Saint_Tiki
Well-Known Member
Hello again!
Been looking into some good Level 1 cert kits and started thinking about designing my own! There are a few good looking kits but nothing has exactly what I have in mind. I have some questions though about materials, weight, etc.
I know there will be some naysayers and I understand that a scratch build is probably not the best idea for most people coming into the hobby. However, I’m quite engineering oriented and my other hobby is combat robotics which is all about designing things from scratch, sketching, graph paper, CAD'ing, parts lists, weight sheets, etc so I’m pretty confident in design and building from scratch as a general process. I just think it would be a lot more satisfying to fly something of my own creation and get certified that way and have total control over each aspect of it. I’m also not really worried about failing my L1. Don't get me wrong, I’d prefer not to! I’m fortunate to have two clubs nearby that appear to do monthly launches so there will be plenty of opportunities to fly and try again if something goes wrong. And I’m planning on designing and building something that I can fly on mid-power at a nearby site and do some local testing before I go high-power for cert so the rocket should have a few successful flights already before I take it out for a cert attempt.
1. Total parts. With all of that being said, I need a little guidance. From what I can tell, a high-power L1 attempt kit is usually two tubes (airframe and motor), 3-4 fins, 2-3 centering rings, motor retention, nose cone, eyebolt, shock cord, parachute, lugs/buttons, and a few other nick-nacks. So designing my own rocket would essentially be decisions on airframe diameter/length/material, motor tube diameter, fin shape/size/number, nose cone shape/size, etc. That sound about right? All simulated first of course for stability.
2. Tubes. I'm looking at BT-80/66mm so I have some room for future options and these seem easy to source. Slots seem a little trickier though. My first thought was to CAD and 3D print a cutting guide/jig, tape it in place, then I could cut out fin slots in the exactly correct spot. I feel like I could probably do this in paper tubes with a hobby knife and some patience but I’m also leaning towards going fiberglass. I want to keep my build pretty light so I can launch on G or even F motors at home, and also so I have the option to add an e-bay and altimeters in the future without getting too heavy.
(EDIT: I realized fiberglass tubes seem to actually be heavier than paper tubes. The BT-80 "kraft paper" tubes certainly are not meant for high power? They seem a bit thin.)
I'm a tinkerer so I know L1 is just the beginning and I'm gonna want some payloads. How hard is it to cut slots in fiberglass? Dremel and particle mask? Do you recommend I go for it with a fiberglass tube? Can I order one from somewhere pre-slotted to my design spec? I’m more concerned about time invested than money. If I put a ton of hours into making it and it explodes, it doesn’t matter to me that it cost an extra $50 for the tube at that point, lol. But if fiberglass is going to be significantly harder to cut, glue, paint, etc, then that changes the equation. Also, if I do go fiberglass for the body, should I fiber the motor tube as well or is that unnecessary?
3. Fins. I found a few places that sell pre-cut plywood fins. I don’t love the shapes though and that’s kind of part of designing my own, right? Looks like G10 is the go to fiber material for fins. I have some good cheap CNC contacts through combat robots and I’m thinking I could probably get a few fins CNC’d for relatively cheap. What kinda thickness should I be considering for G10 fins?
4. Centering rings. Looks as simple as buying a couple plywood rings sized for my build (probably 66mm to 38mm) and drill a hole for an eyebolt, anything I’m missing here? Worth going fiberglass on these as well?
5. Nose cone. There are some really cool looking nose-cones out there in some of these kits but I can’t find them as standalone parts, only a few generic BT-80/66mm nose cones. Any other options besides a friend with a lathe?
I think that’s it for now. Thanks for any help or advice!
Been looking into some good Level 1 cert kits and started thinking about designing my own! There are a few good looking kits but nothing has exactly what I have in mind. I have some questions though about materials, weight, etc.
I know there will be some naysayers and I understand that a scratch build is probably not the best idea for most people coming into the hobby. However, I’m quite engineering oriented and my other hobby is combat robotics which is all about designing things from scratch, sketching, graph paper, CAD'ing, parts lists, weight sheets, etc so I’m pretty confident in design and building from scratch as a general process. I just think it would be a lot more satisfying to fly something of my own creation and get certified that way and have total control over each aspect of it. I’m also not really worried about failing my L1. Don't get me wrong, I’d prefer not to! I’m fortunate to have two clubs nearby that appear to do monthly launches so there will be plenty of opportunities to fly and try again if something goes wrong. And I’m planning on designing and building something that I can fly on mid-power at a nearby site and do some local testing before I go high-power for cert so the rocket should have a few successful flights already before I take it out for a cert attempt.
1. Total parts. With all of that being said, I need a little guidance. From what I can tell, a high-power L1 attempt kit is usually two tubes (airframe and motor), 3-4 fins, 2-3 centering rings, motor retention, nose cone, eyebolt, shock cord, parachute, lugs/buttons, and a few other nick-nacks. So designing my own rocket would essentially be decisions on airframe diameter/length/material, motor tube diameter, fin shape/size/number, nose cone shape/size, etc. That sound about right? All simulated first of course for stability.
2. Tubes. I'm looking at BT-80/66mm so I have some room for future options and these seem easy to source. Slots seem a little trickier though. My first thought was to CAD and 3D print a cutting guide/jig, tape it in place, then I could cut out fin slots in the exactly correct spot. I feel like I could probably do this in paper tubes with a hobby knife and some patience but I’m also leaning towards going fiberglass. I want to keep my build pretty light so I can launch on G or even F motors at home, and also so I have the option to add an e-bay and altimeters in the future without getting too heavy.
(EDIT: I realized fiberglass tubes seem to actually be heavier than paper tubes. The BT-80 "kraft paper" tubes certainly are not meant for high power? They seem a bit thin.)
I'm a tinkerer so I know L1 is just the beginning and I'm gonna want some payloads. How hard is it to cut slots in fiberglass? Dremel and particle mask? Do you recommend I go for it with a fiberglass tube? Can I order one from somewhere pre-slotted to my design spec? I’m more concerned about time invested than money. If I put a ton of hours into making it and it explodes, it doesn’t matter to me that it cost an extra $50 for the tube at that point, lol. But if fiberglass is going to be significantly harder to cut, glue, paint, etc, then that changes the equation. Also, if I do go fiberglass for the body, should I fiber the motor tube as well or is that unnecessary?
3. Fins. I found a few places that sell pre-cut plywood fins. I don’t love the shapes though and that’s kind of part of designing my own, right? Looks like G10 is the go to fiber material for fins. I have some good cheap CNC contacts through combat robots and I’m thinking I could probably get a few fins CNC’d for relatively cheap. What kinda thickness should I be considering for G10 fins?
4. Centering rings. Looks as simple as buying a couple plywood rings sized for my build (probably 66mm to 38mm) and drill a hole for an eyebolt, anything I’m missing here? Worth going fiberglass on these as well?
5. Nose cone. There are some really cool looking nose-cones out there in some of these kits but I can’t find them as standalone parts, only a few generic BT-80/66mm nose cones. Any other options besides a friend with a lathe?
I think that’s it for now. Thanks for any help or advice!
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