Hello Guest it is October 16, 2019, 06:33:48 AM

Author Topic: Limiting motor acceleration  (Read 11418 times)

0 Members and 1 Guest are viewing this topic.

Offline ftec

*
  •  80 80
    • View Profile
Re: Limiting motor acceleration
« Reply #20 on: August 01, 2008, 12:50:05 PM »
After reading your example, I see that I mis spoke in my last post. Mach doesn't always accelerate at the set rate. It will not, however, ever exceed it. Which answers your question I think. :)

OK, then I think I will be pretty safe for the time being. I'm quite familiar with calculations for pick 'n place robots but CNC is so much different with the constant interpolation. If necessary I can reduce the gear ratio to slow down the top speed as this is a hobby machine, not needing full scale production speeds. Thanks Gerry and Rich too.

PS. Obviously there was a typo in my previous post, should of course have read dx/dt and dy/dt.
« Last Edit: August 01, 2008, 12:53:15 PM by ftec »

Offline Hood

*
  •  25,855 25,855
  • Carnoustie, Scotland
    • View Profile
Re: Limiting motor acceleration
« Reply #21 on: August 01, 2008, 01:36:11 PM »
You dont need to gear to limit your top speed, whatever velocity you set in motor tuning will be the max you will ever get.

Hood

Offline ger21

*
  • *
  •  6,288 6,288
    • View Profile
    • The CNC Woodworker
Re: Limiting motor acceleration
« Reply #22 on: August 01, 2008, 01:37:55 PM »
If necessary I can reduce the gear ratio to slow down the top speed as this is a hobby machine, not needing full scale production speeds. Thanks Gerry and Rich too.

No need to gear anything. Rapid speeds are set in software. If your talking about slowing down cutting speeds, just change them in your code or use the Feedrate override to slow it down. There's also a separate rapid feed override.

Edit: Damn, a hair too slow. :)
« Last Edit: August 01, 2008, 01:39:33 PM by ger21 »
Gerry

2010 Screenset
http://www.thecncwoodworker.com/2010.html

JointCAM Dovetail and Box Joint software
http://www.g-forcecnc.com/jointcam.html

Offline ftec

*
  •  80 80
    • View Profile
Re: Limiting motor acceleration
« Reply #23 on: August 02, 2008, 02:05:56 PM »
Uh guys, are you serious, I thought you knew the physics;-)

Offline ger21

*
  • *
  •  6,288 6,288
    • View Profile
    • The CNC Woodworker
Re: Limiting motor acceleration
« Reply #24 on: August 02, 2008, 05:45:56 PM »
There's a difference between slowing down because you want to and slowing down because you need to.
Gerry

2010 Screenset
http://www.thecncwoodworker.com/2010.html

JointCAM Dovetail and Box Joint software
http://www.g-forcecnc.com/jointcam.html