After assembling the engine it would not turn over, the piston was hitting the head! My boring of the crank web must have been a few thousand out giving a longer stroke. I have now fitted a thick gasket between the crankcase and cylinder and it turns over fine. Hope to try running it soon, fingers c...

In Steves equation the 4.4 is the milliamp hour of the lipo i.e. 4400 changed to amp hours then times 60 to get to minutes.
He then divides the amp minutes by the amps to give minutes! Simples!

Barrie

Cary, I think the torque is constant but the force increases as the distance decreases, and of course visa versa.

Barrie

I finally got time to machine the parts and fit a bush between the shaft and the disc, these were a made a tight fit and then 2 off 3mm pins inserted axially between each of the parts. Not sure if it will work but enjoyed the challenge.

I think Falcon Aviation make and sell them.

The fan you looked at would do the job and cost over twice as much and need 8 or 10s lipo!
Is the esc you have HV or not, what voltage will it handle?
With edf you need the highest c rating you can get as the currents are high.
You would get around 4 mins flight time.

It gives 3.2kg thrust at just over 90amps would need a 6s 5000mah lipo

Barrie

Hi Luke,
Gliders at Newark sell a nice 90mm edf with 14 blades including motor for £99 needs a 120 esc and 6s makes a good turbine sound. A clubmate has two of them.

Works fine now, thanks Rob.

Cheers,
Barrie

Hi Rob, just tried again and it still says paid up until 31/12/16

Cheers,
Barrie

There was a tool similar to this in every kit of the Regal Eagle by Paper Aviation, I've still got mine somewhere in the shed.

Now sold, thanks

A few pictures

For sale is my YT Cessna 188 crop sprayer, it is powered by a Wren 44 turboprop, but I am offering this as airframe only, including 8 servos. It is fitted with gas strut suspension. Wingspan is 110inch suitable for 50 to 80cc petrol engines. Colour is white and yellow. A blue and white one is shown ...

I have found the instructions that came with the engines ( I bought 2 ) they are Wolf Predator not Matador and built in the USA by A J Engneering in Ilanois, think they only made a few hundred using Homelite barrels.

I don't have soft jaws and the bore is worn so having difficulty finding the centre. If I know the stroke of the engine then the centre is half the stroke from the centre of the crank pin is it?

Thanks Alan, 8mm was the biggest diameter I could get and remove all the flat, that's why I went that small. With the web is it best to spin the web and bore it or mount the web fixed and then use a milling cutter?

Hi Tony, there is a flat in crank web hole so I need to remove the flat first before getting the bore true.

Gave up on the boat so started a repair! I have turned the end of the crankshaft down to 8mm then made a bush and pressed it on. Now got to figure out how to bore out the crank web? Maybe just set it up in a 4 jaw and go for it.

What size boat then???