Scratch DC-20 Digital Camera Rocket (light) Original Design / Scratch Built

Scratch - DC-20 Digital Camera Rocket (light) {Scratch}

Contributed by Morgan Hendry

Manufacturer: Scratch
DC-20 Digital Camera Rocket (light)
(Contributed - by Morgan Hendry) 

Rocket Pic This project be an extension o' me original DC20 camera rocket. I has underestimated t' finished weight o' the Initiator rocket camera, thinkin' it could be lofted on an E t' 500'. Big mistake. Avast! T' finished weight be 2.2 lbs. Avast! An F engine would be needed t' reach t' same altitude. Well, blow me down! Blimey! I read a thread on RMR concernin' a light weight rocket camera booster. It described a Estes Phoenix kitbash, usin' traditional white glue construction, ya bilge rat, that should be able t' loft a camera on a D or E engine. Arrr! I thought about it and decided on another approach. Well, ya bilge rat, blow me down! I would use a minimum diameter section for t' 24mm motor tube (BT 50) and then a transition t' a 2.6" diameter payload tube (BT 80). As I was experimentin' with a BT 80 nose cone with an open bottom, me bucko, I found that the electronics and about one half o' t' camera would fit inside a Fat Boy type cone. Begad! In theory, shiver me timbers, me bucko, I could create a nose cone payload section out o' t' nose cone and a BT 80 transition section. Aye aye! Maybe for t' next rocket... Ahoy! Ahoy!

Construction began with t' minimum diameter section. Blimey! I glued (white glue) a BT 20/50 green centerin' rin' in a piece o' BT 50 body tube about 3" from one end. Avast, me proud beauty! This will allow me t' use Estes and Aerotech single use and reloadable motors. Well, blow me down! When that dried, matey, I glued a 3/32" basswood BT 50/80 centerin' ring on t' top o' t' motor tube (facin' t' front o' t' rocket). Arrr! Below that, I glued a 1" piece o' a BT 80 transition section, me hearties, then another ring. Arrr! The 2" long BT 50/80 transition section (made on VCP) be printed out, copied onto file folder material, cut out and glued on with white glue. Well, blow me down! Glue a screw eye in t' top ring. Ya scallywag! I used scraps o' basswood t' stack on top o' one another to make a thicker joint. Avast! This completes t' lower section except for t' fins (which I still have t' do).

Rocket Pic I made a basswood bulkhead and glued a screw eye into it (in t' same way as before). Ahoy! This was glued 2" into a BT 80 section. Avast, me proud beauty! I then rolled some corrugated cardboard (with one flat side pealed off) into t' section o' BT 80. Ya scallywag! Where it overlapped, shiver me timbers, I made a cut and glued the edges together t' form a custom tube coupler. Ya scallywag! When it dried, me bucko, I cut off a thin strip and glued it into a t' BT 80, usin' t' lower section as a guide t' push it in t' appropriate length. Aye aye! This will act as a thrust ring. I then took the nose and cut t' base off so that thar was a 1" base. Begad! Avast! This will contain the electronics and possibly some o' t' camera.

T' fins follow G Harry Stine's "high performance" clipped delta shape. Begad! Root chord is 48mm, ya bilge rat, tip is 24mm, ya bilge rat, and span is about 3" from root to tip. Aye aye! I cut them from 3/32" basswood and rounded them t' a streamlined shape. Aye aye! They were then coated with thin CA and sanded smooth. Well, blow me down! They are VERY smooth. Aye aye! Ahoy! I have t' say t' first fin turned out t' be one o' t' best I've ever made. Aye aye! T' streamline t' fin, ya bilge rat, I masked off t' area 1/2" from t' base of the fin with duct tape and sanded t' a point on both sides. Blimey! Blimey! I then rounded the leadin' edge o' t' fin and smoothed t' round leadin' edge into t' sharp trailin' edge. Avast! Nay too hard.

I used t' Estes fin alignment guide t' hold t' three fins on while the white glue dried. I then filleted t' fins. Ya scallywag! Arrr! All I have t' do is add a shock cord and chute. Blimey!

T' predicted altitudes are (if t' model is 10 oz. Blimey! or less) 260' on a D12, 1000' on an Aerotech E15. Aye aye! And you don't even have t' call air traffic control to launch!

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