Hi friends,

just would like to introduce you my latest project.
Its an enlarged Backlash with a XXtreme tuned 58cc Zenoah twin engine and electric ignition (Matho Powerspark). The aluminium pipes are from ChungYang, just removed the water cooling flange of them. For the maiden run I was using a small propeller (ABC 3116-2) just for testing.
The length of the Big Backlash is about 1,40m. (Length of Original Backlash: 1,25m)
I was looking for a special and unique project which doesn't exist so far. I think it should be the first and only one Big Backlash in the world. Or not?

Here some pics:

The maiden run was beginning of May 2014.

Maiden Run - Part 1


Maiden Run - Part 2

Now it needs some height and angle adjustments of the strut and angle adjustment of the turnfin. Then she's ready for the next run.

I'll keep you up to date!

Greetings
Johannes

Very cool build. Engs sound good. Gotta love the throttle response with the power spark. Good luck testing. Keep us updated as you get it setup.

It looks Fantastic! Can't wait to see some video.

Very nice and cool build

Looks great! Did you streatch the back of the hull?

I didn't stretch the back of the hull. The whole hull is 12% larger than the original one. Means this Big Backlash scale is 1,12:1.
So I printed each frame on paper and glued the paper on 2mm plywood. Afterwards I had to cut out each single frame by using the electric saw. That was a "nice" work @@. In German we say: It's called model build and not model purchase. Means everybody can buy parts from dealers but to built something with your own hands is a different thing. So that's what I'm interested in and I love our hobby!

Cheers!
Johannes

Excellent

"It's called model build and not model purchase. Means everybody can buy parts from dealers but to built something with your own hands is a different thing. So that's what I'm interested in and I love our hobby!"

I couldn't agree more. Makes me wonder why, when the entire hull & all hardware are purchased, it is referred to as a "MODEL BUILD"? Is your cowling vacuum bagged or is it laid up carbon fiber on a mold.

Jim Allen

Actually I was using a very interesting and simple method. I know that it would work out cause I was using this merged for the cowl of my twin rigger already. So I had some experience in producing a good cowl.
Picture can explain better and easier

First I soldered a sort of metal frame.

Then put some thick paper on it and fix it with hot glue. Bring it all in shape.

Then put some self gluing plastic foil to have smooth surface.

Several layers of carbon/Cevlar and full carbon

Then some grinding and the final carbon layer.

After grinding and spreading some more very liquid resin the cowl is ready. It's very stable and will survive some potential blow over. Hopefully...

Greetings
Johannes

Delete post.