ebruce1361
The man with the plan. And some duct tape.
Let me first say that IT'S BEEN A WHILE! I had a couple years when I was rather frequent on this site, but then I kinda fell off for quite a while. We've been through some major life changes, a move across the country, a couple of new jobs, the works. During all this, rocketry took a bit of a back seat for a while. Well, now the family is all back together in Colorado, close to Estes, Apogee, and the SCORE club in Pueblo. We attended the family day for NARAM 65, and my appetite thus thoroughly fired up.
Anyway, I hadn't built a rocket in a while, and I wanted to get back into my groove. So, I looked in my build pile, and I picked up an obscure passion project. Estes kit 1981, D.A.R.T. This rocket was only available from 1987 to 1988, and as best as I can figure was it was designed to use up nose cones designed for the SCUD missile kit that were piling up. It wasn't very popular, and I've never actually seen anyone with one at a club event. I have only ever actually seen two of them, and I have both of them.
The first one was built by my best friend's dad, presumably when the kit was available, so about the time my friend and I were born. When my friend's dad found out that I was into rocketry as of early 2003, he gave me his whole collection which had sat in a box in the garage attic for years at that point. D.A.R.T. was the most complete rocket in the box and needed the least amount of repair to get flying again. Sadly, my friend's dad, Chuck, passed later that year in a motorcycle accident. Since then, I have vowed to keep his D.A.R.T. unaltered and in flyable condition. When I do fly it, the most I'll do is repair the occasional broken fin or burned parachute. Beyond that, that's Chuck's D.A.R.T., and flies in his memory.
But I wanted one of my own! So a few years back, I found a mostly complete kit on a listing of rockets in one of those buy/sell/trade groups on Facebook along with a few other vintage kits I wanted to get my hands on, so I threw money at the project. I finally dug it out a few weeks back and inventoried what was and wasn't in the kit. Present were the face card, instructions, body tube, nose cone, balsa fin sheet, decal sheet, and parachute pack. Missing were all the motor mount parts and launch lug. Additionally, the nose cone was squished and bent a bit, making it still usable but not ideal.
That's when I decided to fire up the 3D printer and come up with something that was absurd and over-engineered. Like most of my designs. First, I decided to make this a low to mid power rocket with a 24mm mount instead of the original 18mm setup. With a 24-to-18 motor adapter, I can fly this on everything ranging from Estes C6 motors to Aerotech F39 reloads (once I buy a case that is). I printed a single piece tube that doubles as centering rings for the motor tube as well as a shock cord mount out of ASA filament to be able to hold up to the heat about as well as ABS. I'd prefer nylon, but my printers can't handle that stuff. Next, I printed a motor retainer in carbon fiber PLA. I expect this may be a bit melty for spicy composite motors, but should hold up enough even if it requires a spare in my range kit. I'm thinking at some point I'll print another retainer in ASA or ABS as well, but I want to keep the matte black look, and I don't have the appropriate filaments as yet. Given that this rocket can fly on mid power motors as well as C and D motors, I opted for a 3/16" lug rather than the 1/8" intended for the kit because this thing could conceivably whip the thinner rod. Finally, I spent a few days tweaking and testing prints for the most overengineered yet good looking nose cone I have designed to date. Given the potentially higher altitudes this thing can achieve, I opted for a nose that can carry various altimeters inside. I've since come across designs for printed noses that have an integrated electronics sled on a screw-in base/shoulder, but I went with a 4 piece design. A base, tip, and two fairing halves complete with small vent holes to equalize the air pressure. From there, the idea is to cut out the shape of the desired altimeter in some foam, and stuff the foam with altimeter into the nose. While most altimeters are pretty light, this keeps additional weight as far forward as possible which was a concern given almost half the overall length is all nose cone. I could have just hung a JL altimeter from the shock cord at the base of the nose, but that would be about the midpoint of the whole rocket.
Once I got the designed finalized and the screw threads fitting properly, I printed the nose in red silk PLA, and added white paint. The fins were papered, filleted with some stout epoxy, and the back half got two coats of primer with sanding in between and two coats of metallic cobalt blue Rustoleum. The original decals went on mostly fine with only the band just below the nose cracking and causing problems, and then it was two thin coats of clearcoat.
As for recovery, I've got a 15" plastic chute inside with a plenty long shock cord. The original D.A.R.T. has very little room inside for the recovery setup, so I designed the base of the nose cone to have a concave indentation to allow about an inch and a half more room to pack the parachute along with a nomex blanket. Under that should be enough room for about a inch thick pad of dog barf wadding.
