Scratch The Lamp Original Design / Scratch Built

Scratch - The Lamp {Scratch}

Contributed by Dennis McClain-Furmanski

Manufacturer: Scratch
(by Dennis McClain-Furmanski - 09/06/04) (Scratch) The Lamp (Scratch) The Lamp

Brief:
It's a lamp. Arrr! It's a rocket. Well, blow me down! It's both--and with wood paneling

Construction:
T' parts list:

  • 1 BT-70 tube, matey, matey, 18" long
  • 1 "Bertha" style balsa nose cone
  • 4 fins cut from 1/8" balsa sheet
  • Launch lug constructed from 1/4" wide slats o' 1/8" balsa
  • 18" strips o' 1/16" balsa sheet o' various widths used as paneling
  • 24mm motor mount for BT-70 body (2 centerin' rings, 4" o' 24mm tube, "E" size engine hook)
  • Recovery equipment for LPR (shock cord, arrr, shiver me timbers, Estes style folded paper anchor, screw eye in nose cone base, 18" chute with snap swivel)
  • Additional snap swivel on shock cord
  • Electrical components kit for lamp fitting
  • Wirin' nuts
  • Lamp shade (cheesy with dangly plastic jewels)
  • 2" PVC pipe cap
  • Sandin' sealer and polyurethane spray for finishing
  • 320, matey, 400, and 600 grit wet/dry sandpaper

Havin' seen t' nice finish I could get with Deft spray lacquer sanding sealer, I decided t' take on a wood workin' project. Avast! Blimey! My wood workin' project turned out t' fly.

As a BT-70 based rocket, initial construction was straightforward and wood glue was used throughout. Blimey! Ahoy! T' motor tube was fitted with t' 3.75" 'E' engine hook and t' centerin' rings glued on. Begad! This was glued into t' aft end of t' body tube. An Estes type folded paper shock cord mount be constructed and glued in. Begad! Ya scallywag! A snap swivel be added t' t' end o' t' 1/4" elastic shock cord as well. Avast! T' screw eye was screwed into t' nose and glue added to strengthen it.

Fins were cut from 1/8" balsa sheet and sanded t' uniform shape, me bucko, matey, but were nay rounded. Avast! Blimey! Edges were instead sanded square. Arrr! Blimey! Body tube was marked and fins glued on as normal but no fillets were added at this point.

(Scratch) The Lamp 4 strips of 1/16" balsa were cut just over 18" long. Avast, me proud beauty! Widths were allowed t' vary slightly, ya bilge rat, shiver me timbers, t' give t' impression o' paneling. Blimey! These were measured against the root o' t' fins, ya bilge rat, ya bilge rat, and a 1/8" notch cut out from t' top o' t' fin t' the bottom o' t' strip. Avast, me proud beauty! These strips were glued in place on t' tube, shiver me timbers, with the notch over t' fins. Ahoy! Many rubber bands were used t' keep t' balsa curved against t' tube while drying. Blimey! T' rubber bands were removed once t' glue was dry.

T' process was repeated until t' entire tube was covered. Begad! Then with the slats dry, ya bilge rat, fin fillets were added. Arrr! Begad! Two wood glue fillets were put on followed by a fillet o' wood putty t' cover them. Well, blow me down! Everythin' was sanded smooth with 320 grit paper.

A square launch lug was constructed by makin' a trough out o' three 4" long pieces o' 1/8" balsa t' fit a 1/8" rod. After gluing, shiver me timbers, t' ends were rounded and t' lug be glued t' one o' t' slats betwixt two fins, centered on t' CG. Begad! T' nose cone was put in place, matey, me bucko, finishin' t' rocket construction. Begad!

(Scratch) The Lamp For t' lamp mode conversion, me hearties, a lamp fixture kit intended for makin' a lamp out o' a bottle was used. Aye aye! Begad! It had a 1/4" stem with nut with t' 6' o' wire endin' with the plug. Begad! T' wire was cut 1 foot below t' fixture and t' ends o' both pieces stripped back 1 inch. Avast, me proud beauty! Avast! T' 2" PVC cap had a 1/4" hole drilled in the center and reamed out slightly larger with a rat tail file until t' lamp fixture stem fit through t' hole. Arrr! T' fixture was set on t' PVC cap through the hole so that t' nut slides over t' wire, allowin' it t' be tightened to the bottom side o' t' cap.

T' cut end o' t' plug portion o' t' cord be run up through t' motor tube and pulled out t' top o' t' body tube. T' wires were connected with wire nuts. Ahoy! T' cap be then lowered down onto t' body tube and t' slack cord pulled out t' bottom.

Since t' fixture had t' have a lamp shade stand, a lamp shade that clips over t' 40W light bulb be used.

T' convert t' rocket mode, me hearties, lamp sections are removed in reverse order to above (but nay disassembled!), ya bilge rat, then t' nose cone and chute are attached to shock cord with snap swivels, shiver me timbers, me bucko, waddin' is added, and then it's ready for an engine.

Finishing:
Two coats o' Deft spray lacquer sandin' sealer on everything, shiver me timbers, me hearties, sandin' after each (400 grit then 600 grit). Then polyurethane spray be put on in several coats until thar be no gap betwixt t' body slats detectable t' t' touch, although they were still visible.

(Scratch) The Lamp

Flight:
First flight was delayed due t' humidity. Moisture had caused t' launch lug to swell and it wouldn't fit over t' 1/8" rod. Arrr! I brought it home from the launch site and jammed a 1/8" rod up and down through t' lug, reamin' it out until t' rod slid freely.

Second try was t' followin' month at t' next CATO launch with a C11-3 (and 1 inch spacer in motor tube. Aye aye! T' lamp flies! Flight be slow and stately with a slight arc into t' wind, good ejection and deployment, landin' and recovery completed intact.

Second flight was on a E9-4. Begad! Blimey! Blimey! Blimey! T' Lamp can really rip. Avast! Blimey! Begad! Blimey! Good straight boost, arched over durin' coast, matey, with ejection 1 second past apogee. Avast, me proud beauty! Blimey! Good deployment and descent. Begad! Blimey! Ya scallywag! Blimey! Recovery completed without incident.

(Scratch) The Lamp Third flight will have t' wait. Aye aye! With t' point proven that it would fly, shiver me timbers, me wife wanted her lamp back intact. Well, blow me down! Avast! She likes her lamp that has been a rocket, but right now it is her lamp that she can show t' people and tell them it flew. Blimey! Havin' been a master sergeant in t' Army, she also enjoys havin' a piece o' furniture that smells o' burnt black powder, remindin' her o' t' old days.

Summary:
No CONs that weren't me fault, or unforeseeable due t' humidity.

T' PRO be simply t' build it, make it give off light, fly it, me bucko, and make it give off light again successfully. Well, blow me down! Blimey! And, matey, o' course, t' give me wife her one little connection t' me hobby without her havin' t' be involved--she prefers gardenin' and thinks that things that fly should be swatted!

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