Back to the beginning: Project Tiger Cub Story part 8

Making and fitting some new bits

Some of the bonding of the foam panels to the longerons is not so good, due mainly I think. to clumsy handling over the years as the bits lay uncared for in the hangar at North Coates. Still that is a simple enough repair with a bit of care.

A trial fit of the rear cockpit section, now bolted together again, to the rear fuselage, is now due. After a lot of careful jiggling about of the clumsy components all the bracket angles are correct and the alignments right she slides together. Probably the first time in more than 20yrs most of the fuselage stands as one unit, really satisfying.
I finish that evening with a big grin on my face.

Then I fall into temptation. What I should be doing is trial fitting the fuel tank and incorporating a fuel drain as the original totally lacked one and I am almost paranoid about clean fuel. I guess I spent too long working in and around working fishing boats also I still need those seat belt measurements.. That was what I should be doing, instead I was unable to resist making up the two replacement tubes for the front cockpit section. My only excuse being that after all the dismantling checking, filling repairing and reassembling I wanted to MAKE something. I had four that were bent, damaged or otherwise unsuitable, no shortage of patterns then. Careful checks showed that, as with all the rest of the tube work they were jig made and identical. I removed the nylon inserts that I would need from damaged tubes and cut the sleeves that fit over the inboard ends of the tubes. I then carefully marked one end of each tube with centre marks top and bottom and the top of the far end of the tube. I then measured along the tube and marked the distance from the inboard end to the bolt hole for the forward bulkhead. Setting up my laser line and level gadget to give a nice clear red line centre to centre and marked the intermediate hole position with it’s centre line. Turning the tube around I marked the bottom of the tube and turning it over I then marked the bottom intermediate and extended inboard end marks beyond the length of the sleeve. Next job was to drive the centre nylon insert into position using a drift marked with the position of the insert as obtained from my patens. The end insert was then tapped into position and the sleeve glued on with epoxy. So far so good

Next thing was set the new tubes into position to ensure that my marking out was accurate. This would mean putting together the front section of the cockpit framing including the engine bulkhead. There was one tube that would not be put in place at this stage. On this tube I had to make up a throttle quadrant as the original double lever unit incorporating a choke lever needed to be changed to conform with a mandatory mod. This had come about because the double unit had  identical levers side by side. no unreasonably the powers that be decided that this was not a good idea. However the mod notification included a drawing of the replacement, so that’s another little job. Making up a spacer so that this tube could go in later I pressed on. Only to encounter another little problem, this time one of my own making. The diagonal tubes that run that run from the cockpit frame to the top of the engine bulkhead could not depress far enough. they being prevented by bolts below the top mounting brackets, some clot had put them in the wrong way around. Damn, to turn them I’d have to remove the top fore and aft tubes of the rear cockpit frame. Oh well, on with the motley, has anyone got a use for secondhand Nyloc nuts? When that is done and the tube work and bulkhead assembled I shine a torch into the bracket holes and the cockpit end and my little cross marks show nicely centered. My mood restored I slip the tubes out and drill them. Replacing them I check the forward holes and my little crosses are again just where I want them. All my pedantic measuring and aligning paid off, good stuff.

Now I ought to start getting my mods sorted with drawings, photos and calculations. As one of my main ideas is to re route the seat harness to save my spine I need to make sure that my proposed route will not foul the fuel tank or control runs. In order to sort this I’ll need to fit the tank. To do that I’ll have to offer everything up to see just how Jim Romain did it.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s