A couple of SheetCam Questions

[vacextar]

I know there is a dedicated SheetCam forum here, but it doesn't seem to get much traffic, and since this is plasma-related, I'm guessing many of you are already familiar....

Anyway, I'm brand new to all of this stuff, and actually just got SheetCam loaded a couple days ago and have been messing with it for a few hours here and there. My questions so far:

1. If I have a square inside corner drawn, and I need the material removed from that corner on the actual part, is there a way to do this? I've done some messing around and looking at the various settings, but can't seem to find anything that will allow me to "push" the plasma cut-path into that corner to clear out the material. Yes, I know I can't cut square corners with plasma, but in order to fit a square plastic bezel into a square I've cut out of the sheet with plasma, I'm thinking there has to be a setting somewhere to allow me to push the plasma path farther into the corner.

2. I've got some areas of my drawing where I've got a .045" wide slot cut out, but since the plasma kerf is listed as wider than that, it just skips the plasma cut path over that area. Is there any way to force it to cut there even though I know that area will end up at larger than .045"? Most of the drawings I'm trying to cut with plasma I was formerly having farmed out to laser or water-jet. I don't really want to spend day re-drawing dozens of drawings just to open these slots up .010" when they are not that critical if they are plasma-kerf width.

[BBchevy396_]

Lets see if I can help.......
#1: No, you will not be able to cut a sharp inside corner. There will always be a radius due to the round nature of the plasma stream. Example... Can you drill a square hole with a round drill bit?
You may be able to cut a relief into that corner by putting a small diameter circle overlapping the corner.

2: I ran into the same issue on a couple projects. I essentially "tricked" sheetcam by entering the kerf width smaller that it really is.
Otherwise, dont draw it as a slot, draw it as a line. Move the lines to another layer and cut them with no offset.

[vacextar]

Thanks BB....Yes on #1, I do realize that I can't make a sharp inside corner with plasma, but I guess I was assuming that there would be a setting somewhere in there that would allow me to push the cut path into the corner far enough that the program would know that all of the material had been removed from the corner....even though it would obviously leave a "bulge" in each corner where the radius of the kerf goes past the sides of the square. So I will have to change my drawing to do this.....right?

# 2........so, for an example, let's say I want to cut out a square opening in a part, and off of one of the corners, I want a slot cut at a 45 degree angle, 1" long.....and whatever my kerf width is wide. When I do my dxf drawing, I just need to draw a single line diagonally out from that corner 1"?.....and do I move them to another layer in sheetcam or on the original dxf before I import it into sheetcam?......wow, I've got some learning to do.....

Thanks for your help!!

[BBchevy396_]

1: I was thinking about this corner thing. I often use the corner loop setting for outside offset, but have no idea what it would do on an inside, or even if it's possible. Essentialy, thats what you are wanting to do.
Edit: After trying it, evidently, the corner loop setting is disabled on inside offsets. It makes sense that it is.

2: I tried it a few ways. First, by moving the diagonal line to a layer in sheetcam, and second, leaving the square and line on the same layer. It worked fine both ways. Just dont check the "offset open paths" in the operation window.

Either way, S.C. wouldn't put a lead-in on the diagonal line, so to avoid a pierce crater in the corner, you may want to add one in your drawing by extending the line into the interior of the square.

Keep in mind, I'm as new to this as you, so........ LOL
Perhaps a veteran will chime in and set us both straight.



Load these dxf's into sheetcam and see if the operation results in what you want.

[vacextar]

Thanks again BB. Yes, I was also hoping that the corner-loop option would do the trick.

I am very happy to see that it will allow me to just draw a single line and will automatically slit the material along that line. It will completely change the way I think about drawing my parts from here on out.

*******************
Edit....after thinking about this, will that slit in the corner mess up the DTHC or plasma when it goes back to cut that corner out and hits that slit?





Sent from my DROID PRO using Tapatalk

[BBchevy396_]

Probably for a split second, but the tip saver ought to catch it. That's it's intended function.

[matttargett4]

Hi,

I was reading the thread with interest and really only came up witht he answers already mentioned, i also have a sheetcam problem that i cant figure out so i figured i might hi jack the htread and ask it anyway!

With my old setup the way the drawing appeared in the sheetcam window was the way that the machine would move to cut it, ie when you specify the part in the material bottom left it was int he bottom left on the table, my new machine work with the scrren at the other end so everything is backwards and it makes it a swine to get the offset correct before zeroing my position on the plate, is there a way i can change this around??

Thanks and sorry for stealing your thread!

[millman52]

I predominately use oxy fuel which doesn't round out corners as bad as plasma.

Unfortunately you are in the learning curve of making parts like you want them as opposed to the reality of what actually happens. It may take you a while but you will learn to incorperate lots of what you want to achieve in your initial CAD drawing.

You may be able to "fix" some parts with the loop feature, but you will probably get more accurate results by drawing the looped corners in CAD.