Re: Clarification for microstepping requirement
Posted by
jeffalanp
on 2005-12-12 15:44:57 UTC
Hi,
With your [do you get there "all-at-once" or gradually] senario,
don't forget, that with the "all-at-once" FULL step mode, you
actually OVERSHOOT the FULL STEP point. After reaching the maximum
point at overshoot, you start moving back towards the full step
point, but again, because of momentum, you overshoot again, though
not so much. This oscillation around the full step point can take a
while to die down, and while doing so, transfer its vibrational
energy directly to your machine.
So, instead of a FULL step, move a smaller step (1/8th, 1/10, or
1/16th for example). Your acceleration to get to the closer point is
less, so your overshoot is less, so less ringing and vibration, and
less time to wait for vibrations to disipate so you can actually move
faster in many cases, and power is not wasted trying to bring the
motor to the FULL step point.
Jeff
--- In CAD_CAM_EDM_DRO@yahoogroups.com, "Andy Wander" <awander@v...>
wrote:
With your [do you get there "all-at-once" or gradually] senario,
don't forget, that with the "all-at-once" FULL step mode, you
actually OVERSHOOT the FULL STEP point. After reaching the maximum
point at overshoot, you start moving back towards the full step
point, but again, because of momentum, you overshoot again, though
not so much. This oscillation around the full step point can take a
while to die down, and while doing so, transfer its vibrational
energy directly to your machine.
So, instead of a FULL step, move a smaller step (1/8th, 1/10, or
1/16th for example). Your acceleration to get to the closer point is
less, so your overshoot is less, so less ringing and vibration, and
less time to wait for vibrations to disipate so you can actually move
faster in many cases, and power is not wasted trying to bring the
motor to the FULL step point.
Jeff
--- In CAD_CAM_EDM_DRO@yahoogroups.com, "Andy Wander" <awander@v...>
wrote:
>steps,
> Eric:
>
> It's not how many positions you have(in this case, every .000025"
> instead of every .00025"), but rather how smoothly you get from one
> position to the next. While you CAN stop in between the "full"
> your position will NOT be guaranteed to be so many 1/10ths of a fullstep
> step. Rather, it is that while you are traveling, going from full
> to full step, do you get there "all-at-once" or gradually(well, ofdrive
> course, you DO get there gradually, but I am referring to what the
> is telling the motor to do.the
>
> It's kind of like a dimmer on a light. If "OFF" is one full step
> position, and "ON" is the next full step position, do you "switch
> lights on" or do you dim them up gradually and smoothly.on,
>
> From what I understand, the dimming up, as opposed to the switching
> can make your light bulb filaments last longer as there is lessstress
> imposed by a gradual change in applied voltage.have
>
> The situation with the steppers is that at certain speeds you can
> nasty resonances cause by the "switching" of the motor voltages, andQUARNSTROM
> that by gradually changing the voltages(micro-stepping) you are much
> less likely to have those problems.
>
>
> Andy Wander
> Verrex Corporation
>
> -----Original Message-----
> From: CAD_CAM_EDM_DRO@yahoogroups.com
> [mailto:CAD_CAM_EDM_DRO@yahoogroups.com] On Behalf Of ERIC
> Sent: Monday, December 12, 2005 4:20 PMrequirement
> To: CAD_CAM_EDM_DRO@yahoogroups.com
> Subject: [CAD_CAM_EDM_DRO] Clarification for microstepping
>work
> Hey all:
>
> I read the great FAQ's on this site regarding steppers and how they
> and microstepping. Very inciteful and I think I even understand howthey
> do it.FAQ's
> What I can't quite figure out is why it is required. In one of the
> it says the primary purpose for microstepping is to eliminate theset
> jerkyness between steps. However, when I do the math on my proposed
> up I come up with a movement of the axis per step that is so small Ididn't
> can't consider it to be 'jerky'. Therefore I am afraid I either
> understand what I read well enough or I'm missing something. Mymath is
> below and I welcome comments.steps/revolution
>
> System statistics:
> Lead screw with 10 TPI
> 1:2 gearing between motor and lead screw motor with 200
>has 200
> My math:
> Every turn of the lead screw gear produces .1 inches of travel.
> Every turn of the motor gear produces .05 inches of travel Motor
> steps per turn of the motor so every one step would produce .05/200small
> inches of travel
>
> In summary .00025 inches of travel per full step seems like a very
> amount of movement. So why would I need to divide that by 10 for a
> microstepping drive?
>
> Thanks in advance,
> Eric Q.
>
>
>
> This communication including any attachments, are intended
> for the exclusive use of the addressee(s) and contains
> confidential or copyrighted materials. Duplication,
> distribution or reproduction is strictly prohibited by law
> without written permission of Verrex
>
Discussion Thread
CalBoy101
2005-09-07 15:01:25 UTC
Ball lead screw backlash problems
R Rogers
2005-09-07 15:53:06 UTC
Re: [CAD_CAM_EDM_DRO] Ball lead screw backlash problems
jacoby01
2005-09-07 17:40:38 UTC
Re: Ball lead screw backlash problems
CalBoy101
2005-09-08 09:48:21 UTC
Re: Ball lead screw backlash problems
CalBoy101
2005-09-08 12:55:38 UTC
Re: Ball lead screw backlash problems
ERIC QUARNSTROM
2005-12-12 13:20:30 UTC
Clarification for microstepping requirement
Andy Wander
2005-12-12 13:30:01 UTC
RE: [CAD_CAM_EDM_DRO] Clarification for microstepping requirement
Crs Hawk
2005-12-12 14:24:22 UTC
Re: [CAD_CAM_EDM_DRO] Clarification for microstepping requirement
jeffalanp
2005-12-12 15:44:57 UTC
Re: Clarification for microstepping requirement
Paul Kelly
2005-12-12 17:43:52 UTC
RE: [CAD_CAM_EDM_DRO] Re: Clarification for microstepping requirement
ericq47
2005-12-12 17:46:28 UTC
Re: Clarification for microstepping requirement
John Dammeyer
2005-12-12 18:02:33 UTC
RE: [CAD_CAM_EDM_DRO] Re: Clarification for microstepping requirement
Richard Garnish
2005-12-13 05:55:33 UTC
Re: [CAD_CAM_EDM_DRO] Clarification for microstepping requirement
juan gelt
2005-12-13 11:03:49 UTC
Re: [CAD_CAM_EDM_DRO] Clarification for microstepping requirement
Vlad Krupin
2005-12-17 07:37:22 UTC
Re: [CAD_CAM_EDM_DRO] Clarification for microstepping requirement