The plans show a 2 deg down thrust, but the instructions (and plan) don't show doing anything to create this angle. I'm using the standard engine mount with the kit and an OS 91 FS Surpass.

Is the 2 deg down thrust built in to the fuselage?

It's been so long since I built my 4*40 that I don't remember. But check the parts (I'm assuming that you haven't started building it yet). You should be able to see a 2 degree angle with the naked eye.

Yep, started building. I will double check the centerline on the print and let you know. Can't tell by the parts. You have to align the engine to the mount using the plans as a guide. That takes some good eyes, which I don't have.

Yep, started building. I will double check the centerline on the print and let you know. Can't tell by the parts. You have to align the engine to the mount using the plans as a guide. That takes some good eyes, which I don't have.

On my 4*60 I used a YS 91 and a different mount. I did nothing except mount it and the plane flies very well. I would assume it's built in. Just my opinion of course.

I have to look at the plan again, but I'm sure the down thrust is built into the firewall.

There is not a center line through the engine shaft of the print, only the one showing 2 deg down. But by drawing a line back through the plan, I was able to determine that it's definetly not straight. The only thing I can see is the firewall is built that way.

Thanks all.

It's built into the fuselage.
Have a goodun,John.

The firewall leans "forward". It is built in and obvious on the sideview of the plans. Note that no side thrust is either built in or called for. It specifies 0.

Craig

I guess when you have bad astigmatism 2 deg isn't too obvious.

Makes you wonder if I should be flying.

They have things like corrective lenses to take care of astigmatism.

Hi hoppy,
had me one of those astig-----things once,but the handle broke off ,so traded it off for Futaba 9Z,IT ALWAYS WORKS OUT DOESN'T IT??
Don't worry bout the flying,most of us land in trees so we don't hurt the landing gear anyway, shoot, you like family.
Have a goodun,John.

I spoke to Justin Van Dee at Sig Mfg via email today. The engine thrust angle for the 4 Star 40 is 0 degrees L/R ( straight, no thrust angle L/R at all) and 2 degrees down. The 2 degrees down is built in to the firewall. At least as far as the ARF is concerned.

no right thrust on plan or instruction.
asked other owners with 4*.
some have right thrust others don't.

i moved engine mount around 1/4" or less to the left from center.
added washer or drilled mounting holes at an angle
to compensate for centering of the spiner.
that's how it tells me how to do it on other airplanes.

the question still remains...
is it designed to have right thurst or not?[sm=spinnyeyes.gif]

I am in the process of finishing my 2nd Four Star 60. Powered both with an OS 91 FS. In both instances I put the plane together as per the plans. The parts fit together so well that you would have a difficult time changing the placement of the firewall. My 1st Four Star 60 flew just perfect, best flying and easiest flying plane I have ever built. Based on this I would have to assume that whatever thrust is called for is already fixed in the design.