Due to pilot error, I have a 70 free and clear (literally, about 10 yards free and clear)... I also have a Sig Midstar under the bench. Has anyone built the midstar around an OS70 before? Any experience out there? Thanks.

My daughter and I have a Midstar..put a 46 AX on her that's plenty of engine...so a 70 4 stroke would be in there

Weight and prop clearance would be a problem. Maybe you could set the firewall back a little as that OS70 4stroke is much heavier than the engines the plane was designed for.
Fred

Agreed Fred... I know I would have to beef up the firewall and add size and weight to the tail... I was curious if anyone has had success with this combination or am I "on my own" with the kit bashing. Do you have a Midstar and if so, with what engine?

Thanks for your insight.

built two mid stars with 46 ax, did it with two threads here in kit building forum.
battery behind the servos, it is flying very well, 11x5, 11x6 props, no prop clearance issues, build as a tail dragger.
You can change the landing gear.
Came out less the 5 lb flying weight.
I have also four stars, the mid stars are flaying better.
http://www.rcuniverse.com/forum/m_6569140/tm.htm

Alex

I've got an ST .51 in my mid star, and there was more than enough room to move the servo tray and battery to get it balanced right. While I haven't tried a .70, I bet it'd work just fine and balance by simply moving the battery back a little. It is going to be a tight fit though. Getting the engine bolted down to the engine mount might be a little tricky with so much engine in a .30 - .40 sized engine compartment.

I have my battery behind the servos as well....