I’m doing some fine detail work (topographical maps) and there are places that have some residual fuzziness or places that need sanding. I’m wondering how I can address this.
I will say up front that I probably need to readjust my Shapeoko 3, tension on the belts is good but the tension on the rails could probably be tighter. I don’t think that’s the whole issue though because some things I do come out perfectly.
I’m using ArtCAM for this round of things. I’ve attached some photos of a grand canyon project I’ve been working on, pictures are of two versions. You’ll see in some of the cavities there are stray bits of attached chips and/or sawdust. Tiny curls mostly.
I’ve been playing around with different finishing strategies but I’m not consistently getting what I’m looking for. I’ve played around with raster finishes, x/y raster, radius cuts, the direction of cuts, direction of cuts as the relate to the grain of my stock. There’s something I’m missing. (And I’m fully open to the idea that my cutting speeds or some other basic thing is wrong with my jobs.)
Here are some pics. I can post any other info you’d like, just let me know what you need to help me isolate this.
Make a final finishing pass w/ a razor sharp HSS (high speed steel) endmill – if need be after spraying the piece w/ lacquer.
Non-optimal geometry will create results similar to a dull bit, e.g., fuzzy cuts in softer species of wood. Making a final finishing pass may help (w/ a HSS bit if possible), another alternative is to spray a clear finish on the wood, allow it to dry and then re-run the finishing pass (the sprayed finish will soak into the wood and harden it).
Non optimal geometry is a function of material remaining and path direction and endmill cutting — one can address it to some degree by getting conventional / climb milling setting right, and using an endmill suited to the material in question. For wood, a different piece may cut better as well, or if the piece allows, try a different grain orientation.
This though, is the difference between carving by hand, and using a machine.
I’ve always been surprised that there isn’t a physics-based simulation which analyzes machine path and remaining stock and optimizes machine path and speed appropriately — arguably CAM should do that, but AFAICT, only really expensive software does.
Another option would be to just clean up the areas in question w/ a sharp chisel or gouge.
Wood cutting: I recommend that you (anyone) use router bits when ever possible. Carbide end mills are never as sharp. Trust me. Try it, you’ll love them.
strong textPS they leave a nice clean burr free edge.
Can you tell me what type of wood bits you are using? I’ve been ordering from carbide and amazon, all end mills and ball nose bits. I have regular router bits in my shop, but am having trouble finding software that would allow me to enter the tool profiles (if they vary from those basic profile types).
