Help with drill-Mill conversion

[Ross77]

Thanks Robin, not sure i understand, so is the buzzing/ frying noise when holding ok then? or Have I got problems?

I have basicly had to rewire the driver chip and followed the data sheet and other similar designs but I not sure about the control pin. It sets the chopper for either the 4 phases or on the inhibit wires, could this be causing the noise?

If the noise is ok (typical) then I can increase the vref to gain more current which seems to help with the missing steps at the higher speeds. At the moment its set at 0.5v which i think means I've only got 1amp going to the motor. As it uses 2 L602 output chips I belive it is capable of 4amp but I'm too chicken to just crank it up.

Thanks in advance

[Robin Hewitt]

Thanks Robin, not sure i understand, so is the buzzing/ frying noise when holding ok then? or Have I got problems?

The frying noise is probably a sympathetic vibration to the chopper frequency, possibly worse if you pause between half steps. Nothing to worry about so long as the motor isn't getting hot.

I'm no expert on this, my max stepper speed actually decreases if I wind up the current which seems totally wrong, so I am not understanding something. My motors clack out if I set the G0 to 12mm/s so I keep them set 8mm/s to avoid losing position. I'm waiting for Gary to send me some fancy 220 volt drivers which will hopefully make everything wonderful.

I suggest you wind up the current slowly, test the top speed and see if motors, or heatsinks on the driver start to get excessively hot.

Good luck

Robin

[Ross77]

Thanks Robin,

The motors dont seem to get hot if left holding but they get dam hot in use, almost untouchable!! I'll have to see how it goes.

Thanks again

[irving2008]

Get a cheap thermoprobe from Maplin (£19, here) and check motor case temp. Anything above 85degC and you need to be thinking cooling/heatsinks on the motors.

[Ross77]

Thanks Irving, Already got that on my meter, and one of those infrared jobbies.....Just forgot to use them.:whistling:

So is it ok for the motors to get hot if i provde cooling to hopfully keep below 85 degC?

With regard to your L297/ 6203 driver do your motors buzz whilst hold?
Also have you got the contol pin set high or low?

Cheers

[Robin Hewitt]

Anything above 85degC and you need to be thinking cooling/heatsinks on the motors.

D'uh

I've never run a stepper past comfortable to touch, usually lukewarm to tepid. Am I not trying hard enough :naughty:

Isn't there something about eddy currents heating things up? No possibility he's driving one coil with the other shorted out I suppose? That would be the perfect recipe for slow'n'hot :heehee:

Robin

[Ross77]

Problem solved........:whistling:

It all went up in smoke tonite, flames an all. quite impressive :heehee:

Looks like I need a new 3 axis stepper driver.

2 steps forward 5 steps back eh.

[Robin Hewitt]

It all went up in smoke tonite, flames an all. quite impressive :heehee:

Bit late for a photo i suppose :whistling:

Unless you chuck a bit of paraffin over it :naughty:

[Ross77]

Glad you found it funny. I'm £50-60 out of pocket now to replace it tho

Unless you chuck a bit of paraffin over it :naughty:

Could be arranged, and very tempting, but being a tight git i'm going to rob the heat sink ect from it first.:dance:

I cant find any cheap drivers that work over 40v so looks like I cant even use the psu.

[irving2008]

Glad you found it funny. I'm £50-60 out of pocket now to replace it tho



Could be arranged, and very tempting, but being a tight git i'm going to rob the heat sink ect from it first.:dance:

I cant find any cheap drivers that work over 40v so looks like I cant even use the psu.

Sadly most stepper driver chips are 35 or 40v max... so 30 or 35v supplies. To go above that you need to be looking at discrete MOSFET drivers, but these tend to be are rare and expensive..