Showing posts with label foam shaping. Show all posts
Showing posts with label foam shaping. Show all posts

Monday, April 8, 2013

Seat Design

With the bike stripped down and the engine out, and with nothing to do but wait for new parts, I decided to start customizing a little.  I searched the web for a bit for ideas, and found a bike similar to what I was hoping to build, posted on Pipe Burn.  I dropped this image into photoshop and edited up this:

Following this virtual modification, I went for the seat.  Removing the former cover and drawing the new shape on the old foam.  From this sketch, I cut the foam on a band saw, I shaped a rough version.

Using an angle grinder with one of the wheels with staggered sand paper, I shaped the corners and details I was looking for.

Finally, I cut the seat pan down to match the new shape of the seat.  This resulted in the pan not having any structural components anymore, so I ended up scrapping the part all together and just fabricating a new part from some 16 g sheet steel. This is the old pan after I cut it down:

For the new pan from scratch, I put mocked the shape up with some card board, then laid it flat on my steel.  I then cut this shape out with a bandsaw and made the contour bends on the edge of my bench with a few clamps holding the pan in place.  The pan was still a bit wobbly, so I took it over to the english wheel and with some channel rollers, put a nice channel through the flat parts of the pan, adding a lot of rigidity and strength.  I then lined the pan up to the bike and marked exactly where I would need to add tabs for clipping/screwing it down to the frame.  Since I planned on mounting my taillight to the seat, I welded a tab at the back.  Lastly a line of holes drilled around the outside perimeter for some rivits to hold down the vinyl finished off the build.  

A shot of the seat pan being fitted: