Search results

Flew my "Bondo Umbrella" saucer on an I1299

Got in another flight with my 24mm nitrous/kerosene rocket (technically yesterday but I'm slow on video editing).

Technically yesterday, but I successfully flew my research (nitrous/kerosene) F motor.

I don't know if they will ship it there, but there are some on ebay: https://www.ebay.com/itm/354586001388

I got in my box of 50 today and they fit in the Micro Hybrid. The neck is a little different, and it feels like a slightly tighter fit on the diameter, but I think they should work. Time to fly some Pringle motors...

I successfully flew another grid fin rocket the other day, and uploaded the files to Thingiverse: https://www.thingiverse.com/thing:4487758 Launch video here:

Yes! The more the merrier! If it helps, I recently made a ~5 foot long model of a Congreve rocket. I used a 1/2" wood dowel from Lowes for the stick and have been protecting it with a single wrap of aluminum tape that extends about 10 inches behind the motor. I've flown it twice on E12s and...

One way to do it would be to use multiple chamfers. You could use the first set of chamfers to taper the fin from the base to the tip, and then two more sets of chamfers to add the airfoil shape. A more advanced way of doing it would be to use a loft tool. I don't know if Fusion 360 has this...

Finished painting my latest grid fin rocket today. Normally I use different filament colors rather than painting, but the available filament colors have been rather limited lately.

I'm using Solidworks FEA for the stress calculations, but I haven't run a buckling sim on it. I decided to load test it to be on the safe side, so I mounted it vertically on some 8020 and stacked some metal blocks on the engine. I took it to 2.2 times the expected thrust load (for a total of...

The peak thrust is about 20 pounds, with an impulse in the G range. The max stress in the engine mount should be around 400 psi (~1ksi is my normal cutoff point).

Printed out an engine mount for my test stand. I'll admit I haven't simulated the soakback heating, but it *should* be fine thermally during the ~2 second run when it is under actual load (the hot part is far away from the plastic and the injector has some cooling from the propellant flow).

I made a short presentation last year on some lessons learned in 3D printing model rockets. There are some specific tolerances, but most of it is on the more basic side (except for the cad example at the end). The slides are located here...

Thanks! The motor is in front of the CG, so that is what we have been thinking. I'm going to fly it with more nose weight and see if that fixes it (mine is not made from sheet iron, so it's a little lighter in the nose than the original).

I flew the Congreve today on an E12, and it was stable for most of the flight. It pitched over at the very end of the burn, so I might make a new nose cone with slightly more nose weight. Overall it flew better than I thought.

I don't know how stable it will be, but I finished my semi-scale Congreve rocket. Should be an interesting launch.

Tempting. I think I have a Big Daddy kit laying around somewhere....

I have never printed a stand-alone centering ring, but I have flown 3D printed motor mounts up to J impulse. Most of my stuff is fully integrated, so I use centering "cones" instead of rings to avoid support material (they also take the load a little better). PETG/ABS/Nylon are all fine, just...

I uploaded a small grid fin model for 18mm motors: https://www.thingiverse.com/thing:4178213 It was part of a series of experiments on grid fin performance. All of the files from that test series, as well as a short report, are also on Thingiverse: https://www.thingiverse.com/thing:4178253

Have this one, but it is on the bigger side: https://www.thingiverse.com/thing:3419162 I'll post the small one assuming it works, but that will be a few weeks from now.