Hello Guest it is March 28, 2024, 09:55:55 AM

Show Posts

This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.


Topics - deaddave

Pages: 1
1
General Mach Discussion / motor madness
« on: October 07, 2009, 05:34:16 AM »
hello friendly mach people ;D

I have recently purchased components for a cnc machine I intend to build and I'm
already running into some real problems, hoping someone might be able to help me.

Components:

GWR Elektronic SM44PCV5.1 driver board
(http://shop.strato.de/epages/61125483.sf/de_DE/?ObjectPath=/Shops/61125483/Products/%22SM44PCV5.1/RK2%22)

GWR Elektronic SMN 4515V1 power supply
(http://shop.strato.de/epages/61125483.sf/de_DE/?ObjectPath=/Shops/61125483/Products/SMN4515V1)

M5776/2.0/1.9 2 Phase High-Torque stepper motor 2,0A
(http://shop.strato.de/epages/61125483.sf/de_DE/?ObjectPath=/Shops/61125483/Products/"M5776/2.0/1.9")

I would much have preferred a geckodrive of some sort for this project but being in the colder end of Europe the shipping and taxes and toll added up to be about the price for a geckodrive 540. I now regret cutting costs in this particular area :(

Setup 1 is a  2,8Ghz ibm thinkcentre PC with xp SP2 running mach3 and nothing else. On board and off board gfx cards. Mach3 drivertest reports excellent.

Setup 2 is a 1.6Ghz noname (asrock mobo)  PC with xp SP2 running mach3 and nothing else. On board and off board gfx cards. Mach3 drivertest reports excellent.

Setup 3 is a 500Mhz noname (msi mobo) PC with xp SP2 running mach3 and nothing else. Off board gfx card only. Mach3 drivertest reports excellent.

The motors are noname (literally) motors, 8 wires, 2 phase, 2,0A bipolar serial, parallel 4A, coil voltage 4V, coil resistance 2,0 Ohm, coil inductance 6,4mH. 200 steps/rev with 1.9nM holding torque. Wires are red – blue – green – black – red/white – blue/white – green/white – black/white.
Wired as bipolar serial:

blue and red/white connected and isolated
green and black/white connected and isolated
A - blue/white
B – red
C - green/white
D – black

Above motor information supplied by seller.

The SM44PCV5.1 driver board is configured at 1.5A and hooked up to
a 36V supply.

Test procedure:
I start everything up, enter mach3, set up ports and pins for just 1 stepper to test this out. Board has led's to indicate ready status, hitting e-stop on the board registers in mach 3, all is well.

Now come the problems. I've made a small test axis, 300mm in length with a motor attached to one end via a flex coupling. The drive screw is a 12mm, 60 degree thread, 1.75mm pitch. A preloaded nut is attached. Action is smooth and the nut spins easily. The board is set to half-step. Motor tuning is initially set as follows: 200*2/1,75 = 228,57 steps/mm. Velocity 100mm/min. acceleration 4.

This does work, the stepper moves, but nowhere near 100mm/min. Fiddling around with the numbers the very best I have been able to achieve is less than 1 rev/s. Any higher and the stepper loses all control of itself, losing steps (often every step), moving backwards, sounding like a hammer drill... it isn't good. And even at very low speeds where it does work it runs faster in one direction than in the opposite. I tried increasing the kernel speed in desperation and that does actually work, makes it run smoother but not a lot faster. Worked best at 100khz, which I understand from the mach3 setup video tutorial to be way excessive.

Hooking up another stepper, same type as the first, things get even weirder. The settings for the first axis I copy to this new axis. This motor behaves as screwy as the first one, but not in the same manner, jerks are different and what will make the first axis slow but smooth makes the second jerky in 1 direction and not working in the other. I have tested with a few older steppers salvaged from various places, all were 6 wire types. Behaviour persists regardless.

I'm really at my wits end here I just can't figure this out. Doesn't help that I'm rather new at this - almost all I know, I've read, so practical experience is not abundant. If anyone has any insight, any at all, or has maybe worked with this particular board before please help me.

Pages: 1