jps
|
| posted on 17/1/13 at 01:04 PM |
|
|
Putting stress in a fibreglass seat...
So... As i'm building a Haynes it's 'start from scratch' on every job. I've bought some GRP seats from RoadTrackRace and
have made some mounts for one.
So far I have:
1. Made a wooden jig to work out what angle the seat needs to be mounted at and where the holes in the seat need to be (roughly).
2. Copied the dimensions onto a basic frame, made from 25x3mm steel - triangulated for strength in some key places.
3. Drilled holes in the seats and offered up the bits - then welded them together in the right place.
PROBLEMS:
1. The backside of the seat (i.e. the bit that makes physical contact with the metal frame) isn't nice and flat - it is radiused. So when I
tighten up the mounting bolts things start to get pulled in different directions to that which I anticipated...
2. Despite best efforts - not everything is 100% aligned correctly - and bolting things up tightly pulls some of the metal framework about a bit...
Primarily - the rails that run parallel to the floor of the car bow slightly...
Now - i've come across a simple solution to the first problem.
1: Use some rubber shims/washers where the bolts go through the GRP - makes it much easier to get things to sit at the correct angle under tension.
The second part is worrying me more though - i can:
2: Bolt the seat frame down to the chassis rails before tightening everything up - and letting the components take the strain. I'm fairly sure
it'll work - i've flexed it all by hand and it moves to the position I want it to. However - is it a bad idea to put that stress into the
components - assuming that at least some of it is movement in the fibreglass seat...?
|
|
|
|
|
jps
|
| posted on 17/1/13 at 01:07 PM |
|
|
Not a great pic - but here's some illustration of the seat sitting in the frame...
|
|
|
BenB
|
| posted on 17/1/13 at 01:38 PM |
|
|
If you clamp the GRP under some strain the first time it gets hot it will soften the GRP and it will reset in the new position. At least that's
how I did my bonnet which had sprung a little- strapped it on to the car, started up the engine and let the bonnet get toasty hot, leave it to cool
still strapped in place and voila.
IE the strain it is currently under will go the first time you leave the car out in the sun 
|
|
|
jps
|
| posted on 17/1/13 at 01:53 PM |
|
|
quote:
Originally posted by BenB
If you clamp the GRP under some strain the first time it gets hot it will soften the GRP and it will reset in the new position. At least that's
how I did my bonnet which had sprung a little- strapped it on to the car, started up the engine and let the bonnet get toasty hot, leave it to cool
still strapped in place and voila.
IE the strain it is currently under will go the first time you leave the car out in the sun
Makes perfect sense...! Cheers for the feedback!
|
|
|
