R. C. Day

My Feedback: (7)

I have been carrying around a framed up Nosen Citabria I built in 1984. The power choices I have on hand at this time are:
Used Webra speed 60 with built in gear reduction.
New in box Super Tiger 2500.
New in box 1980 Quadra 35.

It is already built for the Webra, but I am getting cold feet about the .60, which would you power it with, it's not to late to change?

Thanks for your help in advance.
R. C.

beepee

No question! Put the Quadra in it. You will have a blast. Think of all the savings in paper towels and cleaning fluid!

Bedford

smchale

My Feedback: (67)

I believe this a/c was designed for the .60 back in the day. I've flown one with a 60 and it was marginal at best. A ST 90 was a great fit for this a/c. Anything larger I'd make sure you strengthen struts, tail bracing, etc because it will be a rocket.

Bipeguy

My Feedback: (2)

Hi.....smchale is right. These were built for .60-.90 size engines. I am finishing a Nosen Champ and have a 25cc gas in it. Had to change the firewall for that. It comes out at 17+lbs and shud fly well with the 25. See my post "Bud Nosen Champ" for more info.

Scott...

R. C. Day

My Feedback: (7)

Bipeguy

I also have a Homelite conversion approx 22 to 25 cc displacement. Perhaps that would also be a suitable powerplant.

BeePee

If using the Quadra, any recommendations on where to research the strengthing mods?

Thanks all.
R. C.

Bipeguy

My Feedback: (2)

R.C. Perhaps smchale can expound on what he's thinking there. I suggest to just make sure you have the tail wires on for strength there and also make sure your wing struts are spruce or dowels because they ARE functional. I used dowels and made them more scale ("y"shaped). My kit came with 1/8" luan ply for the firewall. I threw it out and used 1/4" good stuff with some standard reinforcing. That will handle the 25cc or the Quadra just fine. I don't know of any other mods that would be needed.

Scott..

beepee

R.C.,

Bipeguy has got it right for strengthening. You should look at the firewall position relative to the engine size. It may be best to move the firewall back so that the prop hub lands in the right spot. This could help balance too with the heavier engine.

If this is necessary it is not hard, even if the airframe is completed. As Bipeguy suggests, you might need a new firewall anyway (even if not, a fresh gluing would be good insurance). A big plus is that you can leave the fuselage sides extended beyond the firewalll about 1/2" or so giving you a good opportunity to add triangle stock reinforcement in front of the firewall in addition to that behind. A tremendous strengthening feature.

Have fun!

Bedford

gachezem

My Feedback: (20)

I would use the ST2500, it will swing a 18x8 and do a good job of hauling that plane around, just use throttle to keep speed down, which will get much more time on a tank of fuel you should not have to cut up the cowl, just make sure you have plenty of opening on the air out portion, beef up the firewall

G.F. Reid

My Feedback: (1)

In regards to strengthening the airframe for gassers...I like to tie the firewall, landing gear and wing mount together with spruce. For example, glue quarter inch spruce sticks from the wing saddle to the landing gear block along each fuse side. Maybe at the front of the cabin door frames. Run a couple more from the lower firewall to the landing gear block on each side and a couple more from the upper firewall back to the sticks that tied the wing saddle and the landing gear block together in the neighborhood of the dash/doorframe. I also like to replace maybe a couple of the balsa fuse longerons with spruce. Say from the rear wing saddle to the tail end. Also the bottom two from the firewall to the tail.
The gassers really shake a lot and these mods will add very little weight in relation to the strength they add.
I basically copied this idea from designers who build with gassers in mind from the beginning...Unlike the old Nosen designs. It's worked well for me in the past.

R. C. Day

My Feedback: (7)

Bipeguy,

I had built tail wires, Spruce wing struts and installed a 1/4" firewall. Surprizing enough they were all identified as a requirement in the kit.

Beepee,

I do need to relocate the firewall back as you sugested for the Q 35, I really like the recommendation of leaving the longerons at the stock length to receive additional gussets on the forward side of the firewall.

Gachezen,

As I had originally purchased the Super Tiger 2500 (when it first came out) for the Citabria, I am leaning toward gas this time out.

G.F. Reid,

I also recgonize and appreciate the added benefit you recommended for tying the firewall, wing saddle and the landing gear together.

I had given up on glow fuel birds and had not flown since the early 80's. I have started flying again and have been flying electrics for the past 2 years (I really got tired of the glow goo).

I retired from the Navy (24 yrs.) and can now try the things I have wanted to try but never had the time.

I have been thinking of trying birch door skins (with material cut outs to save weight) to build a bird simular to the design of a rubber model (Gullows), any comments?

Thanks all for your help and assistance.
R. C.

G.F. Reid

My Feedback: (1)

R.C., I don't have any of experience with the birch doorskin material but it looks good to me.
I have used Luan in place of light ply in scratchbuilding which looks to be a little tougher than the lite ply included in most kits. A 4x8 sheet of Luan is less than $10. How does the birch compare in price? It looks to be of much better quality than Luan.
If you try it, let us know how it works out. I'm always on the lookout for alternative materials.
I think the Luan is lighter than birch and could probably be better for use as fuse formers and such if you want to save weight. I wouldn't use it for load bearing parts. I believe that Jim Meister uses a lot of it in his Giant Scale designs for wing ribs and that type of stuff. You might research that subject a bit in the Scratchbuilding forums.

gachezem

My Feedback: (20)

the birch ply looks pretty but check the thickness of the ply's I think you will find the inner core is thicker than the outer's, so it is not as strong, it is mostly for looks, and will not be as strong as lite ply.