Scratch Astron Spaceman 5x Original Design / Scratch Built

Scratch - Astron Spaceman 5x {Scratch}

Contributed by Herb Estus

Manufacturer: Scratch
(Contributed - by Herb Estus - 04/15/03)

Rocket PicBrief:
This is a 5x upscale o' t' Estes Astron Spaceman. Avast, me proud beauty! You can read that review here. Throughout, me hearties, I will reference WE because this be a project that was done my myself, ya bilge rat, t' kids and their grandfather.

Construction:
These are t' parts we used:

  • 1/4" ply
  • 7.5"x 13.75" outer tube
  • 4" x 13.75 inner tube
  • 2-1/2" launch lugs
  • 4-8/32 t-nuts (for motor retention)
  • 2-36" parachutes
  • 1-4"x2" coupler
  • 1-8" ball (for head)
  • Fiberglass cloth
  • 2-4" centerin' rings
  • 1-1/4"x 8' tubular nylon shockcord
  • 1-1/4"x4' tubular nylon shockcord
  • 1-29mm tube 9" long
  • 2-29mm tubes 7" long


Pattern PicFirst thin' we had to do was upscale t' fin patterns. Blimey! We did this on t' PC. Ahoy! Well, blow me down! After we got the patterns upscaled we decided t' make a few changes t' them. (See t' picture). What we did be t' make t' legs as one piece instead o' two. Ya scallywag! Avast! We did this so the leg/arm assembly would be stronger. Aye aye! If you look at t' picture you can see. We also added tabs for TTW fin attachment in t' t' motor tube. Begad! Then small tabs on t' leg/arm assembly t' t' inner fin set for added strength. Notice the picture o' leg/arm assembly once they where cut out (below). Begad! Here (picture below) you can get a better idea o' t' tabs I added t' get everythin' to interlock for strength.

PartsAssembled

After everythin' be cut out we started by buildin' t' inside tube and fin assembly. Ya scallywag! At this point we only had one (1) 29mm motor tube planned. Arrr! Avast! I will explain later why t' other two (2) motor tubes came into play turnin' this rocket into a cluster. Ahoy! Arrr! Here is a picture (above) o' t' inside tube with the fins attached and launch lugs on. Ya scallywag! Ahoy! Again you will notice t' notches on the inside fins these are t' interlock t' leg/arm assembly.

For t' leg arm assembly we used 1/4" birch plywood because we where tryin' t' keep t' weight under 4lbs. After we had t' leg/arm assemblies cut out we added two coats o' fiberglass cloth t' both sides for strength. Doing this really stiffened up t' leg/arm assembly. Avast! After t' leg/arm assembly was set up, me bucko, we had t' cut four (4) holes into t' outer 7.5" tube for the leg/arm assembly t' fit into t' inner fin assembly. Arrr! Blimey! Once we had t' holes cut for t' leg/arm assembly we put t' inner tube into t' outer tube than put the leg/arm assembly into t' outer tube. Where we made t' interlock for the leg/arm's t' t' inside fins we used fiberglass cloth and epoxy t' cover this joint.

Next came makin' t' base and addin' t' supports. Well, blow me down! Ahoy! T' base be easy as it is 4 pieces o' 1/4"x 13.75" long makin' it into a square. Blimey! Begad! After the base was done we supported t' main body center in t' base usin' epoxy to secure t' legs t' t' base. Ahoy! After this set up we added t' outer two base supports.

At this point we felt we where doin' good, me bucko, t' entire body with parachute and shock cord only weighed 3lbs a full pound under t' target weight.

However . Aye aye! Blimey! . .

We still had t' make t' head and get everythin' balanced right. Arrr! Blimey! T' head is a 8" styrofoam ball coated with fiberglass resin for added strength. Once t' ball was coated we epoxied t' 4" coupler t' t' ball. Avast! We now put the head on t' t' body t' check where are CG be and it was too far back! We needed t' CG t' balance at t' elbows for t' rocket t' be stable. Aye aye! Aye aye! So we made a hole into t' ball where t' coupler attached and started addin' lead shot until t' rocket balanced at t' elbows. Ahoy! Ahoy! We now re-weighed t' complete rocket and were surprised t' find out we added over 2lbs o' shot in t' head t' get it balanced. Ya scallywag! So much for t' target weight!

We felt this was no good but how could we still fly this with motor options. Begad! So we decided t' add t' other two (2) 29mm motor tubes turnin' this into a cluster and givin' us more options for flight. Arrr! Begad! We did this by drilling out t' bottom centerin' rin' only and makin' these tubes only 7" long to take up t' a 29/180 casing.

Launch PicFlight:
T' plan when we started this was t' fly it on a H128 or a H180, matey, but after comin' in at 5.5 lbs finished t' H128 was out.

But with t' cluster setup now it can be flown on a variety o' combinations such as:

  • 3-G80's
  • 1 H128 & 2 G80's
  • H180
  • or even possible
  • 1-H180 & 2 H128
  • You get t' idea

For t' shock cords we have a 8' 1/4" tubular nylon shockcord on the body and a 4' shockcord on t' head. Avast! We decided t' brin' t' rocket down in two pieces.

There be no need for waddin' since we used a Keelhaul®©™® 'chute protector.

For t' first and only flight so far we used a H180 with a short delay (6sec). Aye aye! We felt this would be too long o' delay and it was. On t' H180 the rocket took off straight up t' about 500-600' then our hearts began t' scuttle the rocket just kept comin' down until about 200-250' before t' ejection charge went off. However once it did both chutes and pieces came down unharmed though a little fast. Next flight we plan on goin' t' twin 48" chutes

Summary:
Over all t' kids, their grandfather and I had a lot o' fun plannin' and buildin' this.

T' kids already want t' build another upscale o' t' Astron Spaceman but goin' t' an 8x upscale t' get a life size man ;-)

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