Hello all,

Since getting many tips from this forum last month, and finding a source of Blue Styrofoam in Australia I've been having fun with some Tiny Treasures. The designs are from David Theunissen's excellent site www.flyelectric.ukgateway.net/

Both planes were built primarily for indoors, at which they excell, but I havn't been able to resist many before work flights at the local park either. The Nutta darts all over the place and is real fun to fly close up, but the Extra 300 is closer in flying characteristics to a larger aerobatic model and handles some wind better.

Thanks to my friend and test pilot Grant for the photos.

Graham.

The Extra has IPS B drive with 2 x 1020 Kokams and a 1047 GWS prop. Weight is 170g. It will almost hover with this combination. We tried it with 2 x 640 Kokams and it did hover but I am woried about the effects on battery life of the current draw with this set up. It probably draws 1.8 amps, which is nearly 3C.

I used top and bottom 0.3 x 2mm carbon strips epoxied to the foam to stiffen the wings. and fuse. This is lighter than the recommended 3mm tube, and is adequately stiff in bending, but adds no tosrional strength. I will think about a more optimum system next time.

Graham.

The Nutta has an IPS A drive with 2 x 640 Kokams and a 9070 GWS prop. 145g flying weight without wheels, 152g with wheels. This is a nice light and compact plane with a brilliant roll rate, and even better pitch rate. It will do loops from head height coming out at the same height or even slightly higher. Loop radius is about 2m or less. It is great to fly around yourself in close circles. The curved wing plan form helps in crashes, it just rolls around in a ball when it clips a wing! Inverted circuits, loops, and rolls indoors are no problem.

I first flew it with 6 x 110 Nicads, but with the wheels added it was marginal in climb rate. The Li Polys make all the difference!!

Graham.

Both planes are wonderful designs that fly brilliantly, but for different reasons. They ended up relatively low cost scratch built planes, although the batteries are a bit over the top here in Aus. ($100 plus for the 1020s). Fun for dollars they are great value.

And finally, a flying shot at our local electric club site at Fagan Park, Sydney.

Thanks David for the designs, Bill for the advice, and Grant for the photos.

Graham.

I live in Australia and can't find this foam. Where did you get it ?

As far as I know, the Kokam 640's are high discharge (mine are) - they should be fine with that current draw....supposed to be good for between 6-10C.

Tipsy,
Give me a call 0412 056 300, and I'll give you the details.

Soundman,
The importer here is a bit thin with information on the Kokams. The data sheet for this cell on their web site simply says max discharge current 2C, and there is a general statement that 5C is OK for "pulse discharge". I figure prop hanging and climbing out is probably more than a "pulse discharge".

What is your experience with these cells? If I discharged the 640 at 3C how much would the life be shortened? Can you give me a link to a more comprehensive data sheet?

Graham.

I've been doing some more research and found out that Kokam have at least 2 nominal 640 mAh cells. Mine are SLPB353462 (Kokam number I think), and there is also an LP640HD high discharge cell which is aparantly good for 5C continuous and 7C max.

Looks like I'm limited to 2C or about 1.3A.

Graham.

G'Day I live in Perth and was hoping to get a hold of some blue foam. I did manage to track some down when I was in Melbourne at Xmas time but the cost of transport to WA was prohibitive. Does anyone know of where it can be purchased in WA?

Cheers

Try Bunnings - ask for insulation foam. I saw some at the Balcatta store.

Alfred,

Is this fan fold foam you have seen in Bunnings?

I looked at that, but the fan fold here is lower density (and strength) than the foam I used, plus it doesn't have the well bonded on skin that the US fan fold has, plus it only comes in 6mm thickness which is too thick and won't bend to give a cambered airfoil unless you heat form it.

Graham.

Hi Graham

Yes, that is the one. Fan fold is like that, it is not very stiff and a balsa or carbon spar is needed in most situations. It works well enough. I prefer to use the white poster board.

If you are willing to slice blue foam, you can get it at most construction suppliers. They use it as a light filler for floors that cannot take a thick layer of cement due to weight. I have seen it in Perth before, but I don't have a supplier's name.

I am in Singapore now and will be moving over in a year's time, so I am trying to source all the materials before I come over. Can't let the hobby come to a stand still!

Worst case, is that I will bring heaps of it from Singapore when I make the big move!!

Alfred

If you have the chance try a change in power plants, use a 4.8V RLC Light Power System (GW/LPS-RLC-B) with a 7060 prop on 7.4v's. I've been running one for about 40 flights now with no signs of the motor letting up. Motor runs alot cooler than my IPS S1 or A drive in the same plane and the planes have alot more getup and go. I've flown 7 1/2 oz plane with much more ease with this power plant than with the IPS's. Just a suggestion.

Heres a couple for ya. Both have been flown and fly great. Can't wait to get them in the air together.

Thatovalguy,

Nice planes. they look great! Just when I was starting to get bored with blue foam you have opened up a whole new range of possibilities. Can you post more pics? How have you mounted all the radio bits and batteries? What is the flying weight? What batteries? Do they have ailerons? If so how did you do the linkages?

So you're using the 4.8V RLC with the B drive right? According to the GWS site this draws about 3A at 4.8V on an 8060 prop. So on 7.4V it would be drawing much more than 3A even on your 7060 prop. Will it handle that? Are you sure you're not using the RXC 7.2V variant?

Sorry for all the questions, but you posted!!

Graham.