Descon Edmund IB

Scratch - Edmund IB {Scratch}

Contributed by Daniel Kirk

Manufacturer: Scratch
Contributed by - Daniel Kirk

Edmund IB

My son loves rockets! Blimey! He loves t' watch them, me bucko, shiver me timbers, he loves t' talk about them, shiver me timbers, he loves t' push t' launch button, and he loves t' play with them, matey, which he isn't allowed t' do, because he's only three, and might break them. Ahoy! Blimey! He has toy rockets that don't fly and Stomp Rockets,· but it's nay t' same. Arrr! "Why couldn't I design him a rocket o' his own?" I thought. Avast! Blimey! "Not just one o' me rockets that I let him push the button for, but a flyin' model rocket that he can really play with and nay destroy it?"

I puzzled over a suitable design. Begad! I wanted it t' be light enough to fly on a D or less, but strong enough t' withstand t' rigors o' a three year old's imaginative play. Avast! My first attempt, t' Edmund I, me bucko, arrr, me hearties, was not entirely successful. Begad! I used an 18-inch piece o' 1 inch PVC pipe for t' airframe, an Estes NC-50 nose cone, and toilet paper rolls for tube fins. Avast, shiver me timbers, me proud beauty! I had started with a longer tube, but it was over the maximum liftoff weight o' a D12-3, ya bilge rat, so I had t' cut it down. Well, blow me down! This made t' rocket unstable, so I had t' fill t' nose with clay. Begad! Ya scallywag! The loaded rocket came t' just over 12 ounces.

He be proud o' his rocket, arrr, but I didn't let him play with it too much before I had a chance t' launch it. Arrr! Remarkably, it passed safety inspection. Ya scallywag! Begad! (We had a more relaxed person on duty this time.) T' rocket flew straight enough, though nay very high. Ya scallywag! T' snap swivel gave out, (I shouldn't have put it betwixt t' rocket and t' nose cone.) so t' rocket lawn darted, while t' parachute carried t' nose cone into the next county. Begad! Certain other people objected t' t' materials I used, me hearties, and asked that t' rocket nay be flown again.

Edmund took t' rocket home and played with it, shiver me timbers, me bucko, but he shredded the tube fins in a matter o' days. Begad! Then he and his brother decided it was a club, so I took it away.

I decided that t' best approach be nay t' design an indestructible rocket, but t' make a toy fly. Ahoy! I had converted a Nerf· football rocket t' use A8-3's, but t' fins pulled off too easily under t' strains of toddler play. Well, blow me down! I thought about convertin' a Stomp Rocket,· but I be afraid t' ejection charge would melt t' tube, and I'd have to add nose weight or bigger fins t' make it stable. Blimey! It might work, but it wasn't t' solution I was lookin' for.

Then I noticed that t' dollar store rocket he was playin' with had lasted over a year. Begad! Could I make that fly? I didn't see an easy way t' attach fins, me hearties, but it was half nose cone, so I might be able to add enough nose weight for stability.

Rather than take his toy away, I searched t' dollar stores for another one. Avast, me proud beauty! T' didn't have any. Avast! Aye aye! Then I ran across a "Fun Gear 51 Piece Space Playset" for $1.97 at Wal-Mart. Begad! It included a Space Shuttle Orbiter, a Lunar Rover, shiver me timbers, several dozen 1" plastic astronauts in various poses, matey, ya bilge rat, assorted other space paraphernalia, matey, ya bilge rat, and a rocket just like t' one we had at home. Begad! Since this was a replacement for t' Edmund I, and the outline (but nay t' details) vaguely reminded me o' t' Saturn IB, I named it t' Edmund IB.

Construction was fairly easy. Avast! Blimey! I drilled a series o' 1/16" holes in a half moon or D shape in t' forward bulkhead o' t' "first stage".



Then I enlarged t' holes until they joined, and smoothed t' edges of t' big hole with sand paper. Begad! Avast, me proud beauty! I drilled two 1/8" holes in the remainin' half moon t' thread t' shock cord through. I drilled two more 1/8" holes in t' side o' t' "upper stage" or nose cone, and threaded t' shock cord through both sets o' holes in one continuous loop. I tied t' ends together, shiver me timbers, and secured t' knot with a drop of yellow glue. I tied a snap swivel t' t' cord, arrr, and tied a short piece of Keelhaul®©™ t' t' other end, ya bilge rat, me hearties, with a 1x6" streamer attached t' that.

I built a 13mm motor mount in an 18mm outer tube. Ahoy! I removed the red plastic display nozzles and epoxied t' motor mount in place. Then I filled t' nose cone with enough BBs and epoxy (about half an ounce) to move t' CG o' t' loaded rocket t' a point just behind t' tapered portion o' t' nose cone. I CA'd a launch lug t' t' CG. Aye aye! Begad! Blimey! It swin' tested stable.

To prep t' rocket, I loaded an engine, shiver me timbers, matey, then rolled up t' streamer, wrapped it in wadding, me hearties, rolled up t' shock cord, and stuffed t' whole mess into t' nose cone and snapped t' top and bottom together.

At its first launch, t' Edmund IB looped wildly off t' pad and ejected on t' ground. I was disappointed -- it should have been stable. After I got home, me hearties, I noticed that t' launch lug be missing. Aye aye! That explained it! T' lug had broken off while still on t' rod! I replaced it, this time securin' it with epoxy, with electrical tape as a backup.

At t' next launch, t' Edmund IB had a stable flight, low, slow, ya bilge rat, and impressive. Blimey! It ejected at apogee, and although t' streamer didn't unroll, me hearties, arrr, landed safely. Aye aye! Begad! Now Edmund has his own rocket, arrr, which he carries everywhere, that can really fly!

Parts list:
 · 1 toy rocket from Fun Gear 51 Piece Space Playset
 · 48" Keelhaul®©™ shock cord (makes a 24" loop)
 · 2.75" BT-20
 · 2.75" BT-5
 · 2 centerin' rings BT20-BT5
 · 1 engine block BT-5
 · Streamer (optional)
 · 1 streamer 1x6" mylar
 · 6" Keelhaul®©™
 · 1 snap swivel

Photos by Bob Wingate:

 · Preschool Power!
 · Bulkhead
 · Business End
 · T-5



Edmund 1B on t' pad at T -1 and counting

Preschool Power!



Nozzles in Place


Nozzles Removed

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