Not sure when I'll get around to flying this thing, but I'm hoping soon enough. Maybe next month if I can manage it. If so, I will absolutely post pics, video, and altimeter data for your nerding pleasure.
Anyway, I hadn't built a rocket in a while, and I wanted to get back into my groove. So, I looked in my build pile, and I picked up an obscure passion project. Estes kit 1981, D.A.R.T. This rocket was only available from 1987 to 1988, and as best as I can figure was it was designed to use up nose cones designed for the SCUD missile kit that were piling up. It wasn't very popular, and I've never actually seen anyone with one at a club event. I have only ever actually seen two of them, and I have both of them.
The first one was built by my best friend's dad, presumably when the kit was available, so about the time my friend and I were born. When my friend's dad found out that I was into rocketry as of early 2003, he gave me his whole collection which had sat in a box in the garage attic for years at that point. D.A.R.T. was the most complete rocket in the box and needed the least amount of repair to get flying again. Sadly, my friend's dad, Chuck, passed later that year in a motorcycle accident. Since then, I have vowed to keep his D.A.R.T. unaltered and in flyable condition. When I do fly it, the most I'll do is repair the occasional broken fin or burned parachute. Beyond that, that's Chuck's D.A.R.T., and flies in his memory.
But I wanted one of my own! So a few years back, I found a mostly complete kit on a listing of rockets in one of those buy/sell/trade groups on Facebook along with a few other vintage kits I wanted to get my hands on, so I threw money at the project. I finally dug it out a few weeks back and inventoried what was and wasn't in the kit. Present were the face card, instructions, body tube, nose cone, balsa fin sheet, decal sheet, and parachute pack. Missing were all the motor mount parts and launch lug. Additionally, the nose cone was squished and bent a bit, making it still usable but not ideal.
That's when I decided to fire up the 3D printer and come up with something that was absurd and over-engineered. Like most of my designs. First, I decided to make this a low to mid power rocket with a 24mm mount instead of the original 18mm setup. With a 24-to-18 motor adapter, I can fly this on everything ranging from Estes C6 motors to Aerotech F39 reloads (once I buy a case that is). I printed a single piece tube that doubles as centering rings for the motor tube as well as a shock cord mount out of ASA filament to be able to hold up to the heat about as well as ABS. I'd prefer nylon, but my printers can't handle that stuff. Next, I printed a motor retainer in carbon fiber PLA. I expect this may be a bit melty for spicy composite motors, but should hold up enough even if it requires a spare in my range kit. I'm thinking at some point I'll print another retainer in ASA or ABS as well, but I want to keep the matte black look, and I don't have the appropriate filaments as yet. Given that this rocket can fly on mid power motors as well as C and D motors, I opted for a 3/16" lug rather than the 1/8" intended for the kit because this thing could conceivably whip the thinner rod. Finally, I spent a few days tweaking and testing prints for the most overengineered yet good looking nose cone I have designed to date. Given the potentially higher altitudes this thing can achieve, I opted for a nose that can carry various altimeters inside. I've since come across designs for printed noses that have an integrated electronics sled on a screw-in base/shoulder, but I went with a 4 piece design. A base, tip, and two fairing halves complete with small vent holes to equalize the air pressure. From there, the idea is to cut out the shape of the desired altimeter in some foam, and stuff the foam with altimeter into the nose. While most altimeters are pretty light, this keeps additional weight as far forward as possible which was a concern given almost half the overall length is all nose cone. I could have just hung a JL altimeter from the shock cord at the base of the nose, but that would be about the midpoint of the whole rocket.
Once I got the designed finalized and the screw threads fitting properly, I printed the nose in red silk PLA, and added white paint. The fins were papered, filleted with some stout epoxy, and the back half got two coats of primer with sanding in between and two coats of metallic cobalt blue Rustoleum. The original decals went on mostly fine with only the band just below the nose cracking and causing problems, and then it was two thin coats of clearcoat.
As for recovery, I've got a 15" plastic chute inside with a plenty long shock cord. The original D.A.R.T. has very little room inside for the recovery setup, so I designed the base of the nose cone to have a concave indentation to allow about an inch and a half more room to pack the parachute along with a nomex blanket. Under that should be enough room for about a inch thick pad of dog barf wadding.
Not sure when I'll get around to flying this thing, but I'm hoping soon enough. Maybe next month if I can manage it. If so, I will absolutely post pics, video, and altimeter data for your nerding pleasure.
Thanks for all the pics
