Week 110 - Fuel Selector

Hours to date: 1124.0

The access panels on the lower fuse are now finished.

Both came out very well - practise makes perfect (well an improvement on last time anyway).

The airstream passing by should hardly know they are there.

Onto the fuel selector.

No expense spared here - top of the range Andair (Made in England). A beautiful piece of kit - and so it should be for £276.

I also bought a check valve from them (a one way valve) - and that was a whopping £62.40. This will be used in the return line for the fuel system.

I've located the fuel selector in roughly the same area as Pete does. 

The French Twister has the fuel selector on the right-hand side of the cockpit area. This is a no-go for me as my oil cooler occupies that space. Also I will have a side pocket in that area - plus I don't like all the extra plumbing that is involved just to have the fuel selector in that place.

I've had to move my location forward from where Pete puts his due to the fact he has retractable gear and I have fixed gear. The fixed gear runs right across where he puts his fuel selector.

I've gone as close to the gear as I dare. The selector is easy for me to reach in the cockpit - although I will have to slacken off my shoulder straps to do so. No bad thing in my mind as changing the fuel should not be a duty taken lightly by the pilot.

The tricky part of installing this selector is that it is a flat plate but I am installing into an area which is all compound curves.

So how to get around that problem?

Simples.

I ground away the top layer of Kevlar on the cell and all the honeycomb in the area needed. Bevelling the edges down as I went to give a smooth transition.

This leaves just the bottom layer of Kevlar which is now flexible and so can be made flat with the selector and top face plate bolted together - thereby crushing the Kevlar layer to make it flat.

After putting release wax on everything and cutting out 2 layers of carbon I was ready to go.

Once this carbon is set hard it will make this area flat. Then I will add another 3 layers of carbon to the bottom of the cell in the same area - should be plenty strong enough.

I used flock to fill in the exposed honeycomb and make a smooth transition to the rest of the cell.

As you can see the selector is nowhere near my leg and can only be turned off by lifting the knob on the dial anyway so there is no danger of it being turned off by mistake. Also the rudder action is not one where you need to move your legs back and forth - just your ankles move the tops of your feet - so again this should not introduce any unwanted bumping of the fuel selector.

Final stage of the access panels - closing the gaps with Micro

Panels and access hole done.

A flush fitting access panel

Andair fuel selector and check valve

Location underneath - black line is where the gear leg runs over

Fuel selector - in relation to pilots leg

Ditto - set to Right tank here.

2 layers of carbon going on top. Face plate bolted down to make it flat.

Week 109 - Cell end cover and Access panels

Hours to date: 1109.75

I've installed the safety cell cover mountings.

As you'll see below these are rather nifty little fixings made for composites.

They have spikes which embed themselves into the honeycomb and then a layer of glass is used over the outside end as a final way to make sure they stay put.

Fits pretty good - one of the easier jobs on a Twister.

Pete says you cannot have too many access panels in the lower fuse area. So I've made another 2 to add to the one already done as part of the oil cooler mod.

The same method is used as before to make the flanges.

I've put one access panel in the front area which will give good access to the fuel system. And the other on the port side - which gives access to the throttle/brake assembly, parking brake and flap drive.

Obviously on a retractable you already have the wheel well holes that act as good access areas.

I also thought while I'm making these holes I may as well go ahead and cut out the holes for the undercarriage legs.

I first tried using the factory markings. But as you will see below they are not enough - I am guessing those markings are for the retractable version.

By doing this job slowly I was able to get a hole that is no bigger than it needs to be but allows the undercarriage legs to come in and out.

I've also started to fit the upper U/C leg fairings.

I'm not going to attach them the way the manual says. Rather I will go for the same idea as Adrian Hatton and put nut plates underneath the fuse and then leave the lower area as it is here - as the U/C leg needs to be able to flex and move in relation to the fairing.

The reason for the change of set up is - I don't believe the fairing can be made to sit flush with the lower part of the fuse using the method described in the manual. It would be an area of great drag if it doesn't sit exactly flush.

Cell end cover in place

Fixing before layer of glass

Composite fixing - note the spikes.

Cut out for the gear leg - using factory markings - not big enough

Too tight in this area

Extra access panel holes - top and right

Gear fairing fits nicely to the leg - after a bit of sanding on the inside.

This is the shape you need to go for.

One flange layed up - one to do.

Week 108 - Control stops and Upholstery

Hours to date: 1097.5

I've made up the carbon plate that goes over the parking brake and am pretty pleased with the way it turned out.

I used 6 layers of carbon and duct tape as a release.

It is screwed into place with 4 self tappers.

Solid as a rock now.

As promised I've included a picture of the rudder control stops in their finished state. I made a small 'mountain' of micro in between both the stops to transfer some of the load. Hopefully this will be strong enough.

The next control stop job was the elevator - which I have to say is one of the easiest jobs so far on the Twister.

