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 was 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. T' finished weight be 2.2 lbs. An F engine would be needed t' reach t' same altitude. Arrr! I read a thread on RMR concernin' a light weight rocket camera booster. Blimey! It described a Estes Phoenix kitbash, usin' traditional white glue construction, shiver me timbers, that should be able t' loft a camera on a D or E engine. Ahoy! Well, blow me down! I thought about it and decided on another approach. Well, 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). Begad! As I was experimentin' with a BT 80 nose cone with an open bottom, I found that the electronics and about one half o' t' camera would fit inside a Fat Boy type cone. Well, blow me down! In theory, me hearties, I could create a nose cone payload section out o' t' nose cone and a BT 80 transition section. Begad! Maybe for t' next rocket... Ahoy!

Construction began with t' minimum diameter section. 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! This will allow me t' use Estes and Aerotech single use and reloadable motors. Begad! When that dried, me hearties, I glued a 3/32" basswood BT 50/80 centerin' ring on t' top o' t' motor tube (facin' t' front o' t' rocket). Ya scallywag! Below that, I glued a 1" piece o' a BT 80 transition section, shiver me timbers, matey, then another ring. Ya scallywag! Avast, me proud beauty! The 2" long BT 50/80 transition section (made on VCP) was printed out, copied onto file folder material, me hearties, cut out and glued on with white glue. Aye aye! 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. Blimey! Aye aye! This completes t' lower section except for t' fins (which I still have t' do). Avast, me proud beauty!

Rocket Pic I made a basswood bulkhead and glued a screw eye into it (in t' same way as before). 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, I made a cut and glued the edges together t' form a custom tube coupler. When it dried, I cut off a thin strip and glued it into a t' BT 80, matey, matey, usin' t' lower section as a guide t' push it in t' appropriate length. This will act as a thrust ring. Blimey! I then took the nose and cut t' base off so that thar was a 1" base. Ya scallywag! This will contain the electronics and possibly some o' t' camera. Avast! Begad!

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

I used t' Estes fin alignment guide t' hold t' three fins on while the white glue dried. Well, blow me down! Begad! I then filleted t' fins. All I have t' do is add a shock cord and chute. Ya scallywag! Avast!

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

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