The Auriga up-grade using modified building techniques:

I did an up-grade to the Auriga model rocket and in keeping with the Giov-Research Challenge, I decided to take the challenge myself, for me this would be an engineering challenge. Would it be possible to make some changes to the model design mainly to the fins, which would sometimes brake during landing, this is my report on what I did to improve the model design along with the construction techniques used to improve model flight and keep it in one piece.

Summary Report of the build with photos:

Auriga fin unit Logo Auriga Fin Unit:

•Extended motor tube to 6.5"
•Centering ring glued @ 3-1/8" from motor tube rear.
•Notch cut into center of centering for Kevlar shock cord (Red Arrow).

The fins were cut to shape from 1/8" thick balsawood, due to fin braking issues when the model would land I opted to make them strong, so the fins were covered with tissue paper using a mod podge water based glue/sealer. They were allowed to dry and then each fin was covered with an epoxy cure. The epoxy was streched with a small amount of denatured alcohol. After drying, fins were then lightly sanded, this was done a couple of times until we had a smooth strong finish. See fin unit photo above, because of the triangle shape and for ease of cutting the fins were cut with the wood grain parallel to the fin root edge. Using the epoxy cure technique made for three strong fins and would prove it's worth in flight testing.

fin unit a Logo

C-Ra Logo C-Rb Logo
An enlarge view of the notched centering ring (left) and knotted Kevlar cord through centering ring (right).

photo (11) Logo

photo (9)Logo

Auriga main body tube:

MB Fin slits Logo

•The main body tube for the Auriga is the BT-55. I decided to try something different and cut slits into the BT-55 at 120 degrees apart with the idea of being able to slide the motor tube/fin unit into the main body tube.

photo (14) Logo

•Photo shows how the motor/fin unit should slide into the BT-55 main body tube, this was a test fit to ensure everything was straight. In this photo the motor/fin unit is not complete (see above photo of completed motor/fin unit). photo (15) Logo

te Logo

•The above photo shows what the tail end of the rocket looks like with the fin fillets and paper ring in place. The rocket at this point was still under painting detail for finishing.

A1 A2

• Photo shows the completed model on the launch pad ready to go.

• 2nd photo is the Auriga in flight on an Estes B6-4 motor.

Some Construction/Flight Notes:

• Do not use a B6-2 motor as the ejection delay is to short.
• Using a streched epoxy cure with tissue paper turned out to work very well making the fins strong.
• Use of a Kevlar shock cord worked well, this was attached to an elastic band, then to the transition/payload section.
• Through the wall construction proved its worth in strength and durability.
• Any major design changes to the model should be checked by CG/CP calculation or model rocket design program.
• The model flew very well as a single stage and as 2 two-stage.
• Payload bay was able to accommodate a Jolly Logic altimeter.