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poor cut quality

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Jaybe2
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poor cut quality

Postby Jaybe2 » Sun Dec 25, 2016 9:04 pm

I'm not sure if the problem is in the software or the hardware on my table. the problem is the movement of the gantry is very hitchy it will stop for a split second right in the middle of a cut. I'm using shop data systems and mach 3 software the table is a northern plasma 4 x 8 table with a hypertherm 105. Table is brand new just a couple of weeks old but I cant contact them till Tuesday when they are back from Christmas. so I thought I would throw it out here, I'm trying to get a pic of the cut but having trouble with my email. any help would be great thanks.

radicalrescue
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Re: poor cut quality

Postby radicalrescue » Mon Dec 26, 2016 7:58 pm

check ur file an make sure it does,t have two layers,,an or the lines are joined ..might try a different file or post ur file so some one can check it

motoguy
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Re: poor cut quality

Postby motoguy » Mon Dec 26, 2016 11:33 pm

May want to check Mach settings, and make sure it's set to CV mode, and not Exact Stop. Also, may want to see if there are a bunch of nodes in the drawing file, and/or see if the nodes correspond to the areas where the machine is "hiccuping".
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Jaybe2
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Re: poor cut quality

Postby Jaybe2 » Tue Dec 27, 2016 3:40 pm

I don't think it is the file because it will do it with any file that has an arc or turn in it. it will not do it on straight lines. Northern plasma is working on it now to try and fix the problem. I will let you know what they find.

Jaybe2
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Re: poor cut quality

Postby Jaybe2 » Tue Dec 27, 2016 5:03 pm

I am very new to this so I apologize if I ask dumb questions. But how do you check a file for layers, I did check the lines and they are all connected. also what is CV mode

mike 1948
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Re: poor cut quality

Postby mike 1948 » Wed Dec 28, 2016 1:42 pm

CV= Constant Velocity. This is set inside the Mach3 settings. Turn on CV but leave the other settings for CV off.
Make sure all your vectors are joined with no gaps between nodes.

Mike

Jaybe2
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Re: poor cut quality

Postby Jaybe2 » Thu Dec 29, 2016 7:24 pm

Northern Plasma is coming to replace the smooth stepper board ( that is what they called it ) tomorrow. Hopefully that will fix it.

Jaybe2
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Re: poor cut quality

Postby Jaybe2 » Fri Dec 30, 2016 7:42 pm

board Not the problem!!! After they left I turned the CV mode on and it cut very nice fast smooth and almost 0 dross, however it will not cut a corner everything is turned into a radius. also the cut in and cut out do not overlap and it leaves a tab. This is what I have come up with, If I draw a part say a circle it is basically 4 arcs all connected but it will stop and start at the end of every arc likewise if I draw line and put an arc and then another line it will stop at end of the line and at the end of the arc. If I put it in CV mode the problem goes away but if I draw a rectangle in this mode it will cut an oval hole instead. The software that came with the table is from shop data systems I had them log on today and make sure their program is connecting all the line and they said they are and that the problem is in Mach 3. Any thoughts?

Jaybe2
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Re: poor cut quality

Postby Jaybe2 » Sat Dec 31, 2016 1:19 pm

Any chance someone could take a snap shop of there mach3 general config. screen so I can see if all my settings are correct?

tcaudle
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Re: poor cut quality

Postby tcaudle » Sat Dec 31, 2016 6:18 pm

MACH CV lets the machine "fudge" the toolpath to get as high a Constant Velocity as it can. So you get rounded corners. The first thing is that you need to get as much ACCELERATION on the motor tuning as it can take. The faster you cut the more acceleration you need. Of course its limited by the amount or FORCE (linear force from torque) and the MASS (weight/32) it has to move. The closer you can get to 35 ips/sec accel numbers the better you corners will be. Not all machines can do that. One famous vendor (left unnamed with initials BT ) has a stunning top acceleration of 4. (10 on their "new" twin motor design). Your table vendor should be able to give you the optimum tuning your table will produce.

Jaybe2
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Re: poor cut quality

Postby Jaybe2 » Tue Jan 03, 2017 2:35 pm

Ok this is what they did,turned on CV and the set it to shut off In corners greater than 45 deg. I'm just wondering are they just fudging it or is this the correct solution.


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