As Greolt has indicated - the usual route would be to use an outside offset cut for SheetCAM.
I've cut some of the dino dxf files on this thread using SheetCAM, but a few have a single line for the slot on the pieces. I've had mixed results with these, as some contain very tiny loops of lines, and SheetCAM isn't too happy with them.
In general, using outside offset is the best bet, but it's always worth checking the gcode output with something like CNCSimulator, or just getting your machine to cut a couple of pieces as a test.
You can of course fix minor issues with a free CAD package like ProgeCAD, but it is time consuming.
Lets say you use a 6mm bit and the material is 10mm thick, then cutting along, or even to the outside of the line, means the slot is still too thin for the pieces to slot together.
This is why I originally said that the first method is to use the same sized tool as the thickness of the material.
If you changed the drawing, as I suggested in the second method, this means you can use any sized tool on any sized material, so long as the tool was thinner than the material. You then use the cut outside the line option.
I Hope the drawing explains this.
Qualify: I would only use the edit option if you knew you wanted to make a few of the same design, and you wanted to use a smaller tool to reduce cutting and mess and strain on the machine.
A smaller tool is better for cutting than a bigger tool.
Here are a t rex and a spider in DXF format, hope this helps.I think the t rex was made for 2mm material so just scale it up until the slots suit your required material, the spider is made for 1/8" material.
Edmond
I have cut the spider and am having a "brain fart" on trying to get it together. The legs are easy, but the rest looks like it might need some modification.
I have not yet had a chance to cut the spider I posted, I found it on some German website.The rib pieces go into the slots along the curved section, there should be 9 ribs and 9 slots.I will post the file again but will number the parts as soon as I have cut it.My machine has being down for a while but should be able to cut it at work on our laser cutter.
Thanks for the reply ... I got most of it together. My biggest problem was that several of my slots were too short. I still have no idea where 2 identical pieces; that have no slot; fit into the spider.
I guess a picture would be helpful ... I will try to post one tonight.
The spider looks awesome, didn't realise it was that big.I had a good look at the file in my CAM program and also saw some of the slots are way too short for the pieces to fit snugly into.I will lengthen the slots as well as number the parts to make assembly much easier.Im also puzzled about the 2 pieces that have no slots.I plan on cutting the spider the weekend if my collet 3mm - 1/4" collet adapter arrives.
The spider looks awesome, didn't realise it was that big.I had a good look at the file in my CAM program and also saw some of the slots are way too short for the pieces to fit snugly into.I will lengthen the slots as well as number the parts to make assembly much easier.Im also puzzled about the 2 pieces that have no slots.I plan on cutting the spider the weekend if my collet 3mm - 1/4" collet adapter arrives.
I used AutoCAD to scale the drawing for ~1/4" slots. I had to move pieces around alot to make it fit into my 15" x 30" work area. After I connected the legs together, I noticed that it was going to be very large. I really should 1/3 to 1/2 scale it again.