View Full Version : Real Carbon Cub

Dave Biggar
03-25-2019, 04:41 AM
I am currently in the process of re-designing the Cub to be completely built out of carbon/foam sandwich. I am planning on using carbon infused flat panel that is all cnc cut and then laminated back together in a jig with the associated bulkhead structure. The wing has moulded ribs with a combination infused panels for spar, upper and lower skins as well as a eps hot wire cut nose section. Any further feed back on this topic would be appreciated. I have a business in composite construction and this project from a construction method seems very straight fwds to me!!! Wielding lots of small pieces of tube together is not my skill and not up my alley

03-25-2019, 06:09 AM
You might look at the Draco construction videos on youtube to get some idea of what you are about to get into.

03-25-2019, 06:26 AM
Maybe check out some composite-by-design builds?
Hereís a Glasair build log I found googling:


Iím interested to see your project!

03-26-2019, 02:05 AM
well look at sailplanes, 91ft wingspan open class gliders have this type of construction. very tough, very flexible. I say go for it.!!

Dave Biggar
03-26-2019, 04:09 AM
I have been watching all these... Maybe twice. Awesome plane. It is much like the carbon cub though as it is really a metal structure with some nice carbon fairings

You might look at the Draco construction videos on youtube to get some idea of what you are about to get into.

Dave Biggar
03-26-2019, 04:13 AM
Thanks CamTom, yep I am familiar with these planes. I have had Lancair and currently have an Arion Lightning.

Maybe check out some composite-by-design builds?
Here’s a Glasair build log I found googling:

I’m interested to see your project!

Dave Calkins
03-26-2019, 02:51 PM
Dave. you are talking about a project I have had in mind for years.

A REAL Carbon Cub.

My thought was to keep some steel in the pilot area for crash/tipover structure.

Since you are a composite guy, you are likely far ahead of Draco's tech already.

I am not sure infused methods are necessary, but if yu think so, great!!

Dave Biggar
03-26-2019, 05:54 PM
HI Dave, The crash/tipover points are an area that I have not finalised yet. I would almost say it will be impossible to get the minimal amount of structure as what is in a current cub around the front wing support. This is obviously important for vision from the cockpit. I will attempt to get some concept put togther an uploaded in the near future. I guess at some stage in history others have faced the same problem and over come it with composites. ie Formula 1, indy, other fast composite planes etc I have some smart composite engineers at my finger tips so I will be interested to see what they come up with.

Infusion is a very fast, simple and clean process when you are set up for it. By no means is it the lightest but it is strong and consistent. I currently have vacuum tables 16m x 3.5m with CNC router to match it. We supply the marine and transport industry with large format panels. our business in the past has been involved in building medium to large size performance cruising Sailing catamarans and we have achieved very good results from flat panel construction. Most people would not know that boats have actually all been built from flat panels.

The Cub like most early planes are mostly flat sections which makes it reasonably simple to transfer this type of design over carbon panels and with the accuracy of cnc I am presuming that I will assemble these structures very quickly with a well thought out cnc build jig.

I have been getting some private msgs about some of the finer detail like hard connection points and from a composite engineering point of view I am not looking at this any different to how these things are approached in high performance yacht construction. ie Keel attachment structures. rudder attachment, chain plate connection.

I have also been getting comments around the cost of carbon versus standard materials. I have seen the prices for cub fuselages and I am would guarantee that I will have a carbon fuselage for less. This formula is obviously mix of Materials + Labour = Component

By no means was I saying that Mike Patey does not know about composites... That Guy is legend

don d
03-26-2019, 06:34 PM
No way am I riding on a total carbon fiber structure. Very strong unless damaged . I shook my fly rod and a foot of the tip fell off!

03-29-2019, 09:18 AM
No way am I riding on a total carbon fiber structure. Very strong unless damaged . I shook my fly rod and a foot of the tip fell off!

And the stuff Iíve been around burns like gasoline. Maybe thereís something else out there though.

