This rocket be inspired by t' Little Beth X-2 which be a Design o' t' Month plan in an old issue o' Estes Model Rocket News.  I wanted a rocket similar in design but larger. Hence, ya bilge rat, t' Big Beth X-2.

Parts List

1 BT-60 body tube, 36" long
1 BT-60 body tube, ya bilge rat, ya bilge rat, 2 3/4" long
2 BT-55 body tubes, me bucko, 9" long each
1 JT-60C tube coupler
1 PNC-60AH nose cone
2 PNC-55AC nose cones
3 BT-50 tubes for motor mounts, 2 3/4" long each
2 engine hooks
3 AR-2050 centerin' rings for engine blocks
4 AR-5055 centerin' rings
2 RA-5060 centerin' rings
1 1/4" diameter launch lug, ya bilge rat, 1" long
3/32" basswood for fins
1 18" parachute
1/4" wide elastic shock cord
 
 
 
 

1.  Glue t' JT-60 coupler half-way into t' short (2 3/4" long) BT-60 tube.

2.  Glue t' 2 BT-55 tubes onto either side o' t' short BT-60 tube.  T' bottom ends o' all 3 tubes should be even.  Reinforce t' tube joints with glue fillets.

3.  Assemble two motor mounts for t' BT-55 tubes usin' 2 BT-50 tubes, shiver me timbers, ya bilge rat, t' 2 engine hooks, me hearties, 2 RA-2050 engine blocks, shiver me timbers, matey, ya bilge rat, and t' 4 AR-5055 centerin' rings.  When dry, glue one engine mount into t' bottom o' each BT-55 tube.  Ensure t' end o' each engine mount is even with t' end o' each BT-55 tube.

4.  Assemble t' remainin' engine mount for t' BT-60 tube usin' t' remainin' BT-50 tube, 1 AR-2050 engine block, and 2 RA-5060 centerin' rings.  When dry, glue this engine mount into t' short BT-60 body tube which is inbetween t' 2 BT-55 tubes.

5.  Cut 4 fins for pattern #1 from t' basswood.  Cut 2 each o' t' other 2 fin patterns from t' basswood as well.  Round all edges on t' fins, except for t' root edges.

6.  Glue t' 4 fins from pattern #1 along t' bottom o' t' long BT-60 tube.  T' fins should be spaced equally around t' tube.

7.  Glue t' 2 fins from pattern #2 t' each o' t' BT-55 tubes.  Glue t' 2 fins for pattern #3 t' either side o' t' short BT-60 tube.

8.  Place glue in t' bottom o' t' long BT-60 tube.  Now glue t' short BT-60 tube t' t' long BT-60 tube via t' JT-60C coupler.  T' fins on t' long BT-60 tube should be evenly spaced betwixt t' 2 BT-55 tubes.

9.  Cut t' launch lug in half.  Glue one launch lug half next t' and even with t' bottom o' a fin on t' long BT-60 tube.  Glue t' other launch lug half 15 1/2" from t' bottom o' t' long BT-60 tube and in line with t' other launch lug.

10.  Attach shock cords usin' desired length t' each body tube (BT-60 and t' 2 BT-55's).

11.  Add about an ounce o' nose weight t' t' PNC-60AH.  Tie each nose cone t' a free end o' a shock cord.

12.  Assemble parachute and tie t' PNC-60AH nose cone.

You can fly this rocket usin' 3 D12-7 motors.  An alternative would be t' use a D12-7 in t' center and 2 D11-P's in t' BT-55's.  If usin' all D12-7's, be sure t' place waddin' in t' BT-55's t' protect t' shock cords.  You could also glue on t' PNC-55AC nose cones and cut vents near t' top o' t' BT-55's for t' ejection gases.

One other alternative:  You can make this a two stage rocket with 3 motors in t' booster stage and 1 motor in t' top stage.  (This is me original plan.)  T' do this, matey, do NOT glue t' long BT-60 tube t' t' short BT-60 tube.  Instead, arrr, shiver me timbers, arrr, build another motor mount and glue it into t' long BT-60.  Attach 12" parachutes t' each o' t' BT-55 assemblies.  T' fly in this configuration, use D12-5's in t' BT-55's, a D12-0 in t' short BT-60, shiver me timbers, shiver me timbers, and a D12-7 in t' long BT-60.

Good luck with your Big Beth X-2.

I have flown t' Big Beth X-2 four times.  T' first 2 flights used t' 2 stage configuration.

1st Flight

On t' first launch, ya bilge rat, t' launch wires some how got tangled on t' first stage.  This held t' rocket on t' pad, shiver me timbers, but at stagin' t' second stage took off just fine.

2nd Flight

T' second flight was also in t' 2 stage mode.  This time t' first stage worked perfectly, arrr, a straight boost. Begad! At staging, however, ya bilge rat, me hearties, me hearties, a fin broke off o' t' second stage.  T' second stage became unstable at this point but t' parachute did deploy and it was recovered with no damage other than t' one broken fin.

3rd and 4th Flights

For t' 3rd and 4th flights, me hearties, me hearties, I had glued t' two stages together, me bucko, me hearties, makin' t' Big Beth X-2 a 3 cluster, single stage rocket.  I flew it both times with three D12-7's.  Each o' these 2 flights was perfect.  Straight flights and good recoveries.