Push Block Addon, Floating Heel Pins Assist

7/18/2025: (It worked but not as well as I wanted. I reworked it to make it better. It has three pins now versus two. The pins are now flattened on one side and is to be printed on the side to give the layer lines better strength. I added a hone piece to push in the holes to push down printing imperfections. Print all small parts on a raft and sand pins and hone on flat side to remove raft marks. The holes are 3 degrees tilted toward the end of the board. That helps to prevent the push block heel from wanting to lift from the board end.) (I deleted all old files to avoid confusion.)

I have seen commercially made push blocks with a heel, but I did not want to buy more push blocks. I made an adapter with floating pins for my existing blocks that easily retracts when placed on a flat surface but extends by gravity when lifted. The block is 60 x 10 x 15mm high. It uses two 4mm x 16 to 20mm screws into the push block. The pins have a 0.4mm gap to slide in the holes. Due to variations and imperfections in printing, the holes and/or pins may need to be sanded to give a good floating fit. The dust plugs are slightly tapered and will press fit in the holes without glueing. They can be knocked out if the pins need to be replaced.

Assembly: Use a slow speed stationary disk sander or coarse grit sanding block to make the end of the push block flat and close to 90 degrees. I then set the block on a flat surface and clamped the body to the block with about a thickness of a 6" (150mm) scale 1/32" to 1/16" (1 to 2mm) under the body. This will prevent the pins from dropping too low and interfering with the pad. Use a 11/64" (4.5mm) drill bit in the screw holes just enough to mark a spot. Unclamp the body and use the spots to drill a 1/8" (3.2mm) hole about a ½" (13mm) into the block. I used a 4mm tap just enough to make a few threads for the screws. That may not be necessary, the screws may force thread into the plastic. I used 4 x 16mm screws fine but drilling deeper allows you to use 20mm. Retest pins for floating before pressing in plugs.

I used PLA on an Ender3 with a PEI plate. Body 0.2 layer, 25% infill, 3walls. Pins and plugs, I printed together at 0.1 layer, 100% infill, small raft