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Author Topic: corners getting radiused at higher speed on plasma table  (Read 14259 times)

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Re: corners getting radiused at higher speed on plasma table
« Reply #30 on: January 30, 2012, 08:45:54 PM »
Look at the posted code. The re is ONLY one operation listed in all the code and that is an OUTSIDE cut.

That tells me that when you cammed it out in Scam you did NOT set up a layer and operation for the inside cut but used the outside offset process to do everything.

So it really did NOT cut where you thought it would.

It would treat an outside cut differently from and inside, MAYBE

Just a thought, (;-) TP




Sheetcam automatically cuts inside profiles on the inside, and outside profiles on the outside, when outside offset is selected ( That's a mouthfull )
If what you're saying is correct, then my pieces would not be to size. My pieces are perfect except for the rounded corners.

Dan
Re: corners getting radiused at higher speed on plasma table
« Reply #31 on: January 30, 2012, 09:17:50 PM »
OK;
I ran some test pieces, and here's the results.
I hope the picture is clear enough. I tried running the first part at 340 IPM, but it was just too fast.
The second one I turned the CV distance on and set it to 25 units (whatever a unit is , I dunno).Also, I re-drew the part so that the inside corners have a .125 rad.
The third I slowed it to 238IPM. Still no difference.
The last one I checked off the "stopCV ON >0". The results were way better, and something I could live with. It's only thin material that will be an issue anyways.
The machine didn't seem to run any harder than normal.
Dan

« Last Edit: January 30, 2012, 09:22:48 PM by hemi43 »

Offline BR549

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Re: corners getting radiused at higher speed on plasma table
« Reply #32 on: January 30, 2012, 09:37:20 PM »
We must be running different versions(;-) I'll go back to drinking coffe now.

(;-) TP

Offline stirling

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Re: corners getting radiused at higher speed on plasma table
« Reply #33 on: January 31, 2012, 04:51:33 AM »
Took me a while to get my head round your pics at first but then I realized (I think) you've rotated the parts in your pics anti-clockwise by 90 degrees!!! (Your start/end from your code is top-right but in your pics it looks like it's top-left!

The second one I turned the CV distance on and set it to 25 units (whatever a unit is , I dunno).
This is saying it can start rounding when you're within 25 inches (your units) of the corner. Your whole hole is only a couple of inches so your ALLWAYS within 25 inches so this setting is going to have no effect at all. I'd suggest you try a CV distance of 0.25 and work down to 0.125 or so - that sort of range.

The third I slowed it to 238IPM. Still no difference.
Well I wouldn't say NO difference. It's slightly better but I agree still no good. Again your CV distance of 25 inches is going to have no effect. BTW - are your X and Y axis vel and accel the same? The rounding doesn't look symetrical.

The last one I checked off the "stopCV ON >0". The results were way better, and something I could live with. It's only thin material that will be an issue anyways.
The machine didn't seem to run any harder than normal.
Stop CV on > 0 is turning OFF CV - you're effectively cutting Exact Stop. If your happy with this then OK but I'd take this as a clue to trying CV feed starting at say around 50%. Of course if you get down to just a few % your effectively turning OFF CV again.


We must be running different versions(;-) I'll go back to drinking coffe now.
Yeah - but what's in the coffee Tel?  ;D

A vid for our viewing pleasure.
http://www.youtube.com/watch?v=aXEFGmkqvQs&feature=player_embedded
« Last Edit: January 31, 2012, 04:56:12 AM by stirling »

Offline BR549

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Re: corners getting radiused at higher speed on plasma table
« Reply #34 on: January 31, 2012, 11:46:04 AM »
 ;D  >:D  ;)


It's just hot blonde and sweet with a little extra coolant mixed in.    ::)


Even slower with CV bascially off the cut is a bit rough on the corners and seems to be squirly on the staright cuts BUT that might be the pictures.

It looks as thought the cut height may be too high and the arc is not stable. What are the cut paramaters? Material ?pierc ,cut preset voltage,etc

Are you running with the DTHC active ?  It it maintaining voltage?

(;-) TP
« Last Edit: January 31, 2012, 11:51:29 AM by BR549 »
Re: corners getting radiused at higher speed on plasma table
« Reply #35 on: January 31, 2012, 03:39:09 PM »
;D  >:D  ;)


It's just hot blonde and sweet with a little extra coolant mixed in.    ::)


Even slower with CV bascially off the cut is a bit rough on the corners and seems to be squirly on the staright cuts BUT that might be the pictures.

It looks as thought the cut height may be too high and the arc is not stable. What are the cut paramaters? Material ?pierc ,cut preset voltage,etc

Are you running with the DTHC active ?  It it maintaining voltage?

(;-) TP

All the parameters are by the book, except for the speed that I had to slow down. All the pieces I've been cutting are .060 aluminum. The last piece was steel because I had no more scrap aluminum kicking around. :-)

DTHC was turned on, and maintains a steady pre-programmed 117 volts. My pierce height is .15 and cut height is .060.

Maybe the parts above are a bad example, because I'm very happy with the cut quality.

Dan

Offline BR549

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Re: corners getting radiused at higher speed on plasma table
« Reply #36 on: January 31, 2012, 09:42:34 PM »
Pictures are somtimes very hard to go by If you are happy that is ALL that matters.

Keep um Burning, (;-)TP

Offline docltf

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Re: corners getting radiused at higher speed on plasma table
« Reply #37 on: January 31, 2012, 10:49:51 PM »
Hemi

try your start point in the middle of the long X-axis and stay away from the corners.

bill
Re: corners getting radiused at higher speed on plasma table
« Reply #38 on: February 01, 2012, 09:01:52 PM »
rrc1962 - a peace offering  ;D


No biggie.  I'm kind of in the "build the machine to suit the need" camp rather than the "build the machine and then figure out how to make it work" camp.  We pretty much agree.  The best solution is acceleration...which is a bit confusing.  With 960oz/in motors and a 50 pound gantry, his machine should be able to run some very high acceleration numbers.  Up until this post, I hadn't noticed where he posted his accel numbers.
Re: corners getting radiused at higher speed on plasma table
« Reply #39 on: February 01, 2012, 11:42:39 PM »
rrc1962 - a peace offering  ;D


No biggie.  I'm kind of in the "build the machine to suit the need" camp rather than the "build the machine and then figure out how to make it work" camp.  We pretty much agree.  The best solution is acceleration...which is a bit confusing.  With 960oz/in motors and a 50 pound gantry, his machine should be able to run some very high acceleration numbers.  Up until this post, I hadn't noticed where he posted his accel numbers.
My very first post stated that I had increased my acceleration rate to 40.
Dan