Airco DH2

[André Wind]

I'm building this model from a plan that I've reduced to 1:16 with a wingspan of 57cm
The engine that I'm going to use is a GM120.
Is there someone who can give an advice about the up and site trust?

[nickhawk]

Welcome Andre, I like the DH2 and it is definately in my future plans. I hope that the "sparkie " will be powerfull enough for a decent flight...   

[g_kandylakis]

Hi Andre,

looking very nice and quite interesting.

Regarding thrustlines on a pusher, have a look at this:

https://hpa.aeromodelling.gr/index.php?topic=159.0

[André Wind]

Thanks Georg,

The thread is very helpful.

[Stunthenk]

The interesting thing about this subject is that every side-view or pictures of a fullsize airplane I've ever seen shows a massive amount of downthrust on a pusher engine (which is actually upthrust when converted to a tractor engine in the same position). But every model built shown so far has a perfectly straight engine, either originally or after trimming flights. Anyone understand this?

[OZPAF]

I suspect that the drag of the fuselage is proportionally much higher at the lower flying speed of the models, moving the centre of drag closer to the thrust line.

John

[André Wind]

Tryout if everything is lined up correctly.
The struts are connected with small pieces of PLA that I've drawn in SolidWorks and printed.

[billdennis747]

Reply to stunthenk (are we unable to reply to individual messages?)
I built a diesel FF FE8 and it specified, and needed, no offsets at all. Reminds me of my 0/400 with tractor engines also close to CG which also needed none.

[André Wind]

One size fits all 
GM120

[André Wind]

Wings covered tissue and only sprayed with water.

[André Wind]

Printed a few parts with one layer and 5% infil.

[André Wind]

Still a lot to be done, but.....

[dputt7]

Nice work, well done!

[André Wind]

The last parts are drying after a treatment with dope and the last step is to paint them in the right color.

[g_kandylakis]

Hi Andre,

looks very nice! You could not settle for a simplier model?

George