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canopyflier
10-24-2010, 05:27 PM
Looking to start this winter on an Experimental Cub and fly under LSA rules. I noticed the Carbon Cub doesn't use the formers on the rear of the fuselage. Any advantage to this? Is this one of the places that they are saving weight? Should I build it stock (Wag-Aero plans) or like the Carbon? My main mission is to keep it light. Not looking for a cross-country ship. Just want something simple and safe to fly.

Tiger cub
10-24-2010, 05:46 PM
Contact Chris Hatin at Bushwhacker aircraft. He will be supplying tube kits for what you want.

Gordon Misch
10-24-2010, 05:48 PM
I think I'd try to get a good look at a Carbon Cub for ideas; they're pretty innovative. I forget their empty weight, but it's low, and suitable for LSA.

Cub Crafter's E-LSA Carbon Cub kit looks really sweet, but kinda spendy. If it were me and IF I thought I could afford it, I'd sure consider it. You can put in their 180 HP engine, and de-rate it to meet LSA requirements. Cub Crafters has the details figured out for that process. Dunno if they've received their 51% certification yet.

Just my opinion :wink:

Bushwhacker Air
10-24-2010, 06:40 PM
On the CC Carbon Cub, they moved the upper longerons up to connect to the headrack - hence no turtle deck arches (before I get beat up, I'm sure they made other changes, too) Their idea is not new, just new in a "Cub" - it's just like a Taylorcraft, Piper Vagabond, Pacer/Tri-Pacer and others. It makes for a very strong fuse at the headrack. I am not sure how much lighter it is - maybe someone here knows the bare weight of t heir fuse.

If you build the Cub/Supercub fuse the way Piper built it, using the same diameter/thincknesses in 4130 tubing, the back end will be stronger by virtue of using the 4130 over the 1025 mild steel Piper used. The headrack is still very strong. The added advantage of the Piper designed fuse is that there is an abundance of support for the design - every measurement is well documented. Build it stock and you'll build it light.

Saving weight goes well beyond the fuselage structure, though - that's just a start. Everything adds up, and Cub Crafters did a fine job engineering weight savings into their wings, controls and whole aircraft in general -right down to the final paint.

To save weight, we are using carbon fiber in the wings, fuse, controls, cosmetics - anywhere it will replace metal without sacrificing strength or integrity. Piper didn't have advanced composite technology in 1948, but we do now. It costs us between $100-$200 to save a pound using carbon fiber, but it's worth it to spend $3000 and save 15-30 lbs.

Whichever way you go, think about weight thoughout the whole process. In the end, you'll have a strong, light, fun to fly aircraft.

Nocub
10-24-2010, 11:31 PM
On the CC Carbon Cub, they moved the upper longerons up to connect to the headrack - hence no turtle deck arches (before I get beat up, I'm sure they made other changes, too) Their idea is not new, just new in a "Cub" - it's just like a Taylorcraft, Piper Vagabond, Pacer/Tri-Pacer and others. It makes for a very strong fuse at the headrack. I am not sure how much lighter it is - maybe someone here knows the bare weight of t heir fuse.

If you build the Cub/Supercub fuse the way Piper built it, using the same diameter/thincknesses in 4130 tubing, the back end will be stronger by virtue of using the 4130 over the 1025 mild steel Piper used. The headrack is still very strong. The added advantage of the Piper designed fuse is that there is an abundance of support for the design - every measurement is well documented. Build it stock and you'll build it light.

Saving weight goes well beyond the fuselage structure, though - that's just a start. Everything adds up, and Cub Crafters did a fine job engineering weight savings into their wings, controls and whole aircraft in general -right down to the final paint.

To save weight, we are using carbon fiber in the wings, fuse, controls, cosmetics - anywhere it will replace metal without sacrificing strength or integrity. Piper didn't have advanced composite technology in 1948, but we do now. It costs us between $100-$200 to save a pound using carbon fiber, but it's worth it to spend $3000 and save 15-30 lbs.

Whichever way you go, think about weight thoughout the whole process. In the end, you'll have a strong, light, fun to fly aircraft.

So how many pounds heavier would your cub be than the CC kit ? Assuming that a builder used same engine, paint process, etc.

Bushwhacker Air
10-25-2010, 08:16 PM
If their engine weighs 250 lbs, as stated in their specs, our aircraft would come in at around 900-910 lbs. I am not sure what the Carbon Cub SS weighs.

mikeo
10-26-2010, 03:38 PM
The only limiting factor in exp that fits the LSA rules is weight ,speed, an 2 place,not engine horsepower The horsepower is if your manufacturing! Chris is right build his airplane build it light you will have a much stronger airplane plus parts are much less expensive an available mike o

tcraft128
10-26-2010, 04:54 PM
Chris what are you guys doing with carbon in your wings?

Bushwhacker Air
10-26-2010, 06:32 PM
Leading edge, tank cover, wing tips. I have been toying with hybrid ribs - not right now though. Maybe drag struts.

mike mcs repair
10-26-2010, 07:08 PM
Leading edge, tank cover, wing tips. I have been toying with hybrid ribs - not right now though. Maybe drag struts.

I would think if you place them right, making the drag strut part of some ribs...

eliminate some parts that way, real weight savings.....

Clay Hammond
10-26-2010, 07:58 PM
I fly a Carbon Cub from time to time that weighs 930lbs. It has steam gauges with a 496, sl40, and transponder. 26" ABI Airstreaks and a 3200 tailwheel. With me (225lbs) and full fuel it gets off in 4-5 plane lengths no-wind, lands as short as the pilot is capable of.

qsmx440
10-26-2010, 08:51 PM
[quote=Bushwhacker Air]I would think if you place them right, making the drag strut part of some ribs...

eliminate some parts that way, real weight savings.....

Way cool idea! any elaboration on those thoughts like maybe a "box" rib at drag strut locations?

canopyflier
10-28-2010, 10:00 PM
Thanks for all of the input! Best forum I have seen.