Help with drill-Mill conversion

[Lee Roberts]

Amazing Ross, coming along nice mate !

What paint did you go with in the blue ?

[Ross77]

Thanks Lee. Hope to get it assembled soon....Other projects and uni looming...........................

Can't remember the makers name but its supposed to be a hardwearing hammered finnish same as Hammerite. The casting was so so rough I thought a flat paint would look terrible.

This should be a good test for the paint. If it can resist way oil, coolant, grease and all the other nasties that will be thown at it.

[Ross77]

After 2 months I've been able to fit in some workshop time

So the z axis is done and I've managed to hot-wire the controller board to work with step and direction so "IT WORKS" just need to find a better way to transfer the IC to another board.

Tested the x axis and there is no backlash, using a 0.001" gauge it always returned to the same place

The breadboard circuit is the stepper exerciser that Irvine designed for me. Thanks again it works great, no need the drag the pc out.

Now for the question........
Should steppers hum/crackle whilst holding? it only seems to happen on certain motor positions. It also gets worse/louder when I turn up the Vref to increase max current.

It also seems to buzz/miss steps at about 300 rpm, is that normal?

Thanks in advance.

[Robin Hewitt]

Should steppers hum/crackle whilst holding? it only seems to happen on certain motor positions. It also gets worse/louder when I turn up the Vref to increase max current.

It also seems to buzz/miss steps at about 300 rpm, is that normal?

Steppers usually make their best noises when in action, on hold the current is usually cut because you don't need the pulling power.

300rpm is not bad for a stepper, but it isn't good either :nope:

[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