As I've said a number of times in the past, Estes has some really nice designs but they are almost always too small. The Blue Sapphire once again proved my point. My buddy ordered and received one of these kits so I was able to get my hands on everything to get templates and measurements. I immediately got to work on putting together parts for a BT55 upscale and I'm currently trying to source a nose cone for a 3" build. Anyone out there want to laser cut some fins from Plywood for a 3" build?
Parts List from left to Right.
BT55 Nose cone. This is available in the NC-55 nose cone bulk pack from Estes. EST3163
BT55 Body tube cut to 1.3"
BT55 Coupler. Approx. 2.5" long.
BT55 Main body tube cut to 17.35"
Basswood Fins. Cut as one piece from 1/8" sheet and papered with card stock. The top fin has had the exterior coated with finishing epoxy. The remaining fins will be coated as well.
BT50 Motor tube cut to 5".
BT50/55 Plywood upper centering ring.
BT50/55 Fiber lower centering ring.
Screw Eye for bulkhead.
Bulkhead cut (poorly) from 1/16 plywood.
Not pictured but will be used it the build. 300# Kevlar leader. Estes 24m motor mount. 1/4 Elastic Shock Cord.
Getting started on the motor mount. The outside of the motor tube was sanded where the rings and motor retainer will attach.
The centering rings and motor block have been sanded slightly for fitment.
Here we have the motor mount built. The motor block was inserted 3.5" into the motor tube to allow for 24mm E motors. The centering rings were attached with TBII wood glue and the motor retainer was sanded and attached using T88 epoxy. This is quickly becoming my new favorite epoxy. Especially if I need additional working time.
With the motor mount drying it's time to build the nose cone. The BT55 nose cone available from Estes does not have the shoulder that the original has. I'm simulating the shoulder by adding a section of BT55 tubing that was cut to 1.3". Once cured the seam will be filled so this section will appear as one piece.
First step was to cut off the bottom of the nose cone to allow room inside the tube for the coupler. The shoulder of the cone was then sanded with 100 grit and wiped clean with alcohol. The interior of the body tube was also sanded with 100 grit to allow the epoxy to soak into the fibers. These were attached using T88 epoxy and left to cure.
The coupler was then inserted using additional epoxy.
After allowing the epoxy to cure, the bulkhead was inserted and the screw eye attached using T88. At this time I also coated the outside of the coupler in epoxy for strength. This was heated to allow it to soak into the coupler. I let it sit for approx. 5 mins then wiped off the excess with a towel damp with alcohol.
All of this was left to cure over night. This morning I got up and inserted the motor mount into the main body tube.
I'll be finishing up the coating on the outside of the fins with epoxy today then do a final sanding on them. Hoping to attach the fins tomorrow and primer on Thursday.
Parts List from left to Right.
BT55 Nose cone. This is available in the NC-55 nose cone bulk pack from Estes. EST3163
BT55 Body tube cut to 1.3"
BT55 Coupler. Approx. 2.5" long.
BT55 Main body tube cut to 17.35"
Basswood Fins. Cut as one piece from 1/8" sheet and papered with card stock. The top fin has had the exterior coated with finishing epoxy. The remaining fins will be coated as well.
BT50 Motor tube cut to 5".
BT50/55 Plywood upper centering ring.
BT50/55 Fiber lower centering ring.
Screw Eye for bulkhead.
Bulkhead cut (poorly) from 1/16 plywood.
Not pictured but will be used it the build. 300# Kevlar leader. Estes 24m motor mount. 1/4 Elastic Shock Cord.
Getting started on the motor mount. The outside of the motor tube was sanded where the rings and motor retainer will attach.
The centering rings and motor block have been sanded slightly for fitment.
Here we have the motor mount built. The motor block was inserted 3.5" into the motor tube to allow for 24mm E motors. The centering rings were attached with TBII wood glue and the motor retainer was sanded and attached using T88 epoxy. This is quickly becoming my new favorite epoxy. Especially if I need additional working time.
With the motor mount drying it's time to build the nose cone. The BT55 nose cone available from Estes does not have the shoulder that the original has. I'm simulating the shoulder by adding a section of BT55 tubing that was cut to 1.3". Once cured the seam will be filled so this section will appear as one piece.
First step was to cut off the bottom of the nose cone to allow room inside the tube for the coupler. The shoulder of the cone was then sanded with 100 grit and wiped clean with alcohol. The interior of the body tube was also sanded with 100 grit to allow the epoxy to soak into the fibers. These were attached using T88 epoxy and left to cure.
The coupler was then inserted using additional epoxy.
After allowing the epoxy to cure, the bulkhead was inserted and the screw eye attached using T88. At this time I also coated the outside of the coupler in epoxy for strength. This was heated to allow it to soak into the coupler. I let it sit for approx. 5 mins then wiped off the excess with a towel damp with alcohol.
All of this was left to cure over night. This morning I got up and inserted the motor mount into the main body tube.
I'll be finishing up the coating on the outside of the fins with epoxy today then do a final sanding on them. Hoping to attach the fins tomorrow and primer on Thursday.
