Another Mini-Drill Press

thingiverse

Yet another mini-drill press, but one that I can truly call my own. The COVID-19 pandemic has me confined to my home, so I decided to take matters into my own hands and design a drill press from scratch. This project was born out of necessity, but it turned out to be an exciting challenge. I scoured the internet for parts and landed on some great components from a discarded HP 637 printer. The 37mm 18VDC motor and power supply were perfect for my needs. I also found a 3/8" smooth rod that was just the right length, and an 8mm rod with splines where rubber wheels fit. To house the motor, I designed a bracket using inexpensive sleeve bearings like these: https://www.mcmaster.com/1688K13-1688K13. These little wonders made it easy to keep the motor stable and smooth. For the threaded rod, I opted for a 5/16" 8-8 Stainless Steel rod that was 8 inches long. Any clean threaded rod of this size should work just as well. You can get one from here: https://www.mcmaster.com/95412A323-95412A323. The 8mm rod that attaches to the gear wheel to raise and lower the drill motor came from the printer, but I cut it so that there are splines under the lever arm only. The printed gear wheel has a wide spot in the gears with a 3mm hole and space for a nut on the inside. To keep everything secure, I filed a matching flat spot on the rod where the gear fits. Assembly is relatively straightforward: 1. Check the clearances of the holes using drill bits of the proper size. You'll need to use 1/2" drill bits for the sleeve bearings and 3/8" drill bits for the smooth rods. The rest are 5/16". If you need to make any adjustments, be careful not to overdo it. 2. Press the sleeve bearings into the motor bracket. They don't require much force, so a small plastic hobby vise should do the trick. 3. Attach the gear wheel, 8mm rod, and lever arm to the motor bracket. Make sure the screw going through the gear hits the nut and flat spot on the rod. 4. Run the smooth rods through the motor bracket's sleeve bearings one at a time. Be careful not to insert them into the base or top first, as this can cause the bearings to jam. 5. Place the drill stop on the rods. 6. Put the rods, with the drill stop and motor bracket attached, into the base. Don't worry about getting them fully seated just yet. 7. Install the 5/16" threaded rod. I put a nyloc nut on the bottom first, but it's not necessary. 8. Install the top. Tap it down enough to fit a nut on the top of the threaded rod, and then use the cutout in the topcover to tighten the rod and push the smooth rods into the base and top. 9. Fit the motor bracket to the drill stop. Push down on the motor bracket so the screw head on the gear is showing as in the picture. The lever arm should then turn easily, lowering the drill motor. Parts needed: * 37mm motor and power supply * 2 x 3/8" smooth rod of desired height (I used 7 1/2") * 1 x 5/16 threaded rod, 1/2" longer than the above smooth rod * 8mm rod with splined end, about 70mm long * 3 x 5/16 nuts (1 nyloc, if desired) * 2 x 3mm x 16 screws and nuts for holding 37mm motor * 2 x 3mm x 10 (or longer) and nuts for lever arm * 1 x 3mm x 8 screw and nut for gear wheel