Towing Clamp Thing
Please note that this is my starting version. Assuming I actually get this thing working at some point, I'll post a final, revised version with a link from here. See my progress.
materials:
- 4 boards such as 2x4s or 2x6s, approx 20-26 inches, in matching pairs*
- 4 nails long enough to go through one piece of wood and far enough into another to hold it securely (I used 3-inch ones but would have been happier with 2 1/2-inch ones)
- 2 bolts, approx 6 inches long
- 2 nuts (I prefer wing nuts**) to fit the bolts
- 4 medium screw eyes
procedure:
1. Work out which boards will be ends and which sides.
Possibly optional, but recommended for better strength/durability: Mark a line straight across each end piece about an inch from the middle, then use the side pieces to mark a second line further from the center. This is going to be a slot into which the sides will fit. At this point you can do something fancy with a router or band saw or something to make a wide groove, but here's a simple hand-tool technique (and they said I was wasting my time watching The Woodwright's Shop; does anybody know if the first couple of seasons are available on DVD anywhere? I should look for it, it was a good show). Make a shallow cut into one side of each end piece where the two lines are marked. They should be the same depth and maybe 1/4-inch deep or a little less. Then use a chisel to shave off the face of the board between the two cuts (at this point, I went in and rooted out my ear plugs, but suit yourself). Test that the side pieces will slot into the groove thus created.
2. Drill two guide holes in the end pieces where the sides will connect. Drive nails into these holes until they just emerge inside the grooves (if you've made grooves). At this point you can apply some glue if you wish (I didn't, mostly because I didn't have anything weatherproof on hand). Stand the first side piece on end, place the end piece over it with the (slot and) nails ready to go into it and, if using a different width for the side pieces, one side lined up so it will sit flat when turned on its side. Drive the nails through.
Before starting the second side, make sure it's lined up so it will make a box with the other piece when finished, then glue/nail it together as above. Allow glue to dry if appropriate.
3. Decide if the bolts will be going between the spokes or around the rim and position your holes accordingly. If between the spokes, the holes should be fairly high and about 1/3 of the way in; if outside the rim, you'll want them lower and quite near the end pieces. Since I was using 2x6s for the side pieces, I opted for between the spokes to make sure the wheel doesn't fall out. Drill holes through one side piece, then stack them together (in what will be their closed position) to drill through the second side. If you have a wheel handy, stick it between the two sides to test your clamp, insert the bolts, realize you forgot to get washers, and secure with the nuts (scrounge up or buy a couple of washers before the ride test unless you decide not to use them). The clamp should be fairly stable and hold the wheel easily.
4. Drill a guide hole at each end of the end pieces and screw in the screw eyes as anchor points. I'm thinking rope or strong twine will probably be better than bungees for attaching the clamp to the trailer, but will have a better idea once I can make a proper trial.
