Re: [CAD_CAM_EDM_DRO] Skipping steps, avoiding resonance

Peter wrote:

>Hi Randy,
>
>I've had a number of similar problems with 3D contouring and lost steps
>on a BP clone retrofit. In spite of a LOT of experimenting, I never was
>able to resolve the mystery with my stepper motor setup but I have made
>significant progress since converting the mill to servo motors. I still
>don't understand why a stepper system wouldn't work - provided the
>motors have sufficient reserve power etc., it should have worked! I was
>running direct drive 1800 oz-in steppers with Geckos and Flashcut
>software. I should point out it worked great for all my 2D and 2.5D
>stuff.
>

(snip)

Peter,
Your not alone with your peculiar loss under 3d compared to 2.5d with
the Geckos under FC control. I know of 2 others with the same issue. I
wish they were nearby so I could go and fiddle with them. It must come
down to compatabilities. It's not necessarilly a Gecko problem, nor is
it a FlashCut problem. Both sides have stable use reported.
Compatability problems can give you grey hair fast. That is why I
always recommend a "whole system from the same Vendor" when I sell a
plan set. Obviously, most of us can not afford to do that.

FlashCut has taken some steps to add more configuration in regards step
and dir output. It looks like the newer versions will include additional
configuration settings for ""lead" or "trailing" timing , so you have a
better chance of making things work no matter what driver. The
compatability issue is not unique, I have used other controls that
needed signals "cleaned", "inverted", "delayed" Etc. Not that I always
did it, but I knew it needed it done to work right. Flashcut has
typically worked with the bigger name drivers that we hobbiests can't
always afford like Anahiem and IMS.

I'm finding it works great with the API's tim Sold... Again, pricey
drives. I'd be curious for someone like Mariss to tell us why there are
these differences in drivers.
After a while, we can get in a corner trying to explain why we need to
spend more time with a machine than our wife just because we lose .001"
occasionally!

With the older version of FC, I have found that sometimes you can use
all the wrong Signal settings to make it run right with some drivers.
(you'd need to be a rocket scientist to figure out why} It can have an
affect on speed, but at least it ran.

In that you moved on to servos and still suspect issues, it might be
possible that you could benefit from the new versions additional
settings when it gets released.

Chris L