Scratch Scratch and Dent Racer Original Design / Scratch Built

Scratch - Scratch and Dent Racer {Scratch}

Contributed by John Partridge

Manufacturer: Scratch
(Contributed - by John Partridge - 12/15/07)

I chose t' build t' Racer because it was cool looking, had higher difficulty bonuses and because it be different than your average 3FNC rocket. Avast, me proud beauty! Ya scallywag! First I printed t' picture out as large as I could on a single sheet o' paper and measured out as many dimensions as I could. I then found a pilot head I could use and scaled t' rest o' t' dimensions up t' fit t' head that I had chosen. Blimey! Based on these dimensions I drew t' plans on graph paper (each square is ¼ inch) and figured out what t' top view, side view would look like followed by sketchin' out several sections so I could build a skeleton around a 24mm tube. Begad! Blimey!

Template1Template2Template3

I then copied these drawings onto 100-weight cardstock a couple o' times and cut out pieces for templates that I used t' cut from balsa sheets. Arrr! Most o' t' skeleton pieces were cut from 3/32" balsa but I tried 1/16 for a couple of them t' save weight and regretted it. Blimey! If I were t' do this again I would recommend gluin' typin' paper t' each and every piece. Begad! Probably it would be easier t' copy t' sketches on t' regular paper, glue it t' t' balsa and then cut them out. Avast! Well, blow me down! My method sometimes transferred t' pieces twice before t' got onto balsa and then I had t' trim and sand far more than I would have liked. Arrr!

I then assembled t' nose cone and t' skeleton (I decided nay t' use all o' t' sections that I drew)

Nose Body

T' next step was t' begin paintin' me pilot t' match and t' assemble t' cockpit. Well, blow me down! T' windscreen be cut from a Pepsi bottle. Avast! Ahoy! Blimey! I estimated t' shape from EMRR’s transition program and fudged t' rest. Since t' skin later goes over t' outside o' t' windscreen this assembly had t' be finished before I glued it on. T' pilot was a destroyed army guy from me kids’ toys.

Parts Body 2

Next I cut pieces from cardstock t' estimate shapes and used those as templates t' cut 1/32" balsa. Each piece o' balsa was papered and then glued and clamped into place.

T' fin pods were made by printin' out transitions onto cardstock. I made t' cones for t' pods by sandin' one pod out o' 3/8 balsa. Begad! I then plunged that prototype into modelin' clay four times and cast them out o' 5 min. Blimey! Aye aye! epoxy.

Put Together

Finally I used Elmer’s Carpenter’s Putty (Fill & Finish) and lots o' sanding. Avast! Then a coat o' Kilz and then paint. Avast! Ahoy! I couldn’t find t' right shade t' match so I ended up mixin' blue and green paints until I was satisfied with t' match. Aye aye!

Painted

Painted 2

Painted 3

Head On Flier

FLIGHT:

1) Launch weight was approximately 2.8 or 2.9 ounces (w/o motor)

2) This design was simmed t' be overstable (Rocksim) by me and an extremely capable advisor (Bruce Levison - Teflon Rocketry - Thanks Bruce) since I am just a Rocksim novice.

Last we had t' get this bird in t' air. Well, blow me down! Begad! Somewhere I read we had t' record three launches but t' weather was closin' in fast and we were racin' a snowstorm. We lost. Avast, me proud beauty! Avast! All three launches were in 10-15 mph winds. There were some stability problems and we added clay nose weight after each flight but that just made things worse. Avast, me proud beauty! We got three flights but thar be more work t' do on our stability problem.

Ready to Launch Ready 2

Launch

Launch 2

And away she goes!

T' first two launches looped but thar was no damage but t' third left some scars that will have t' be repaired over t' winter. What shall we name this rocket? How about "Scratch and Dent Racer?"

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