still seeking RL01/02 unit select plug

On Tue, Mar 20, 2012 at 4:58 PM, Dave McGuire <mcguire at neurotica.com> wrote: I was looking at the shape and especially the tines... I think it would be a great thing to make with a 3D printer, but long, thin parts tend to be fragile, especially when "drawn" on a fused filament deposition printer "against the grain". Liquid polymer and sintered powder objects don't have as much of a dimensional strength/weakness issue, but a tower made of stacked slices of 0.5mm-wide filament isn't particularly strong. For the application of an RL/RK unit select plug, once the plug is in place, it's supported and isn't likely to see much lateral stress on the thin bits, but handling and insertion could damage the plug. One thought I had was a generic plug with slots that would admit long, thin select cams that are printed flat then glued into place (neutral-color ABS would great for this, for the translucent milky color and the fact that acetone welds ABS well). So you'd print generic bodies, face down (orientation also matters with inexpensive FDM printers with no support material), then print two "legs" per plug, also flat to the bed. You would then select the legs based on what the unit number is desired. Slide/place the legs in slots in the body and a swipe of acetone later, it's a finished device. The heated bed on most printers would give the face of the plug a smooth appearance that would require little finishing, just a digit sticker or a moment with a Sharpie. You might have to remove the flash around the rim of the body that happens when the bottom layer spreads on the heated bed, but that's a few seconds with a file or knife. ABS welding rod is $15/lb. Plugs are so small and light that the amount of plastic is trivial. Liquid monomer resin for stereo lithography is not as cheap - $600-$800/gallon, so even small parts can be expensive. Fill a graduated cylinder with water and measure the displacement of one plug to estimate the resin cost there - probably on the order of $0.25-$1.00 - easy to get samples from a friendly source, but if you wanted dozens, somebody is likely to want the resin paid for. -ethan