Dynomotion

Group: DynoMotion Message: 13214 From: janbbeck Date: 5/2/2016
Subject: Set up KmotionCNC for open loop steppers
I am having trouble with the cnts/inch parameter in KmotionCNC

I am using open loop steppers on SnapAmp, and have set up the axis in Kmotion leaving the InvDistPerCycle at 1.0

The lead screw is 0.2 inches/rev. So in KMotion a Move() of 250.0 results in 5 rotations of the 200 step/rev motor yielding 1.0 inches of movement.

However, I can't figure out what units KMotionCNC expects for the cnts/inch parameter. Neither the 250 I use in the Move command nor the 1000 steps the stepper has to make work. When putting in 1000 for that parameter a Move() of 250.0 in Kmotion moves the axis correctly to 1.0 inches but kmotioncnc shows the position as 6.35 inches. I could just divide by that number, of course, but I want to understand what I am doing.

I looked at the documentation and the mailing list but was not able to find any help. Sorry if this has been answered before and I simply did not find it.
Group: DynoMotion Message: 13215 From: Tom Kerekes Date: 5/2/2016
Subject: Re: Set up KmotionCNC for open loop steppers
Is KMotionCNC in mm mode?

6.35 x 1000/250 = 25.4mm

TK

On May 2, 2016, at 3:04 PM, homeloan@... [DynoMotion] <DynoMotion@yahoogroups.com> wrote:

 

I am having trouble with the cnts/inch parameter in KmotionCNC

I am using open loop steppers on SnapAmp, and have set up the axis in Kmotion leaving the InvDistPerCycle at 1.0

The lead screw is 0.2 inches/rev. So in KMotion a Move() of 250.0 results in 5 rotations of the 200 step/rev motor yielding 1.0 inches of movement.

However, I can't figure out what units KMotionCNC expects for the cnts/inch parameter. Neither the 250 I use in the Move command nor the 1000 steps the stepper has to make work. When putting in 1000 for that parameter a Move() of 250.0 in Kmotion moves the axis correctly to 1.0 inches but kmotioncnc shows the position as 6.35 inches. I could just divide by that number, of course, but I want to understand what I am doing.

I looked at the documentation and the mailing list but was not able to find any help. Sorry if this has been answered before and I simply did not find it.
Group: DynoMotion Message: 13216 From: janbbeck Date: 5/2/2016
Subject: Re: Set up KmotionCNC for open loop steppers
Yes it was. Duh!

I feel like I just asked why my computer did not turn on and did not check if it was plugged in...

Thanks for taking the time
Group: DynoMotion Message: 13217 From: TKSOFT Date: 5/2/2016
Subject: Re: Set up KmotionCNC for open loop steppers
:)

Quoting "homeloan@... [DynoMotion]" <DynoMotion@yahoogroups.com>:

> Yes it was. Duh!
>
> I feel like I just asked why my computer did not turn on and did not
> check if it was plugged in...
>
> Thanks for taking the time