I need to put a floppy end on a 1/2-10 Acme shaft. Think of the pad on a C clamp. But, it needs to pull back under light pressure. I'm making a wood clamping device for the drill press. A fixed 3" x 4" x 5/8" aluminum block with 2 guide rods sticking out. A similar block slides along the guide rods to clap a piece of wood in between. When you loosen the clamp it pulls the block back away from the wood.
A store bought version uses a rounded bolt head that fits into a keyhole. They used a tee slot cutter on the slot and the bolt just slides up in the groove. They used plastic and it ain't worth a damn. I have already re-milled it twice. That is one option. The other is to use s depressed center washer and secure it to the shaft with a C clip. Then attach two strips too the block to sandwich the washer in. The third way is to run the shaft through the block and secure it with a C clip.
The reason for the slop/flop is to handle the square blocks not being so square. Clamping force is about "snug", un-clamping is what is needed to slide the block back on the guides. any other solutions come to mind?
When I do this on "real" work jigs, I sandwich a piece of metal between thrust washers. Then I am only limited to the shear force on an Acme rod or my welding. On this job I'm trying for the KISS principle. I'm leaning toward idea 3. The Acme rod is aound 3/8" when turned down for the handle or C clip. Comments anybody?
Thanks Charles
A store bought version uses a rounded bolt head that fits into a keyhole. They used a tee slot cutter on the slot and the bolt just slides up in the groove. They used plastic and it ain't worth a damn. I have already re-milled it twice. That is one option. The other is to use s depressed center washer and secure it to the shaft with a C clip. Then attach two strips too the block to sandwich the washer in. The third way is to run the shaft through the block and secure it with a C clip.
The reason for the slop/flop is to handle the square blocks not being so square. Clamping force is about "snug", un-clamping is what is needed to slide the block back on the guides. any other solutions come to mind?
When I do this on "real" work jigs, I sandwich a piece of metal between thrust washers. Then I am only limited to the shear force on an Acme rod or my welding. On this job I'm trying for the KISS principle. I'm leaning toward idea 3. The Acme rod is aound 3/8" when turned down for the handle or C clip. Comments anybody?
Thanks Charles