engine for Sig Actomaster

[Dan Burns]

Hello...This is my first post, so please bear with me for any inadvertant "foe-paws". I have a question..Would an OS25fx be too much engine for an Acromaster? I realize it's an r/c engine, but I'll just wire the throttle wide open as I have done on other motors. Or maybe make the throttle ground adjustable. Whatcha think? Thank you in advance for your replies.    Dan

[John Tate]

Dan.
I would thank the .25 would make it a little nose heavy. I am running a .15 in mine.
John Tate

[Dan Burns]

Thanx, John. If it's a little nose heavy, how about shortening the nose, say 3/4 or maybe an inch?

[Garf]

The thing is designed for the light .15 engines like Fox 15X, and Cox Medallion 15. The high powered .09 or .10 engines would also do well. 

[Terry Bolin]

Dan, the 25 would just be too big to be friendly. You would enjoy the plane alot more if you could round up a 15 from maybe a swap meet or used somewhere else. Good luck!

[Alan Hahn]

I ran mine with an FP10.

It would be overpowered with an LA25. With the 25FX it would be darn near supersonic! If you still want to try, use as low a pitch prop as you can find--like a 9-3 or 10-3 perhaps.

Actually nose heaviness is the biggest issue.

[Bill Little]

Hi Dan,

I have to agree with the others.  That ship was designed for the old baffle .15s.  Light and not real strong.  It has a 3/8th" fuse, IIRC, and a 25FX would be a problem.

An LA 15 would be plenty to fly it with no problems, even an OS 10FP if you can find one (as someone else mentioned).  My son's used an Enya 19 (old baffle piston engine from the '70s) and it was still nose heavy with that!  And the old Enya 19 is significantly lighter than the 25FX.

I'll bet John Tate has a Fox 15X in his!

Mongo

[ray copeland]

Dan, the 25fx is defintely too much engine for this plane. They are almost too much for slow combat on 48 inch wings. I flew mine with an old fox .15 for awhile and then switched to a la15 and was much happier with the performance. The Akromaster is a great trainer and i plan to build another in the near future, mine met the dirt hard because of leadouts getting hung together after praciticing a bunch of consectutive outsides, i had left hard edges on the crimps and now cover every crimped end with shrink tubing. As was already stated the Akromaster will fly fine with a lot of different engines in the .10 to .20 size range.   

[Dan Burns]

Thanx for your input. guys...I will round up a 15 and try that..I'm running an OS 10 on a Sig shoestring goodyear racer, and it does o.k. Not real fast, but fun to fly around. By the way, what is a good size plane for my 25, in sq.in. wing area? Thanx again...Dan

[Russell Shaffer]

Why don't you move the .10 to the Akromaster and get a Flite Streak or Skyray for the .25?  As long as you don't have to fly the Akromaster and the Shoestring close together it should work. Flite Streaks and Skyrays fly VERY well with 25's. 

[Geoff Goodworth]

Dan, we have one at our club with a 15 fp in it and the owner says it tries to bore him into the ground it goes so quick.

The fuse is only 3/8" thick as Bill suggested and I have one ready to cover and paint that will use a 10 FP. Even for that, I did a moment check with the weight of the little Fox that it was designed for and had to shorten the nose. I'm not convinced that I took enough off the nose but if I had gone further, I would have had tank problems.

Use an FP 10 or a Thunder Tiger GP 10 if you can get one.

Cheers, Geoff

[Bill Heher]

I fly mine with an OS .15 FP, and am sure it would do fine with a .10.

One thing to consider before cutting the nose back for balance is fuel tank space. Another choice is to extend the rear of the fuse 2-2.5 inches to help balance it with a modern muffled engine.

[Clayton Berry]

You really have only one choice.  Forget the Foxes and the Enyas and even the OS Max III suggestions.  The only engine for this plane is a Cox Olympic 15 from about 1959.  Coolness is a major aspect of this round and round flying, and a beautiful red bue and silver Olympic is clearly the only way to go if you want to remain cool, pick up chicks, and have a line form just to take a pic of your cool machine.

And leave the flaps stationary.  The thing will do all of the pattern stuff, but it ain't quite a stunter.  Alas, what a cool plane.

Let us all know.  You can post a pic of you and two babes with the Olympic mounted, or you can show us the broken pieces attatched to a steel fin Fox.15 that was worn out just after break-in.  You choose.  Re-construction articles are always welcom.

PS - wear earmuffs.  Boogers are noisy as a Chuckie Cheese on a Saturday afternoon.

[George]

I have one with a Thunder Tiger .10 and another with a far from worn out slant plug Fox .15. 

George

[Neville Legg]

Clayton, what colour is the sky on your planet? Man, you've been reading to many of those Fast Richard articles from the '60's in FM!!!

Cheers       Neville

[Clayton Berry]

Was probably recovering from a half hour of Chlesea Lately, and in a good mood.  Now that I've kicked the cat, I'm still in a good mood, albeit a bit different.

I had one with the last OS model 15 before they went schneurle or whatever (FP).  Max III, I think.  All film, and probably pretty light.  Stationary flaps.  Was a good combo.  May build one soon for my little guy.  Then again, a Skyray would probably be a quicker build.  Hmmm.

Gotta go.  Them chicks wanting see my Olympic are scheduled only two hours apart.

[Russ Danneman]

mine has norvel .15, flys nice. sharp looking akro you have  Bill Heher.  r.d.