ptwizz

If that's true, your dreams are not nearly imaginative enough.

This is a good reason to manually check prop clearance before starting. When I've fitted the prop, I get hold of each tip in turn and rotate the prop through one full turn, checking that there is clearance to the cage, engine etc. all the way. A backwards blade won't clear the engine, so it's not possible to start. This check will also show up errors in cage assembly, sagging engine mounts, things dangling through the netting etc.

Between a new job, starting NPPL training and life in general, I have made some progress with the engine: The first picture shows one of the barrel base plates. 7 of these make up the outside of the crankcase, with a cylinder barrel mounted to each one. In this pic, the plate is bored and drilled but has yet to be machined at the angled ends. The second pic shows the setup for machining the angled ends. These are individually matched so that when everything is bolted together, there is equal compression in all the joints. The third pic shows the crankcase partly assembled with 3 of the barrel base plates machined and one part machined.

This concept has been around for a while now and I believe one has flown in tethered tests. http://www.hover-bike.com/MA/the-hoverbike/how-you-can-own-it/ Presumably requires a heli license? Noteable that it uses a BMW motorcycle engine. See any of the microlight forums for experience with these engines in aircraft. With fixed pitch fans (i.e. no autorotate facility) a full recovery system would be essential.

All clear, thanks Wayne.

Cheers Simon. NB it's not my C42. By the time I've got my license, I may be able to stretch to a very used Thruster

Do I read correctly, this is for a pilot with NPPL(M) to add a Powered Parachute rating?

I can't say for sure, but I doubt that the Bailey generator has 26W going spare. My Bailey 175 produces enough to recharge its battery in about an hour of running. A small modern lithium battery like this http://www.maplin.co.uk/p/brunton-torpedo-2800-portable-power-bank-silver-n28dt will heat your gloves for over an hour.

Handy guide:

Translation for mortals: Hide (or actually fix) the error before it is abused by a virus.

Get well soon Pete. Looking forward to seeing you at the Fly-in.

As with other safety gear, tell us what crash you're going to have and then we can make recommendations. What would be the benefit of a small reserve to a relatively new pilot? Go for a big one. If you can mount it on your lap with a double handle (where you can see it and reach it more easily), why wouldn't you? As you gain experience and confidence, you may decide that your reserve is too much weight, or that a front mount doesn't leave room for instruments, lunch, etc. Until then, I would suggest that you err on the side of caution.

Very interesting paper on the Phoenix inflatable. It is mentioned that it contains 200lb of air. replacing some of that air with hydrogen would reduce mass (allowing faster acceleration) and weight (allowing slower flying). Hydrogen is preferable to helium as a lifting gas for many reasons. The perception of fire risk is misplaced.

So long as the boyancy of the helium in air (about 1.1grams per litre) offsets the weight of the gas bags, you would reduce the effective weight of the aircraft. The relatively small dimensions of the wing pockets would force the use of small gas bags, so the ratio of bag material to helium would be poor compared to a simple balloon containing the same volume of helium. So, broadly yes, you could add some bouyancy by filling the wing pockets with helium balloons. I'm guessing there could be a range of issues associated with obstructing the movement of air within the wing, the way the wing is launched, the way it moves in response to control inputs, the way it recovers from 'aerodynamic incidents' etc.

I think Rob's point was that if you replace your 'saggy' mounts with stiffer ones, you may have a vibration issue.

Booked holiday from work on the Friday. I now have a van, so will have room to bring some lumps of engine for others to point and laugh at. The site is close enough to home that I could actually fly in.

I will let you all know when the first 'public' run will be. I will be making a test stand so that I can take the engine to events (such as the fly-in). Don't expect to see it running this year. Don't get your hopes up for next year either.

Performance is not really my goal here. The supercharger exists primarily as a means of improving mixture disribution between the cylinders. The ability to add some modest boost is a bonus. This week, I have mostly been marking out and machining heptagons. I have also learnt to post the pictures in reverse order so they show up in the intended order.

2300cc. I'm aiming for about 100BHP at 3500rpm. The heads are from a motorcycle engine which develops 18bhp per cylinder, so I think that 100 total (approx. 14 per cylinder) is not unrealistic. What happens when the supercharger is engaged is anyones' guess. I've had a swipe at the boost pressure calculation, but there are so many assumptions that I can't have any faith in the results. There may be some fettling of supercharger gear ratios when it's up and running.

Temporary assembly to verify correct balance. The counterweights match the sum of the oscillating parts (rods, gudgeon pins and pistons, I balanced the rings on the pistons for the check). Also a photo opportunity.

Seven pistons

Boring the valve head clearances.

Turning the ring grooves.

Milling the pocket in a piston.

... and now I need to make the trip to Membury.