Scratch Estes Astron Star Blazer (Upscale) Original Design / Scratch Built

Scratch - Upscale Astron Star Blazer {Scratch}

Contributed by Moe Bertrand

Manufacturer: Scratch
Style: Upscale
(Contributed - by Moe Bertrand - 04/29/07)

Rocket PicBrief:
180% upscale o' t' classic Estes Astron Star Blazer (K-31) usin' BT-55 (1.325") and parts from t' spare parts box.

Construction:
T' parts list:

  • BT-55 11 5/8" long
  • BT-55 4" long
  • PNC-55 (5 3/8" long)
  • balsa sheet 1/8" x 4" x 36"
  • strip basswood 1/8" x 3/16"
  • JT-55 tube coupler
  • block balsa t' carve canopy
  • BT-20 3" long
  • 2 AR-2055
  • EH-2 engine holder
  • AR-520 engine block
  • 18" parachute
  • screw eye
  • elastic shock cord
  • shock cord mount o' your choice

Estes rated t' original Star Blazer as a Skill Level 3, which I feel is accurate based on t' curves o' t' fins, the long, shiver me timbers, thin root extensions, t' cockpit canopy that is supposed t' be carved from a block o' balsa, me hearties, and t' 4-color paint scheme. Begad! I decided on BT-55 and after downloadin' t' instructions and patterns from JimZ and makin' correctly sized patterns on a photocopier, matey, I began construction. Arrr! Blimey! I decided on a suitably shaped plastic nose cone from a designers special or nose cone pack. It may nay exactly replicate t' original BNC-20N from t' kit, me bucko, but it works for me. Aye aye! I suppose I could have special ordered a near clone from BMS, me hearties, but I opted for what I had on hand. I decided on an 18mm motor mount t' keep flights on t' (relatively) cheap. Avast! Well, blow me down! Blimey! Like t' original, matey, me bucko, t' body tube separates behind the canopy. Ahoy! Ya scallywag! Blimey! Rather than usin' a relatively pricey balsa nose block, matey, I scratchbuilt a nose block from t' JT-55 tube coupler and some scrap 1/8" balsa. Arrr! Blimey! I strengthened t' lower end with a cardstock centerin' rin' for t' recovery system screw eye t' attach to. I traced t' inside diameter o' t' JT-55 on t' balsa and cut it out, securin' it inside the JT-55 with a good fillet o' yellow glue. Avast, me proud beauty! Begad! Blimey! I then glued t' cardstock centerin' rin' t' t' balsa and cleaned it up to ensure a smooth fit in t' body tube.

I secured t' nose cone in place t' t' short length o' body tube t' canopy will be glued to. Blimey! T' 4 inch payload section is non-functional. Ya scallywag! Aye aye! Its only purpose is a place t' glue t' canopy to.

For t' fins, I first traced t' pattern onto 0.040" sheet styrene and carefully cut that out, me bucko, me hearties, bein' careful to preserve t' curvature o' t' pattern. This would serve as a guide t' help me cut t' graceful fins from a 4” wide piece o' 1/8” balsa. Aye aye! Avast! These are big fins! I used 1/8” strip basswood for t' root extensions, matey, thinking they would stand up t' finishin' and handlin' better than balsa. Well, ya bilge rat, blow me down! Then I started thinkin' about how t' tackle t' carved cockpit canopy. My first attempt didn't work out well. I selected a piece o' square balsa stock cut it in half lengthwise on t' diagonal (corner t' corner) and traced t' basic kite-shaped pattern as indicated in t' original instructions downloaded from JimZ. Ahoy! Then I wrapped a piece o' coarse sandpaper around a length o' BT-55 and started sandin' longitudinally. Arrr! Before too long I be creatin' a dusty mess. Begad! Instead o' gettin' t' desired results, arrr, I realized I was sandin' off course... Ya scallywag! T' resultin' cavity was driftin' t' one side as I sanded. I shelved that idea and decided on gettin' a larger block o' balsa. Begad! Avast, me proud beauty! Before cuttin' it in half, I chucked a 1.25” spade bit in me drill press and drilled a lengthwise hole down through t' center o' t' balsa block. Begad! Then I cut t' block in half as before. Avast, me proud beauty! Now at least I had a cavity t' start with, even though it was a bit smaller in diameter than a BT-55. Ya scallywag! After layin' out the kite pattern and cuttin' off t' excess balsa, ya bilge rat, I started sandin' on t' body tube again. Avast, me proud beauty! Ya scallywag! This time me efforts were workin' as planned. I was gettin' a piece o' balsa that would conform nicely t' t' diameter o' t' BT-55. Well, blow me down! Ahoy! Satisfied with that effort, t' next task be t' shape t' canopy. Try as I might, me hearties, matey, I just couldn't (or didn't want to) replicate the relatively complex shape o' t' original. Ahoy! Arrr! I decided on a fairly simple canoe-shaped design that would probably pass for a canopy once painted. Avast! Arrr!

Once t' fins and root extensions were attached and dry, I glued t' canopy t' t' tube and used Fix-It epoxy clay t' blend t' canopy t' t' tube as best I could. Durin' this time I be realizin' me finishin' skills needed much improvement. I broke out me 8-year old pint can o' Sandin' Sealer and started applying. Blimey! I used some Fix-It t' fill some shrinkage holes in t' yellow glue fin fillets, ya bilge rat, ya bilge rat, which worked quite well.

Finishing:
After sealin' and primer, shiver me timbers, me bucko, I painted t' red/white/blue scheme shown in t' early Estes catalogs. T' canopy is gloss black. Avast, me proud beauty! I don't have any decals for t' Star Blazer yet. Well, blow me down! I might try Tango Papa. Ahoy! Aye aye! Engine selection will be C6-5 and recovery by 18” chute.

CONs: fairly complex maskin' required t' get good separation betwixt t' body tube and fins/fin fairings, ya bilge rat, 3-color pattern on fins, and isolatin' t' black on t' canopy.

Flight:
First flight was conducted at SSS "SpringBlast" in April 2007 on an Estes C6-5. Ya scallywag! Well, arrr, blow me down! Good motor for this rocket given t' 3.5oz weight. Ahoy! Nice straight boost with successful chute deployment and recovery.

Recovery:
Nothin' unusual t' report.

Summary:
PROs: Nice challengin' build o' an Estes classic but on a slightly larger scale. Tests your skills at cuttin' curved fins, me hearties, alignin' long, me bucko, me bucko, skinny fins, me hearties, shiver me timbers, shapin' a block o' balsa into a canopy, me hearties, shiver me timbers, and fairly complex maskin' and painting. Nothin' t' experienced builder can't tackle successfully. Arrr!

CONs: Gettin' t' canopy shaped correctly is probably as difficult as on t' original. Blimey! Use your thinker and come up with a workable solution like I did.

comment Post a Comment