When I mentioned a few months ago that I intended to use carbon fiber to make my gantry, there were a number of people who ask me to provide details of the design and methodology. I am going to use this thread to start sharing info on my progress now that I am little closer to a working prototype.

This is where I am up to so far with the design and build:



https://s5.postimg.org/a2fugmklj/IMG_3820.jpg




The side supports are carbon fiber rectangle tubes at 2" x 6" x 12". The wall thickness is approx 1/2". There is an addition 1/8" steel plate sandwiched between layers of cf on the inside walls to hold screw threads for easy mounting. The void is filled with 1/4" chopped carbon fiber wetted out with resin and high density urethane foam (for "harmonics").

The main gantry beam is only the front half so far. The part you can see is the face plate which will hold the rails. It's approx 3/4" thick of pure carbon fiber plus an additional 1/8" of thickness from two steel plates sandwiched between layers of cf (to hold screw threads for the rails). When finished, the gantry beam will probably end up around 3x thicker as the rear half has sections of 1" cf tubes embedded at 90 degrees to the rails.

The gantry face is molded against optically flat mirrors to achieve a perfect mounting surface for the rails.

Both the gantry beam and the risers use a mix of woven twill weave carbon fiber, non-woven random matrix fabric, tri-axial fabric and chopped 1/4" 12k strands. The directions of the lay up is designed to put all the strength and stiffness where all of the force will come from when in use. Aside from the front two layers of cf, the rest is wetted out with carbon nanotube resin which increases stiffness by an additional 30%. These components are stronger and stiffer than steel, aluminum or titanium etc.

So far, I had only planned to make the gantry, table and electronics enclosure out of carbon fiber but I might change this soon. I'm feeling a little outdone after seeing an excellent all carbon fiber CNC mill made by a CZ based company. The rest of my frame components are currently all steel and aluminum. I figured that a heavy base frame would be an advantage but as I'm learning... you can always add more weight if needed....

Anyway... I'll update this thread when I have more progress to report. If anyone has questions or suggestions then feel free. I'll post more info on how the parts are actually made soon.