Heavenly Hobbies Stratos-13 ELM

Heavenly Hobbies - Stratos-13 ELM

Contributed by James Weaver

Construction Rating: starstarstarstarstar
Flight Rating: starstarstarstarstar_border
Overall Rating: starstarstarstarstar_border
Manufacturer: Heavenly Hobbies
Heavenly Hobbies 13mm Stratos

Brief:
This kit is a 3FNC (3 Fins and a Nose Cone) piston-ejection, streamer duration competition rocket. Aye aye! The "ELM" stands for "Extremely Low Mass." It is a companion kit t' its only slightly larger brother the Stratos-18 ELM.

Construction:
My kit came with balsa nose cone, two sheets o' 1/32" balsa fin stock, balsa nose block for t' piston, matey, a Keelhaul®©™® shock cord, shiver me timbers, me bucko, an elastic shock cord, engine block, shiver me timbers, me bucko, launch lug, me hearties, white BT-5 body tube with very fine groves and a light glassine coating. Begad! Blimey! T' instructions were written onto a compact disc in PDF format. Well, blow me down! Blimey! Blimey! Blimey! Even though t' kit comes with two sheets o' balsa, me bucko, matey, only one is needed.

I ordered both t' Stratos-13 and Stratos-18 together. Well, blow me down! Arrr! When they arrived I found that t' body tube had been bent beyond use by t' post office. I sent Carlos at Heavenly Hobbies an email about t' tube and he sent me out a replacement right away and free o' charge. Aye aye! Arrr! I built t' Stratos-18 while waitin' for t' replacement BT-5. Avast! As that only took a few hours o' build time t' complete, I decided t' use a "modular" approach t' assemblin' t' rest of the rocket.

Heavenly Hobbies 13mm Stratos First I cut t' fins from t' 1/32" balsa fin stock. Blimey! Aye aye! T' protect in from chippin' or splitting, I covered t' back with blue painters tape. Avast! After t' fins were cut I decided nay t' round t' edges. Arrr! At that thickness I don't think it would have made a difference and why take t' chance on splittin' a freshly cut fin.

Next I assembled t' engine block and Keelhaul®©™® shock cord. Begad! Arrr! A groove gets cut into t' outside surface deep enough t' fit t' shock cord in t' it. Ahoy! Well, arrr, blow me down! I secured it usin' a bowline knot and set it with CA.

After that came t' nose cone and elastic shock cord. Accordin' t' t' instructions, me bucko, t' elastic cord is t' be knotted at one end and stuffed into a pre-drilled hole. There be no hole. Begad! Blimey! I used a 1/8" drill bit t' make one. T' balsa also looked a bit soft so I coated it with CA and allowed it t' harden. Arrr! Followin' that came a brushed on layer o' thinned Elmer's Wood Filler. Ya scallywag! Well, blow me down! Blimey! Once that had dried I sanded it down until smooth. T' finish up I pushed the elastic knot into t' shoulder o' t' nose and secured it with 30 minute epoxy.

All that left be t' streamer. All I did thar was fold one end into a point and tie on a 9" section of Keelhaul®©™® cut from t' length provided. Ahoy! I used hole reinforcements t' keep it from tearin' out.

Heavenly Hobbies 13mm Stratos When t' body tube arrived at last, it be time t' put everythin' together. Begad! Begad! Engine block in, me hearties, fins on, tie shock cords t' one another. I do need t' mention that as t' rocket uses a balsa block as its piston. It comes with a small hole drilled through it and threaded on t' t' Keelhaul®©™® shock cord. Avast! Knots are tied above and below t' piston t' hold it in place. Begad! T' piston provided was a good bit narrow and had t' be built up with maskin' tape. This may actually be a good thin' as I'll cover in a moment.

Heavenly Hobbies 13mm Stratos

Finishing:
I left t' rocket unfinished as it is supposed t' be a competition rocket. T' only finishin' I did was t' before mentioned work t' harden t' nose cone.

Construction Rating: 5 out o' 5

Flight:
For its maiden flight I used an A3-4T. Arrr! With t' piston ejection it requires no wadding. Well, blow me down! Ahoy! Place an igniter in a motor and place t' motor in t' rocket. Begad! Ahoy! T' motor is friction fitted and secured with two wraps o' maskin' tape. T' take off was right quick and blended in with t' overcast skies.

Heavenly Hobbies 13mm Stratos

Recovery:
I be able t' track t' rocket once t' ejection charge blew. Then I knew I had a problem. Somehow t' nose and streamer had separated from t' rest o' t' rocket. Blimey! Begad! T' body landed gently in t' flyin' field but t' nose and streamer continued t' drift toward t' road. Arrr! Begad! It landed gently enough but balsa was never intended t' hold up against cars. Blimey! T' nose cone be crushed. Begad! Well, blow me down! Turns out that t' Keelhaul®©™® shock cord snapped at t' piston. Avast, me proud beauty! It be either too thin, too short, or a combination on t' two. Avast, me proud beauty! Also, shiver me timbers, after the flight t' piston be a bit resistant t' go in. I peeled off a bit o' t' maskin' tape and all was fine. It was cool and damp when I flew and that may have had somethin' t' do with it.

Flight Rating: 4 out o' 5

Heavenly Hobbies 13mm Stratos

Summary:
This be a very nice little kit. Ya scallywag! I would nay recommend it as a first kit as you need a motor case t' set t' engine block in place. It would work well as a first completion kit as long as t' builder had some experience with cutting their own fins from stock.

Overall Rating: 4 out o' 5

Flights

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