Fatboy Experimental

[KindaSuper]

Fatboy Cub

Meet the team,

Eric Lewis (lewaero works). Eric has built several planes that are recognizable such as the twin cub or double ender, and the Ascender. Lewaero works also makes carbon fiber pods for carbon cubs both fuel and cargo versions. Cubcrafter buys our pods when a customer orders one through them.

Chris Reese is a CFI that is passionate about aviation and wants people to be better pilots. He is currently a pilot for Ericson in the Casa 212 moving cargo or parajumpers. He is also a CFI and tailwheel instructor when he is not flying for Ericson.

Josh Peterson is a CFI and tailwheel instructor that wants to keep stick and rudder flying alive in the upcoming generations of pilots. Josh is new to aviation building but has a lot of experience building race trucks. He is a shop aid for Lewaero works when he is not instructing.

The premise behind Fatboy

When looking for planes that can fit bigger and taller guys we really didn’t have an option in the cub market. That is when we set out to make something that will have all the cub performance but be able to fit a 6’6” pilot with a helmet. The design is based on a cub but several modifications are made to make it fit our mission. The fuselege is hand built in the shop extended 18.25” widened 4” and the roof was raised 2” and was design with Alaska flying in mind. All super cub Alaska mods taken into account while designing the fuselage and are built in.
Some spec for Fatboy

· Engine O-360-C2P 180hp
· Prop Still researching
· 3” extended Gear 1.5” axles
· 35” Bushwheels
· Baby bush tailwheel
· Acme Shocks
· Custom Carbon floor boards
· Custom Seats
· Single Controls
· Massive cargo door
· Angle of incidence change
· Javeron wing kit
· keller flaps 50/50 split with ailerons
· Custom carbon fiber leading edge droop cuff
· Gross weight will be 2300lbs


Fatboy designin software


Window start



Longerons Start



Starting to Square the fuselage



We widened the foot well for more leg room



Our custom cargo door that fits a 85qt cooler in no problem!



We made a landing gear fixture to make sure we are square



Here is the view from the back with a tailwheel mounted



Gear test fit nice and strait and parallel with each other



Wing test fit and strut length sizing



Back view with some shop tail surfaces and wings mounted



Sit test with Josh in it he is 6'6" 260 on a stock cub seat.



Floor prototype 300lbs test and only weighs 8oz per sqft



Here is one of our fuel pods that we make in house.

 

[skukum12]

I am 6'8' and 270 lbs. Good on you guys for helping out us guys that don't fit the standards of the 180 lb pilot. Leg room is what I have always wanted. I could roll the seat so far back in my 180 that I couldn't reach the pedals. Moving pilot seats back in Cubs isn't much of an option. What about putting pockets in the floor boards and the firewall?

 

[stewartb]

Joe, drop by and try my Rev on for size. Very roomy in width and height.

 

[KindaSuper]

I am 6'8' and 270 lbs. Good on you guys for helping out us guys that don't fit the standards of the 180 lb pilot. Leg room is what I have always wanted. I could roll the seat so far back in my 180 that I couldn't reach the pedals. Moving pilot seats back in Cubs isn't much of an option. What about putting pockets in the floor boards and the firewall?

We were initially thinking about doing the heel drops like in a husky but we went with making the foot well wider and longer. The panel will be well out of the way for our knees not to knock on it. The seat will be lowered an inch and moved back from a stock cub to allow for more leg and head room.

 

[skukum12]

Joe, drop by and try my Rev on for size. Very roomy in width and height.

Don't threaten me with a good time! I have been wanting to see your plane up close for a while now. I shall pm you when I get a few more ducks in a row.

 

[KindaSuper]

Update

We have the tail feathers on and somewhat rig to test our electric trim design out. It runs nice and smooth for the full throw of the jackscrew and the motor will be out of the way of all the cabling.




These are the Javron square tail set




These hat bushing are made in house that allow the wire to turn even when the bolt is tight.

 

[behindpropellers]

Update

We have the tail feathers on and somewhat rig to test our electric trim design out. It runs nice and smooth for the full throw of the jackscrew and the motor will be out of the way of all the cabling.

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View attachment 61396

These are the Javron square tail set

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These hat bushing are made in house that allow the wire to turn even when the bolt is tight.

Those gears and chain are heavy, use a belt and aluminum sprockets.

 

[Crash Jr.]

Neat looking build!

Just want to mention the normal bushings for the flying wires don't have any issues turning when the bolt is appropriately tight. The bushings are intentionally slightly longer than the bores they go into so as to hold the head of the bolt away from the flying wire bracket and allow them to turn freely. Of course if you ham fist the bolts and over-tighten them you can smash the bushing and cause it to bind.

 

[KindaSuper]

Crash Jr all the cubs we have seen the washers/bushing for the flying wires have been crushed or missing. We are fortunate to have a CNC lath in the shop and made these to take the headache from loosing them or crushing them out.

Behindpropellers We looked at the weight of cables vs the motor and chain and there isn't much difference between them. we are looking at maybe making the sprockets out of titanium but we don't think we need it.

 

[wireweinie]

Behindpropellers We looked at the weight of cables vs the motor and chain and there isn't much difference between them. we are looking at maybe making the sprockets out of titanium but we don't think we need it.

