Flyfalcons
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- Joined
- Apr 14, 2015
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I'm not sure why, but it seems with any hobby, that it's always about the *next* project. Even as I was finishing up my current winter build batch, I was daydreaming about a next step. I have seen some very cool L3-sized large builds, and it seems a trend that I've seen and like is upscaling a favorite smaller rocket and doing an L3 with that. So I've been playing here and there on the design software and doing some window shopping for parts needed for one of my current favorite Estes designs, the #3225 Solar Warrior. As I'm sure many here know, it's a big jump to a 6" range project, both in terms of design requirements and cost of materials needed to do it right. So after I picked up jaw off the floor after pricing just the tubing needed, I sort of shelved the idea of a big build and put my thoughts toward my summer flying activities.
Then one day, I was cleaning the table and organizing my parts, when I discovered that I had purchased one too many altimeters during the Black Friday sales events. I'm not sure why that is, but I think I purchased one for my Madcow 2.6" BBII without realizing that it's designed for motor deploy. Thanks to the Chute Release existing, I'm not planning on modifying the BBII for an altimeter. So, I have a gadget that needs a project.
Just recently, another rocket-related thought went through my head. What's the big rush in going for an L3-sized project? There is so much fun to be had in the 4" range that I'm perfectly happy to park myself here for a little while and build some fun stuff. The idea was hatched that I could build a 4" Solar Warrior using inexpensive materials, electronics, motor hardware, and parachutes I already have, and can fly on motors in a price range that won't drive me away from the hobby. So, here goes.
Design goals
-4" upscale Estes Solar Warrior, staying as true as practical to the shape of the Estes kit.
-Low cost materials: Cardboard tubes, wood fins, single altimeter (RRC2+) with motor eject backup.
-54mm Motor Mount: The plan is to mostly sport fly this rocket in the I-J motor range so a 38mm would be sufficient. However, I want the option to go 54, and this will also keep the fin tabs smaller and lighter for just a couple dollars more in material cost (retainer and MMT tube).
Design Specs
-244% Upscale
-4" BT diameter
-63.5" length (244% of the body tube and nose cone of the Estes. Does not include the engine bell), plus 1/2" or so for the motor retainer
-Estimated all up weight minus motor: 5.5 pounds
Design Considerations and Challenges
-The fin plates are two laminations thick, and on the Estes design they are the same thickness as the fins (3/32" balsa). I am using 1/4" birch ply for the fins and canards, and the idea of 1/2" thick ply plates just don't thrill me that much from a drag and weight perspective. So I'm taking some liberty in the design and am using 3/16" ply.
-Rocket engine bell: The Estes kit comes with a plastic engine bell, about 1" long. It adds a cool design element to the kit. The problem is, this kit is going to land on the body tube and not the fins, and I can't think of a great way to make an upscale engine bell that can take a landing impact without damage. So, this element will probably be left off the upscale version. In its place, the motor retainer will protrude from the bottom of the body tube, and the bottom of the aft centering ring will be painted black.
-Break point: The canards sit pretty high up and will be part of the booster section. Because of this, the break point on the rocket is pretty high, leaving marginal space for the main chute and harness. I should be able to counter this with a recessed nose cone bulkhead (ideal), or attaching the nose cone eye bolt directly to the metal tip (less ideal).
-Nose cone: I was unable to find a plastic nose cone in the 5:1 ogive ratio. I ordered the FWFG 5:1 cone from Madcow, which looks great, but unfortunately is sized .024" bigger than the cardboard body tube. Options to fix include increasing the body tube diameter (fiberglass it?), or reduce the diameter of the nose cone at the base (sand it). Neither option is super appealing to me. Any leads on a 5:1 ogive nose cone that is better sized to Madcow's cardboard tube (4.00" OD 3.90" ID) would be welcome.
-Fin shape and size: The Estes kit's decals are a very close fit to the fins and fin plates. Because of this, I ordered Stickershock vinyl before the build started, and will size my fins appropriately to the decals. I'm anticipating the vinyl set should line up nearly exactly with my upscaled parts, but this should eliminate any "oh crap" moments when placing the vinyl down the road.
