Messages

1

General Mach Discussion / Re: Setting up a Motor/Driver for high torque

« on: July 24, 2013, 02:42:46 PM »

Thanks Hood, I think we were saying the same looking from 2 different angles. I was saying that the motor torque REQUIREMENT decreased by 12, while you were saying that the motor torque CAPABILITY increased by 12. :-)

2

General Mach Discussion / Re: Setting up a Motor/Driver for high torque

« on: July 24, 2013, 02:08:14 PM »

Hi Hood, I don't know if my description is confusing, but my motor torque requirement decreases. If I manually take the gear reducer and spin the shaft at the motor end, it is pretty free and the load end rotates slowly. If I do the same with the load end shaft and spin it, it's a lot harder to spin, but the motor end rotates faster. I would use the gear reducer the opposite way if I didn't have an issue with torque and wanted my load to spin 12 times faster than my motor. No?

Barry.

3

General Mach Discussion / Re: Setting up a Motor/Driver for high torque

« on: July 24, 2013, 12:54:14 PM »

Hi Ian, thanks for the reply and moving this to the General forum.

The gear reducer actually reduces the torque. It takes 12 revolutions of the motor to drive the output shaft 1 revolution.

Barry.

4

General Mach Discussion / Setting up a Motor/Driver for high torque

« on: July 24, 2013, 11:57:02 AM »

Hi, I have a 4 axis CNC machine with a spindle running on a profile. I have added a fixture with it's own motor/driver that I want to run on it's own profile. It is never required to run with any of the other axis or spindle at the same time. I do not need to worry about speed, it is mostly to run to programmed positions when an input is actuated, and set an output when it reaches the position. The torque required to drive the fixture is quite high and unknown. All I know is that the motor gets very hot as it runs, and I don't want to 'fry' it or the driver. My components are:

Driver - 1.4A -5.6A (dip switch set), 400 - 25000 pulse/rev (dip switch set)
Motor - Nema 23 565 oz/in (4NM), 8 wire, 4A wired parallel, 2A wired series
Gear reducer 12:1 (to reduce the torque)

My question is, what sort of settings should I be looking at on the driver? I have my motor wired Bipolar Series, is this the best?
I can work on my Motor Tuning when I know everything else is optimised.

I hope this combination works as I really don't want to purchase a larger motor (Nema 34) as I will have to also purchase a new gear reducer, driver, and possibly a power supply.

Thanks, Barry.

5

General Mach Discussion / Re: Help controlling a stepper motor as a lowRPM spindle

« on: September 25, 2012, 08:34:39 AM »

Hi Hood,
Here is what I am trying to do.
I have a round bar that I need to put on a bead of weld along the length. The bar can vary in diameter and length (between 0.5" - 1.5" diameter and 3" - 24" in length). Up to now we have never had an issue, as the calculation is based on a surface speed length of 59 ipm. The calculations for the different diameters is relatively easy, and I have created an Excel form that spits out the RPM for the spindle. I now have a part that is tapered, and is 0.5" at  the small end, getting to 1.25" at the large end over a length of 8". I wrote a program that started at 0 at the small end of the part, and made the appropriate moves in the -X and +Z direction to get me to the large diameter end of the part. I then had to split up my G01 moves, and insert a new spindle speed based on the diameter at that point. As I split it up 5 times, there is a noticeable thickness change in the part at each point I changed speed, and I know the more I split it up, the smoother the part.
As my boss wants a completely (or smoother) finish, I looked into the CSS function and have tried a sample I read on the forum. The one I sent you runs at the X-10" at F0.03 without changing the spindle speed. I have deliberately left out the Z moves to avoid confusion, and I did set my G48 max speed to S100 ( I never should have to get to that speed, 30 RPM is usually the fastest). Is there something I'm not doing right?

Thanks, Barry.

6

General Mach Discussion / Re: Help controlling a stepper motor as a lowRPM spindle

« on: September 24, 2012, 03:48:02 PM »

Hood,
I have been reading some comments on the forum about Constant Speed of a Spindle RPM and the feed rate of of an axis. One of the Administrators put up some code that I tried but do not see a difference in the spindle RPM when I run it. The code is basically

G96S20M3
G95
G01X10Z0.5F0.03 (feed 10" @ 0.03"/min)
G97S10M3
G01X0Z0F10
M5
M30

Is there anything you can see that I am doing wrong? I have not touched any settings in my Configuration, is there something I need to set?

Barry.

7

General Mach Discussion / Re: Help controlling a stepper motor as a lowRPM spindle

« on: September 12, 2012, 03:29:39 PM »

And in respect to a certain tennis player:

M215 (Hood)
M216 (Terry)
M215 (Hood)
M216 (Terry)
M215 (Hood)
M47 (Andy Murray return and keep on going)

 

8

General Mach Discussion / Re: Help controlling a stepper motor as a lowRPM spindle

« on: September 12, 2012, 10:54:41 AM »

As I have to repeat the code 5 times per cycle,  out of respect for both you guys my code will now look a little something like this:

M215 (Hood)
M216 (Terry)
M215 (Hood)
M216 (Terry)
M215 (Hood)
M47

Barry 

9

General Mach Discussion / Re: Help controlling a stepper motor as a lowRPM spindle

« on: September 12, 2012, 10:27:16 AM »

I tried both codes, and they both work great  Thanks to both Hood and Terry.

10

General Mach Discussion / Re: Help controlling a stepper motor as a lowRPM spindle

« on: September 11, 2012, 03:23:58 PM »

Thanks Hood and Terry.
I am finishing work now (trying to catch the second half of the England/Ukraine game). I will try those codes tomorrow and let you know how I get on.

Barry.