Dynomotion

Group: DynoMotion Message: 14590 From: yanvrno@frontier.com Date: 4/14/2017
Subject: Controlling a external Disc Brake on Rotaty Table
Id like to control a pneumatic disc brake on a Rotary positioning axis, wondered other than creating and using a Mcode as i am now, if I could tie the on/off signal into the control of the servo / rotary commanded move.

I am basically using this as a parking brake to alleviate backlash and create a more rigid positioning system. I was searching for examples that would make this an integral part of the commanded move to the drive but found no references to brake controls. So a delay of approximately 300ms would be needed before motion to release the brake then back on when position is met.

I love my 6axis Kflop/Kanalog system and it just keeps getting better,
thanks for your support.

I have posted a photo of the new disc being machined and brake actuator I hope to put into service this week.


Mac
Group: DynoMotion Message: 14591 From: Tom Kerekes Date: 4/14/2017
Subject: Re: Controlling a external Disc Brake on Rotaty Table
Hi Mac,

I can't think of a better way to handle that other than MCodes to clamp and unclamp with delays.  If you try to automatically detect motion and release the brake then there wouldn't be any time for the brake to release. 

Brakes can be difficult as sometimes clamping introduces a small error. The servo may then command a huge torque trying to correct the error that is not possible to correct.  So sometimes it is necessary to enable/disable the servo just at the right time. And/or Limit Integrator windup. 

Regards 
TK

On Apr 14, 2017, at 8:28 AM, yanvrno@... [DynoMotion] <DynoMotion@yahoogroups.com> wrote:

 

Id like to control a pneumatic disc brake on a Rotary positioning axis, wondered other than creating and using a Mcode as i am now, if I could tie the on/off signal into the control of the servo / rotary commanded move.

I am basically using this as a parking brake to alleviate backlash and create a more rigid positioning system. I was searching for examples that would make this an integral part of the commanded move to the drive but found no references to brake controls. So a delay of approximately 300ms would be needed before motion to release the brake then back on when position is met.

I love my 6axis Kflop/Kanalog system and it just keeps getting better,
thanks for your support.

I have posted a photo of the new disc being machined and brake actuator I hope to put into service this week.


Mac
Group: DynoMotion Message: 14595 From: Federico Javier de la Cruz Riz Date: 4/14/2017
Subject: Re: Controlling a external Disc Brake on Rotaty Table

I believe hydraulic brake will be much faster, as it need almost no flow to build up/down pressure, the pneumatic approach is easy, but takes too long to release all the pressure. In a brake system there is almost no displacement of the braking pads, but there is a big difference on aplied force (in both cases this is pressure).
Almost sure speed can be hi enough to can control in the servo loop. If i was you, i would try to find the valves used in antilock brakes systems (ABS unit), that valves might be really fast in release pressure.
Hope it helps.

El 14/04/2017 08:28, "yanvrno@... [DynoMotion]" <DynoMotion@yahoogroups.com> escribió:
 

Id like to control a pneumatic disc brake on a Rotary positioning axis, wondered other than creating and using a Mcode as i am now, if I could tie the on/off signal into the control of the servo / rotary commanded move.

I am basically using this as a parking brake to alleviate backlash and create a more rigid positioning system. I was searching for examples that would make this an integral part of the commanded move to the drive but found no references to brake controls. So a delay of approximately 300ms would be needed before motion to release the brake then back on when position is met.

I love my 6axis Kflop/Kanalog system and it just keeps getting better,
thanks for your support.

I have posted a photo of the new disc being machined and brake actuator I hope to put into service this week.


Mac
Group: DynoMotion Message: 14602 From: yanvrno@frontier.com Date: 4/17/2017
Subject: Re: Controlling a external Disc Brake on Rotaty Table
Thank Tom

Still could you post an example how a script might be used to control an output before and after a commanded move? Might just send a signal to my light stack.
Thanks again

I did post a couple more photos of the completed upgrade. Works great.
Group: DynoMotion Message: 14604 From: Tom Kerekes Date: 4/17/2017
Subject: Re: Controlling a external Disc Brake on Rotaty Table

The example InitKStep4Axis.c controls the KStep Enables in a similar manner to your brake requirements.  As soon as any axis begins to move it enables (releases the brake).  After a specified period of time with no motion it disables (applies the brake).  But as described earlier there is no easy way to anticipate an up coming move to release the brake prior to the movement.

Regards

TK


On 4/17/2017 4:53 AM, yanvrno@... [DynoMotion] wrote:
 

Thank Tom

Still could you post an example how a script might be used to control an output before and after a commanded move? Might just send a signal to my light stack.
Thanks again

I did post a couple more photos of the completed upgrade. Works great.