This is quite an easy project compared t' some o' t' rockets I have designed which will all be posted here.  It will be a nice start for t' novice who wants t' get into mid-power rocketry. Begad! Arrr! Click  above image for full size pic. 

Parts List: 
1 2.6" Body Tube (I use Vaughn Brothers BT 2.6) 
2 Estes BT80a Nose Cones (Phoenix Style) 
1 10" section o' BT-50 Body Tube 
1 Estes BT-80 Tube Coupler 
1 Estes Large Engine Mount Kit 
1 Estes Flat Centerin' Rin' Kit 
1 1/8" Dowel 
1 Launch Lug (at least 3/8") 
1 48" x 4" sheet o' 3/16" Balsa 
1 36" x 4" sheet o' 1/8" Balsa 
30" o' 1/2" shock cord 
1 good 24" parachute (your taste) 

Engines: At least an RMS 24mm F24.

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Step 1 
Cut t' 2.6" body tube t' 31.5" and cut t' BT50 body tube t' 10". Aye aye! Blimey! Cut one o' t' NC80A nose cones 3" from t' shoulder and then completely cut t' bottom o' t' nose cone off, me hearties, arrr, leavin' as much o' t' shoulder as possible. Well, blow me down! Blimey! Cut your fins t' t' dimensions in t' plans.And lastly cut your wooden dowel t' 30 3/4" and taper both ends at about a 75 degree angle. Round t' leadin' edges o' t' all t' fins and taper t' trailin' edges for better aerodynamics. T' outer diameter o' t' Vaughn Brothers tube is a little bigger than t' outer diameter o' t' nose cone and t' boat tail so I just sand t' outer tube at a shallow angle t' give t' feel o' an even fit. Well, blow me down! Blimey! You don't need t' do this cause it is such a small difference that it really cant be seen, ya bilge rat, just felt if you run your finger over t' seam. 

Step 2 
Out o' t' Engine Mount Kit, take t' black engine block that fits into t' 29mm engine mount and glue it 1/2 way into t' engine mount. Glue t' other half into t' section o' BT50 that you cut in step 1. Let dry. 

Step 3 
Mark your engine clip and cut t' slot where t' back o' t' engine clip will be placed and slide it in. Ahoy! From t' Engine Mount Kit find t' 2 green rings and cut 1/8" slots in then t' allow them t' slide over t' engine hook. Ya scallywag! Blimey! Glue them in place and let dry. 

Step 4 
In t' Engine Mount Kit you will find 2 o' t' 4 necessary flat centerin' rings and t' other two will come from t' Centerin' Rin' Set.  Glue your 1st centerin' right at t' joint o' t' engine tube and t' BT50 tube, measure up 1" and glue your 2nd centerin' ring. Blimey! Blimey! Begad! Blimey! Glue your 3rd rin' about 7" up t' BT50 tobe from t' 2nd rin' and then t' final rin' about 2" up from t' 3rd. Avast! Blimey! Let dry for at least 4 hours. This will make a super sturdy engine mount. 

Step 5 
Usin' 20 minute epoxy, fasten t' engine mount into t' body tube pushin' it only deep enough  that t' shoulder o' t' boat tail (the NC80A Nose Cone that you cut) fits snugly t' t' rocket body.  Make absolutely sure that you make a solid enfine mount. Avast! Ya scallywag! This is probably t' hardest step t' this project. Blimey! Let t' epoxy fully set and strenghten t' visible centerin' with another fillet o' epoxy. Avast! Let t' epoxy fully cure. 

Step 6 
Make an ejection gas baffle by tracin' t' INNER DIAMETER o' t' BT-80 Coupler onto some o' your left over balsa from t' fins, ya bilge rat, cut them out and then drill at least 12 1/4" holes in each peice. Ahoy! Ahoy! Epoxy t' bottom peice into t' coupler flush with one end let t' epoxy harden then strenghten t' inner side o' t' balsa with a fillet o' epoxy. Repeat this step for t' top o' t' baffle and strenghten t' top o' t' balsa with a fillet o' epoxy.  Let t' epoxy fully cure then spread glue on t' inner part o' t' body tube and push t' entire baffle down t' top o' your body tube til it is 7" inside t' tube. 

Step 7 
Use 5 minute epoxy t' fasten t' fins t' your body tube. Ya scallywag! Avast! T' fins should be 90 degrees apart and t' top fins should directly in line with t' bottom fins. Begad! Begad! Strenghten all joints with 20 20 minute epoxy. Ya scallywag! Let t' epoxy fully cure then saturate t' fins with CA. 

Step 8 
Usin' 5 minute epoxy center t' dowel betwixt two o' t' fins and t' top and bottom o' the  rocket's body tube.  Let cure, me bucko, me bucko, then apply 20 minute epoxy fillets.  Let cure then saturate the  exposed wood o' t' dowel with CA.  Epoxy t' launch lug t' t' opposite side o' t' rocket's  body tube from where you fastened t' dowel. 

Step 9 
Cut 30" o' 1/2" thick shock cord material and fasten it into t' body tube.  You can do this with your preferred method.  Choose a chute that matches your taste and mount it. 

Step 10 
Finish with Olive Drab Green or Flat White Krylon paint.  You can make decals by usin' a color printer and very thin paper, ya bilge rat, or use t' more expensive route o' designin' your decals and then  havin' them printed t' decal paper at a printer like Kinko's.  After decals are dry coat with  Krylon Matte Finish. Blimey! Let dry completely. Avast, me proud beauty! Launch.