All of these pics were taken 12/2002. We were busy trimming fettling and tacking so obviously didn't find time to document as well as I'd like. They do however, show some interesting bits of the jig and the pile of tube which we converted into airframes. Four and five show a completed airframe. Six shows the other three standing patiently in my garage. The last one shows the lozenges we added to the top of the mast. The thought of hanging from six inches of butt weld just made my hair stand on end. Physics tells me that there's plenty of strength but the organism revolted. Look upon it as an ounce of insurance against the welder having a bad hair day.
Here's a few pics of the controls. We knocked up a simple fixture in MDF to support the bits for tacking and the results are above. The roll limit stop has provision for a neoprene tube to be slipped and wired over each horn to avoid metal to metal contact. We added a primer coat on everything, as we expected them to be hanging about for a while before we sent them off finally for powdering. We incorporated a ballrace at each end of the roll pivot to match those in the pitch axis. Each end of the tube had to be bored out about .010 to accept the race and we have an internal spacer tube which can just be seen in the pic. Except for the last one, these shots were also from 12/2002.
Some shots of the embryo rotorheads. I did all of the machining except for the gearcutting which I shopped out. I was lucky to find a local shop with a gear hobbing setup. He did all of the gears in one pass. I machined the plates to size from cut discs and made a mandrel which clamped them together so he gave me back what looked like a single gear, nearly two inches thick. There's still lots of work to be done at this stage and I've left some meat for finishing after welding. It will be interesting to see how much is left after final machining. You'll notice that there are six of most items here. I like to make at least one spare as I go along. It's easy then to prove a setup without the worry that one of the real pieces will be scrapped. Notice that there's a torque tube missing? Despite checking everything twice, I managed to counterbore the recess for the &deity bolt on the wrong side. And then there were five....
The first mould we made for the main gear spring and the rather rough result. We laid up a spring just two metres long and 32mm square from UNI tape and have been jumping on it regularly since then. So far it hasn't shown any signs of deterioration, no delamination and no crunching noises. We're going to set up a test rig so we can clamp some weights to it and drop it repeatedly from about six feet. We'll see how that pans out with 600Lbs! The bow shape is copied from the plans but the crossection is square. It's really difficult getting a good shot of an article like this so you'll have to put u with the grass and flowerpots. I'm going to see if I can have an aluminium mould with an oval crossection machined up so we can try the resin infusion process. It should avoid the mess of wet layups as the glass is laid up dry in the mould. It should also make it easier to control the glass/resin ratio. I'm looking to the future when we mould the rotor blades. If it's a success with the gear then we should be able to use the same process for the blades.
