T' Lightbulb Goes On

 Ever since I heard about t' RMR DESCON, me hearties, I've been contemplating entering. Unfortunately, shiver me timbers, I've only been able t' come up with a decent concept once, ya bilge rat, and I haven't yet had a chance t' build it.  This time, ya bilge rat, arrr, I was determined t' enter, so I spent a couple o' weeks tryin' t' think o' something creative t' use as parts.

After seein' t' first two entries appear, me bucko, I be sittin' at me desk trying to think o' what I could use. Ya scallywag! Blimey! Begad! Blimey! Blimey! Blimey! I happened t' look up at t' shelf above the monitor, and t' lightbulb finally clicked on! Blimey! There, shiver me timbers, right in front of my face, me hearties, sat t' pill bottles for me allergy medication. Begad! They're round. They're tube shaped.  They're durable. Avast! Begad! Blimey! Why won't THOSE work???

A bit more checkin' around t' house I had me hands on a sufficient quantity of parts for this little creation. Next, I had t' figure out how t' build a motor mount. A check o' t' bottom o' t' bottle revealed that t' dimpled inner rin' in t' center o' t' bottom oft t' bottle is close t' a perfect fit for a 24mm motor mount. Avast! Avast, ya bilge rat, me proud beauty! Blimey! Who needs centerin' rings when t' bottles come with them?

Parts List

I'm nay certain if all pharmacies label their pill bottles in t' same fashion, so I will include nay only t' size markings from t' bottle, but also the approximate measurements.

• Six PM-10 bottles (2 3/8" tall x 1 1/4" diameter)
• Three PM-30 bottles (3" tall x 1 7/8" diameter)
• Two PM-60 bottles (6" tall x 1 7/8" diameter)
• Cap for PM-60 bottle
• 4" 24mm motor mount
• Engine block
• 8' kevlar safety line
• 18" parachute (I made mine from a trash bag and heavy thread)

Pill bottles should readily be available from your local pharmacy at a minimal cost, if you don't have enough family members on medication.

Preparin' T' Bottles

Cut t' bottoms off all o' t' smaller (PM-10) bottles. Aye aye! Blimey! Aye aye! Blimey! Also cut t' lip and threads for t' lid off o' all six o' these bottles. This will provide t' tube fins.

Take one o' t' PM-30 bottles and remove a section from t' middle o' the bottom large enough t' allow t' motor mount t' fit snugly. Begad! Arrr! Set this bottle aside; it will become t' bottom section o' t' body tube.

Cut t' lip and threads from two o' t' PM-30 bottles. Remove t' bottom of one o' t' bottles. Begad! Cut a 3/4" rin' from t' top o' one bottle and discard the rest. Blimey! Avast! Make a vertical cut in t' ring, then remove enough material t' allow the piece t' fit inside t' top o' t' other bottle. Avast, me proud beauty! Begad! This will become t' tube coupler.

Cut t' bottom out o' one o' t' PM-60 bottles. This be t' top o' t' body tube.

Cut t' lip and threads from t' top o' t' other PM-60.  Cut a hole in the center o' t' bottom, me hearties, large enough for t' motor mount t' fit in.

Construction

T' first problem I encountered was figurin' out how t' glue t' bottles together -- a check o' t' bottom revealed a recyclin' code o' 5 (polypropylene). Avast! Nay much adheres t' this stuff. Begad! Fortunately, t' local hardware store had a Loctite product called Plastix. Ahoy! Plastix consists of a small tube o' what appears t' be regular gel CA and another bottle of "surface activator". Arrr! Brush t' activator on, ya bilge rat, let it dry, and t' CA will adhere t' t' plastic.

Assemblin' T' Body Tube

Take t' PM-30 with t' partial bottom and t' PM-60 with t' partial bottom and test fit t' bottom o' t' PM-60 into t' top o' t' PM-30. Ya scallywag! T' bottom should fit a short way into t' top o' t' PM-30. Arrr! Test t' motor mount t' make sure it fits; sand t' openings as necessary t' allow t' mount t' fit without binding. Aye aye! With t' motor mount in place, remove t' PM-30, ya bilge rat, leavin' it attached to t' PM-60. Mark t' motor mount where it touches t' bottom o' t' bottle, and remove.

