Warco Major CNC build log

**Robin Hewitt** · 05-07-2009

Hi Kip

The cable goes from the front of the cabinet, out the back, up by the column and then forward again.

I'm using the MSD542 driver at 40 Volts.

18mm/s is top whack, would never dare run it at top whack, 10-12mm/s is probably credible for the G00 though.

It's a bit cluttered at the top, but I could probably mount a driver and PSU within 6-10" of the motor if I had to :naughty:

Robin

**irving2008** · 05-07-2009

Originally Posted by Robin Hewitt

Hi Kip

The cable goes from the front of the cabinet, out the back, up by the column and then forward again.

I'm using the MSD542 driver at 40 Volts.

18mm/s is top whack, would never dare run it at top whack, 10-12mm/s is probably credible for the G00 though.

It's a bit cluttered at the top, but I could probably mount a driver and PSU within 6-10" of the motor if I had to :naughty:

Robin

As John said, speed is a factor of voltage and, I'll add, inductance of the motor. Higher inductance, lower voltage = lower speed. Also remember torque, speed and power are related. So it may well be that these motors running at that voltage simply can't produce enough torque to operate reliably at a higher speed. Can you get higher revs (step rate) off load under the same conditions?

Cable length is going to make little difference unless its so thin as to be dropping considerable volts.

What size/spec of motor are you running?

**Robin Hewitt** · 05-07-2009

Originally Posted by irving2008

As John said, speed is a factor of voltage and, I'll add, inductance of the motor... What size/spec of motor are you running?

Yes, but the question is...

Why did the max speed decrease when I doubled the Amperes?

**BillTodd** · 05-07-2009

Did you saturate the motor?

**Robin Hewitt** · 05-07-2009

Originally Posted by BillTodd

Did you saturate the motor?

Possibly right

I'm sitting looking at the motor spec sheet and it shows parallel as 4.2A/phase, but series as only 3A per pair. Sounds illogical

If I knew what "hybrid" meant it could explain it...

...perhaps

**Gary** · 06-07-2009

That motor is 4.2A in unipolar and 3A in series and 6A in parallel.
If you are connecting it is parallel and only giving it 4.2A, you are under powering it.

Originally Posted by Robin Hewitt

Possibly right

I'm sitting looking at the motor spec sheet and it shows parallel as 4.2A/phase, but series as only 3A per pair. Sounds illogical

If I knew what "hybrid" meant it could explain it...

...perhaps

**BillTodd** · 06-07-2009

If I knew what "hybrid" meant it could explain it...

As I understand it, Hybrid motors have a magnetised rotor as opposed to the soft iron cores used in earlier types.

If you are connecting it is parallel and only giving it 4.2A, you are under powering it.

That makes it very unlikely to be motor saturation :(

I wonder if it's a resonance (force/mass) issue - extra current = extra force. Might be worth trying a mass damper on the motor (i.e. I would stick a large/heavy washer to the motor pulley with a bit of double sided tape and re-test)

[edit] ISTR you have a spare pulley, try sticking that on top of the existing one (use DS tape or blu-tack something with a bit of 'give')

**Robin Hewitt** · 13-09-2009

Today I reworked the tapered Gibb strip fixings.

The original adjusters are totally naff allowing the the Gibbs to move, so they went from tight to loose as you reversed direction on the slide :nope:

To fix it I fitted 35tpi x 3/8" studs, screwed the adjusters on to them, (still sloppy) then bolted on end caps to pinch it all together... TIGHT

**BillTodd** · 13-09-2009

That's a good idea Robin, consider it stolen ;)

I have a small snippet of steel wedged between the adjuster and gib ATM doing the same job.

**Robin Hewitt** · 22-09-2009

Next, tramming it 'cause it ain't square

I chucked up a dti on a 9cm radius and measured to the bed at 4 points of the compass. Plus is a dip, minus is a bulge.

North 0.0"
East -0.004"
South +0.0035"
West -0.0087"

As I measured each point I drew a circle around the DTI tip so I could measure all four points moving the bed rather than the dti...

North 0.0"
East +0.002"
South +0.001"
West +.0025"

Yes, my column is out of square and the bed is a ski jump :nope:

RS do pre-cut shims with a MOQ of 10, so I ordered the 0.05mm (0.002")

Never tried this before, think I need 8 of them and a bed skim :whistling: