i'd like to share this build info.sorry for the poor pics.i chose the 16 1/2 inch 109 kit as i figured it would be a light weight air frame to transplant the running gear from a park zone ultra micro p-51 into.the flying weight is right at 2 1/8 oz. and that is with a 1/4 oz. nose weight.i used hangar9 park lite covering on this build and really liked it that alone saved nearly 1/4 oz. i used all of the kit wood and in this one i think some of the balsa was mixed up with oak .but it was mainly for parts which were higher strass that i would have used thin ca to beef up anyhow.
i used the same basic operation for the ailerons as the pz p-51 uses.

love these balsa builds

i kept the brick as far forward as i could as the battery is kept right behind the firewall. it uses a corsair 3 blade prop. the control surfaces are hinged with thin strips of hinge material.

i tried something new on the cowl with this one.i used cotton cleaning patches with ultra thin ca to strengthen the frail plastic.this one will take some abuse and it added weight where i needed it.

60 grams with the battery? That's really a good weight!
One thing I have learned after 2 of the 500 series conversions, you will need more prop pitch for it to fly successfully. I would suggest using a GWS 5 x 4.3 prop for the maiden flight to get it trimmed out. Try the 3 blade later but I think you will find it will not generate the velocity required for controlled flight. I have resorted to adding pitch to the 3 blade props by heating the blade root and twisting in a bit more pitch.
This one modification turned my 500 series FW190 from a dog that barely flew into a sweet flying model.
Glenn

why dont you use a brushless micro motor?

There isn't much to be gained by running a micro brushless motor on a single cell.
These conversions are at the upper end of the weight range already, and I feel a 2 cell battery along with the additional weight of the esc would push them to the point of not flying well.
Did you see the video of my FW 190? It flies in a scale manner and you really cant tell how small the model is until I pick it up at the end.
http://www.rcgroups.com/forums/showt...1544230&page=9

Glenn

This big thing to do with any of these Rubber conversions is bust out the dremel tool or Xacto blade and remove all of the excess balsa aft of the CG.

The Keels and Fuselage formers are so thick because they have to withstand the crushing forces of a Rubber band.

At least of a third of the balsa in the formers and keels behind the CG is dead weight. Forward of the CG, the extra material can help with crash resistance, but aft of the CG, dead weight.

i did carve on the fuse formers and sanded alot of weight off from the rear of the fuse.i also kept with the built and covered tail surfaces.it all helped but i still had to put a 1/4 oz weight up front.i have been running 250mah 30 c batterys in this and my other micros.the big 500mah just didn't fit very well in the fuse on the 109 and i really didn't want to attach it to the bottom with velcro.
well,this is my 16 1/2 inch 109 ready for it's maiden flight.i hope to have some flight footage soon.

just another pic.there may be flight footage very soon

Originally Posted by UNGN

This big thing to do with any of these Rubber conversions is bust out the dremel tool or Xacto blade and remove all of the excess balsa aft of the CG.

The Keels and Fuselage formers are so thick because they have to withstand the crushing forces of a Rubber band.

At least of a third of the balsa in the formers and keels behind the CG is dead weight. Forward of the CG, the extra material can help with crash resistance, but aft of the CG, dead weight.

I even go to the trouble of cutting new formers out of 5-6lb stock 1/32 sheet from the trailing edge back.

Nice work! Hope it flies as good as it looks. Good luck on the maiden!

Glenn

Looks great Meltor,

I'm not sure about that AUW of 60grs seems a bit beefy for the PZ P-51 set up.

Did you do a few glide tosses onto a soft surface with the battery? If she glides nice then she should fly fine.

Pete

we just had a little snow so as soon as the temps get around freezing i will do some tests.i do have other props to try but we'll see how this works.my #95 j-3 cub is over 2 1/2 oz and it flys great with the p-51 set up and stock prop but it is also has that big high wing.

My experience says it will fly fine but might be close to the stall with the low pitch prop. Just be aware of that and keep your turns flat and gentle until you get a feel for it. This is one that will drop a tip and spin in before you can say OH !

Glenn

glenn your prediction is spot on.it flys well but under powered. so i adapted it with a gws 5043 prop.i havnt flown it but i can really feel the difference static testing it.i found that a small rubber electrical groment and a piece of the straw from a can of carb cleaner worked great for an adapter.the small red straw/tube threaded on nicely.i'm working on a spinner.
now the wait .it may be weeks before we see any weather near freezing or warm enough to fly it.