I'm making a penny farthing, and it's going to be rad. I had already begun construction when Tim and Star convinced me to post an instructable about it, so I don't have original pictures of the first steps of construction, but I am creating some dramatization pictures to show how I bent the rim.
Step 1: Make the Rim
Dramatization! Not actual footage!
So, I took a 4' diameter tabletop that was kicking around, and drilled a 1/2" hole near the side, and tied a bit of rope around it, as shown. Next, I laid my channel iron face down (the open side - the side you want facing outwards) down on the ground, put the table on top, looped the rope over the end of the iron (of which I had about 16'), and began to pull back as shown. This little piece of aluminum I'm using in the picture is obviously much easier to bend than the channel iron; be strong!
The steel will spring back a bit, so on a 4' table, I got about a 6' circle of steel. I stretched it down to be just under 5', cut and welded.
Step 2: See, Look!
Isn't it great! Star thinks so!
Step 3: Welded
Here is the seam in the rim. I welded the outside and inside using a mig welder, and then ground down the welds. If you're going to grind down your welds on something structural like this, be SURE you got good melt-through with your weld.
Step 4: Make Spoke Attacher Thingers
I took 6' of 3/8" steel rod, inserted the end into a hand brake with 1.5" sticking out, bent, then chopped 1.5" off after the bend, thereby making these little thingers. I then found a piece of crap about 1/2" tall to support them as I tack welded them to the inside of the rim as shown.
Step 5: The Hub
So, I found a bunch of these. They seem to be feet from some optical equipment (or so Tim says).
So, go find some :-P
Step 6: Drill Out More Spoke Holes
I made a small jig for them by drilling two screws into a small piece of plywood, and mounting the plywood onto the drillpress so when the piece was pushed against the screws, the drill bit would be directly above where it should be.
Step 7: Connect the Two Sides
I found this piece of thin-walled steel tubing that just happened to fit snugly into the hub sides. I drilled out two small holes in it to line up with the pre-drilled holes in my hub sides.
Step 8: Finished Hub Shell
I'll get to the crank spindle later, but for now, just insert the steel tubing between the two sides, and throw some bolts into the threaded holes.
This is the strangest look I have ever seen on Tim's face.
Step 9: Attach Spokes
I bought from some company online a lot of 3/32" stainless cable, 100 thimbles (the little tear-drop shaped things), and 100 brass ferrules. For my rim and the size of my hub, a 48.5" piece of cable is enough to attach to the rim in the middle of the cable, and then on the other ends I attach turnbuckles. These equate to my wheel's nipples.
I have also attached a picture of the tool I made to crimp the ferrules. It's just a cheap pair of bolt cutters that I disassembled, ground notches into the teeth, and then reassembled.
MORE TO COME
Step 10: More to Come!
still working on it