Hello Guest it is July 14, 2020, 07:56:54 PM

Author Topic: Step / Velocity mode  (Read 10118 times)

0 Members and 1 Guest are viewing this topic.

Offline DMBGO

*
  •  200 200
  • Time is the same in a relative way
    • View Profile
Re: Step / Velocity mode
« Reply #10 on: October 20, 2010, 07:10:56 AM »
Rich we are OT, but such is life, I had the same idea re 2 mpgs on the lathe, but they are still in their boxes and probably will stay ther for the time being.
Hood, I'm using Scott's plugin with Peter's pendant, but to switch between multi step and velocity, I have to do multiple button presses, a switch sounds easier. I' m sure Scott in his normal helpful manner will change his plugin to remove multi step from the button push cycle if I ask him :) my lathe is quite a distance from the pc screen, so at the moment, i have trouble seeing what mode I'm in. This will change! I was trying to be nice to the SS, which is very scared of my VFD.
Cheers

David

Offline Hood

*
  •  25,846 25,846
  • Carnoustie, Scotland
    • View Profile
Re: Step / Velocity mode
« Reply #11 on: October 20, 2010, 07:54:22 AM »
I am not sure how the plugin actually works but I think I remember Peter saying that the MPG with Modbus via Plugin is not as good as  Modbus via the old serial interface.
My MPG is not via Modbus at all so cant say one way or the other for sure.
Hood

Offline Hood

*
  •  25,846 25,846
  • Carnoustie, Scotland
    • View Profile
Re: Step / Velocity mode
« Reply #12 on: October 20, 2010, 07:56:49 AM »
Just went to the Yahoo to search to make sure and it just so happens Peter is discussing this at this very moment, heres what he is saying

"Hi Andy,

Wether the MPG is coming from a ModIO or MP-01 pendant, the Modbus data
entering Mach3 is identical.

The only difference I can see is that using the legacy Modbus serial
interface produces smooth movement, whereas using the new Plugin support
Serial interface does not.

In the early days, Art and I had a lot of correspondence to get the MPG
smooth in the Legacy serial Modbus interface.

I have asked Brian a couple of times to look at the MPG issue that Mach3
now has. I even sent him a ModIO to test with.

As I understand it, Brian is too busy with other issues, so fixing the MPG
issues is lower on the list.

If there was anything that I could do from my end, I would. If Brian needs
anything from me, I'm happy to provide it.

It's a bit of a shame that Modbus does not bet a higher priority,
considering it is probably the most widely used communications protocol in
industrial control."

Offline DMBGO

*
  •  200 200
  • Time is the same in a relative way
    • View Profile
Re: Step / Velocity mode
« Reply #13 on: October 20, 2010, 09:02:49 AM »
I wonder if it's my inexperience with mach3 that makes me put such emphasis on this?
I would have thought that this would have been discussed and resolved ages ago if it was a real issue. I suspect that once I've spent a bit more time on Mach I will realize that it's not particularly important.
Having said that, when showing off one's new cnc machine to the uneducated, it is nice if it moves in a smooth and controlled manner :)
Cheers

David
Re: Step / Velocity mode
« Reply #14 on: October 20, 2010, 09:23:33 AM »
Thanks Ray and Hood,
Ray when you say that is the way it does work, is it working that way for you?
If it is just one of those things that should work but doesn't I'll drop it, but  if you have it working, I'd really like to know what might be wrong.
Cheers
Dave

Yes, that is how it works for me, with a VistaCNC pendant.  Should work that way with any MPG.

Regards,
Ray L.
Regards,
Ray L.
Re: Step / Velocity mode
« Reply #15 on: October 20, 2010, 09:24:49 AM »
I am not sure how the plugin actually works but I think I remember Peter saying that the MPG with Modbus via Plugin is not as good as  Modbus via the old serial interface.
My MPG is not via Modbus at all so cant say one way or the other for sure.
Hood

Hood,

I run my VistaCNC through a ModIO, and it works fine....

Regards,
Ray L.
Regards,
Ray L.

Offline Hood

*
  •  25,846 25,846
  • Carnoustie, Scotland
    • View Profile
Re: Step / Velocity mode
« Reply #16 on: October 20, 2010, 09:42:06 AM »
Ray
 Certainly doesnt work via SS that way, also cant remember it working that way via the PP or maybe I am just remembering that it didnt work very well. It works well in Velocity mode and also in Step or multistep  mode but Step/Velocity mode doesnt, I hav to physically change between Velocity and Multistep via switch or screen.


Dave
 Have just taken a vid of the mill moving via MPG and am uploading to you tube as I type. I have a cold so you will maybe not be able to make out what I am saying very well but at least you should see the motion.
Will post a link when its done.

Hood

Offline Hood

*
  •  25,846 25,846
  • Carnoustie, Scotland
    • View Profile
Re: Step / Velocity mode
« Reply #17 on: October 20, 2010, 09:46:41 AM »

Offline DMBGO

*
  •  200 200
  • Time is the same in a relative way
    • View Profile
Re: Step / Velocity mode
« Reply #18 on: October 20, 2010, 10:42:15 PM »
Hi Hood, your video seems to be gone from you-tube (video removed by user). I will try one of my spare encoders on the parallel port today and report back. I am starting to wonder if it is a configuration issue somewhere if it works for Ray.
Time will tell.
Cheers
Dave
Cheers

David

Offline Hood

*
  •  25,846 25,846
  • Carnoustie, Scotland
    • View Profile
Re: Step / Velocity mode
« Reply #19 on: October 21, 2010, 03:02:30 AM »
Yes I removed the video as I presumed you had watched it :(
What it showed was the motion was smooth and controllable in Velocity mode, the biggest issue being the detents in the MPG making it hard to keep a very consistent slow speed if you were wanting to use it for actual machining on a regular basis. Taking the detents out and replacing with a small amount of constant friction would solve that. I dont need to do that personally as I only use for positioning and edge finding and find MDI much quicker and better for quick machining if needed.
Hood