First Light: BDBD

[DynaSoar]

"First light" is what astronomers call the first sighting through a new telescope. This is the first time all the pieces for this bird were assembled for fit.

BDBD is for Big Dumb Booster Design (as well as Buck Roger's robot buddy, beedeebeedeebeedee...). It started out as another "dunsel", a way to use up left over parts. I had a 6" piece of 4" body left over from turning a V2 into a Canadian Arrow, and half a full length 3" body left from cutting it for the Rock-A-Chute Mk IV (plus the nose cone that came with the tube). I got a PML urethane tail cone to use as a transition. The MMT is a 29mm tube with my 2 dollar PVC retainer, attached to one 3"/29mm and one 4"/29mm ring. The motor tube is 15", to accomodate an Ellis Mountain H50 (11") plus thrust ring plus metal colling baffle and its top retainer. Shock cord is 5/16" tubular nylon attached to the top ring and will have a double layer loop of 1/2" elastic for a bungee shock absorber. Lugs will be 5/16" styrene, four of them around the 4" portion between the fins, because I think it'll look cool. Fins are 1/8" basswood. I'm considering laminating them with some thin e-glass fabric.

Given the parts I started with, it couldn't have ended up looking much different. Still, now that it's together, well, take a look at the cover of the 2001 AT catalog at https://www.aerotech-rocketry.com/c...s_Flyers_Data_Sheets/AeroTechCatalog2001a.pdf

I wonder if they have a decal like that they'll sell me?

 

[DynaSoar]

Oh yeah, the fins are TTW, to the motor tube, notched to fit around the transition. All the inside epoxy is JB Weld. External will be Devcon 5 minute.

 

[DynaSoar]

Didn't get to fly it this weekend. Twice I loaded it on the rod and twice the lug came off. I had 2 more lugs to choose from, but chose not to risk it.

Styrene lugs look great and are easy to work, but they don't hold epoxy worth a darn unless you roughen them up real good with very coarse sandpaper and/or stick them to the tube with CyA also.

 

[Karl]

Sweet! Looks like a Fat Albert crossed with a over-streched V2
Karl

 

[gerbs4me]

nice design
rocket looks really cool

 

[DynaSoar]

Originally posted by gerbs4me
nice design
rocket looks really cool

Thanks. It looks really sharp right now, all solid very shiny white with appliance epoxy paint, and a 5/16" lug between each fin. I'm trying to decide on a paint scheme that looks realistic without being so sparse as "commercial" boosters. Maybe black nose and fins (also appliance epoxy), and a roll pattern on the body done in carbon tape (so I can put it on for anti-zipper and not have to cover it).

 

[DynaSoar]

Here's how it turned out.

Right after this it tipped over and fell 5 feet to the concrete floor, landing nose down at a 30 degree angle. Chipped the paint off the tip of the nose, but not a hint of dent or bend around the body edge. The carbon tape works.

 

[Karl]

wow, that looks sweet! You got nice, crisp lines where you masked it off!
Karl

 

[DynaSoar]

Originally posted by Karl
wow, that looks sweet! You got nice, crisp lines where you masked it off!
Karl

Appliance epoxy masks well because it's so thick and self adhesive. In fact it's soo good that sometimes the tape along the masked edges won't come off the woth rest -- the edge acts as a fillet of sorts. It comes off easy enough when you pick at it, it just doesn't always pull off first try in one piece.

It does require a little extra drying time before putting the tape on though.