SHP countersink hole stop

thingiverse

# Background While working on a charity: [Sleep In Heavenly Peace Syracuse NY](https://www.shpbeds.org/chapter/ny-syracuse) bed build event, I was assigned to the "clean-up" station, in which I was doing the finial touch-up of the head-boards. One of the operations, required countersinking the bolt-holes for the head-boards, required some finesse. The countersink tool is aggressive and I believe designed to work in a drill-press. It would "grab" and drill deeper than I intended... so I started thinking of solutions (**engineer always!** ). The weekend was a little rainy, so I went through several iterations of the design. I am uploading two versions of the design: - Design-one -- Simple, works, will wear-out, easy to print, can be printed 4 or 5 at a time and each should last an bed-build shift - Design-two -- Better functioning, but harder to print, uses a skate bearing to prevent damage to the head-board and to the depth stop. - Design-three -- Better yet, easier to print but requires 6000 bearings. All the advantages of two but much easier to print. Design two uses skate bearings are used in Skateboards, and Roller-blades. The bearing is readily available from sporting-good stores in packs of 8 or 16. I used this bearing because my son has lots of old-ones-laying around in my house. *(I have depleted my stock of these... I will need to start buying them!)* The bearing is an industrial standard "608" bearing. Design three uses industry standard "6000" bearings. Selected due to it internal bore is large-enough to print the 1/4" hex collar without being brittle, and due to it low cost (<$1 when buying in boxes of 10). The Counterbore bit is a 5/16" x 3/4" 3-flute counterbore with a 1/4" counterbore. [Amazon link](https://www.amazon.com/Snappy-Bottom-Counterbore-Countersink-16in/dp/B01MA55I10?th=1) (You can find it less expensive other sites on the internet). Due to popular **(blue-shirt)** demand *(from the few folks who have seen this in action)*, I am uploading my design to allow other chapters of **Sleep in Heavenly Peace** to start printing and using them. #Design 1 This design is simple and works, has lower tolerances and is easy to print. It does have the down-side that it spins on the work-piece and will wear-out, and the wood-chips will pack into the cavity. The only critical tolerance is the size of the hex shaft of the drill bit... it needs to be large enough that the bit fits, but does not spin. #Design 2 The part tolerances on this are somewhat critical. *For my printer calibration cube the outside dimension are smack on, however internal dimensions are not accurate.* So I ended up tweaking the tolerances to make the design work. I think this can be done by scaling in the slicer. Let me know if you have difficulty with this and I can remix it to fix any issues. **Outer depth stop** -- the recess for the bearing needs to be *"Press-Fit"*, that is tight-enough so that it can be pressed in, but not so tight that it causes the part to deform overtime, or not fit. The countersink need to spin freely inside it as well. **Inner bearing collar** -- this shaft of the counter-sink and the inner diameter of the bearing are too-close for design comfort. As result this part is very delicate and you may want to print extras of this one. I use Cura for the slicer and it prints little fingers (see photos) for this. My guess is different slicers may make different choices on how this prints. Once this part is assembled on the counter-sink shaft with a bearing the design is rugged, before then, it is very fragile and will be a hard print. Luckily, the part is small, and you can print several at a time very quickly, once you have your slicer tuned. # Design 3 -- The "6000" *Use this one, if you need to buy a bearing, and are buying it online* I would only use the second design if I had a bunch of 608 bearing handy. This version uses a different bearing, allowing a full collar instead of brittle little fingers. I chose a inexpensive one, I found them for $1 apiece when buying in lots of 10 from Amazon. The bearing is model 6000. I would get one that is sealed to keep the saw-dust out. You may need to do some small scaling with your slicer to get the sizes correct. For my printer the bearing easily presses into the Depth stop, and the collar presses in to the bearing. Little to no post processing needed other than snapping the support off. Let me know if you have any suggestions or need help getting a design to print. Paul