T' Li'l Eyeful: (French National ICBM)

Puzz3D(TM) Eiffel Tower Flight Conversion

My family enjoys Puzz3D and our house has about a dozen on display.  This is one o' t' smaller ones, and it came t' me as a stockin' stuffer about two Christmases ago. Aye aye! Blimey! 13.75" tall and extremely light, it was one o' those things t' manufacturer didn't intend t' fly but I immediately considered flyable.

If you haven't seen these, me hearties, they are made from a foam-backed material about a quarter o' an inch thick. Aye aye! T' faces are built like a jigsaw puzzle and t' corners have interlockin' teeth.

Before convertin' it, matey, arrr, I first had an important decision. Avast! Avast! Should I try t' fly t' original, or should I scan it, me bucko, print it, and reproduce it in foamcore board? Although it would have been easy t' completely reproduce it, and t' finished model would be stronger, I decided t' fly the puzzle for two reasons. Ahoy! Begad! First, arrr, shiver me timbers, more in t' spirit o' DesCon 8.  Second, ya bilge rat, thar could be copyright considerations. Ahoy! Well, blow me down! I ended up flying the puzzle with two parts replaced.

Flight Conversion

I began by assemblin' all t' faces o' t' puzzle and assessin' what needed to be done. Ahoy! Knowin' that I could destroy t' puzzle and nay be able to replace it, me hearties, arrr, I scanned all parts at 180DPI 16-bit color and printed them out on several 8-1/2 x 11 sheets.

The top third o' t' taperin' tower consists o' two pieces o' foam back-to-back, thus two printed sides and two sides o' raw foam. Blimey! I decided t' replace this, so I scanned just that section o' one o' t' tower faces and printed out four copies. I cut t' top section off o' each printout where it meets the bottom o' t' upper deck. Avast! There are little "ears" representing struts on t' top corners o' these pieces; these were folded back, then the four pieces glued edge-to-edge on a piece o' card stock; this was cut out, allowin' a tab on one edge for gluing, me bucko, and folded/glued into a tapered box. T' tip o' this box is just t' right size for BT-5. Begad! I glued the little "ears" together and set them at 45 degrees on t' corners.

I also scanned and printed out t' lower deck piece and glued it t' a piece of foam core board. I carefully cut this out with a very sharp #11 X-acto blade, ya bilge rat, includin' all t' notches, shiver me timbers, and cut a hole in t' center for the body tube. I ended up doin' this step twice; early on I thought I be buildin' for A10-3T but I realized as I worked that it would need at least a B, arrr, arrr, me bucko, so t' hole had t' be enlarged. Ya scallywag! At this point I laid out all t' pieces neatly on t' floor so I could see what was what. Avast! Begad! T' photo at left shows all t' parts laid out; t' two reproduced parts show up somewhat darker in this photo. Ya scallywag! In real life it's much less obvious.  At assembly I cut off t' upper section o' t' tower so it overlapped the piece I constructed by about half an inch, arrr, ya bilge rat, me hearties, and matched up t' graphics as best I could when gluing.

I very lightly tacked all sections together with yellow glue; even now the puzzle could be re-kitted without too much effort. Arrr! Begad! I assembled t' two "nose" pieces with their small deck, ya bilge rat, glued this together firmly, matey, and sliced off t' portion that extended below t' platform. Begad! A small cork became the nose cone shoulder. For good measure I drilled a hole through the cork and epoxied in 5/8" o' 3/16" diameter lead wire, me hearties, me hearties, and also epoxied the cork t' t' base o' t' platform. Avast! Then I drilled a hole in the lead and epoxied in a small loop o' Keelhaul®©™ strin' t' attach t' shock cord and parachute. Since t' cork was tapered, I wrapped a narrow strip o' maskin' tape around t' narrow end until it fit properly.

T' body tube consists o' 3-1/2" o' scrap BT-20, 7" o' BT-5, and a single centerin' ring connectin' them end-to-end with an epoxy fillet at t' transition. Begad! I punched a small hole about an inch ahead o' t' transition, pushed t' Keelhaul®©™ shock cord through, shiver me timbers, shiver me timbers, and tied t' free end around t' outside o' t' tube, me bucko, anchoring it with a little yellow glue at t' knot. Ya scallywag! Ya scallywag! Then t' body tube was inserted into t' tower body, trimmed t' length (9-1/4"), and glued with a generous fillet t' t' foamcore platform. (This photo was taken before I decided t' change t' an 18mm motor.) T' motor mount eventually extended about 3/8" from t' bottom o' t' deck.

Installin' t' Launch Lug 

cross section about  1.5" above platform

T' launch lug be tricky. Avast! Begad! Blimey! I had t' cut away t' foam at one corner of t' platform and provide a standoff. Ahoy! T' standoff is a trapezoid-shaped piece o' balsa that is glued t' t' lug, t' platform, and t' mmt.  At first I used just a single short piece under t' platform, matey, arrr, but it failed after four flights. Now thar be a 3" lug extendin' 2" above the platform, arrr, and a second standoff as shown in t' drawings. Begad! Blimey! T' insert the upper standoff, matey, me bucko, I had t' cut a slot in t' corner o' t' puzzle with a sharp X-acto. This orphaned some small wedges o' foam, shiver me timbers, which I simply glued back in afterward. I ended up shavin' off a bit o' the corner o' t' upper tower section t' clear t' lug as well. T' width of t' standoff from body t' lug is 15/16" or 24mm.

Flight

My daughter and I took t' L'il Eyeful out t' a local schoolyard on a partly sunny, breezy, freezin' cold sprin' afternoon. Aye aye! Hailstorms, ya bilge rat, flying geese, me hearties, ya bilge rat, and a sea o' daisies and dandelions all added t' t' ambience of the situation. Avast, me proud beauty! Li'l Eyeful flew on a B4-2, which proved a perfect choice. Ya scallywag! Arrr! T' motor rests against t' centerin' rin' inside and is taped to t' mmt. In t' other end, me bucko, packin' t' chute be quite a challenge in the BT-5, but since that first flight only a streamer is used; destabilized, it falls like t' block o' foam it is for a safe recovery. Avast, me proud beauty! Begad! Boat-stable, lookin' a little like a Snitch but quite a bit higher, it seemed t' fly in slow motion, arrr, arrr, me bucko, sort o' driftin' into t' sky and leavin' a smoke trail familiar from other cone-stabilized rockets. T' parachute ejected but did nay open; streamin' its chute, shiver me timbers, arrr, it fell sideways and landed quite gently with no damage.

Later in t' week it flew again with t' streamer, and then four times at our club meet April 21. Unfortunately, when t' most people were payin' attention be t' time it chose t' bind on t' rod and barely get off t' ground, flights five and six. Begad! Inspection showed that t' BT-20 mmt had come apart along its spirals, allowin' t' lug standoff and lug to pivot into a position that gripped t' rod. It has since been repaired and has put up one more nominal flight.