Incline Plane Wrapped Helicly Around an Axis

Hope you get a video of it in flight!

Well, I squeezed in some sanding tonight and let's just say I won't be getting hired for any drywall work any time soon. I had some rough spots on the spackle I couldn't just sand out so I got them as well as I could and then sprayed on some primer. The primer really made those rough spots even worse, so after it dried a few hours, I sanded it a bit and did a bit more patchwork on one of the fins in the bad spots.

I'm not going to be able to make this one all shiny and pretty, and frankly I don't want to, considering it's supposed to look like a screw. It actually reminds me a lot of the augers on the drill rigs I work with (I don't run them, other folks run them) and things like that would never be smooth and shiny. But I did have to improve on those spots.

Here are a few pictures from different angles right after I sprayed the primer. I thought this before, but even more so after getting it all white, the sides and backs of the fins, with me leaving them more stair-stepped, kind of look skeletal. Oh, and I have another idea for attaching fins that I THINK might work quite easily for the next phase. I'm not going to say what it is until I test it out with some card stock paper and another BT80 tube. It seems like it should work great when I visualize it, but I'm a geologist, not an engineer.

I am enjoying watching this creative process.
Thinking ahead, will this start rotating before it leaves the rod, and will that put any lateral stress on the rod? Put another way, wondering if rod and pad may need to be a bit more "fixed" than for other birds of similar size and motor configuration. I suspect however you are all over this. I had to go back through thr thread to see the launch lug was already centrally placed!

Very nice looking rocket. If you were to paint the rocket with yellow and blue stripes, barber pole fashion, it would appear to be green while spining.

[POW]Eagle159;369133 said:

What engine are you thinking for your first flight?

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I'm still trying to decide. I've checked the maximum lift-off weights of the B4, B6, and C6 motors and I should be good with any of them, and I'm leaning to the B6 for the first flight. Though I'm not really sure how to figure the best delay to use, as I'm not sure how the spinning will affect it all. I am open to suggestions.

First color, gloss sunshine yellow, on. After this is good and dry I'll mask off the fins and paint the body flat black. I got the spackle on the fins looking better before painting, but it is still not a great smooth finish. It seemed as I was sanding one area, a small chunk would fall loose from, or I'd accidentally put a small gouge in another area. So I made the executive decision that this one will be launch pad distance pretty.

That thing is looking awesome. The stepped look to the auger blade fins gives a more industrial look. Really cool, can't wait to see the flight report.

Chevis

Weighing in at 9.6 oz without motors, it is done. First launch is planned for August 18 at our club (ROCI) launch. I think it will be on B6-4s.

qquake2k said:

That turned out great!

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Thanks...if only the first flight had as well.

I gave it the old college try today at our club's launch. Some of the things I was trying to do worked, but the overall flight was not what I would call a success. I couldn't get an Open Rocket simulation built. I got all four motors to light. The launch rod through the center worked. I got a balanced spin out of it. But it was not a stable flight. It was close, I guess, but it was not successful. For one thing, shortly after it left the launch rod, it turned sideways where it was almost 90 degrees from where it should have been. It did not flip completely over, and it did not fly sideways into the crowd, but it did not go up any more. It seemed like it just sat there for a bit spinning and then started dropping, still at the angle. Since it hadn't gone more than MAYBE 30-50 feet, the ejection charge did not go off until it was oh...maybe...6 inches from the ground.

I wanted to see it, so I did not take any pictures or video, but there were others there taking pictures and I'll try to track some down and post them. Now I'm left trying to decide what caused the problem. Was the CG-CP relationship off? Did I not get fast enough spin, or the spin didn't get up to speed fast enough? Since it seemed to hold its position, albeit near horizontal, for a fair amount of time, does that mean it might have been stable if I had higher initial thrust (I used B6-4s)? Did it only stop its flip because the thrust had stopped, meaning I had too much initial thrust? If I repair the minor damage, do I try it again with C6 motors and see if more power helps it get up to speed better? Or do I go with maybe the Quest D5s, with a nice slow/long burn which may be better than higher initial thrust? I could maybe throw in a coupler and extend the body tube to add some stability. I could maybe try to add some nose weight (tricky without blocking the path of the launch rod). It might be that the fins simply were not wide enough at the aft end, or that the angle was too large. Hopefully I'll get to see some of the pictures that were taken and maybe get a better idea of what went wrong. If I can figure it out, I may still go on to Phase III making the appropriate corrections, as I'm sure it was a combination of things. I'll have to think on it some. This might be a good time to work on my Flis Stingray that's been sitting neglected for a while.

On the positive side, the weather was just about perfect. I got good flights from many of my rockets, and great flights from some including my boost gliders. Even my prototype two stage version of my Plumber's Helper (I call it Number 2) flew well, even if it had a bit of a wiggle.

keep going and try to work out the bugs--my version is on the build pile---granted a bit longer--but your design efforts apply---hey. it spun , that's one step in the right direction!

I would try some weight in the nose. Sounds like it was almost in the negatives for stability then swung into the positives once it was in the air and at speed. That would explain some of the flight issues.