The up elevator limit is already set by the elevator hexes when you bond them in. This uses the lower carbon rib in the fin area as a stop for the Brass weight and is set at 80mm.

For the down limit the upper carbon rib is used but has to have a small plywood block bonded on to set the limit in exactly the right place. 60mm.

Piece of cake.

As you will see below I have had some samples made up for the upholstery on the seat (and side pocket).

I'm going for a dark grey leather (to match the rest of the cockpit interior) set off with orange stitching.

The centre of the seat will have an orange stripe - most likely in Dynamica (a cheaper version of Alcantara).

Should be a good look.

I need to crack on and get the seat fitted and painted then I can send that off for upholstering.

Rudder control stops

Elevator control stop 'down' position

Set to 60mm 

Leather sample for seat

Ditto

Carbon cover plate over the parking brake

LAA Rally - Sywell

It's that time of year again.

I just paid a quick visit to the Rally this year on the Sunday.

A few of the highlights are below.

For more info about the Verhees Delta follow this link: http://www.verheesengineering.com/gb/delta.html

3/4 scale Mosquito replica from France. 30,000 hours build time!

Morane Saulnier Parasol wing

Brandli Cherry BX-2 Swiss designed plans build.

One off warbird looking homebuilt

Another single seat composite machine (Starlight SL-1) not many of these about

The bizarre and brilliant Verhees Delta

Spitfire Mk26 with Jabiru flat 8.

UKs newest design - Swift. Wonder where they got the wing shape inspiration from??

UK agent for UL Power - Mark Jones

Travel Air Mystery Ship - 1920's air racer (NOT MY PHOTO)

Verhees Delta again...

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)

Week 105 - Rudder control stops

Hours to date: 1069.5

I've not made a lot of progress lately.

Excuses excuses...

Anyway I did manage to get the rudder control stops done.

Figuring out how to do this took a bit of head scratching.

Once the rudder is on there is no access to the area where the control stops need to go - so how to get around this??

I figured on using lumps of plasticine - taped to the mudguard.

Then I put the tailwheel and rudder back on and moved the rudder to the correct deflections (190mm measured at 400mm out from the hinge).

This made impressions in the plasticine of the right depth.

This gave me a starting point for where to put the control stops and how big they should be.

I made them out of micro to start with and roughly the right size and position.

A quick check with more plasticine on top of the micro (once it had set) revealed I still had a little more to add.

So I put some flock on the micro (more than was needed). And left it overnight.

Early the next morning - before the flock had set completely (about 8 hours of curing) - I put the tailwheel and rudder back on and did my deflections again.

This time the tailwheel fork was able to make impressions in the flock in the exact place for the deflections I was after.

Then I just let the flock set completely and hey presto the control stops are now perfect!

I may add a little more micro to the inside and perhaps a layer of glass on the edges of the micro to make the control stops a little more beefy - after all they will have some force going into them if the pilot slams the rudder to full deflection (I can see this rough treatment happening during aerobatics).

I've also begun the task of redoing the horz stab securing pins and front bearings.

It wasn't too hard to remove the old pins and bearings - the Dremel made light work of it.

The technique I'm using now for getting the elevators (and tailplanes) to match up in angle of incidence is as follows.

Clamp the outboard end of the elevator (using 2 wooden blocks to spread the load and make sure it is completely in line with the horz stab).

Then move the horz stab up or down until the inboard end of the elevator lines up with the trailing edge on the fuselage.

Flock in the front bearing.

After this has set the securing pin can be done - and will be in the right place as the incidence has already been set by the front bearing.

My mistake before was doing the securing pin first.

Lets hope this works out.

I am having next week off work so I hope to make some good progress.

Plasticine to determine rudder control stops

Control stops done.

Control stop - top view

Setting the horz stab bearing - again!

Lines up this time!

Holy Cowl!

It seems that for every UL Power engine installation there is a different take on the cowling.

This one is from the Czech-Republic and I think it is on a Bristell NG-5.

Not sure what the NACA duct is on the Port side? Perhaps for an oil cooler.

The lower exit section looks like an afterthought. I wonder if it is fixed or movable like a cowl flap?

Flying Legends

I visited Duxford last month for a great day out.

The Flying Legends airshow. Known as the best warbird airshow in the world.

It lived up to expectations.

Here is a short video of what I saw.

http://www.youtube.com/watch?v=ncTZYNvh6hE&feature=c4-overview&list=UUOkKIXmP2rkfDA6hHGjTu6g

License revalidated

There is a reason for my lack of progress lately.

I've been doing a bit of flying - to revalidate my license.

I was pretty rusty - having not flown as PIC for 2.5 years.

I also had to convert it to an EASA type - lots of forms and quite a bit of money - for another piece of paper that looks almost the same as the one I already have...

So now I've finally got a Cessna 172 in my log book.