Light Aircraft Association

As the title suggests, has anyone got a source for a light tailwheel assembly (inc brackets) to go on a small tailspring? Minimax sort of size.
If you've got any pics of suitable items on your own pride-and-joy then I'd be most grateful for a photo.
I've got a 'Flexello' wheel assembly but it is rather heavy.

tessa dot thomas at tesco dot net is the e-mail.

Ta

Have seen 4" diameter plastic wheels from a kids scooter used on a Taylor monoplane whith no problems. Very light, sealed ball bearings, relatively soft solid rubber tyre for shock absorption. Make the bracketry from 4130 as light as required...

I replaced a very heavy steel leaf spring and Supermarket trolley wheel/castor on Taylor Monoplane G-SUZY with a much lighter laminated GRP spring (Pazmany book used as a guide) and an own design locking tailwheel unit. The plastic spring worked OK for the short time I flew it, but did make the tail end "bounce" up and down when taxiing on anything less than a dead flat surface. The wheel was a small pressed steel/rubber commercial item - this also worked OK, but wore out fairly quickly on hard runways.
I bought a few rollerblade type wheels, but never got around to trying them!

Pazmany book? New one on me. Any chance of some more details or any pics? Might be a good solution.
Thanks, Ian.

tessa.thomas 'at' tesco.net

Cardiffrob,

The book was "Landing Gear Design for Light Aircraft" : L. Pazmany & I think it used to be available from the PFA bookshop. (I borrowed mine from the Devon Strut "library" many years ago.) There may be other books now that have more info. on composite landing gear design?

Ian

It's listed as "Currently awaiting more stock". Go to the LAA On-line Shop link & put Pazmany in the search box. You can also get it from Amazon sellers but at rather inflated prices. Or from ACS for $65.

I made a fibreglass spring rather than use a steel one on the Menestrel to reduce weight and I agree with the earlier comment that it is a bit bouncy. Having said that, I feel that it protects the back end nicely against rough ground and has certainly stood up to some fairly rough treatment. You can also make the spring to just the shape you want and not have to accept whatever shape is available.
I used the shape suggested by the plans as a template and just thickened it up a bit to gain a bit of ridgidity and then used a unidirectional glass cloth, West epoxy and a wooden mould to produce it. I found that using a slow epoxy was the best way to avoid dry drying out during layup and subsequent separation of the laminations (you need a lot of them).
The end result is nicely flexible but massively strong and light.

Is there a published 'method' for doing this sort of thing? Nothing googleable that I've found.

Try these guys: http://www.carboncopyuk.com/acatalog/Ai ... lates.html

This is all model aircraft stuff, but when I contacted them a few years ago, they said they could do one off parts like tail springs for light aircraft without much fuss. They will tell you everything you need to know if you want to do it yourself, though I would probably recommend giving them a mould to work from and let them make the part for you.

I found the hardest part of the job was making the mould - once that's done, it's really just a matter of choosing your materials and plodging away with the epoxy. And the most rewarding part of the job is breaking open the mould when the resin is set - so it would be a pity to give the best bit to someone else !

Since the choice of lightweight tailwheels has been explored, can I highjack this forum and enquire about main u/c wheels. Are there any foam tyred wheels about - something about the size of those battery powered scooters that you see pensioners hurtling about on. This for the SSDR construction.

Bill, Do you mean something like this? http://watsonwheel.com/ (no idea how much they weigh -- may not be a major consideration for garden equipment!)

Roger, how many laminations and what weight of cloth did you use?

P.S. Carbon Copy have an excellent reputation with the r/c modellers (I am one)....

I was searching last night for invoices for the materials but can't lay my hands on them right now - fairly sure the glass was 175g unidirectional 50mm wide tape and the number of laminations was lots ! I just kept going until I reached the thickness I wanted of 18mm - which fitted the tailwheel I have.

I'm sure the spring would have been strong enough even if it were thinner but I wanted to reduce the bounce from having it too flexible.

I guess you could use carbon but I didn't see the need and I find it harder to work and wet out nicely.