|Project by SPalm||posted 09-04-2010 03:40 AM||12445 views||104 times favorited||32 comments|
I posted a project a couple of days ago on making small wooden hinges. This is a follow-up to that post.
One of the hardest things to do when making these is to drill the barrels for the hinge pin. I made a jig to help with that and it works quite nicely. I made it, and since I am me, I am calling it a Stincra jig. It is used to craft hinges.
The first three pics show how the Stincra is constructed. I purchased some quarter inch round by quarter inch long aluminum spacers. They come drilled but I slightly enlarged the hole to 7/64 inch (the drill bit that is just less than 1/8) and filed them to make them just a little less long so they would not bind with the wooden barrels. I ploughed a dado with a quarter inch bit down the length of a scrap to a depth of 3/4 inch. I then drew a line 1/2 inch down on top, marked off 1/2 inch tic marks, drilled pilot holes, and inserted sheetrock screws. (Somehow I measured funny and the screws are not exactly on center, but heh.) The net result is that the tips of the screws just touch the outside of the spacers and the more you turn them, the more the spacers get locked into place. It does not take too much pressure to lock them in place.
I bought the spacers from MSC Industrial Supply. Part number 67716407. They were 42 cents apiece, so I bought 10: http://www1.mscdirect.com/CGI/GSDRVSM?PACACHE=000000152815682 Or look at all the different sizes and material options on page 2059: http://www1.mscdirect.com/CGI/NNPDFF?PMPAGE=2059&PMITEM=67716407&PMCTLG=00 I will probably buy some more at different sizes so I can make 3/8 and 1/2 inch barrels as well.
I somewhat changed the order of the operations from my first post, and I have learned a few things. To form the barrel I still used a bull-nose bit with both the horizontal and vertical cuts. But now I didn’t let the bit cut as much by moving the fence towards me a little. This leaves some flat sides on the barrel which helps by having more area for riding along the fence. These flat sides are easily rounded with sandpaper after the final assembly.
I did the box joint operation before drilling and then lightly filed the insides of each barrel to make sure that they could be mated with another without binding. Then I inserted the plate into the side of the Stincra making sure that it was seated all the way. The dado is deep enough to keep the plate steady while drilling the hole with a hand drill. The spacers keep the bit straight all the way through the drilling operation. Yea.
The last pics are just showing a couple of hinges before creating the thin plate. I used the drill bit as a temporary pin to check alignment. I could not ask for more. You can see the gaps are equal on both sides and at the top and the bottom. The hinge swings square, even when I tested it with these long plates.
One last thing is wood selection. You want to use quarter sawn wood. Hold a plate horizontally and look at the endgrain of your blank. Make sure that the growth rings run up and down (as much as possible), and not from side to side (no smile faces). The walnut blanks in these pictures are not quarter sawn, and they ended up breaking very easily. You can see a chip already formed on one of the barrels.
-- -- I'm no rocket surgeon