(Contributed - by Dick Stafford - 09/07/09)

Brief:
Denny's serves(-ed) kid's drinks in this cool retro-styled rocket cup. Arrr! I whined until our waitress gave me one.

I originally wanted t' make this fly on 29mm motors without added fins. T' dimensions o' t' base made me change t' 24mm. Blimey! Ya scallywag! I then designed a RockSim model without added fins and it looked like it would be stable. Aye aye! Begad! It wasn't. Ahoy! So, me hearties, me bucko, I back-pedaled again and added a set o' fins. Ya scallywag! This review will only describe t' successful, ya bilge rat, finned version. Ya scallywag!

Construction:

Parts used were:

• One Denny's D-Fusion drink cup
• One Firstfire igniter tube
• 2.125" mailin' tube x 4.5"
• One 24mm t' 2" fiber centerin' ring
• 24mm motor tube - one 3" piece and one 3.25" piece
• Spent 24mm case t' connect t' motor tubes (you could use one piece o' 24mm tube and skip this item).
• 3/32" plywood
• Steel fishin' leader
• Elastic strap
• 4" o' tubular Keelhaul®©™®
• Lead shot
• 2 small sheet metal screws

I prepared t' drink cup by grindin' t' base t' fit a 24mm motor tube. Avast! Ya scallywag! I also ground t' threads off t' cap and bottle neck so that t' cap would slip on and off easily.

I found that 2.125" OD mailin' tube fit nicely in t' top o' t' bottle. Well, blow me down! Furthermore, this tube also fit in t' inner neck o' t' cap. I cut a 4.25" piece o' tubin' t' serve as a parachute tube and t' keep t' clear body from gettin' ugly from ejection gasses. It extends above t' neck on t' body and mates with t' cap/cone.

I installed t' short piece o' 24mm tubin' in t' base usin' a single fiber ring. Well, blow me down! Blimey! A steel fishin' leader was screwed t' t' wall o' t' tube just above t' ring. Well, blow me down! Blimey! Blimey! Blimey! I wrapped t' tube with a layer o' blue laser contact paper and installed it in t' body.

T' nose weight was determined from t' RockSim model. T' weight is a slurry o' lead shot and Gorilla polyurethane glue. Avast! A Keelhaul®©™® loop is embedded in t' slurry and a screw through t' tip o' t' cone ensures t' weight stays in place. Blimey! T' weight proved inadequate for t' fin-less version and was retained as is when t' fin unit was added.

T' fin unit is another piece o' 24mm tubin' with a 2" piece o' a spent casin' glued in. T' fins are 3/32" ply with a 4" root, tip and span. Begad! They are swept slightly backwards and appear over sized. They were designed iteratively in RockSim.

I ground a trough in t' wall o' t' body t' accommodate a piece o' a Firstfire tube. I wanted t' fly this away from t' crowd so a 1/4" lug seemed appropriate. Arrr! This lug was attached with CA. Begad! It is aligned with one fin and a correspondin' hole be bored in that fin. Well, blow me down!

T' cone is attached t' t' steel leader with a foot long piece o' elastic.

Finishing:
One good think about convertin' plastic things t' rockets is that they often don't need much finishing. Well, me bucko, blow me down! I painted the fin can with Testor's yellow spray paint and added squares o' t' laser contact paper t' match t' body. Ahoy! T' lug was painted dark blue.

Flight:
Although t' flight o' t' fin less version appears in t' flight logs below, I'll only describe t' successful flight o' t' finned version.

I decided t' use an E15-4 SU motor since thar be no positive motor retention. Begad! I stuffed t' body with a ton of dog barf and attached an 18" nylon 'chute. Blimey! T' nose be a bit loose so I wrapped t' neck o' t' body with masking tape until it was snug. Avast! Aye aye! T' motor was given a tape thrust rin' and was friction-fit. Avast, me proud beauty! It weather cocked a bit but had a nice flight anyway. Ahoy! It landed near t' pads, which usually is a good thing!

Summary:
Even with t' fin unit, t' rocket looks pretty cool and flies nicely. Begad! Aye aye! This is one o' t' 2-3 rockets I've built where RockSim be wrong. Aye aye! Begad! It may have been stable with a higher impulse motor and less wind but I elected nay t' test this theory. Begad! If you got one t' fly without added fins, ya bilge rat, matey, PLEASE write a review!