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Author Topic: Tweaking constant velocity mode (laguna smartshop)  (Read 3080 times)

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Tweaking constant velocity mode (laguna smartshop)
« on: September 08, 2011, 11:56:13 AM »
I have a Laguna Smartshop router (Industry Controls MCB-1 controller/Mach3/4 with stepper motors) and am trying to find a common ground between exact stop and constant velocity. The see the stop at angle setting and it is at 90, but that doesn't seem to do anything because I'm still left with 1/2 radius corners on 2x2 parts cuttings at 300ipm.

I use cabinet vision and aspire, cabinet vision files are almost always longer segments and arcs, but aspire turns many moves into small incremental moves and in exact stop the machine crawls and vibrates through these parts of the code. I though this might be able to be handled in the post, switching between G61 and G64 depending on the distance between points, but I'm not sure that's possible. Any advice would be appreciated.

Offline Greolt

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Re: Tweaking constant velocity mode (laguna smartshop)
« Reply #1 on: September 08, 2011, 05:21:16 PM »
First thing I would be looking at is the acceleration in motor tuning.

Manufacturer may be setting acceleration too conservatively. 

Not saying this is so, just where I would be looking first.

Then if you can not get better machine performance, look at the CV notes PDF for guidance.

There are a few settings that can be tweaked to try and get better CV outcome for lower performing machines.

Greg
Re: Tweaking constant velocity mode (laguna smartshop)
« Reply #2 on: September 08, 2011, 09:50:06 PM »
At 300IPM, the acceleration will have to pretty high to get square corners.  Depends on your steps per to some degree, but I'm guessing at least 50 or 60.  The CV helper settings are a way of making a machine produce decent results at speeds greater that it was designed to run.  If a machine is designed properly and is run within it's design parameters, you'll get nice square corners in CV mode all the way up to max cutting speed.
« Last Edit: September 08, 2011, 09:56:27 PM by rrc1962 »
Re: Tweaking constant velocity mode (laguna smartshop)
« Reply #3 on: September 08, 2011, 10:18:27 PM »
I read some more posts and figured out where the problem was: the CV Dist Tolerance setting. It was set at 180, I had experimented in the past all the way down to 1 and saw no change. I read a post where someone indicated that the value was how much it deviates from the programmed path and was using a much lower number. At .05 there was still a little bit of jerkiness is a 12" long bezier segment, at .15 it cuts the curve at the set speed and leaves the corners on the part square. I haven't looked into the acceleration settings, but now I'm getting the results I was hoping for. Thanks for the help.
Re: Tweaking constant velocity mode (laguna smartshop)
« Reply #4 on: October 03, 2011, 03:55:33 PM »
Where do I find the acceleration settings and how do they work? I'm running a file and the results are good, but the file consists of long curves and small loops and u-turn moves, I would like to keep the feed rate at 400 ipm since most of the work is longer lines and the machine is more than capable of doing that, but at 200+ I think that machine is handling the small moves too fast and I'm getting more jerk and vibration than I want, but I don't want to slow down the whole program. If there is something else that might help resolve this situation I'm open to other suggestions.