How about direct drive. Eliminate chains and sprockets all together.

Web

 

[KindaSuper]

How about direct drive. Eliminate chains and sprockets all together.

Web

We looked at that but wanted the motor out of the way of any cables running to the tail feather. If it was a direct drive the motor would sit right in the way of the cables.

-kindasuper

 

[stewartb]

Big boy Cubs have pros and cons. With slats and Pstol flaps you’ll quickly appreciate electric trim. My linear actuator works great, by the way. No interference.

You’ll wish for more power.

 

[Steve Pierce]

I don't think a trim cable, handles and aluminum pullies weigh much at all opposed to a motor, chain, sprockets and that steel plate. Do you have a weight comparison?

 

[stewartb]

My extended airframe-slats-big Pstol flaps Cub requires using the full range of trim on every flight. Electric trim is an important addition regardless of weight. To have the ounces add up to pounds conversation in this case is secondary to benefit of the system. That said, I doubt Super’s system adds much if any weight. It may redistribute a few ounces aft of a stock system but that’s actually a benefit. How it compares to an actuator system weight is probably unimportant, too. If it works, it’s a worthwhile mod.

It appears the sprockets provide a 1:1 drive ratio. If so, why not make a shaft coupler and do direct drive? Alas, there are lots of ways to build it. God bless experimental aviation!

 

[Formandfunction]

Weight is the enemy and creativity is heavy.

 

[stewartb]

Kindasuper, have you done any actual testing of your tail section’s flex at full weight? I’m curious about how you chose your baggage door size, too.

 

[KindaSuper]

I don't think a trim cable, handles and aluminum pullies weigh much at all opposed to a motor, chain, sprockets and that steel plate. Do you have a weight comparison?

its a 2 oz. difference between the stock cable system and the electric system we have. yes the electric system is slightly heavier but we also have more trim range then a cub currently sitting at 5 degrees tail up 4 degrees tail down.

-kindasuper

 

[KindaSuper]

Kindasuper, have you done any actual testing of your tail section’s flex at full weight? I’m curious about how you chose your baggage door size, too.

We have not done a flex test on the tail yet. For the baggage door we wanted something that would fit an 85 qt cooler for camping. we also wanted something big enough we can fit through for sleeping in the back. the tube structure of the door came from another project we work on call The Ascender you can see pictures on bushplanedesign.com.

For the drive gears we are sitting at a 1.8:1 with a motor rpm of 25 which is plenty fast. we can go throught the full jackscrew bottom to top in 45 secs.

 

[Olibuilt]

Waiting 45 secs between every landing and takeoff would get on my nerves. Would have to time mine, but about 10 secs per travel.

Awesome built, keep us posted!!


Envoyé de mon iPhone en utilisant SuperCub.Org

 

[stewartb]

My Cub has the upper longeron on top, too. With a simulated load of a tail hit with a load my uppers bow, and with mine they bow downward. Being covered that’s the path of least resistance, I guess. I can add some clamp-in vertical tubes to limit the flex but I haven’t needed to yet.

 

[KindaSuper]

Olibuilt we can put a faster motor (50rpm) in if we want but would like to test fly it first to see if that is what we want plus don't mind waiting a bit anyways it because more time in a plane the more fun I'm having.

Stewartb Our triangulation spacing is tighter then a standard cub which theoretically allow us to have a heavier load before we get bowing. we also went a tube size up to the triangles and them them being closer that should also put a stop to bowing under heavy load.

 

[stewartb]

You should consider a Safety Trim. Timeout protection and two speeds selectable from the panel. I use full nose down trim for takeoff. I’m on the trim switch as soon as the tires lift off. The fast setting works best until making fine adjustments in cruise. My full range takes <20 seconds. Not picking on your plan, just sharing what mine does.

 

[KindaSuper]

You should consider a Safety Trim. Timeout protection and two speeds selectable from the panel. I use full nose down trim for takeoff. I’m on the trim switch as soon as the tires lift off. The fast setting works best until making fine adjustments in cruise. My full range takes <20 seconds. Not picking on your plan, just sharing what mine does.

Any advice I can get I will take! I can defiantly wire a 2 speed switch into the panel no problem thanks for the idea! We do have 2 degrees more trim up and down then a standard cub trim so we are expecting it to take longer for the throw. We will be putting limit switches in and I can run a timeout protection never thought about that!

-Josh

 

[Steve Pierce]

its a 2 oz. difference between the stock cable system and the electric system we have. yes the electric system is slightly heavier but we also have more trim range then a cub currently sitting at 5 degrees tail up 4 degrees tail down.

-kindasuper

That isn't mush difference at all. I would have thought quite a bit more looking at the install. I guess I didn't think about stock jackscrew and yoke as well.

 

[stewartb]

Any advice I can get I will take! I can defiantly wire a 2 speed switch into the panel no problem thanks for the idea! We do have 2 degrees more trim up and down then a standard cub trim so we are expecting it to take longer for the throw. We will be putting limit switches in and I can run a timeout protection never thought about that!

-Josh

Finally back home and thought to check. My actuator runs my trim from up 4° to down 6°, so very similar to your plan. I’ve never heard owners of similar planes talk about trim range before now. Another data point for other guys to ponder.