spadbat

My Feedback: (3)

I would like to lighten this older version of the Carden 35% Extra airframe a bit. I bought this plane used (I was told I am the 4th owner), put a BME 102 on the nose, 6 x JR8411's, + 2LBS LEAD in the motor box. All up weight is 32-1/2lbs. I'm doing all the obvious things to reduce weight (CF tailwheel, CF Wingtube, move rudder servos from tail to just behind wing tube, Li-Ion's, etc.).

I stripped some of the covering off last night and it looks to me that I should be able to cut some lightning holes in several places.

Rudder -- Is is possible or smart to just cut holes in the rudder itself? Being the farthest point from the CG, a little could go a long way.

Fuse Bottom -- Currently sheeted with solid balsa over stringers. Should I cut holes between stringers with hole saw?

Fuse sides -- Large solid area under horizontal stabs & above wing saddle?

Engine box -- All 1/4" aircraft ply. Currentlly no lightning holes at all?

I'll try and post a couple of photos of the plane too.

Thanks for any suggestions,
Marty

spadbat

My Feedback: (3)

RCPilot100

My Feedback: (4)

Marty,

I have two of those planes - a 3W80 and a 3W100 for power - and both weigh a tad under 26 pounds. Both were built normally - no extreme measures were taken to make them lighter. The sheeting over stringers would suggest that whoever built your plane wanted to make it 'stronger' and in the process added over six pounds of weight. If that is what happened, I don't think you will find enough ways to reduce the weight to where it should be - I would say it would be easier to build a new plane.

Dan

spadbat

My Feedback: (3)

JLB

My Feedback: (2)

Marty,

Listen to RCPilot100 as I think he's giving you the best advice. I have owned 3 of these myself and it is one fine airplane. However, it wasn't really designed for the 3D stuff being done today if that's what you're after. The kind of lightness you might be looking for really needs to be designed/built into an aircraft from the beginning. My advice would be maybe a few holes here and there (very few) and most of all get the 2# of lead out of the nose. I'll do anything and everything I can to avoid adding lead to an airplane. Personally, I would install a pull-pull rudder system, if it doesn't have one already, to get servos out of the tail and move everything as far forward as you can. Just get rid of the lead!! Recover it and go have a blast. This airplane is still a lot of fun at 30# as I've seen more than one. Another thought might be to replace the lead with a good smoke system and really have a winner.
Go do some nice big loops, rolls, spins, low passes etc. with smoke blowing on a sunny day and that brings 'em to their feet faster than hovering over the middle of the runway anyway. That's why I fly helis too, 'cus they're supposed to do that

JIMMYTHEEAGLE

My Feedback: (47)

I'm surprised yours weighs that much. I just finished building one that was sitting on a hobby shop shelf for 5-10 years. I drilled lightning holes in all the plywood and did a lot of sanding of the airframe once built to shave off weight. I have 8411 servos throughtout with two for rudder above the wing. I enlarged the elevators, rudder and ailerons for better 3-d and I have the DA 100 in it. I have a smoke system on mine and the smoke battery and ignition battery are in the nose but the servo batteries and fuel tanks are on or just in front of the cg. I added about 8 ounces to the nose and it balances 3/4 behind the cg. It flies great and 3-d is very good with this plane. Anyway, mine weighs 26-27 lbs. It flies great and plenty of power. I wouldn't be as worried about the weight as I would be about enlarging the control surfaces. Jim

spadbat

My Feedback: (3)

Thanks guys. I'm not looking for a ultralight 3D Machine. I couldn't hold a hover if my life depended on it. The plane flew great the way it was. The only time I could feel the weight was landing. It had pretty good vertical, but didn't "rocket skyward". I weighed the batteries and I had 24oz. of nicads. I think by swapping out some of the hardware and relocating things abit I think I'll make a substantial improvement in things.

The more of the old monokote I pull off, the more I'm glad I'm striping it. Im finding cracked and loose sheeting on both the bottom of the fuse and the side of the fuse over the wing root. I'll probably cut a few lightning holes in some of the ply, repair whats needed, sand everything down well, recover it and go fly.

The rudder already looks like it's been modified by adding about 1-1/2" to the trailing edge.

And, I've also ordered one of the new BME Ultimates. Probably won't arrive until next year though.

Thanks again,
Marty

JIMMYTHEEAGLE

My Feedback: (47)

I forgot to mention I used lithium ion batteries for (2) on the servos and one on the ignition. If my wife doesn't deliver our second child tomorrow I'll snap a couple of pictures and send them your way. I think some of the plywood you could still cut some lightning holes in if you clamped another piece of wood behind it when you drilled it out. Jim