center pierce holes help?

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jordf

center pierce holes help?

Post by jordf »

I would like to make some different parts and just use my plasma to center punch the holes for me so I can drill them out to the correct size..

I use Hycad for my CAD drawings and it as a feature to put a point in (or a dot),, but when i load it into sheet cam, it doesnt come up... In order to make this happen i have to draw a tiny hole.. like. .20 or so and then the plasma will cut that....problem with that is my machine doesnt cut small holes very round and when I drill them after, its sometimes off center,,,

any help would be great thank you
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Les Newell
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Post by Les Newell »

Draw the holes as circles but put them on a different layer to the outline. This stops SheetCam from trying to cut the holes. You can now use a drilling operation in SheetCam to select these holes and mark the centres. In the drilling operation you have options for min hole size and max hole size. Circles between these two sizes will be marked.

If drilling appears to work in simulation but doesn't in your final code your post may need to be modified. I can explain how to do this if you need it.
mlebrecht
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Re: center pierce holes help?

Post by mlebrecht »

Hi, we have been trying for a week or so to get this center punch to work. We have tried a few different ways and the machine goes over to the hole, but will not drop down and strike off. It just moves on to operation 2. What are the code modifications you are talking about?
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Les Newell
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Re: center pierce holes help?

Post by Les Newell »

What post processor are you using?
mlebrecht
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Re: center pierce holes help?

Post by mlebrecht »

We are using Qcad to make the drawing, Sheetcam to process and CandCNC to cut. We have tried a drill operation with a rotary tool as the manual shows for CandCNC as well as a drill operation with a plasma tool. Both give the same results. Shows the hole in the the drawing window but does not show z codes in the cammand list.
mlebrecht
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Re: center pierce holes help?

Post by mlebrecht »

CandCNC
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Les Newell
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Re: center pierce holes help?

Post by Les Newell »

This sounds like a post processor issue. Do you have the most recent CandCNC post?
mlebrecht
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Re: center pierce holes help?

Post by mlebrecht »

I would assume so. The machine is only a couple months old now. How do i see what ours is?
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Les Newell
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Re: center pierce holes help?

Post by Les Newell »

Go to OPtions->machine->post processor. CandCNC usually add a version number to the name of the post. I'm afraid you will have to contact them to see if it is the most recent.
regpye
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Location: South Australia

Re: center pierce holes help?

Post by regpye »

I am having the same problem.
Can draw the circle and get it all to work in sheetcam, but when actually doing the cutting, the punch operation is bypassed.
I am using UGCS to send the gcode, drawing are made in Corel Draw 12, the machine is running GRBL 1.1h and the post processor is a modified version of GRBL plasma.

GRBL plasma post processor

Generic plasma post for machines with or without THC

Modal G-codes and coordinates
No comments
M04/M05 turn the torch on/off
Incremental IJ
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Les Newell
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Re: center pierce holes help?

Post by Les Newell »

Take a look at your post and see if it has this code:

Code: Select all

function OnDrill()
   OnRapid()
   OnPenDown()
   endZ = drillZ
   OnMove()
   OnPenUp()
   endZ = safeZ
   OnRapid()
end
If it doesn't that is probbly the problem. If it does post a job file here (File->save job) with everything set up ready to cut.
WyoGreen
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Re: center pierce holes help?

Post by WyoGreen »

I just did this a few weeks ago on my CandCNC (CommandCNC) system, so I know it works. I did it with the CandCNC rev27 post. I use a HT45 Plasma cutter and turned down the amperage to 30 amps to mark the holes, then back to 45 amps to cut the part out. I put a pause in the job to turn the amps back up (don't know if that was really necessary, but I did it anyway.) I took a couple of screenshots to show my settings. Hope this helps some.

Steve
SC2.png
SC2.png (57.51 KiB) Viewed 3068 times
SC1.png
SC1.png (127.51 KiB) Viewed 3068 times
regpye
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Location: South Australia

Re: center pierce holes help?

