Playing with frame designs...
First stab at a frame concept--Click to enlarge
Since this is the first time I've ever done anything like this, I recognized that steel is way too expensive to be making mistakes with. Twelve foot 2X4s are $3.50 apiece, and 1x2s are less than a buck. I already had the front & rear ends, now how to hook them together? Here the pub takes over my garage.
This wood prototyping worked well for me and I highly recommend it for your designs to see how it evolves.
This wood prototyping worked well for me and I highly recommend it for your designs to see how it evolves.
The truss & bedpost concept...
As I mentioned, the commercial version appears to use large beams (I think) for a frame. I thought a truss would give a better strength to weight ratio. Corner uprights ("bedposts") would hold everything together & provide support for the canopy.
Note the crossmembers that are supporting "pillow block" bearings, thru which the driveline (3/4" cold-rolled steel) is suspended.
Note the crossmembers that are supporting "pillow block" bearings, thru which the driveline (3/4" cold-rolled steel) is suspended.
The bike posts
I've included this photo to show how I built the bike posts. It's a little hard to see in this photo, but note that the two opposing pedal seats are actually welded to the same cross member. The cross member doubles as the support for the driveline bearing. That way, the chains can be routed to the sprocket on the driveline. This might be a good time to point out that the chains on one side of the bike need to be crossed, or "figure-eighted" so that pedallers on one side don't pedal against those on the other side.
I ended up building four of these double seat posts to put on the frame for the eight riders.
I ended up building four of these double seat posts to put on the frame for the eight riders.
More on bike posts....
Bottom bracket saddle
As I mentioned, I bought old bikes off Craig's list and cut them up for use. I was worried about my welds failing when occupied, and I was attempting to weld the round tube of the bottom crank onto a square post. So I cut a short piece of angle iron to act as a saddle to set on top of the 1 1/2" square stock (1/8" wall thickness) used for the crossmember. Here's a closeup of the pedestal I built for the bike posts. There's a piece of 3/4" square stock on the back that is only there temporarily to hold the saddle 'till I tack it.
Still more on bike posts....
Okay, ready to weld the bike post to the crossmember!
Later, I'll add another piece of 16 guage 3/4" square stock from right under the seat to the top of the frame truss for strength.
This is the first one I made. Later I felt like it was a little too laid back, so I made the rest a little more vertical. Meant to make them all the same, but ran out of time, and stuck this one on with the others. Nobody seems to care tho (o:
Later, I'll add another piece of 16 guage 3/4" square stock from right under the seat to the top of the frame truss for strength.
This is the first one I made. Later I felt like it was a little too laid back, so I made the rest a little more vertical. Meant to make them all the same, but ran out of time, and stuck this one on with the others. Nobody seems to care tho (o: