Monday, 28 December 2009

The Obalob Method of navigation

I was looking for a cylinder which would wrap around my leg to provide a "slippery" map-board which could allow me to rotate a map around my leg (see this earlier experiment). Then Lizzie, a keen gardener, suggested using a plastic flowerpot! Genius!

As an aside, watch Bill and Ben, the Flowerpot Men (BBC, 1953),
as only anyone of my generation will remember where obalob comes from.
(whiz past first three minutes)

I cut the base off one and slit it top to bottom. Then I colour copied 2xA4 views from my 1/4mil chart of England South, stuck them together and laminated them (interleafing two A4 pouches carefully to make a longer one), mounted the chart around the pot with duck tape and then tightened the pot around my suited leg, securing it with a final bit of tape (in the final version I think velcro might be more suitable).

Ordinarily, I could expect to get a map of the route from Sutton Meadows to Sackville on one leg, but my new method allows a flight North-South from say Sutton to Peterborough or East-West from Sutton to Leicester. That isn't a massive distance (45 x 25 Nautical Miles), granted, but one leg-map would cover all my favourite
airfields, including Sackville, Sywell, Leicester, Bakersfield, Deenethorpe, Grafton Underwood, Kimbolton, Chatteris, etc. And for a novice like myself, that is more than enough to be getting on with while I hangar at Sutton for the next few months. (see 2nd Update below!)

I will risk the ridicule. It is a "potty" solution but an efficient one, which will allow me
good access to undercarriage controls and a clear view of the countryside below me and instruments in front.

I have now fitted it out with velcro, so that it is fully functional; no longer just a prototype. I made a point of putting the fluffy side closest to my leg (wrapping a length of it along the inner and outer of the rough edge), so that the inner surface will slide easily against my suit. I will secure it on top of my leg then just slide it round. Simple.

I am really pleased with it.

2nd Update
While fixing the pot to my leg just now, I realised that I still have room for another 35 or 40 nautical miles under my leg (near the fixing velcro)! This could be a different route . . . leg, if you like, ahem. . . or the space could be used for landing / circuit info for the destination!

Sweet as a nut!


Sunday, 27 December 2009

Sod the Rules

The highlight of xmas was this t-shirt from Lizzie, by Ben Ashman, who as well as being a cartoonist, designed my Dragonfly. He is also, famously, the designer of an outstanding powered hang glider, called a Doodlebug. And a year or two back he fitted a jet engine to it and stunned a crowd at a flying show (watch it through - the sound alone is worth it!). Some of us are nagging him to fit a jet to the Dragonfly...and this t-shirt is the idea in blueprint!

Thanks Lizzie xx

Friday, 18 December 2009

a freebie from flylight

Ben Ashman has offered to solve my monopole bearing plastics problem for free! They are using different plastic sheets now and new adhesive.

Ben said, "
Since we changed to these we have had no more problems of damaging the plastic, it is a lot easier and does not effect the grip of the monopole. Your method will cause uneven clamping pressure on the monopole upper and lower tubes which is not desirable." ....I don't really understand this but Ben knows what he is talking about.

It means going up to Sywell, which is a bit of a pain (though nice to see the Flylight people)....and I wonder if there is a quick fix in the meantime, as I hoped to fly this xmas.

In the meantime, thanks Ben



With hangaring in mind, I just got hull insurance as well as my 3rd party and the whole lot came in at £233.60, which struck me as bloody good, when you think that covers me for accidental damage on the ground, fire, theft and public liability if I crash into someone. And having cranked up my flying hours, my deductible is half what it was last year!

I got it from OnRisk.
Maybe I should have offered the mention for a discount ;)


Tuesday, 15 December 2009

staying behind after class

The only trouble with my rather old vario is that it had only a small area on its oddly shaped bodywork which could act as a velcro surface for fixing it to my binnacle's face, so today I designed and made a mounting bracket using scrap polythene and the strip heater in the school's DT department. The solution, which is lined with velcro, more than doubles the surface touching the binnacle...and when I tested it out, it was bloomin' difficult to remove....No way will it just fall off, however severe the jolt. But just in case, there is a safety lanyard included.

It looks pinkish, but actually it is very nearly the same red as my Dragonfly :)
The photos I took are really awful (must be able to do better than my phone)...but they give the idea.

Rarely has a better hour been spent staying behind after school!


Sunday, 13 December 2009

articulated seat for seat-break rigging

I never can just leave things as they are. Now I have been thinking....wouldn't it be possible to make a seat which articulates (or with two or three parts) that it needn't be removed to break the seat tubes? I am working on it.

ok, I have now found a way to have a two part seat which will allow for a seat-tube break, while still being able to have the front two fibreglass panels in place. Now working on being able to have the rear-side panels fixed. Be very cool if, as well as being able to have the seat of a naked Dragonfly which can be left attached when rigging, it could be done with a fully faired one. That would be worth patenting!

Sutton Meadows for the winter.

Last night I rang Mary Robinson at Sutton Meadows and confirmed that I am going to keep my Dragonfly up there for the winter, semi-rigged in a hangar bay. I think I will get more flying in. I will keep my wing rigged and use the seat-break method to fix my trike to it. It means a longer drive, but time saved rigging and de-rigging the wing will more than compensate....and with less time taken with de-rigging at the end of the day, I will be able to fly closer to sunset - this is more relevant in winter when the days are so short.

I may keep the trike there in the bay....having the option to bring it home for fiddling around with. I have a lockable steel box which I can keep tools etc in, and I think I will make a shelf unit for panels etc. With everything to hand in my bay...waiting for me at Sutton, all I will need to do when I decide to fly is grab my kitbag and leap in the car (at present I have a couple of hours of loading and prepping before I can set out, and I need someone to help me carry the wing to the van..around difficult corners).

I think Sutton is really the way to go.

Also, flying from Sutton will mean that Lizzie and I will be at the same field, which will be fun
. And if the trike is at Sutton, we will be able to go up together in the van.

how I plan to modify the monopole

You might need to click on the image to see it clearly (not very well sketched)....but essentially the modification I propose is one which will stop the plastic getting snagged as the monopole slides in between the two splinting plates (no idea if they have a proper name). A single sheet of plastic is heated and formed around three faces of the monopole (the rear and two sides), then the holes drilled out again....and the plastic countersunk to avoid bolt threads snagging it. Incidentally, I have drawn it too needs to be long enough to accommodate both monopole bolts.

An alternative mod Dave Broom suggested was that the plastic be stuck inside the splinting plates, as Ben designed it, but that it have a flange. What is encouraging about the fact that Dave had been thinking about it, is that it meant that others had encountered this problem; not just me rigging badly. I think this probably happens anywhere that rigging is being done outside a hangar......the slightest wind getting under a tip will make the monopole twist as it slides between the splints.

frustrations wiped out by glorious flight

Finally, after hours of rigging hassle yesterday, I flew......and the sheer pleasure of independence in the air wiped out all the frustrations on the ground.

I had just about rigged my wing by the time Steve landed at Rougham and I felt I was making good
progress, though I regretted using the semi-tensioned method which I had forgotten had been such a hassle before, and had to take several battens out to allow me to cam-over the tip-wands.

Steve landing in G-IWIZ

Poor, long-suffering Steve should have flown on by!
Once committed to lending a hand, he became caught up in my problems rigging my trike. I think essentially that the short rig is just not suited to out-of-hangar rigging....the hint of wind on one wing-tip is enough to twist the base of the monopole so that it grazes the plastic bearing sheet inside the trike splints and rips and buckes it.

The twisting is quite horrible to watch, Steve says. I had to lower the wing and then remove the plastic at the base. Then, when Steve raised the wing again I couldn't get the monopole holes to line up....incredibly frustrating. I was all set to give up and go home, but Steve saved the day, not for the first time, by suggesting we try a seat-break rigging, which is the way it was originally designed to be done....before the short-rig was designed to enable users to keep their panels on their Dragonflies.

hen he must have been regretting having landed, Steve was treated to the sight of me falling flat on my face in the mud in my idiotic propeller beanie, when I tripped on a cable. I think that must have cheered him up.

Steve demonstrated the seat-break method....and it was so much easier! Fact is, I like the really is great design...and so much more stable. It worked great! Steve flew back to Honington before I started flying and once I had flown I had the challenge of de-rigging without his assistance. Splitting the seat tubes is a smooth process. It went fine.

Steve is feeling very pleased indeed that he didn't bother with panels, and I can now see why. That said, once you have your seat on again, fitting panels would not be too much bother really...and not nearly as time-consuming as other processes involved.

Flying was glorious! Having boshed just about everything up on rigging, I decided not to push my luck and raise my undercarriage, but all the same, the flight ticked all the boxes. I flew three extended circuits, skirting Bury St Edmunds, did three sweet landings and one too-high go-around...and left the circuit heading North for a little while, just bimbling about. Wonderful. (total 1hr 10)

De-rigging, as I say, was straightforward, though I finished off in the dark. I made a neat job of packing the wing; I'd thought that would be one of the hardest parts when it was first demonstrated, but I make a decent job of it now.

A long day, but I realised as I soaked in the bath, that even when it was going badly, I had enjoyed every bit of it.

Thursday, 3 December 2009

Tuesday, 1 December 2009

a cure for wind

The BMAA magazine carried an article a month or two ago, which caught my imagination: what if it is too windy to fly? Why not exploit that wind and sail....ON THE AIRFIELD!

I love it! It is inspired!

At the Flying Show I met Jane and Mike, who sell the X Sail land-yacht, and a very tidy bit of design it is! Lizzie and I have given serious thought since to buying one together, though it will only be practical if I am able to persuade Rougham Estates to let me "fly" it there, as I don't know if there is anywhere more suitable nearby. It may not be practical, as grass is not the ideal surface (friction)....but tempting nonetheless.

The whole yacht assembles without tools and breaks down into a bag which can be carried in the boot of a car...and for those of us with bad backs, it can be pulled along on its own wheels, as the bag wraps around the knocked-down fuselage - ingenious!

As a design graduate I love clever design! Have a look.