Another plasma component...

John, I tried your post thinking it might be better than mine but I could not spot holes so it looks like I have to clean mine up

Also for Phill when he gets to updating the tool table, how can plasmac cut accurate engineering parts if it does not have a kerf width to set the tool offset? I just noticed that. We'll have to think of a way to do that.

I have to say some of my yoyo problems are confined to earlier versions of Plasmac. I've now deleted some obsolete configs....

Here was today's job cutting 1.6mm Aluminium at about 5000 mm/min,

This impressive as it shows the THC coping well with my uneven table as on the dry run, the torch hit the sheet and paused.

Rod

Sorry my post doesn't have drilling support because I don't need it, easy to put back in.

Right now I use my PP to compensate for kerf width as I think most do. You are right on target with suggesting putting kerf width (tool diameter) into the tool table and using G40-G42 to control the part cut side of the cut. Moves Plasmac closer to a generic CNC application.

John

islander261 wrote:

Rod

Sorry my post doesn't have drilling support because I don't need it, easy to put back in.

John

No its alright. I actually tried your post because I was not sure after all my hacking I might have broken the centre punch but fortunately it worked.

I think the bigger concern for engineering work is not having the kerf width to set the tool offset. Hopefully as we deal with the tool changing stuff, we find a way to send this back to the gcode without having to record it in the post.

What are you guys using for cam softwhere?

JTknives wrote:

What are you guys using for cam softwhere?

Sheetcam, very well priced, runs on Windows and Linux. John has posted a plasmac compatible post in the last few days on this thread. I have another post processor for it that needs cleaning up that also includes a drill tool so you can spot holes for subsequent drilling. The free version is enough to get you going, its limited by the number of lines it will output (but enough for a simple part). Its a very powerful tool.

Tommy

Having used Inkscape and Gcodetools in the past I think you have left out quite a few (not too well documented) steps to get from a drawing to Gcode. It gets much harder when you want to cut other than simple shapes. Inkscape and Gcodetools are certainly a workable solution and the price is right if you have the time to fool with them. I still use Inkscape as my main graphic design tool. Nesting and multiple tools can be done but you will need to be an Inkscape and Gcodetools expert to make it work, and I think Tommy is the only person I have heard claim success doing it (please make us a video showing the process with nontrivial parts). When I used it exclusively I would CAM each part separately and then hand build nested Gcode to run. For those conversant in Python the code is right there to make it work the way you want it to. Gcodetools does a much better job of converting the .svg native Bezier curves to linked circular arcs than SheetCam does.

I happen to use SheetCam almost daily. For the price it works pretty good though unfortunately the Windows version is much better at importing .svg files. Not a big deal if you are mostly working with engineering stuff because you can then use .dxf files for input. Some times I will even run it under Windows to import the artwork and save the job file and reopen it later under linux. The real win for me is the easy nesting of parts because I only cut full sheets to avoid having to inventory drops. I am sure I paid for the program the first week I had it in saved time and material. The post processors are written in the Lua scripting language and are quite easy to modify once you play with it a bit. It comes with PPs for many different machines. Most users here do use their own custom PP that suits the features of their machine and workflow.

John

i have been chatting with bobcad about their plasma cam package. thy said thy had a version for home hobbyists. I got all excited and then i find out its on sale for $499 but for home use its 399. kinda blows the budget out of the water compared to the other software out there.

Unless you require some special interoperablity don't go with any high dollar commercial package for plasma. It is simple 2D that can be done with open source or low cost tools. The more capable the tools the longer the learning curve to get proficient. You already have asked someone for a drawing in a .dwg format which tells me you already have 2D CAD. From one of those CAD programs you can export to Inkscape (free) or SheetCam (about $170) and do your CAM. This is really the simplest CAM there is to do. Actually my guess is that knife blanks are so simple that you can hand code them from drawing dimensions pretty easily. When you get into full sheet nesting of parts that aren't just simple closed shapes is when hand work gets tough. Because you are just starting out on a budget and I suspect not going to be cutting full sheets right away I strongly suggest finding the beginning HAAS training books on line and going through them working the examples. In the mean time install Inkscape with Gcodetools (I think it is part of the default distro now) and practice with simple closed shapes.

John