1960s Coupe d’hiver postal comp

[billdennis747]

Looks nice. Don't put it in those trees; I've never seen a wood-coloured model before!

[cvasec]

Very nice, and a good glide.
Ron

[dputt7]

   Thanks for the video Tim, now I don't have to describe just how good it flew. It really did fly straight off the board.

[THB]

Thanks Jeremy - yes trial-and-error likely to be the best option.

Mike - thanks for your advice with the prop - I'm a single-blade convert now - half the work! No real lift about that morning - too early/cold. Polish designer Juliusz Jaronczyk claims "Coffee" will do 105secs in still air on 6 strands of Pirelli rubber, 6 × 1 mm, wound to a maximum of 320 turns. Mine has 6 strands 3/16in SuperSport. (I do have have some Pirelli - but it is long ago reduced to a crystallised form... I keep it out of nostalgia / a need for authenticity / hoarding issues.)

Bill - Thanks. With the name 'coffee' I couldn't resist doing it in coffee colour. When summer arrives the model will be exactly the colour of our larger field - brown soil and straw grass :-) Dave seems to be able to find his scale models painted in German splinter camouflage in bushland, so I'm up for the challenge!

Ron & Dave - thanks - yes very pleased with the floaty glide. We just need now to get some official flights in for the postal over the next couple of months!

cheers
Tim

[Jmk89]

I'm a single-blade convert now - half the work!

The issue that gets a lot of people about the single-bladed prop is the balancing.  As well as static balancing (making sure that the counterweight holds the blade horizontal at rest), there is a dynamic balancing issue caused by the blade creating  thrust and the counterweight not doing that. While there are theoretical/mathematical ways of calculating this effect and trying to work out the rearward bend in the counterweight arm that will correct for this (there's an article by Martyn Pressnell that calgoddard has referred to elsewhere on HPA 3), the May 1942 issue of AeroModller has a jig to empirically determine the correct angle.  I attach a pdf of the AM article

[Jmk89]

Here's a pdf of the Martyn Pressnell aricle

[dputt7]

I remember going through the single blade folder balancing when I built a Pinocchio and then again when I built another after the first was lost on it's fifth flight