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I can't believe this, but I may have actually found the tubes that would allow me to upscale the Cineroc and Omega to a 4" diameter rocket here in China. And they came (from all places) McDonalds. I might be building a McRocket! I was at the local McD's when they were changing out their displays, and they had some tubes that the stuff came in. I asked if I could have them, and they were happy to give them to me.
So, now I've got 3 tubes that are 4" OD, 3.8" ID, and 37" long. A 4" Omega needs 34" for the sustainer body tube. Along with that I scored a smaller diameter tube that is (approximately) .09" thick with a 77mm ID (there's some damage to the ends of the tube, so I'll have to cut a clean edge to truly know). The tubes are thick and kind of heavy, but I wouldn't be looking to push this design into orbit or much past mach 1 (if even that).
For the Cineroc, I've got that PVC pipe that is 4.375" OD. Upscaling a BT-60 to 4" would increase the diameter of the Cineroc to 4.398", that's really close... I'd need the nosecone, transition, and camera shroud 3D printed (perhaps a couple of copies of the nosecone (one for the look up, one for the look down recovery options)).
As I was creating and uploading the cutaway image, I realize that this would probably be easy to damage with a 75mm motor mount if the fins are removable. I'd need to build this as a 54mm powered two stage rocket, but I could live with a 75mm design rocket, but the fins would have to be permanently mounted to be strong enough to survive. I had been thinking of how I would be able to make the fins removable (for transport) for a while now, and came up with an idea on how to make the MMT removable. My more realistic idea would be to have this fly as a single stage 54mm rocket using an adapter that would link the "booster" and "sustainer" (which would also be screwed together).
I've got a question for anyone who's made a rocket with removable fins... Did you try to give them an external fillet (that was really just an extension of the slot? I'm thinking that I might be able to give the fins a wrap of teflon tape (should I be able to find it, then using epoxy putty to create the fillets. Allow the fillets to harden, remove the fins, and tape, and finish as normal.
Next question... Presume that I have an internal thrust ring to prevent the motor mount from blowing through the body tube, this thrust ring would be made of two centering rings (made from .197"/5mm thick birch ply) that are glued to a 4" length of motor mount tube. The motor mount would push directly up against this, and then there's the TTW fins (mounted into slots mounted to the motor mount tube). My question, would a single screw (like the rail button screw) be sufficient to keep the motor mount from blowing out the back, or should I use screws to lock the thrust ring to the upper CR of the MMT. I'm thinking that the rail button would be screwed into a wood block that is glued to the MMT
Of course, as long as I don't have the RMB to buy anything, this is all just a thought exercise. Oh... a word about the fin slots, they would fit inside the body tube, but due to the limitations of OR, I had to make them flush with the surface.
So, now I've got 3 tubes that are 4" OD, 3.8" ID, and 37" long. A 4" Omega needs 34" for the sustainer body tube. Along with that I scored a smaller diameter tube that is (approximately) .09" thick with a 77mm ID (there's some damage to the ends of the tube, so I'll have to cut a clean edge to truly know). The tubes are thick and kind of heavy, but I wouldn't be looking to push this design into orbit or much past mach 1 (if even that).
For the Cineroc, I've got that PVC pipe that is 4.375" OD. Upscaling a BT-60 to 4" would increase the diameter of the Cineroc to 4.398", that's really close... I'd need the nosecone, transition, and camera shroud 3D printed (perhaps a couple of copies of the nosecone (one for the look up, one for the look down recovery options)).
As I was creating and uploading the cutaway image, I realize that this would probably be easy to damage with a 75mm motor mount if the fins are removable. I'd need to build this as a 54mm powered two stage rocket, but I could live with a 75mm design rocket, but the fins would have to be permanently mounted to be strong enough to survive. I had been thinking of how I would be able to make the fins removable (for transport) for a while now, and came up with an idea on how to make the MMT removable. My more realistic idea would be to have this fly as a single stage 54mm rocket using an adapter that would link the "booster" and "sustainer" (which would also be screwed together).
I've got a question for anyone who's made a rocket with removable fins... Did you try to give them an external fillet (that was really just an extension of the slot? I'm thinking that I might be able to give the fins a wrap of teflon tape (should I be able to find it, then using epoxy putty to create the fillets. Allow the fillets to harden, remove the fins, and tape, and finish as normal.
Next question... Presume that I have an internal thrust ring to prevent the motor mount from blowing through the body tube, this thrust ring would be made of two centering rings (made from .197"/5mm thick birch ply) that are glued to a 4" length of motor mount tube. The motor mount would push directly up against this, and then there's the TTW fins (mounted into slots mounted to the motor mount tube). My question, would a single screw (like the rail button screw) be sufficient to keep the motor mount from blowing out the back, or should I use screws to lock the thrust ring to the upper CR of the MMT. I'm thinking that the rail button would be screwed into a wood block that is glued to the MMT
Of course, as long as I don't have the RMB to buy anything, this is all just a thought exercise. Oh... a word about the fin slots, they would fit inside the body tube, but due to the limitations of OR, I had to make them flush with the surface.