I will be starting a Herr piper cherokee soon. Anyone have any advice? I plan on doing the aileron mod and maybe flaps if I have room. Will be using a bigger engine, an Enya .09 iv. Shouldn't be to big... Oh and bigger wheels for my grass runway. I'll post build pics as soon as I get started. Any advice would be nice.

Top Flite Schoolmaster has about the same wing area as the Cherokee. I used an OS Max .10 Baffle R/C engine on it, would really haul. This was with a 7x4 prop. Half throttle was like flying a Black Widow .049. Your Enya .09 IV should be comparable. Enjoy!

My camera was MIA for a bit, so its not going to be much of a build log. Any how here are some pics of the little Cherokee so far. I did not add the flaps. Not much room for them, and I think they are not really needed. I'm thinking about sheeting the LE of the wing and the back upper fus. Maybe even doing a build up cabin of some sort. I want to keep it light. Specs say it should be around 17 to 19 oz. With the larger engine how much do you think I can go over?

Just the motor will be likely 2 oz. over the .049, plus the tank. I would just make it and it will likely be fine. The tank does look like it will be kind of low. Maybe a sideways motor? It will likely work that way though?

Originally Posted by aspeed

Just the motor will be likely 2 oz. over the .049, plus the tank. I would just make it and it will likely be fine. The tank does look like it will be kind of low. Maybe a sideways motor? It will likely work that way though?

OS Max has good draw, but yes, could be a problem. Turning motor into a sidewinder or cocking at an angle might be a good solution, with tank mounted as high as possible. Sometimes one needs to be creative to be able to get things to fit with the muffler in place. Might have to move the battery pack back and rearrange servo location to get a good CG balance, IMO.

I plan on using a few rails to lift the tank up. It's not as low as it looks. I have used this engine in a similar set-up before. it has good draw..it should be ok.

Originally Posted by ithia

I plan on using a few rails to lift the tank up. It's not as low as it looks. I have used this engine in a similar set-up before. it has good draw..it should be ok.

That is good to know. I had a Top Flite Schoolmaster with an older OS Max .10 baffle piston (not Schneurle) engine, with an engine similarly mounted. I put the tank above the fuselage using double stick tape, which placed the centerline of the tank in line with the carb, solving the feed problem.

(OT) Without a muffler, the OS .10 had an exhaust baffle linked to the carb, to provide back pressure during idle. Amazingly at full throttle, it had the same loudness of an .049, but at half throttle or less sounded like it was muffled. At 3 oz. weight, it was light but a great upgrade to an underpowered .049 plane. I still have that engine, bought another in reasonable condition off E-Bay and have an Enya .09 with a similar baffle.

Loud pipes save lives!

So from my estimates it looks like the planes going to be 4 to 5 oz over the spec weight. I do have the larger engine on it. Do ya'll think it will offset the extra weight? My hope is that the extra weight will be negated by the more power full engine.

Definitely. Wing loading went from 9.3 to 11.7 oz/sf, which is still acceptable.

It will be nose heavy with that engine & not enough wing area. It's all about being light when you play with small aircrafts

It's got a 42 inch wing span and 293 sq. inches of wing area, so it can handle a .10 motor easily. It will not be a beginner plane with a slightly faster sink rate in glide but it will stand up to wind better. Regarding nose heavy, one compensates by altering the location of the flight battery pack, receiver and servo locations, to maintain the proper CG.

I know all about moving weight around...it's still going to be heavy...like a flying stone...so all i can say is keep it light! By the way Nice Build!

Originally Posted by ractsaf

I know all about moving weight around...it's still going to be heavy...like a flying stone...so all i can say is keep it light! By the way Nice Build!

No, I don't think it will be stone like. We are talking about 1-1/3 lbs., which is reasonable for a 42 inch (1 067 mm) span, 293 si (0.19 sm) airplane. It is not a 39 inch span scale combat with about the same wing area and .15 power weighing 2-1/2 lbs.

The reason for extra lightness was that it is spec'd for something as small as reed valve .049 power, hence the light frame.

Although I agree with you that building these small planes light fly better. Back in the "old days", a way to build like was silk and clear dope. Now, a way to help lighten is using one of those lighter film or tissue type synthetic coverings. (Which reminds me, I still have a Guillow 42 inch Bellanca Cruisemaster to finish.)

I'm with you OkiThumper I think it should be fine. But hey, I have an old Enya .15 just incase

You could after building use the plan, rough out a fuselage, shape wings out of foam, cover with color tape, voilą! Combat Cherokee .15 SPAD!