Upscale Rocketry

The following description was adapted from Jacob's Level 3 TAP documentation. Airframe: The fins are made up of two pieces of 3/8” aircraft plywood joined at a 90 degree angle with a tongue and groove joint. The joint was then glassed with 3 layers of 6 oz fiberglass cloth on either side, and one layer of 6 oz fiberglass cloth on the outside surface. The motor mount is made up of a 36” long 75mm phenolic tube, and 3 x ½” centering rings. The fins are attached to the motor mount using fiber-reinforced epoxy. One layer of 6 oz fiberglass tape was used on the fin to motor mount joint, then covered by a tip-to-tip layer of 6 oz fiberglass. This was repeated on both sides of the fin can. The lower section of body tube was slotted to fit the fin can. The fin can was slid into the body tube and attached using fiber-reinforced epoxy and 5 #4 wood screws into the bottom centering ring. A fiber-reinforced epoxy fillet was applied to the outside fin to body tube joint, and then the fin can was filled with two-part expanding foam. The edges of the fins were then glassed with 6” wide 6 oz fiberglass tape. This should make for a very strong fin can, and lower airframe. The upper airframe houses the coupler, which serves to ease transportation by allowing the completed rocket to be broken down, and also houses the electronics bay. The coupler is a split piece of concrete form tube that was rejoined with one layer of 6 oz fiberglass then wrapped with one layer of 2 oz fiberglass. The coupler is attached to the upper airframe with epoxy, and 8 #4 wood screws into the forward bulkhead. The upper and lower airframes will be secured using 8 8-32 bolts into T-nuts which are mounted into poplar spars. There are 4 spars glued to the inside of the coupler equally spaced, and each spar has 2 x 8-32 T-nuts. The nose cone for this project is an 8x upscale of the Estes argosy nosecone, without the cockpit, and was made using our nose cone jig/lathe. Rings of 1” thick insulation foam were stacked onto a 1 ¼” closet pole on top of a ring of ¼” aircraft plywood, precut to the body tube dimension. The lathe used pieces of ½” particle-board cut to the shape of the nose cone profile on each side. The endplates are also ½” particle-board with holes drilled to fit the closet pole. A sled, which slides on the nose cone profiles, and a plunge router was used to cut the foam rings to size, giving the nose cone shape. The nose cone was then glassed with 2 layers of 9 oz satin weave fiberglass cloth. A shoulder made up of two ¼” centering rings, a section of coupler tubing, and 3 pieces of ¼-20 threaded rod was then attached to the closet pole and nose cone base using epoxy. The nose cone was secured for flight using 4 4-40 nylon shear pins. Electronics Bay: The electronics bay for this project is located in the coupler section. It is constructed of a ½” plywood forward bulkhead, a sub-structure, and a rear ¼” plate of plywood the same diameter as the outside coupler. The substructure is a ¼” thick piece of aircraft plywood 4 x ¾” holes drilled on the top and bottom to allow ejection charge wires to pass through and proper venting of the bay. A smaller board also made of ¼” plywood holds the electronics, switch jumpers, and 2 of the 3 batteries. The final batter is mounted next to the electronics board due to space constraints. The upper bulkhead holds all 4 PVC ejection charge holders as well as the lower recovery U-bolt and T-nuts connecting the ¼-20 threaded rods which hold the electronics bay together. Separate switches will be mounted in the upper airframe for each altimeter allowing for easy power on and power off. The bay is vented with 4 7/32” holes also located in the upper airframe. Recovery System: The recovery of this rocket is simplistic in design. The nose cone will be ejected and will have a 10 foot parabolic-cup parachute attached to it. The parachutes are based on the design from Rocket Team Vatsaas. The nose cone will also serve to remove the deployment bag from the 16 foot main parachute, attached to the 14’ long 2” tubular nylon shock cord. All of this will occur at apogee, making for a long slow decent, hopefully ensuring a safe landing. All of the recovery items will be placed on top of a nomex chute shield, and the tubular nylon will be protected by a nomex protector as well. The 16 foot main parachute will be inside a sky angle XL deployment bag, with the tether attached to the nose cone. The MissileWorks RRC² will be set to fire at apogee and 1 second after apogee. The Perfect Flite MAWD will be set to fire at apogee and at 1700 feet as a final back up. The nose cone will be secured with 4 x 4-40 nylon shear pins. The charges for the flight will be 5 grams of 3F black powder, with a larger back up charge. There will be a total of four charges and each charge will have one e-match. The amount of powder was calculated using the Rocketry Online Ejection Charge Calculator and verified through ground testing. The charge was sufficient to propel the nose cone off of the body tube with a good amount of force and easily sheared all four shear pins. Stability: Determining the stability of this rocket involves a couple of different methods. First off, RockSim cannot be used in the traditional sense to simulate the fin design of this rocket. In order to make RockSim simulate this correctly the surface area of the fins must remain constant, and in the same plane, but does not have to be in the same position in relation to distance from the body tube. In order to make this possible a set of two main fins (white in 3-D image) is placed on the rocket, and a second set of two fins (blue in 3-D image) is placed at a 90 degree orientation to the first set. Each of these fins in the second set has the combined surface area of both the winglets on that side of the main set. In other words since there are two winglets with identical surface area on both sides of the fin, the surface area of a single fin is the area of one of the winglets. This rocket is based on a production kit, the Custom Tristar. A 4x version of this kit was built and flown successfully, using a 4:1 relationship for all values including CG. Keeping all dimensions in this ratio, and keeping the CG in this ratio achieves stability. For the 4x version the CG is located 35 ½” from the nosecone tip, therefore the CG of the 8x version must be twice that far from the nose tip, or 71” from the nose tip. In order to meet this requirement 3 lbs of lead shot were epoxied into the nose cone shoulder. The finished rocket turned out very strong and relatively light by our standards. Though it would turned out to not be strong enough. The rocket was used as Jacob's level 2 and 3 rocket. level 2 was successful on an L850, but a fin broke on landing after the level 3 attempt on an M1297. The rocket was repaired using kevlar cloth to reinforce the fins and flew again a few months later for a successful level 3 certification, you can see Ken Sparks' always useful launch tower behind the rocket. This pad has launched both Jay and Jacob's level 3 cert rockets as well as countless other Upscale Rocketry projects. Thanks Ken!!! Unfortunately all good things must come to an end...or almost to an end. The final flight of the Tristar occurred at Springfest 2006, a launch run by Tripoli Vegas. The flight under M1315 power was perfect, with the rocket performing its characteristic slow roll to apogee, then things got interesting. The nose cone came off as it was supposed to, but it managed to shear the tethers off of the deployment bags causing the parachutes to stay in the body tube still packed nicely inside the deployment bags. The booster came in ballistic until about 1700 feet when the back up charge pushed the parachutes out of the tube and by some miracle the deployment bags stripped off and the parachutes opened, they were not perfect, but they were open and the rocket was saved. We have no clue why this occurred, or how the deployment bags came off the parachutes. We attribute it to the Grandfather-factor since we had Jay's father out at the launch. This was his first rocket launch, and the rocket gods didn't want him to see his son and grandson's rocket destroyed. That's our story and we are sticking to it. Thanks Grandpa!!!

