The Mach Ness Monster, A 76mm Minimum Diameter Build

First tip to tip layup

I settled on two layers of tip to tip carbon fiber on the fins; should be more than enough to keep the fins on. A few bubbles, but nothing a little sanding can't fix. Now just to make it pretty!

So I've pretty much finished building! Just needs a nice paint job and a layer of clear coat. I did run into a few problems however. I thought I was having issues fitting my motor into my carbon tube because it was a tight fit to begin with and my case is pretty beat up, turns out that was only part of the issue. The main issue was that somehow my carbon tube isn't perfectly straight.. Best thing I could figure was a warped phenolic mandrel or I messed it up driving it home. (I wrapped it at a friends house and drove it home) So I ended up cutting off the fin section, which I had already attached to the tube and buying a commercial carbon tube. I'm happy with the result. Considering how big of an issue that is it ended up being a fairly easy fix. Here are some photos: For laughs and giggles I placed it next to my L2 cert. rocket in the last photo.

Solarover12 said:

Best thing I could figure was a warped phenolic mandrel or I messed it up driving it home.

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I made an entire 4" two-stager a few years ago. I took it to a launch to show it off, and I guy asks me how come it's bent. Sure enough, the thing looked like a banana, although I was able to get the motors in just barely. Of the four airframe sections, I turned the second and fourth 180 degrees to make like a snake shape. I don't have that rocket anymore.

I swear that when I started making tubes, the phenolic tubes for mandrels were very straight. It seems like over time they have gotten worse. I got one a few years ago that wasn't very good. I was in a hurry so I cut slots in it to straighten it out. It worked, but I can't recommend it.

Good luck on your flight. The rocket looks great and you have some interesting flights planned. Sorry about the tube though, too bad.

Jim

JimJarvis50 said:

I made an entire 4" two-stager a few years ago. I took it to a launch to show it off, and I guy asks me how come it's bent. Sure enough, the thing looked like a banana, although I was able to get the motors in just barely. Jim

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Did you ever fly it? I'm considering putting a 38mm mount in my bent tube and flying it instead of just throwing it out. Or maybe using it as a motor casing.

I am glad to see that tubing is being used

Everything looks great!

Solarover12 said:

Did you ever fly it? I'm considering putting a 38mm mount in my bent tube and flying it instead of just throwing it out. Or maybe using it as a motor casing.

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Sure. It flew fine, but both the sustainer and booster were lost in separate flights due to other problems.

Jim

BLKKROW said:

I am glad to see that tubing is being used

Everything looks great!

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Thanks! That tubing was absolutely PERFECT for this project. I didn't have to cut it down at all.

JimJarvis50 said:

Sure. It flew fine, but both the sustainer and booster were lost in separate flights due to other problems.

Jim

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That's interesting. I totally thought that any kind of slight bend would cause the rocket to cone. That was an amazing build by the way. It's too bad you lost them. I would've been quite upset about it to say the least.

-Clay

Solarover12 said:

That's interesting. I totally thought that any kind of slight bend would cause the rocket to cone. That was an amazing build by the way. It's too bad you lost them. I would've been quite upset about it to say the least.

-Clay

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I'm reasonably sure that this rocket is the one that flew to 100K but shreaded at that point due to the Raven altimeter firmware problem. The sustainer was lost (its first and only flight). The booster was lost on the subsequent flight on what remains my worst flight to date (and why I harp on the subject of two-stage safety). I think it was a sign from the rocket gods.

Stu Barrett was over last night (we were talking to an L3 candidate). That flyer wants to make is own airframe, and I relayed your experience and my own to emphasize the need to procure a straight mandrel. Stu mentioned that he has a few motor tubes that are curved. Oh, my ....

Jim

I've finished up painting, here is what it looks like. I couldn't resist adding Nessie to this flight

Like the bright blue!

That is gorgeous! I like how you painted did the fins. Will have to do that on my next one!

Here are the pictures I have of your flight. It was spectacular.

Kool! How high did it go and on what motor?

I'll let Clay fill in the details.

ChrisAttebery said:

Here are the pictures I have of your flight. It was spectacular.

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Thanks!! Those are beautiful! If you needed photos to show off your tower those are perfect.

BayouRat said:

Kool! How high did it go and on what motor?

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I managed to hit 24,300ft on a Loki M1200. Sadly I did not get my L3 due to a tangled chute and cracked a fin. I will post photos/video soon.

ChrisAttebery said:

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One of the coolest rocket shots ever with the sparks bouncing off the top of the tower!

Here's the video: [video=youtube;SxI1GhdZurI]https://www.youtube.com/watch?v=SxI1GhdZurI[/video]

Solarover12 said:

Here's the video: [video=youtube;SxI1GhdZurI]https://www.youtube.com/watch?v=SxI1GhdZurI[/video]

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Never think I'd say this, but screw the L3 -- that was a great flight!!!

+1

It just means you can fly another SkidMark.

dixontj93060 said:

Never think I'd say this, but screw the L3 -- that was a great flight!!!

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I never thought I would care this little about not getting my L3. This would've been an amazing cert. flight, but now I have an excuse to buy another motor and fly it again!

Thanks! It is one of my favorites too.

dixontj93060 said:

One of the coolest rocket shots ever with the sparks bouncing off the top of the tower!

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Mark's flight was more aggressive, but yours was more spectacular.

Solarover12 said:

Thanks!! Those are beautiful! If you needed photos to show off your tower those are perfect.

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ChrisAttebery said:

Mark's flight was more aggressive, but yours was more spectacular.

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Yeah I was seriously worried about your tower after seeing this big of a hole. It all held perfectly though! Wish I had a side by side comparison.