Wednesday 30 May 2012

Week 42 - Safety cell mod - Part 3

Hours to date: 382.0


Been working solidly on the cell mod for the last 2 weeks - the end is in sight now.


Had a little delay while I waited for some Kevlar Shears to arrive. I tried cutting the Kevlar with normal shears - no chance! Also the rotary cutter was defeated by this most strong material. The shears are not cheap at £28 - but essential for the job.


I started off by doing a test piece - to see if I could make a sandwich of honeycomb properly. This worked out very well and is incredibly strong even with just one layer of Kevlar on each side.


Next up I 'tacked' the front of the cell in exactly the right position using Flock. I used duct tape and pieces of wood to hold it in the right place while the flock set.


Then it was a case of making up templates in many sections out of cardboard, these were then covered with aluminium tape and given 3 coats of release wax. Taped in place these provided a perfect shape for the outer layer of Kevlar to assume when bonded.


Once the outer layer was set it was time to make up an inner layer that consisted of another layer of Kevlar on each side of honeycomb (Nomex), followed by peel ply.


If this sounds time consuming it's because it is!


It's worked out well though and when the pieces are overlapped the whole thing becomes very strong.


Almost done this now - just a few small fiddly pieces to go around the firewall support area. I will finish by putting another layer on all round of Kevlar - maybe even 3 layers on the part where my feet will be.


The other thing I've been working on is modifying the block that is bonded into the footwell and is the attachment point for the rudder pedals.


I had to change the angle of the back of it to match the new angle of the cell (a side effect of the mod). Also I found it needed to be made taller - by about 20mm to have the carbon bracket fit on it properly. I did all this with micro - as you will see from the photos - and finished up with a layer of glass (same as the factory had done).


Hopefully I will have finished the cell mod by the end of next weekend - which is a 4 day affair due to the Queens Jubilee and Bank holiday falling on consecutive days, Monday and Tuesday. I should be able to make some good progress.


Test piece bonding and after cutting

Kevlar Shears

Tacking in place with Flock

Cardboard templates with aluminium tape

3 coats of wax helps them release from fabric

Partly done.

Almost there.

Block needs to be made taller to fit Carbon bracket

Cardboard to make micro assume the right shape

With micro in place and drying

Block done (pre layer of glass)



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