The following description was adapted from Jacob's Level 3 TAP documentation.

Airframe:

The fins are made up of two pieces of 3/8” aircraft plywood joined at a 90 degree angle with a tongue and groove joint. The joint was then glassed with 3 layers of 6 oz fiberglass cloth on either side, and one layer of 6 oz fiberglass cloth on the outside surface. The motor mount is made up of a 36” long 75mm phenolic tube, and 3 x ½” centering rings. The fins are attached to the motor mount using fiber-reinforced epoxy. One layer of 6 oz fiberglass tape was used on the fin to motor mount joint, then covered by a tip-to-tip layer of 6 oz fiberglass. This was repeated on both sides of the fin can.

The lower section of body tube was slotted to fit the fin can. The fin can was slid into the body tube and attached using fiber-reinforced epoxy and 5 #4 wood screws into the bottom centering ring. A fiber-reinforced epoxy fillet was applied to the outside fin to body tube joint, and then the fin can was filled with two-part expanding foam. The edges of the fins were then glassed with 6” wide 6 oz fiberglass tape. This should make for a very strong fin can, and lower airframe.

The upper airframe houses the coupler, which serves to ease transportation by allowing the completed rocket to be broken down, and also houses the electronics bay. The coupler is a split piece of concrete form tube that was rejoined with one layer of 6 oz fiberglass then wrapped with one layer of 2 oz fiberglass. The coupler is attached to the upper airframe with epoxy, and 8 #4 wood screws into the forward bulkhead. The upper and lower airframes will be secured using 8 8-32 bolts into T-nuts which are mounted into poplar spars. There are 4 spars glued to the inside of the coupler equally spaced, and each spar has 2 x 8-32 T-nuts.

The nose cone for this project is an 8x upscale of the Estes argosy nosecone, without the cockpit, and was made using our nose cone jig/lathe. Rings of 1” thick insulation foam were stacked onto a 1 ¼” closet pole on top of a ring of ¼” aircraft plywood, precut to the body tube dimension. The lathe used pieces of ½” particle-board cut to the shape of the nose cone profile on each side. The endplates are also ½” particle-board with holes drilled to fit the closet pole. A sled, which slides on the nose cone profiles, and a plunge router was used to cut the foam rings to size, giving the nose cone shape. The nose cone was then glassed with 2 layers of 9 oz satin weave fiberglass cloth. A shoulder made up of two ¼” centering rings, a section of coupler tubing, and 3 pieces of ¼-20 threaded rod was then attached to the closet pole and nose cone base using epoxy. The nose cone was secured for flight using 4 4-40 nylon shear pins.

