CEF speed contest Design Discussions (2014)

Marleysky wrote:Roddie, I really like your Plan, your Plane and your Pattern...for the "blade guard, hole cover"  My table saw has a similar over size hole for the blade, and I will use your pattern next time I have to rip down some stick stock.  Thanks!

cox24711 wrote:did you use nylock nuts?

Ken Cook wrote:I assume your going with a tank? If what I'm seeing is correct then yes I see a problem. The TD is very sensitive to the tank. If the tank is going to be mounted on the outboard side of your engine crutch, the centerline of engine is now further inboard. In the event you do mount a tank place it on the same side of the beams as your engine lugs. In other words if that cylinder is to be mounted for outboard position, the tank will be on the inboard side which means the tank has to be replumbed if your decide to use a stock tank. This now leads to other problems because the faster the plane flies the richer the fuel mix goes. Where most tanks typically get shimmed up and down, this now would require to be shimmed left to right which isn't practical unless you leave that area open for access or shim your engine off the beams. Just for the record, Cox engines were meant to be mounted with 3-48 screws which are increasingly getting rarer. Ken


Just for clarification, is the TD allowed to be used in these speed contests? I wasn't aware of that if it was as I have current designs using the TD.

roddie wrote:

cox24711 wrote:did you use nylock nuts?

Hi Greg! There's lock-nuts included with the hardware package.. and I figured I'd use them unless cautioned against it. I thought about using wood-screws.. but the 1/4" (6.35mm) square beams don't have a "comfortable" amount of meat to hold them.. not to mention the short length they'd need to be. There's also the risk of splitting the beam if the pilot-holes are drilled too small. I drilled .070" (1.78mm) pilot-holes first.. then enlarged them to .098" (2.5mm) which is the hole size in the engine-lug. A 3-48 machine-screw has a .095" diameter. The spacing between holes is .375" (9.53mm) on center for the Cox Tee Dee .049 engine. I used an awl to mark the holes beforehand.. to help start the drill in the center of the beam.

getback wrote:Ok here you go some cuts / more sanding and sanding primer cut with clear dope           Yes I am going to fly a Knife Edge the whole flight LOL Thanks Kim for the Kicking I needed. Bearers tomorrow sanding and epoxy. Need to figure out the tail feathers placement /  getback

getback wrote:Looking good Roddie here is were I am , thought about what U said man I am too far along to redo it now (pm) Greg its suppose to bee a P-51 D             when it breaks I will fix it  getback

akjgardner wrote:looking good Roddie

getback wrote: The paint for fuse was Krylon (satin nickel/brushed metallic ) and Rust -Opium for the blue.    Roddie your moving right along , what engine is that .051 ? Those beams running back that far should give you plenty of strength and I like the way they look too .

roddie wrote:

getback wrote: The paint for fuse was Krylon (satin nickel/brushed metallic ) and Rust -Opium for the blue.    Roddie your moving right along , what engine is that .051 ? Those beams running back that far should give you plenty of strength and I like the way they look too .

Rust-Opium.. I've never tried that.. The Satin-Nickel is sweet! So you paint-brushed it  looks really nice man! Are you gonna clear-it.. or does it test as fuel resistant? I saved photos from a Krylon orange-color test that you did a while back.

I bought a can of Minwax aerosol clear-gloss lacquer a few months ago (on clearance)




I need to test for both; undercoat compatibility.. and fuel resistance.

Yes, that's a Tee Dee .051 in the recent T33 model photos. I mounted it to keep the psych going! I can't afford to have this build take the amount of time that the Rare-Bear did..