I have been using Baltic Birch plywood from Woodcraft for model cars but I get rough cuts and broken layers (?). I use good router bits from Tools Today store. Thin plywood may lift up during the cutting. Is using other materials like plastic be better than plywood?
What thickness of plywood are you using @jeffmorris? (to give me an idea of the scale you are working to). I use 3mm and 6mm mdf for making model buildings to 4mm/foot scale, but upcutter end mills and router cutters leave a rough top edge with occasional chipping. I also use 1 & 1.5mm polystyrene but have to use the lowest speed and fastest feed to avoid melting. Alex. Also I use masking tape/superglue sandwich to hold down thin materials.
I use straight flute bits for woods and get nice clean cuts with no tear outs. I like this Freud one, https://www.amazon.com/Freud-Double...+bit&qid=1568835197&sprefix=freud+1/4+&sr=8-4 but it is slightly smaller than 1/4 inch so that needs to be factored into your CAM program. I personally measure every cutter I own with a caliper to ensure accurate cuts.
I usually use 3mm and 6mm plywood to make model cars. I know that there are different kinds of plastic but I don't know which kind of plastic can be cut on a CNC router without any problems. The plastic sheets should be able to be glued or cemented together. I cut ABS sheets using special router bits and I can cement the parts together but I don't like the smell of plastic cement.
Acetone welds ABS, but it also has an odor. So, probably not much help there other than cost effectiveness and your body naturally produces enzymes to help eliminate it from your body. I cut ABS on my CNC often. It is to bad gluing HDPE is next to impossible because it cuts like butter. If someone knows a way, other than plastic welding, please let me know.
You can glue HDPE with CA glue if you flame treat the surface first. Wave a blowtorch flame over the surface, just fast enough to not melt it, with the flame touching the surface. This does some things to the surface properties and lets you glue it, also how they screen-print on HDPE. This is how we make airplanes out of coroplast (SPADs) which is also PE On the wood cutting topic, i just picked up some 1.2mm down-cut spur bits for cheap (on ebay), have not tried them yet, for cutting thin balsa and ply without 100% work hold-down. Will try this weekend and report. Cheers Gary
I think that the kind of router bits affects how plywood is cut. For thin plywood, a video suggested a straight bit instead of spiral bit.
I use a straight for all wood no matter the thickness. I like the finish better due to no tear-out. As for expanded pvc, that should be easy to glue because lots of cements are available for it. I have never tried milling it, though.
