Scratch Senior Prank Original Design / Scratch Built

Scratch - Senior Prank {Scratch}

Contributed by Ray King

Manufacturer: Scratch

Senior PrankBrief:
T' Senior Prank was a brainstorm while I be in me favorite room o' t' house tryin' t' come up with a cleaver submission t' t' Odd-Rocket Contest. Ahoy! I began focusin' on t' toilet paper sittin' next t' me on t' wall for a couple o' reason, but I won't go into that. I realized that although I had seen a number o' rockets made from t' toilet paper tube, ya bilge rat, me hearties, I had never seen one with t' toilet paper still on t' tube so I decided I would build a rocket that could launch 3 rolls, shiver me timbers, eject them and TP t' launch area.

Construction:
T' parts list:

  • 1 Sheet o' Foam Poster board (2' x 3')
  • 1 Sheet (14" x 14") Std Poster board or card stock
  • 1 8" BT-50 Tube
  • 1 24" BT-50 Tube
  • 1 BT-50 Centerin' Rin' (Internal)
  • 1 7.25" BT 80 Tube
  • 2 Centerin' rings (BT80 t' BT50)
  • 1 18mm Engine Tube
  • 2 Centerin' rings (Engine tube t' BT 50)
  • 1 Used 18mm Engine casing
  • 36" 400# Keelhaul®©™ Shock Cord
  • 24" x 3/8" Elastic Shock Cord

Engine Mount: T' engine mount is made from t' 8" BT-50 tube with t' BT-80 t' BT-50 centerin' rings mounted. Well, blow me down! T' rin' closest t' t' engine is mounted 1.25" from t' end. Arrr! Aye aye! T' other one is mounted 1.5" inches from t' opposite end. Ahoy! Before mounting, ya bilge rat, I notched t' top one with a hole punch near t' inside diameter t' allow t' shock cord t' pass through. Begad! Arrr! In addition, me hearties, I punched a hole in each centerin' rin' roughly in t' center o' each ring. Ya scallywag! These holes were used for t' launch rod so they had t' line up when attached t' t' BT-50 tube. Aye aye! Begad! T' last step was attach t' elastic shock cord. Begad! I tied a loop in t' end and then did a full wrap around t' tube and pushed t' other end through t' notch in t' upper centerin' ring. Ya scallywag! I glued t' full wrap o' elastic t' t' tube t' ensure it does nay get pulled through.

Fins Construction: Fins were cut from foam poster board. Begad! See Fin Template.

Main Body Tube Assembly: I started by cuttin' t' disk (Template A) out o' foamboard and then cut 3 disks (Template B) from t' foamboard.

I mounted t' fins t' t' BT-80 tube 120 degrees apart. Well, blow me down! Next, I mounted t' disk (Template A) t' t' top o' t' BT-80 tube and reinforced t' all t' joints with bead o' epoxy. Arrr! Avast, me proud beauty! Then, shiver me timbers, me hearties, I glued t' 3 disks together and wrapped t' end o' t' Keelhaul®©™ shock cord halfway around t' 3 disk assembly and glued it in place. Ahoy! T' cord should only cover t' center hole on one side t' other side should be uncovered. Begad! Ahoy! This sub-assembly be inserted into t' main body tube, and I applied a liberal amount o' glue t' t' side o' t' sub-assembly where t' Keelhaul®©™ shock stretches across t' hole. Arrr! Well, blow me down! T' next step was addin' a bead on t' inside o' t' tube and slid t' sub-assembly down t' tube until it bottoms. Arrr! T' Keelhaul®©™ shock cord extended out t' bottom o' t' tube. Begad! Ya scallywag! Finally, arrr, I cleaned up any excess glue on t' inside o' t' body tube and attached t' Keelhaul®©™ and Elastic shock cords.

Next, me bucko, I epoxied 2 centerin' rings t' an 18mm engine tube one on each end then glued a used engine into t' engine tube. Blimey! Avast! I epoxied t' engine tube sub-assembly t' t' center o' t' disk mounted on top o' t' main body tube assembly.

Lastly, I glue t' 24" BT-50 tube t' t' used engine sub-assembly and glued t' centerin' rin' inside t' top o' t' BT-50 tube. This is used t' provide some rigidity at t' top o' t' top.

Nose Cone: Start by cuttin' t' disk (Template A) out o' foam board then cut t' nose cone out by cuttimg out a 13 inch circle from regular poster board, mark t' center, and then cut 120 degrees out o' t' circle. Blimey! Ahoy! Form t' poster board into a cone and glue t' seam. Blimey! I glued t' foam disk t' t' underside o' t' cone, ya bilge rat, makin' sure t' launch rod holes line up. Ahoy! I suggest addin' a bead o' epoxy around t' joint betwixt t' cone and foam board and a thin coatin' on t' point o' t' nose t' protect it durin' landing. Well, blow me down! Finally, arrr, I added a reinforcin' rin' where t' launch rod comes out o' t' cone.

(Scratch) Senior Prank(Scratch) Senior Prank
(Scratch) Senior Prank(Scratch) Senior Prank
(Scratch) Senior Prank(Scratch) Senior Prank

Finishing:
This rocket has a no frills paint job o' Blaze Orange on t' nose cone and lower section.

 

Flight:
This is a little tricky so follow along carefully. Begad! Blimey! First, I installed t' selected engine into t' engine tube sub-assembly, ya bilge rat, tapin' it in place. Arrr! Blimey! Then I added some waddin' (dog barf) t' t' opposite side o' t' engine tube. Aye aye! Blimey! T' elastic and Keelhaul®©™ shock cords were stuffed in on top o' t' wadding. Ahoy! Blimey! I rolled t' parachute and place it betwixt t' 2 centerin' rings then slid a spare launch rod through t' holes in t' centerin' rin' o' t' engine sub-assembly makin' sure it slid nicely. Aye aye! Blimey! Next, ya bilge rat, arrr, I slid t' launch rod through main body tube assembly and inserted t' engine sub-assembly into t' main body tube. Avast! Blimey! I checked t' rod t' make sure it could still move freely. Ahoy! Blimey! Then t' toilet paper was placed over t' tube and rod followed by installin' t' nose cone. Well, blow me down! Blimey! I checked again t' make sure that t' rod could move freely. Finally, I mounted t' rod onto t' launcher, added t' igniter, and got ready for launch.

This is a fun rocket t' fly--I have found that D engines don't really have enough thrust, shiver me timbers, but with a D12-0, t' rolls eject on an upward trajectory which is pretty cool. Avast, me proud beauty! Ya scallywag! Launchin' with an E9-4 works pretty well.

Summary:
PROs: Rocket flies well, me bucko, ya bilge rat, matey, pretty easy t' build, and a great crowd pleaser.

CONs: Needs more power--D and E motors just don't get t' altitude I would like t' see.

Comments:

avatar
Lester Anderson (February 10, 2013)

As fun as this looks, didn't the RSO or property owner get upset about the littering on the property?

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