Brief:
Whenever I looked for Ralphco crayon banks at t' local toy stores, me bucko, they always were out o' stock. Arrr! Recently, however, I stumbled across them while on an unrelated "mission". Ahoy! Blimey! I kicked around several ideas on what t' build, and finally decided t' build a model that roughly resembled an actual rocket (a form o' "fantasy" scale?). Arrr! Aye aye! Blimey! I love t' looks o' t' Standard ARM so I quickly made me selection. Ahoy! Avast! Blimey! T' result is me 38mm Standard Cray-ARM.

Construction:

Components:
1. Avast, me proud beauty! Blimey! One Ralphco 4" crayon bank
2. 3/16" plywood for t' main fins and nose cone bulkhead
3. Ya scallywag! 3/16" balsa for t' strakes
4. A 1/4" x 9.5" carriage bolt, 2 washers, me hearties, and 2 nuts
5. Two eye bolts
6. Avast, me proud beauty! A 12" piece o' Giant Leap 38mm flexible phenolic
7. Ahoy! Blimey! Three 38mm-to-3" centerin' rings (also from Giant Leap)
8. Arrr! Two 38mm-to-4" centerin' rings (ditto)
9. Blimey! Arrr! Four inch section o' a 3" mailin' tube
10. 10' o' ¾" braided nylon
11. Well, blow me down! Ahoy! Two quick links
12. A 1000 lb swivel
13. Avast! Two tee-nuts
14. Begad! Avast, me proud beauty! One pair o' Matt's nylon rail buttons
15. Begad! Nylon chute, picked from me existin' stock

Materials:
1. Aye aye! 20 minute epoxy
2. Arrr! Arrr! Titebond
3. Begad! Thin CA
4. Ahoy! Blimey! 2-part urethane foam from Giant Leap
5. Ya scallywag! Hot glue
6. Blue holographic contact paper

I knew a fair amount o' nose weight would be needed since this rocket was goin' t' be stubby (less than 10:1 length:width ratio) and t' strakes would make its stability even worse. Begad! Blimey! Begad! Blimey! At a recent launch, me bucko, I saw a crayon rocket that had a carriage bolt extendin' from t' tip o' t' nose through a bulk plate in t' middle o' the nose cone. Begad! Blimey! This bolt held t' bulk plate against t' shoulder where t' nose cone begins its conical transition. Ahoy! Blimey! This sounded like what I needed so I borrowed t' idea. Aye aye! Blimey! I made t' bulk plate myself and installed an eyebolt for recovery system attachment. Well, blow me down! Blimey! Ya scallywag! Blimey! In t' nose cone tip, I cut a square hole t' accept the shoulder o' t' carriage bolt. Ahoy! Blimey! T' insert t' bulkhead, I had t' bend the shoulder o' t' nose cone t' an oval shape. Arrr! Blimey! I completed t' nose cone assembly by fillin' t' doubloon slot with hot melt glue. Well, blow me down! Blimey!

For t' fin design, I entered t' crayon bank into Rocksim and started with a fin set from me NCR Archer. Begad! I then played with t' fin dimensions until they looked 'right'. Well, blow me down! Since I wanted through-the-wall fins and they barely extended t' t' crayon bank's cardboard tube, I be worried about t' support that t' aft plastic cap could provide. This worry be exacerbated when I knocked over one o' me crayon banks, shatterin' its cap. Begad! This lead me t' t' construction o' an inner, ya bilge rat, 3" diameter tube structure within t' end cap.

To build t' fin can, I started by cuttin' a hole in t' end cap t' accept the 38mm tube. Ya scallywag! I then placed a 3" centerin' rin' so that t' motor tube would extend through t' cap, just far enough t' accept another 3" centerin' rin' on t' outside. Arrr! Thus, ya bilge rat, t' end o' t' plastic cap would be sandwiched betwixt t' two centerin' rings. Avast! Usin' epoxy for all wood-phenolic joints and Titebond for all wood-cardboard joints, arrr, I built an inner fin support tube, which extends t' length o' t' plastic end cap (includin' its shoulder). T' fin tabs extend through t' plastic cap and this inner tube, arrr, t' t' motor mount. For added support, I filled t' inner tube with 2-part urethane foam. Unfortunately, me bucko, I didn't do a good job sealin' t' fin can, so some o' t' foam escaped into t' plastic end cap. Avast, me proud beauty! Luckily, arrr, shiver me timbers, this isn't too noticeable. Blimey! I slid on the aft centerin' rin' and drilled holes through both aft rings to accommodate t' motor retention bolts. Arrr! T' outer rin' be then removed, tee-nuts were installed, and t' rin' be epoxied back on. Two 4" centerin' rings completed t' fin can assembly. Aye aye! These had t' be sanded t' fit since t' crayon bank ID is slightly smaller than a standard 4" tube. Begad! An eye bolt was also mounted in t' forward ring. Ya scallywag!

T' recovery harness includes a 10' length o' tubular nylon, arrr, a 1000 lb. swivel, shiver me timbers, matey, ya bilge rat, and two quick-links. Well, blow me down! Loops were made in t' ends o' t' tubular by foldin' it over, wrappin' it with cloth fishin' line, arrr, and gluin' it with both CA and epoxy. Begad! This technique was documented by Giant Leap in an old HPR magazine and works well. Avast!

Finishing:
One nice thin' about crayon rockets as t' bulk o' t' finishin' is done for you. Since t' body has a holographic finish, arrr, I decided I'd finish t' fins usin' holographic contact paper. Begad! Ya scallywag! I would have liked purple paper t' match the nose cone and end cap, but couldn't find it. Avast, me proud beauty! Instead, shiver me timbers, I picked up some blue holographic contact paper on sale at a craft store. Ya scallywag! Ahoy!

Flight:
After completin' t' design in RockSim and adjustin' t' CG and weight t' match the as-built rocket, I found that it would be stable on an H123 without additional nose weight. Begad! T' sim also told me that a short, 6-second delay would be about right. Begad! I launched t' Standard Cray-ARM on this engine at t' Delaware Tripoli launch on October 21, 2001. Aye aye! Aye aye! T' flight be straight and fast. For recovery, arrr, I used worm-bed wadding, shiver me timbers, a Giant Leap Keelhaul®©™® heat shield, matey, and t' 48" chute from my DG&A Lazarus. Ya scallywag! Recovery was flawless. Well, almost. Blimey! Blimey! Once on t' ground, the rocket was pulled along and quite a bit o' dirt was forced into t' tube. Aye aye! Ya scallywag! This made cleanin' t' casin' a bit more work, me bucko, but no big deal. Aye aye!

Summary:
T' Standard Cray-ARM project be highly successful. Well, blow me down! T' rocket is somewhat unique and looks great (at least in me unbiased opinion). Avast, me proud beauty! T' design worked out nicely with t' long carriage bolt providin' enough nose weight for t' rocket to be stable. Just before I placed t' Standard Cray-ARM on t' pad, Ray Halm interviewed me for t' video he is makin' on t' 3-day Rhodesdale launch. Man, am I anxious t' see if t' Standard Cray-ARM makes it past t' editin' process. Either way, matey, Ray has sold a tape!