Stepper Driver Questions

[bcromwell]

Ok folks I need some help please!!

I thought I know which stepper motor driver I wanted until I came across this:

http://www.piclist.com/techref/io/st...step/index.htm

I am pretty savvy with electronics, so I am not worried about the fact of it being a kit vs. a completed product. But I what I find interesting is the:

* 200 step - full step
* 400 step - high-torque half step
* 1200 step - microstep 6th!
* 3600 step - microstep 18th!

And the "Low Power Hold"

My question is there a "need" for the microstepping? I am looking to use this for either a Router or a Plasma/OxyFuel setup.

The stepper driver I was going to get is the Stepper3 ROC from www.stepper3.com because of the 3 to 8 amps per phase rating.

Thought, Ideas???

Thanks

[ger21]

Those are only for 1.5a/phase.

Gerry

[jimglass]

I think Xylotex is hard to beat for smaller steppers at $90. It hooks up in just a few minutes.

Oh Ya, almost forgot, the Xylotex driver has terminals for a 3 axis mahine.
Jim

[bcromwell]

Originally posted by jimglass I think Xylotex is hard to beat for smaller steppers at $90. It hooks up in just a few minutes. Oh Ya, almost forgot, the Xylotex driver has terminals for a 3 axis mahine. Jim

Can you tell me where to get it for that price?? I price price I found for the 3 axis is 150$ on sale for 125? But you are right I do like the specs and layout of the board. Thanks

[jimglass]

Hi B;

Right here: xylotex@hotmail.com

The contact person is Jeff. He is very helpful and provided information to build my first machine.

Oh, another thing, you might get the board for $85. Jeff has a cable and a 5 v power supply that you should also buy from him if you want a quick install. Another $20 for that stuff.
Jim

[ger21]

I think you're thinking of the old price. It went up a few months ago. I just got mine and paid $125.

Gerry

[WOODKNACK]

Xylotex is a good board for the money. I just hooked mine up to some 187oz motors I got. I was able to get over 60IPM and could not stop them with my fingers. Im impressed with the little board. Like someone said it is a very easy board to set up. I going to use my setup with a cnc taig mill I ordered. I'm hoping to get 30IPM rapid moves out of the machine. Im documenting my setup of the mill on my web page as I get the parts ect..

[bunalmis]

Hello bcromwell,

If you need very silent and vibrationless operation you must use
microstep.

[Mariss Freimanis]

Two reasons for microstepping; suppress resonance and increase resolution.

1) Suppress Resonance:

A step motor is a first-order, mechanically resonant system just like a mass-spring. It is ready, willing and eager to resonate given any provocation just like a weight attached to a coiled spring suspended from a ceiling. Left alone, the weight will be still; pull down on it, then let go and it will oscillate up and down for a long time.

The amount of energy invested in oscillation is the old Mass times Velocity squared thing. At 10 microsteps the "tweak" applied to the mass is 1/10th as large as for a full step so the energy will be only 1/00th compared to a full step. The motor turns with almost no perceptable vibration.

2) Increase resolution:

Most step motors have a "+/- 5% non-accumulative tolerance" specification. This means any given step will be 1.8 degrees, give or take +/- 0.09 degrees.

Put another way, any given step will fall within a 0.18 degree error range. 360 degrees (1 revolution) divided by 0.18 degrees gives 2,000 radial locations, meaning as a transducer, the motor's native accuracy is 1 part out of 2,000.

There are however only 200 full steps per revolution and this means accuracy is 10 times better than resolution; you are not getting your money's worth because this accuracy gets under-utilized.

At 10 microsteps, resolution equals the motor's accuracy. Any microstep resolution more than 10 gets you "empty resolution" just like having a digital caliper that displays 1 millionth of an inch but is accurate to only .001". The extra digits look pretty but mean nothing.

Mariss

[bunalmis]

Hello Mariss,

Step motor is a minimum second order system.
First order system can not be osilate.

[tivoidethuong]

did you make Hex file for pic16f628A?