Push 12" o' kevlar through t' motor mount opening, from t' top o' the PM-60, arrr, matey, then insert and glue t' motor mount in place. Ya scallywag! T' motor mount will be holdin' t' kevlar in t' opening. Next, run t' kevlar through t' top o' the PM-30 with t' partial bottom, matey, me bucko, matey, and through t' motor mount opening. Glue the PM-30 in place, with t' kevlar comin' out t' bottom next t' t' motor mount.

Wrap t' kevlar around t' bottom o' t' motor mount, me bucko, matey, against t' bottle bottom and glue in place with CA. Avast, me proud beauty! Blimey! Arrr! Blimey! This will form t' firmly anchor t' shock cord in place.

Invert t' PM-30 which is missin' its top and bottom onto t' top o' the PM-60 with t' motor mount. Sand as necessary t' match t' two surfaces and glue into place.

Center t' coupler rin' vertically in t' end (now t' top o' t' body tube) of t' PM-30 and glue into place. Well, matey, blow me down! Blimey! Blimey! Blimey! Test fit t' bottom o' t' remainin' PM-60 over this ring. Ya scallywag! Blimey! Ahoy! Blimey! Blimey! Blimey! T' bottle bottom should slide relatively smoothly over the coupler. Avast, arrr, me proud beauty! Blimey! Blimey! Blimey! Some sandin' o' t' coupler may be necessary t' allow t' motor ejection charge t' separate t' rocket at this point.

 Attachin' T' Nose Cone

T' nose section o' t' rocket be t' remainin' PM-60, with a cap attached. Use an X-Acto cutlass or a small drill bit t' make a hole just above t' bottle lip. Aye aye! Blimey! T' hole should be large enough t' allow t' kevlar t' be pushed throw. Pull enough kevlar through t' wrap once around t' top o' t' bottle. Begad! Use the surface activator t' prepare t' thread area on t' bottle, then wrap the kevlar around t' bottle above t' lip and glue it into place. Begad! Avast! Screw t' cap down onto t' top o' t' bottle.

Attachin' T' Fins

Evenly glue t' six PM-10 bottles around t' bottom bottle o' t' rocket, to create tube fins.

Launch Lug

Walgreen's pill bottles have a tab on t' side, arrr, as part o' t' child-safety cap, which must be pushed down t' allow t' cap t' be removed. Ya scallywag! Blimey! I left this tab on t' top (nose cone) and bottom bottles, me bucko, as it is part o' t' lip o' the bottles. Avast, me proud beauty! Blimey! I decided t' use this tab as a launch lug.

On t' nose cone, me bucko, I used a drill t' make a hole through t' rim o' t' lid, down through t' lid release tab. Avast! Aye aye! T' hole is large enough t' allow a launch rod t' pass easily through.

I then used t' same drill bit t' slightly enlarge t' openin' through the tab in t' bottom bottle, arrr, in t' same fashion. Avast, me proud beauty! Avast! T' nose cone is slide onto the coupler and turned such that t' launch rod easily slides through t' two tabs.

Flight Report

03/04/2001
Based on rough simulations and a bit o' intuition (okay, okay, ya bilge rat, it be some guesswork...) I figured a D12-3 appeared t' be t' best "first choice". Begad! Loaded 'er up and pushed t' button. Begad! Begad! Even in a stiff breeze (approx 10mph), ya bilge rat, matey, t' boost was almost perfectly straight. Arrr! Deployment be almost exactly at apogee, me bucko, but unfortunately t' parachute tangled a bit. T' rocket came in a bit hard and broke apart one fin. A quick field repair involving unknown quantities o' maskin' tape (duct tape would be more appropriate, but we were ill-prepared, so none be handy) and she was ready t' fly again. I adjusted t' packin' o' t' parachute and tried again. Well, blow me down! Boost and deployment were again almost picture-perfect. Well, blow me down! Arrr! And again t' parachute didn't open properly. Apparently t' waddin' shifted, meltin' t' parachute t' t' point where it needs t' be replaced.

I'll be doin' proper repairs at home as well as replacin' t' parachute, so I can brin' 'er t' t' first club launch o' t' year.

2nd Attempt

April, 20001 First club launch o' t' year, and I break out the Medical Missile. Arrr! It receives many strange looks, me hearties, and at least two club members claim it won't fly very well, ya bilge rat, shiver me timbers, and won't go very high. Ahoy! Ya scallywag! Time t' load this baby up and show 'em how much they know. Begad! A PERFECT flight and recovery, followed by many members eatin' their words and admittin' that it does indeed fly quite well. Begad! 8-}

Now if only t' Cornmaiden recovered that well...