Re: [CAD_CAM_EDM_DRO] Thanks - was: Things to check? is now: RUNNING~!

On Thursday 18 September 2003 01:31 am, Jon Elson spake:

> Gee, that doesn't sound so good. After 2 hours or so, that might be
> acceptable, but if it gets that hot in 10 - 15 minutes, they will burn
> up. You may have to reduce the voltage, or the current.

Well, after seeing that I had two different spec sheets for my
motors with differring amperage values, I decided to try the lower ones.

I dropped the amperage from the Geckos down to 3.5A
using a resistor, but the motors still seemed a little warm.
Not _quite_ as warm, but warm all the same...

Curious.

> >Motors *SEEMED* a bit slow for my likes...
> >Is there a way to speed them up?
>
> Is it the MOTORS that are slow, or the computer? Did it lose steps
> and start rattling if you got above a certain speed, or did it run
> smoothly, just not fast enough? If the latter, that just means your
> computer and software can't go fast enough. Speed that up, or set the
> Gecko 210 to multiply the steps by some factor (reduce microstepping).

Rattling almost sounds a lot like what it sounds like *sometimes*.
Not always, but intermittantly...

> >Also, the Z axis motor seemed to be "hunting" all the time.
> >(do steppers need "tuning" also?)
>
> You must be using EMC and freqmod.o, which simulates a servo
> in software. Apply a little DEADBAND in the .ini file for axis_2,
> something like 0.001 to stop the hunting.

I've been reading the documentation today, and haven't come across the
answer yet, but what *IS* the recommended EMCMOT option for steppers?
If i make it anything but freqmod the motors
don't respond nicely when trying to jog them.
Upon first mouse click, there is a really bad growl.
Upon release, the just start off in one direction, continuously...

I'm mounting the encoders soon, so should I be using smdromod anyway?
Or should I wait until I actually *have* the encoders wired up?

I also noticed that I'm getting about 1.25" per percieved (by EMC) 10".
In other words, if I jog the axis, EMC will read 10.000, but visual
reference will show the dial to have spun only 1.25 times (approx).
These are 10 pitch screws, and I'm running
1:2 between motor and screw with pulleys.
(10 tooth on motors, 20 tooth on screws)
Figuring for 200 step motors, I should be getting .001 per step.
But then there's that step multiplying thing...
Right now, the Geckos are set to half step.

...the whole electronics thing throws me every time...

Weyland