Post by regpye »

Les Newell wrote: Tue Mar 24, 2020 11:58 am Take a look at your post and see if it has this code:

Code: Select all

function OnDrill()
   OnRapid()
   OnPenDown()
   endZ = drillZ
   OnMove()
   OnPenUp()
   endZ = safeZ
   OnRapid()
end
If it doesn't that is probbly the problem. If it does post a job file here (File->save job) with everything set up ready to cut.
Yes I have that coding in the PP.
I have the original job file that I used (attached) and also have the DXF
centre punch test.job
(6.26 KiB) Downloaded 83 times
centre punch test.job
(6.26 KiB) Downloaded 83 times
Attachments
centre punch tool.jpg
centre punch tool.jpg (64.9 KiB) Viewed 3061 times
centre punch test.job.jpg
centre punch test.job.jpg (24.59 KiB) Viewed 3061 times
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Les Newell
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Re: center pierce holes help?

Post by Les Newell »

I can't see anything wrong with the job file. The center drilling looks correct. Could you let me have a copy of your post processor.
regpye
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Joined: Sat Nov 09, 2019 1:12 am
Location: South Australia

Re: center pierce holes help?

Post by regpye »

Les Newell wrote: Thu Mar 26, 2020 4:52 pm I can't see anything wrong with the job file. The center drilling looks correct. Could you let me have a copy of your post processor.
firstPierceTime = 0 --this is an extra delay added to the first pierce as needed by some machines




function OnAbout(event)
ctrl = event:GetTextCtrl()
ctrl:AppendText("GRBL plasma post processor\n")
ctrl:AppendText("\n")
ctrl:AppendText("Generic plasma post for machines with or without THC\n")
ctrl:AppendText("\n")
ctrl:AppendText("Modal G-codes and coordinates\n")
ctrl:AppendText("No comments\n")
ctrl:AppendText("M04/M05 turn the torch on/off\n")
ctrl:AppendText("Incremental IJ\n")
end




function OnInit()

post.SetCommentChars ("()", "[]") --make sure ( and ) characters do not appear in system text
if(scale == metric) then
post.Text (" G21\n") --metric mode
else
post.Text (" G20\n") --inch mode
end
bigArcs = 1 --stitch arc segments together
minArcSize = 0.05 --arcs smaller than this are converted to moves
firstPierce = firstPierceTime
end

function OnFinish()
post.Text (" M05 M9 M30\n")
end

function OnRapid()
post.ModalText (" G00")
post.ModalNumber (" X", endX * scale, "0.0000")
post.ModalNumber (" Y", endY * scale, "0.0000")
post.ModalNumber (" Z", endZ * scale, "0.0000")
post.Eol()
end

function OnMove()
post.ModalText (" G01")
post.ModalNumber (" X", endX * scale, "0.0000")
post.ModalNumber (" Y", endY * scale, "0.0000")
post.ModalNumber (" Z", endZ * scale, "0.0000")
post.ModalNumber (" F", feedRate * scale, "0.0###")
post.Eol()
end

function OnArc()
if(arcAngle <0) then
post.ModalText (" G03")
else
post.ModalText (" G02")
end
post.NonModalNumber (" X", endX * scale, "0.0000")
post.NonModalNumber (" Y", endY * scale, "0.0000")
post.ModalNumber (" Z", endZ * scale, "0.0000")
post.Text (" I")
post.Number ((arcCentreX - currentX) * scale, "0.0000")
post.Text (" J")
post.Number ((arcCentreY - currentY) * scale, "0.0000")
post.ModalNumber (" F", feedRate * scale, "0.0###")
post.Eol()
end


function OnPenDown()
if (preheat > 0.001) then
post.ModalText (" G00")
post.ModalNumber (" Z", cutHeight * scale, "0.0000")
post.Text ("\n G04 P")
post.Number (preheat,"0.###")
post.Eol()
end
post.ModalText (" G00")
post.ModalNumber (" Z", pierceHeight * scale, "0.0000")
post.Text ("\n M04 M8\n")
if (pierceDelay + firstPierce > 0.001) then
post.Text (" G04 P")
post.Number (pierceDelay + firstPierce,"0.###")
firstPierce = 0
post.Eol()
end
end


function OnPenUp()
post.Text (" M05 M9\n")
if (endDelay > 0) then
post.Text (" G04 P")
post.Number (endDelay,"0.###")
post.Eol()
end
end


function OnDrill()
OnRapid()
OnPenDown()
endZ = drillZ
OnMove()
OnPenUp()
endZ = safeZ
OnRapid()
end
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