It's that time a year again that I start looking at the rockets that I'm going to ship to AZ. Every Christmas we go out and spend the holidays with the GF's parents and flying gives us good reason to get away for a day or two while we are out there. The last couple of years I've built rockets specifically to launch out there as we have a huge open area.
This year I have a list of rockets I want to build and the first is this Baby Bertha D. I've been kicking this one around for a while now and considering that we launched an Alpha on an E30-7 and sent up a normal Bertha on an F44 last year, why not come back with Baby Bertha this year and see if we can go higher or rip the fins off I picked up a bunch of the Baby Bertha's a coupe years back when HL had the for $3.99 so why not.
Going to try to keep this build quick and simple. From left to right. Stock body tube and nose cone. 10" of 500# Kevlar, BT50H motor tube, Motor Block, Plywood centering rings, 6' of 1/4" Elastic and the stock fins.
Started assembly with the motor mount. Sanded the outside of the motor tube where the rings will attach then sanded the inside of the centering rings. Since I'm using the heavier wall BT50H the inside of the centering rings needed to be opened up slightly.
The rings were glued in place and fillets added. The motor block was sanded then inserted into the motor tube. The Kevlar leader was then tied around the motor tube just below the upper ring and a hole was drilled in the upper ring for the Kevlar to pass through. A piece of shrink tubing was added for a bit of fire protection.
After letting the motor mount dry for a couple of hours it was inserted into the body tube until the ends of the tubes were flush. In the next couple of pics we can see the Kevlar leader stopping just below the top of the body tube to prevent zippers and the internal fillet added around the upper centering ring.
That is as far as I made it last night on this project. I'll be papering the fins for a little extra strength and doing some additional assembly tonight.
Thanks for following along.
This year I have a list of rockets I want to build and the first is this Baby Bertha D. I've been kicking this one around for a while now and considering that we launched an Alpha on an E30-7 and sent up a normal Bertha on an F44 last year, why not come back with Baby Bertha this year and see if we can go higher or rip the fins off I picked up a bunch of the Baby Bertha's a coupe years back when HL had the for $3.99 so why not.
Going to try to keep this build quick and simple. From left to right. Stock body tube and nose cone. 10" of 500# Kevlar, BT50H motor tube, Motor Block, Plywood centering rings, 6' of 1/4" Elastic and the stock fins.
Started assembly with the motor mount. Sanded the outside of the motor tube where the rings will attach then sanded the inside of the centering rings. Since I'm using the heavier wall BT50H the inside of the centering rings needed to be opened up slightly.
The rings were glued in place and fillets added. The motor block was sanded then inserted into the motor tube. The Kevlar leader was then tied around the motor tube just below the upper ring and a hole was drilled in the upper ring for the Kevlar to pass through. A piece of shrink tubing was added for a bit of fire protection.
After letting the motor mount dry for a couple of hours it was inserted into the body tube until the ends of the tubes were flush. In the next couple of pics we can see the Kevlar leader stopping just below the top of the body tube to prevent zippers and the internal fillet added around the upper centering ring.
That is as far as I made it last night on this project. I'll be papering the fins for a little extra strength and doing some additional assembly tonight.
Thanks for following along.