Hi, I have been using what used to be a CNC Router, and am using it to hold a Laser head to do some marking. I needed to add a spindle (chuck) as I have some parts that I need to spin at no more than 30 RPM. Rather than going out and purchasing a VFC/Motor to drive the spindle, I started experimenting by temporarily using my Y axis motor (disconnected from the axis itself). I set up the parameters for the spindle according to the instruction manual, but so far have ended up with the motor running too fast, too slow, too hot. I just can't seem to get the right parameters to make it run the speed I need. Here is what I have.

Stepper Motor - 4 wire, 2 phase, 1.8 degree step angle, 3 amp, 3.6v
Motor Drive = 2 Phase, 2000 pulse/rev, 3 amp current set, half current mode set.
Pulley ratio, 2 motor rev = 1 spindle rev

I would be so grateful if someone could suggest the base parameters for the Motor Tuning and the Spindle Pulley settings, as I have tried so many combinations, I don't know what to adjust any more.

Cheers.

From the above it would seem your stepper drive is set to 10 microsteps thus the 2000 steps per rev, as you have it geared 2:1 then the steps per unit for the spindle would be 4000. Your Velocity would be what you want the max rpm to be (maybe 50?). Acceleration will be lowish try 1 and see how it goes, setting to that would mean the spindle would take 1/2 second to get to your 30rpm.
Hood

Thanks Hood, I tried all combinations of steps per rev EXCEPT 4000. I tried that and it seems to work nicely. The motor is still a little warm, but that could be because of the crazy values I have been entering trying to get my result.

Thanks again (not Scottish by any chance?)

Sorry, I now see you are from Canoustie... definitely Scottish 

Thanks again (not Scottish by any chance?)

Yes I certainly was the last time I looked

Steppers  get hot, just as long as they dont burn you when you touch them they should be fine.
Hood

I think it was hot from the previous test(s) I had made. I shut it down for a while and ran the new settings and it has maintained a 'warm' temperature.
While I am on the subject of now adding this spindle and ordering a Drive and Motor for my Y axis, I have another question if you don't mind. The 25 pin Breakout Board I have left me with enough pins to control 5 outputs (no inputs) I need. Now that I need 2 pins to control the spindle, this leaves me 1 short of available pins. I looked everywhere on the web to look at the 9 pin (port 2) pin out, but can't find one. I (think) I am using all of my available pins on the 25 pin when I have the following assignments:

X axis - 2, 3
Y axis - 4, 5
Z axis - 6, 7
Emergency Stop -10
O/P 1 - 1
O/P 2 - 8
O/P 3 - 9
O/P 4 - 14
O/P 5 - 16
O/P 6 - 17
Ground 18 - 25

What about pins 11, 12 and 13?

Cheers.

1-9, 14,16, 17 are outputs
10,11, 12, 13 and 15 are inputs.
If you require more then you could add a second parallel port and you can either have it set the same as port 1 or you could have pins 2-9 configured as inputs. That would mean 2-13 and 15 would be inputs and 1, 14, 16 and 17 outputs.

What are you using all the ouptuts (1-6) for?


Hood

When I said in my original mail it was for Laser Marking, I did not explain that is also used for Laser Cladding. The Laser System we have for Cladding requires 5 outputs for 'Laser Ready', 'Laser On', 'Shield Gas On', 'Powder #1 On', and 'Powder #2 On'. I need these 5 outputs for the system leaving me Output 6 as spare, but I am contemplating joining 'Laser Ready' and 'Laser On' as they can come on at the same time. I don't like the idea of having no spare outputs for future use which is why I asked about Port 2. I don't quite understand when you talk about a second 25 pin port and configuring the I/O the way you say, I doubt whether I will ever use inputs, for now anyway.

Barry.

It is an option for port 2 that you can either have it the same as port 1 (12 Outputs, 5 Inputs) or if you require more inputs it can be configured so pins 2-9 become inputs, that would mean you have 4 Outputs and 13 Inputs.
As you are requiring more outputs than you will need in inputs then leaving it as standard would be the best way.
Hood

Thanks Hood, now I understand. Port 2 will be Port LPT2 on my computer, another 25 pin port that I can use like Port 1, but addressing the outputs as pin # and port #2.

From an Englishman in Canada to a Scotsman, I thank you for your help.

Cheers.