Chicken Hawk
03-29-2019, 10:37 AM
If your seriously thinking of doing this, you should visit the Dallara Indy Car factory in Indianapolis. The entire cockpit/chassis is a single carbon fiber tub onto which the engine & suspension components attach. When I first saw it I instantly thought this is how cubs will soon be built. Super lightweight & extremely safe for the drivers. They use self extinguishing resins, Carbon fiber / Kevlar mix for safety & imbedded titanium mounting plates. Designed to survive 240mph crash.
I believe the entire cockpit weighs 78lbs & costs $85,000.


Sent from my iPhone using SuperCub.Org

03-29-2019, 10:45 AM
Many years back I did a large project with similarities to where you are going but did my work on a curved surface. For that project my work surface was a from made from a sheet of Formica over machined wood frames. That job was brush & bucket then bagged. Today I would infuse anything that size.
The first part I did, I did make a mistake. This being a smaller part was a cowl section. The heat was applied from one side. I did not account for the insulating quality of the core and pulled the bag way too early. Oh well, did save the part but knew better after that and left the pump on through the night.
Those were the early days.

Dave Biggar
03-29-2019, 05:57 PM
And the stuff I’ve been around burns like gasoline. Maybe there’s something else out there though.

10 mins of watching flame tests on aircraft covering fabrics on youtube would make me choose Carbon structure every day of the week. Carbon/epoxy is flammable but it takes a while to get going. Some of the latest fire retardant resins and paint systems as well as tissues to include in the laminates are producing some of the most fire retardant structures in the world. I believe most of this technology has come from the commercial aircraft that have the highest requirements.

04-11-2019, 01:42 AM


I've been watching this new design for a little while now. Anybody out there have a better view of it than I have from Fairbanks Alaska, in the middle of the Winter?

The link for Windward Performance and the Bruin Cub is http://windward-performance.com/bruin.html Though sometimes it doesn't work.

Windward Performance and the owner, Greg Cole have some pretty amazing credentials from Chief Engineer of R & D at Lancair to designing a two place glider that went to 76,000 feet.

If anyone could pull off an efficient design for both weight and lift/speed, they seem like a good bet.

928 lbs with the "small engine" 100 hp Rotax 912 ? Seems on the heavy side.

140 knots ! WOW ! Even with me often commuting 8 hours, round trip, to where I hunt; for my mission, I wouldn't be willing to trade even 60 mph more speed for 10 miles an hour on the bottom end. I usually putt along with

my 0-360 turning 2200, anyway. For your mission, it might be the cats meow. Being able to haul half sheets of plywood and sleep in the back would be great !

105 gallons of fuel would be amazing. I MIGHT be willing to give up my 90 gallon Sorrenson belly tank, but never my 30 gallon Atlee Dodge wing tanks. Both Av gas and unleaded are over $8.00 per gallon in Galena and Bettles.

That's double the cost of what I have in my tanks at home.

Gross weight 2430 !!!!!!!!!

Jonny O

04-11-2019, 05:06 AM
To my eyes looking at that page you have linked to, I see allot of hypothetical BS.
Claimed empty weight with a Rotax or such at 928#, fine that can be done.
But then claimed performance figures at 1460# being with a 200hp CS withe two people on board. NOT! There is no way that the upgrade to a Lycoming 200hp with CS and two people will be anywhere near that weight. Their numbers do not add up.

I am quite sure the design team can build an impressive plane but just from their renderings the plane is in no way going to be able to be utilized off anything other than smooth surfaces.

04-11-2019, 07:59 AM
Seems pretty heavy with the lighter engine (Rotax 912?). Should be 150+/- less with that engine to preform good. If that weight was with the typical Lycoming/clone, it might be an awesome combination.
Plane also seems to compete similar to the new RANS Outbound, performance wise. The GW is a big plus though.

04-11-2019, 08:42 AM
Imagine that gross weight with a Rotax or UL power. 900 - 100 to get off the ground?
Yes with 180+ it will perform well but how is the balance, Just what are they truly designing for.
And personally I would take a Yamaha up front long before a Rotax.

Oh, and since it is not uncommon to have a "moment" in a conventional gear plane, so what is going to "give" when a wingtip touches down or digs in?
Looks like the front cabin structure to me.