Building adventures of an Ultralight Glider: A seated situation

Seat progress took two directions and I'm having to down-select.

The EC Goat guys graciously sent me their seat profile so I could make adjustments from a good starting point and make it my own. Fortunately for everyone, they hope to release the whole CAD package at some point in the future, to include their seat, so that will be awesome.

The other seat path was recommended by Jeff, finding a go-kart seat. For $25 + $35 shipping, I found a roto-molded polyethylene seat from BMI Karts in Ohio. The seat came in a huge box and weighed about fifteen pounds stock. While quite comfortable, it didn't sit (har har) well on the Goat nose, so the big question was what to do with it.

My original thought for the seat was to pull a mold off of the outside surface. Instead, the inside surface should be smooth, given the manufacturing process. That also would mean there is no extra part to manufacture either, just prep the inside of the front half. So the first step was to take a brand new seat and cut it in half. After an hour with the oscillating saw, and a mess of plastic debris, it was in half. The edges still need more cleanup to make sure there is no negative draft around the edges, and I'd like to support the lip a bit better with a parting plane. It'll be a while to set all that up, perhaps over the remainder of the weekend. The inside surface is indeed smooth. Awesome.

The most important part was to check the fit of the halved seat to see how it fits on the Goat nose mounting tubes. This will take a little massaging, but is going to work well. It fits down much lower into the seat tubes and I'll be able to bolt it to the tubes for solid structural attachment. Quite happy with this path as the right path forward. (I'll take a better picture tomorrow)

There are just a few items left:

change control stick axis bolt to drilled with cotter pin
flip aft aileron control horn bolt to other direction
rivet aileron crank tube to trailing edge (G4S4)
round off the tail skid to be more roundy than pointy
new cabane aft tubes
cabane compression braces (some are loose after the cabane rework from G3 to G4 design)
AN3-26A bolt into the forward line guide bracket, replacing a rivet (G4T14)
aileron crank tube slot
make a nose skid (G4N10)
glass the right aileron ribs
glass the ribs to LE and TE
leading edge shell (G4S9)
sidewalls in forward nose section (G4N13)
swage aft cables (4x remaining)
stiffener for aileron control line
wrap every pulley with tape and heat shrink to hold stiff and straight
threadlock on every quick-link
neoprene eyebolt spacer: horizontal stab (G4T8), elevator control arm (G4T16), tail strut (G4T19)
check every quick pin for elastic retainers are both present and correct length (several are just singles)
prep seat mold
mold seat
mount seat