Monday, 1 September 2014

Take a seat - Part 5

Time to do some more work on the seat. After a few measurements, I decided I needed to find out if the seat base was going to be wide enough for my hips (kind of crucial). So I sat on the floor and scratched marks either side of my bum on the ground with a screw. Phew, exactly right!

So I drew myself a drawing and headed off to Bunnings for supplies...

After umming and ahhing a bit, I came home with a few wire wheel type devices and a sheet of 9mm plywood. All this was mostly paid for with some old gift cards.

I would have bought steel, but Bunnings now doesn't stock any raw (un-galvanized) steel beyond 1" square tube (painted blue), which was useless to me. So I headed to Masters on the way home and found this...

What we have here is 3m lengths of 40x5mm and 32x3mm flat bar. I had originally wanted some 20mm tube, but I'm happy I didn't buy that now. This is particularly helpful coz Bunnings is miles away and Masters is just round the corner.

The next trick was a lot of grinding old paint and rust off the frame before welding. It was considering beginning welding when it occured to me that it would be a lot harder to trace the seat base and back on the plywood once I'd welded them together...

Hmm, good thinking Sherlock. So after some jigsawing and sanding, I was left with this...

I'm pretty happy now that I cut these out before I started welding for another reason. I'd forgotten just how stiff 9mm plywood is. I know this because a few years back I build a lightweight speaker box out of 7mm. I remember being astounded at just how much stiff the 9mm ply was. The back timber will be recessed into the frame, but the seat schwab sits on the top of the frame.

I did this for two reasons;
1. It's going to need every bit of support it can get with 95kg sitting on it.
2. I want as much width as I can get for my hips.

For those of you thinking, 'that's gonna be a pretty hard seat', you're absolutely correct. What I'll need to factor into my supports and foam is enough support to avoid breaking, but not too much so the ply can flex just a little.

Finding the right foam at the right price will be another challenge. Hmm...

No comments:

Post a Comment