I have my first batches of bits from McMaster-Carr and I'm keen to fire up the laser cutter, but I don't have anything that can read the .DXF format. Are other formats likely to be made available soon, or should I start hunting for a solution to my DXF problem? Many thanks for advice.
Hi Rob, I've downloaded Rhinoceros trail version, gives you something like 25 saves, etc. We have a full spectrum 40W 20x12 hobby laser. The rhinoceros uses the print driver of the spectrum laser to export the modified cut windows to the .xps that the crappy RetinaEngrave software that comes with the laser can use to do the vector cuts. However CorelDraw or DraftSight apparently work better. I've never used DraftSight but it's been recommended. You can export to different formats from either of these. Rhinoceros allows this as well but you are limited to the number of times unless you purchase the suite. Not sure about Sketchup, but that is a good free CAD program that may be able to handle the laser drivers and export different formats, possibly without the drivers.
Long story short, use one of these to convert the .dxf to .xps or whatever your laser software will accept. It took awhile for me to get it straight, and I still have problems with it.
That's a very relevant suggestion, as I'll be using the same model cutter to cut the acrylic parts. I presumed I would to use another cutter for the polypropylene sheet as it's 24x24, unless you have a clever suggestion on that.
I saw that on another thread you posted that this conversion introduced some measurement problems. I'd be interested to hear more about that so that I might learn from your experience.
Also, I have been struggling to figure out which parts from the master layout file are meant to be cut out from which sheets of material. The BOM includes a sheet of 1/8" clear acrylic, 1/8" white acrylic, 1/4" clear acrylic and 1/8" white polypropylene. I thought it would be easy enough to work out by looking at the 2.4 layouts, which are clearly marked for each sheet, but I'm finding it more confusing than I expected. It sounds like you made a cut already -- what sheets did you use for what parts?
OK, I worked out the materials puzzle -- part of what was confusing me is that I picked up the wrong size piece of clear acrylic. But now I'm wondering: given that you are using the same 20x12 laser I plan to use, how did you go about cutting your parts, given that most of the sheets are greater than 20x12? I am thinking that I can do at least most of it in pieces, but I wonder if you've come up with a good solution or have some lessons learned given that you're further along in the process than I am.
Hi Rob, sorry for the late reply, holiday and all that. Yes, the acrylic section was confusing to me as well, however, the files gave me enough info such that I figured out the parts for each type of sheet. As for cutting, I looked closely at openrov supplied files and noted the measurements in Rhinoceros. I used the print function in Rhinoceros to print to an .xps using the full spectrum laser printer driver and scaled to fit, or in some cases modified the scale, such that when I opened the xps in RetingaEngrave, the scale from the original file matched the scale shown in RetinaEngrave. It is tedious, and I screwed up the second cut job so I have to re-cut the components in the coming week. Using Rhinoceros, I deleted the parts that would no fit in the 20x12 by hand and saved the new layout. I did this 3 times, each time had a scale problem. I managed to get it for the first half the other week, and now have to fiddle with the second half again. A colleague of mine has successfully worked through this and I am asking him to give me a review of his approach. I'll be sure to post it as soon as I can.
Rob, here is information from a friend of mine you used a trail version of CorelDraw x6.
"I also had trouble with getting the size correct when using Rhino3D or DraftSight, could never figure out why (I know the other guy who used the printer had no problems with DraftSight, but don’t know how he set it up). I ended up using a demo of Corel Draw X6 which seems to work without problem. It is fairly easy to just turn on/off the layers you want to show/edit and which ones to print (Tools menu -> Object Manager). Set the size of your design area by clicking on the design area and typing in the dimensions on the top left side just under the menu bar.
Tonight I spent some time at my local neighborhood hackerspace (HacDC) cutting parts. Using DraftSight and the Full Spectrum LLC print driver, I got the e-chassis cut to what seems to be the correct size. The problem is that the circles came out as polygons:
...so back to the drawing board with me.
I am not entirely sure how I got the results above, but I was able to replicate the problem. As Jim noted, in order to fit the parts in the smaller work area of the Full Spectrum laser, you have to delete parts of the DXF file and "print" the remainder to the Full Spectrum driver. I found that when I deleted paths and then "undid" the delete (for example, when I deleted too much), the curved paths became polygons. Working from a file with no undos, I was able to cut a set of parts that appear to be the correct size and shape.
I saved the RetinaEngrave files I used with the intention of sharing them, but I discovered that some of the paths on the saved files are a little wonky. Some polygons are lost. So I am hesitant to put them out there for fear someone will inadvertently use them to print out incomplete sets of parts. But if for some reason you think the files will be helpful to you, please let me know.
On the plus side, I cut the shell path onto a piece of cardboard as a test, and to my surprise the Full Spectrum was just barely able to fit the whole thing. I will have to cut my sheet of poly to a size I can physically fit into the laser cutter, but I am pleased that I won't have to find a bigger cutter to use to cut the shell.
Rob, how have you faired with the laser cut frame? I have, as I believe, the properly scaled refit pieces for a 12x20 laser bed if you need them.
Thanks very much, but it looks like the pieces I cut are working out fine. Of course, it might be nice to post them somewhere for anyone having the same hill to climb.
Draftsight is free and I use it to export DWG/DXF drawings to vectorbased PDF files. I use FlexiSign as my primary program for cutting and have no problems with importing said PDF's... ;-)
I know this is a year old, but I wanted to provide some information I’ve discovered to help others in this position. DraftSight gets lazy (my term) when you’re moving and scaling and whatnot. It starts simplifying shapes so it can draw the display faster.
There are two commands I learned which seemed to correct this in DraftSight and in turn, inkscape when I exported the SVGs:
typing REGEN into the command console will force DraftSight (and I gather, other CAD programs) to regenerate the commands.
I’m taking my files in this Monday evening to cut - hopefully the size is right.