I am starting to believe that a fixed gantry design best suits my needs. Although I may need to raise and lower and lock the entire cross bar on my gantry I only need two inches of "Y" and "Z" travel and I could reduce vertical travel to less than an inch if I needed to. My "X" axis should have ten to twelve inches of precision travel and I also need about thirty inches of jog capabilities. Combine that with needing a rotary axis and I am looking at five controls or I think perhaps the better option for precision, four axis including the rotary and hand jogging and locking down the table using a DRO for the long movement.
I was sitting here thinking this morning, always dangerous I know, but why wouldn't a large cam and follower arrangement work for the two axis with only a few inches of travel? It seems like a simple offset circle in the six to twelve inch range could offer great deal of precision and of course fancier profiles could be cut if the first generation machine proved functional.
Thinking a router with ceramic bearings for the spindle but a special spindle may be required. Have a possible idea there too but I'll discuss that sometime in another thread.
This machine would be used for cutting the male and female parts of inlays. The female part would normally be wood but if accuracy is great enough then at times both male and female components may be made of hard and brittle materials.
Am I heading in a reasonable direction or am I trying to reinvent the wheel with the cams? I have a hand turning tool that uses the cam principle and a fixed cutter to make cuts that stretch creditability. The markings are roughly an eighth inch apart and are calibrated in ten-thousandths of an inch. It is easy to split the markings and make repeatable cuts that can't be measured with a ten-thousandths mike. Only the fit assured me that they were consistent. Of course it did take me twelve hours to make 28 tiny pieces.LOL Seems like the cams would allow super accurate positioning of the spindle and then my limiting factor would be spindle runout.
Hu  |