F-Series:
F, for folding. Ok, so I got a different car and instead of monkeying around with a trailer I decided to build a cart that would fit into the trunk.
I'm going to use the base of this folding wheelchair-
In the image above, I sawed off the front caster mounts and the back handles. It's a start.
I whipped up a frame for the top. 3/4" X 1-1/2" rectangular Crew (cold rolled electrically welded). Hmm, I lost my catalog but I got it from Dillsburg Airplane Works (DAW) down towards York. I don't think they have a website but google should get you their phone nr. and you can call for a catalog. The round tube at the foot end is 7/8" crew. Not sure if I went over this stuff elsewhere...
Chopped the arms down to size and put more rectangular tubing across tops. Also going to try these plastic 20" wheels I got from Northern Tool. Their lighter and will lower the project making it easier to transfer on and off from my wheelchair.
I made these arms to extend the casters farther back for a more stable base. It's all 3/4" od crew, the flanged bushings are 5/8" od and can be squeezed into the vertical bits with a bolt. Chamfer the inside edges of the steel tube and then put a bolt through both bushings and the tube and squeeze it all together at once.
Pressing the bushings in kinda squishes them a bit so you gotta ream them out to get the casters in. I have a 1/2" adjustable reamer (above) and have it set for slightly over 1/2". Just grab the crappy end with a vise grip and turn it in through the bushings, cutting deep enough so the caster goes in.
I clamped a long piece of square tubing along the frame then the "A" arm to that, shimming it out from the square tube so there's room for the casters when it's folded. Quick clamps work great, and their only a couple of bucks each at Harbor Freight.
There's one side on...
Tadaaa!
I put some gussets where the extensions meet the wc frame. Should strengthen things a bit.
Ok so I didn't need to angle the caster extensions out, plenty of room when folded. Well, it'll give a wider wheelbase in the rear, yeah, that's right, more stability, yeah, that's why I did that, sure...
It was a nice sunny day yesterday so I thought I'd work outside. Also took more pictures as it's easier to get around...
Lay the top on the sheet and trace around.
My sheet metal isn't long enough but I think I'll try to seam it instead of running all the way down to Camp Hill for more. There's a place there, Glosser, that's great for structural steel and sheet metal.
I cut the large chunk out with a pneumatic shear and finished the rounded corners up front with hand snips.
For the seam, clamp a piece of sheet metal over the piece your seaming. Use a heavy plate as a dolly.
Once you have it bent up you no longer need the dolly and can smack it down over the other piece.
Do the same with the other piece but the other way around, also don't forget to add extra length for the seam as I did. I just retrimmed the "shoulders" and since I didn't cut the foot end to length yet it won't affect anything.
Put a piece of heavy plate underneath for an anvil and smash the seam flat. Then, the trick to a lock seam is to give it an extra bend so they can't come apart. I did this with the sheet upside down, so the top will end up flat. Just use a piece of scrap metal and hammer the last bit down, here you can see I'm halfway across, working from right to left.
Presto!!!
Clamp it all down into position, if the edges are a bit large a sander or file will bring them in. I don't use cleco's or clean up my rivet holes or dimple them, seems to work ok without all that. You should work one end to the other though, or from the middle out. If you jump around or put a rivet in each corner then try to do the rest you'll end up with excess sheet metal and a wrinkle or bubble somewhere.
Work the edges down as you go. Because of the slight curve to the top at the foot end, the edges need a slight bend.
Now to finish the foot.
Notch the corners and where the foot tube bends.
The sheet metal is thin enough to bend by hand, then as you grip it with a pair of vise grips you can twist it a little to crank it tight around the round tube, then put a couple pop rivets through it.