERC TimSav - Cheap DIY CNC Foamboard Cutter

Sero

Elite member
Problem with X-axis

I created a Bronco G-code and I messed up on sheet 2 as the width was set too wide and the X went off. Fixed that and X axis still went off, this time it wasn't following the G-code. So I swapped out the driver on the CNC shield for a new one and all seemed good until X-stopped working all together and the heat sink was super hot.
I'm assuming I fried my CNC shield? Anybody experience this?
 
Its very hard to fry the shield as there are not many components there. Are you sure you installed the driver the proper direction. Also anytime you change a driver you should set the vref max current adjustment on the driver. Also be aware that if you move the gantries by hand, the motors can act as generators and fry the drivers. If the heatsink is that hot then the driver probably toast. Try moving the y driver to that location and see if it works. Good thing is that A4988 drivers are cheap, bad thing is you have to wait to get them. If you fried anything it would be the uno that would take the hit after the drivers. You can also rule out the motors by swapping the x to the y driver and so on
 

Sero

Elite member
Its very hard to fry the shield as there are not many components there. Are you sure you installed the driver the proper direction. Also anytime you change a driver you should set the vref max current adjustment on the driver. Also be aware that if you move the gantries by hand, the motors can act as generators and fry the drivers. If the heatsink is that hot then the driver probably toast. Try moving the y driver to that location and see if it works. Good thing is that A4988 drivers are cheap, bad thing is you have to wait to get them. If you fried anything it would be the uno that would take the hit after the drivers. You can also rule out the motors by swapping the x to the y driver and so on

Driver is installed correctly.
I knew nothing about setting the vref max current adjustment. I don't see any numbers on the stepper motors, I purchased the second kit from Edward. Resistance of the motor phase is 4ohms.

I usually always unplug the motors when moving the gantries, but have forgotten occasionally. Pretty sure that wasn't the cause this time, I feel like it has something to do with the X-axis jamming up when it went out and interfered with the foamboard corner brackets.

I'll give those things a try, thanks for the advise.
 

Sero

Elite member
Try setting the vref to about .8- .9v and that should be close. If the motors are getting hot, turn it down a bit and if you get skipped steps, turn it up.
Vref is set at .6v.

Installed another driver, did a dry run, ok. Cut one sheet all ok, stepper motors at room temp. Started cutting another sheet and 1/4 the way through the driver heatsink got hot and the x-axis stopped.

I think my next step will be to swap the stepper motors.
 

Sero

Elite member
No problems with my x-axis after installing the above mentioned Amazon order. The generic Uno board in that kit did what my first Uno did, randomly stopped, froze and occasionally re-started only to move somewhere very random. Luckily I had a genuine Arduino Uno board and no problems with that. (not yet anyway) So 1 out of 3 generic Unos worked for me.