Monday 26 August 2013

Week 106 - Throttle & Brake assembly, Avionics tray & Parking Brake

Hours to date: 1088.5

I've had 3 good days on the Twister.

Got the throttle assembly done.

Pretty straight forward. Just remember to rough up the top of the Ali plate (that will get bonded to the underside of the cell) before bolting everything together.

I was missing a washer - and I'm not sure if it is some special type (Nylon?) so will ask about that at the factory before bonding the assembly in place.

I have to say that just bonding this plate on with flock does not seem enough to me - I am thinking about backing this up with a couple of bolts through the cell and plate. I'll talk to Pete about this as he used to have this type of throttle before changing to a vernier type.

Onto the parking brake.

Due to my oil cooler mod I am locating the parking brake on the same side as the throttle. (The manual says to put it on the starboard side.)

I noticed that some of the very early kits had the parking brake on the port side and I've done a few trial runs to see if it is an ergonomic nightmare or not. Thankfully it's not.

The only further addition to this assembly is to make a plate over the plywood blocks and brake to hold it securely in place. 

The manual says just to use plywood blocks either side to stop it twisting when you turn the knob. But this means that only a small screw is holding the whole lower assembly in place. I don't think this is enough. Especially as the parking brake assembly weighs quite a bit and when pulling 6G will be a significant load.

I plan to lay up a carbon plate over this (probably 4 or 5 layers) then screw this to the plywood blocks with self tappers.

The other thing I've been working on is installing the tray I made earlier for the Trig Radio and Transponder remote units.

Pretty straight forward - just had to make sure it was being located in a place to miss the back of the EFIS unit.

I bonded it in with lots of flock and 2 layers of carbon on each side - overlapping the flanges.

Again this is a significant weight (just under 1kg) so has to be secure. I may even put some bolts through the flanges and out to the top of the cell for security - we'll see.

I've put some more micro on the rudder control stops - will post a photo of that next time.

Start off with a pile of bits...

And a few hours later you should see this

Lower view - Nothing tightened up yet

Throttle assembly test fit.

Parking brake assembly

Location of parking brake (right)

Underside of cell with brake assembly

Bonding in the plywood blocks - blue tac is to hold it in place while it sets

Trig radio and transponder remote units in tray

Upside down view of bonding in the tray (right way up like here once bonded)



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