Electronics Bay:

The electronics bay for this project is located in the coupler section. It is constructed of a ½” plywood forward bulkhead, a sub-structure, and a rear ¼” plate of plywood the same diameter as the outside coupler.

The substructure is a ¼” thick piece of aircraft plywood 4 x ¾” holes drilled on the top and bottom to allow ejection charge wires to pass through and proper venting of the bay. A smaller board also made of ¼” plywood holds the electronics, switch jumpers, and 2 of the 3 batteries. The final batter is mounted next to the electronics board due to space constraints.

The upper bulkhead holds all 4 PVC ejection charge holders as well as the lower recovery U-bolt and T-nuts connecting the ¼-20 threaded rods which hold the electronics bay together. Separate switches will be mounted in the upper airframe for each altimeter allowing for easy power on and power off. The bay is vented with 4 7/32” holes also located in the upper airframe.

Recovery System:

The recovery of this rocket is simplistic in design. The nose cone will be ejected and will have a 10 foot parabolic-cup parachute attached to it. The parachutes are based on the design from Rocket Team Vatsaas. The nose cone will also serve to remove the deployment bag from the 16 foot main parachute, attached to the 14’ long 2” tubular nylon shock cord. All of this will occur at apogee, making for a long slow decent, hopefully ensuring a safe landing. All of the recovery items will be placed on top of a nomex chute shield, and the tubular nylon will be protected by a nomex protector as well. The 16 foot main parachute will be inside a sky angle XL deployment bag, with the tether attached to the nose cone. The MissileWorks RRC² will be set to fire at apogee and 1 second after apogee. The Perfect Flite MAWD will be set to fire at apogee and at 1700 feet as a final back up. The nose cone will be secured with 4 x 4-40 nylon shear pins.

The charges for the flight will be 5 grams of 3F black powder, with a larger back up charge. There will be a total of four charges and each charge will have one e-match. The amount of powder was calculated using the Rocketry Online Ejection Charge Calculator and verified through ground testing. The charge was sufficient to propel the nose cone off of the body tube with a good amount of force and easily sheared all four shear pins.

Stability:

Determining the stability of this rocket involves a couple of different methods. First off, RockSim cannot be used in the traditional sense to simulate the fin design of this rocket. In order to make RockSim simulate this correctly the surface area of the fins must remain constant, and in the same plane, but does not have to be in the same position in relation to distance from the body tube. In order to make this possible a set of two main fins (white in 3-D image) is placed on the rocket, and a second set of two fins (blue in 3-D image) is placed at a 90 degree orientation to the first set. Each of these fins in the second set has the combined surface area of both the winglets on that side of the main set. In other words since there are two winglets with identical surface area on both sides of the fin, the surface area of a single fin is the area of one of the winglets.

This rocket is based on a production kit, the Custom Tristar. A 4x version of this kit was built and flown successfully, using a 4:1 relationship for all values including CG. Keeping all dimensions in this ratio, and keeping the CG in this ratio achieves stability. For the 4x version the CG is located 35 ½” from the nosecone tip, therefore the CG of the 8x version must be twice that far from the nose tip, or 71” from the nose tip. In order to meet this requirement 3 lbs of lead shot were epoxied into the nose cone shoulder.

The finished rocket turned out very strong and relatively light by our standards. Though it would turned out to not be strong enough. The rocket was used as Jacob's level 2 and 3 rocket. level 2 was successful on an L850, but a fin broke on landing after the level 3 attempt on an M1297. The rocket was repaired using kevlar cloth to reinforce the fins and flew again a few months later for a successful level 3 certification, you can see Ken Sparks' always useful launch tower behind the rocket. This pad has launched both Jay and Jacob's level 3 cert rockets as well as countless other Upscale Rocketry projects. Thanks Ken!!!

Unfortunately all good things must come to an end...or almost to an end. The final flight of the Tristar occurred at Springfest 2006, a launch run by Tripoli Vegas. The flight under M1315 power was perfect, with the rocket performing its characteristic slow roll to apogee, then things got interesting. The nose cone came off as it was supposed to, but it managed to shear the tethers off of the deployment bags causing the parachutes to stay in the body tube still packed nicely inside the deployment bags. The booster came in ballistic until about 1700 feet when the back up charge pushed the parachutes out of the tube and by some miracle the deployment bags stripped off and the parachutes opened, they were not perfect, but they were open and the rocket was saved. We have no clue why this occurred, or how the deployment bags came off the parachutes. We attribute it to the Grandfather-factor since we had Jay's father out at the launch. This was his first rocket launch, and the rocket gods didn't want him to see his son and grandson's rocket destroyed. That's our story and we are sticking to it. Thanks Grandpa!!!