Building another Manual carving machine

[Paul Waddle]

I would like some inputs on making a new carving machine. Would you chose the Gemini design,the North star type, or? Ballbushings for the cross left and right movement, and wheels for the length ? This could also be the up and down,or would a separate up and down plate be a desired ? I am thinking four wheels instead of airplane cable and two wheels-good idea or? If Gemini type is preferred,wouldn't a joint on the end of the arms be better so the stylus and router could be tilted and made perpendicular to any height of work?? Would some type of quadrant angle plate be better or a separate cross member be attached to the arms(this could be rotated) ? Thks pw

[Art kraft]

Paul I was thinking of building one myself. There is a nylon bearing on the market that is great for the wood dust that is typical in this application. Better than ball and can literally run in dirt and less expensive (Pacific Bearing). I would use linear bearing on all axis, use air cylinders for counter balance. With back plate on linear rail router is always perpendicular to x axis. It would also be easy to convert to CNC in the future if desired.

[Paul Waddle]

Thanks Art for your response. Yep it would be better to use ballbushings on all axii, but for cost ,it looks I like I would choose the Gemini wheels for the back and forth(x aixis?). Its the gantry or the moving member that I want to also move at right angles with ball bushings that I really can't decide on a suitable frame work. If you are interested in looking at patents,see the Koenig 03,739,824,its more like you suggest. There is another method that gives the straight up and down movement,the Allen 'bell crank' pat 04,227,557. www.riflebuilders.com uses a variation of this concept wthout bell cranks,just straight parallel joints. Yep, I know if future use may be adding ball screw and steppers,your idea would be best. I still have this buring question: can the Gemini arms be made with a joint so that cutter may be tilted to always be perependicular to surface of work? pw