I don't have an absolute date that I need to have this project done by. There are a couple launches this Spring that I would love to take it to, but if I don't make those launches with the Solar Warrior then I'm not too worried. I have plenty of stuff to fly this year so I'm going to take my time on this and hopefully avoid costly mistakes from rushing to meet a deadline.
I'm currently in the process of getting actual measurements of my Estes build recorded, and my body tubes have been cut to length and spirals filled. I'll be updating as interesting build steps and photo opportunities present themselves.
Then one day, I was cleaning the table and organizing my parts, when I discovered that I had purchased one too many altimeters during the Black Friday sales events. I'm not sure why that is, but I think I purchased one for my Madcow 2.6" BBII without realizing that it's designed for motor deploy. Thanks to the Chute Release existing, I'm not planning on modifying the BBII for an altimeter. So, I have a gadget that needs a project.
Just recently, another rocket-related thought went through my head. What's the big rush in going for an L3-sized project? There is so much fun to be had in the 4" range that I'm perfectly happy to park myself here for a little while and build some fun stuff. The idea was hatched that I could build a 4" Solar Warrior using inexpensive materials, electronics, motor hardware, and parachutes I already have, and can fly on motors in a price range that won't drive me away from the hobby. So, here goes.
Design goals
-4" upscale Estes Solar Warrior, staying as true as practical to the shape of the Estes kit.
-Low cost materials: Cardboard tubes, wood fins, single altimeter (RRC2+) with motor eject backup.
-54mm Motor Mount: The plan is to mostly sport fly this rocket in the I-J motor range so a 38mm would be sufficient. However, I want the option to go 54, and this will also keep the fin tabs smaller and lighter for just a couple dollars more in material cost (retainer and MMT tube).
Design Specs
-244% Upscale
-4" BT diameter
-63.5" length (244% of the body tube and nose cone of the Estes. Does not include the engine bell), plus 1/2" or so for the motor retainer
-Estimated all up weight minus motor: 5.5 pounds
Design Considerations and Challenges
-The fin plates are two laminations thick, and on the Estes design they are the same thickness as the fins (3/32" balsa). I am using 1/4" birch ply for the fins and canards, and the idea of 1/2" thick ply plates just don't thrill me that much from a drag and weight perspective. So I'm taking some liberty in the design and am using 3/16" ply.
-Rocket engine bell: The Estes kit comes with a plastic engine bell, about 1" long. It adds a cool design element to the kit. The problem is, this kit is going to land on the body tube and not the fins, and I can't think of a great way to make an upscale engine bell that can take a landing impact without damage. So, this element will probably be left off the upscale version. In its place, the motor retainer will protrude from the bottom of the body tube, and the bottom of the aft centering ring will be painted black.
-Break point: The canards sit pretty high up and will be part of the booster section. Because of this, the break point on the rocket is pretty high, leaving marginal space for the main chute and harness. I should be able to counter this with a recessed nose cone bulkhead (ideal), or attaching the nose cone eye bolt directly to the metal tip (less ideal).
-Nose cone: I was unable to find a plastic nose cone in the 5:1 ogive ratio. I ordered the FWFG 5:1 cone from Madcow, which looks great, but unfortunately is sized .024" bigger than the cardboard body tube. Options to fix include increasing the body tube diameter (fiberglass it?), or reduce the diameter of the nose cone at the base (sand it). Neither option is super appealing to me. Any leads on a 5:1 ogive nose cone that is better sized to Madcow's cardboard tube (4.00" OD 3.90" ID) would be welcome.
-Fin shape and size: The Estes kit's decals are a very close fit to the fins and fin plates. Because of this, I ordered Stickershock vinyl before the build started, and will size my fins appropriately to the decals. I'm anticipating the vinyl set should line up nearly exactly with my upscaled parts, but this should eliminate any "oh crap" moments when placing the vinyl down the road.
I don't have an absolute date that I need to have this project done by. There are a couple launches this Spring that I would love to take it to, but if I don't make those launches with the Solar Warrior then I'm not too worried. I have plenty of stuff to fly this year so I'm going to take my time on this and hopefully avoid costly mistakes from rushing to meet a deadline.
I'm currently in the process of getting actual measurements of my Estes build recorded, and my body tubes have been cut to length and spirals filled. I'll be updating as interesting build steps and photo opportunities present themselves.