XP-2 Rocket Glider

More to come.

The XP-2c was still flyable after its maiden flight but there were a couple of things that could quickly be done to improve reliability before the big contest. The burn string took a long and tortuous path back from the motor tube and it seemed like there would be a danger of snagging in some of the joints that had not been filleted.

The spaces were filled with Titebond molding and trim glue.

Gordon from Roachwerks/Excelsior made a page of decals for me with the NAR logo and my NAR number. He truly did a great job with these and the others I had ordered for a few other projects. The decal was applied to the tail.

The wind was blowing continuously throughout the day of the competition, hovering around 15mph. My goal was to qualify with causing too much embarrassment to myself or my club. I carefully loaded an Estes C6-3 motor and tied a burn string around its tortuous path. The grooves I filed into the wingtips to hold the thread in place during boost seemed as if they would keep the string from slipping and yet not be so tight as to bind. The glider was taken out to the pad and set up. Now the wait was on as I waited for the wind to die down a little bit.

The boost, when it happened, was fairly quick and pretty straight. The wings stayed back and did not deploy prematurely. The gut wrenching part was the coast phase, wondering if they would deploy at all. I also spent some time regretting not having used a Magic Marker to “paint” the glider. It was hard for me to see. I did have the satisfaction of seeing the wings deploy and seeing it start to really glide. As I had hoped, it was still circling but the circles were not as tight as during the test flight. The wind kept pushing it farther and farther downfield but we all had it in sight as it came ever lower. It was up much longer than my test glide had lasted but became increasingly hard to see.

When I went out to retrieve my glider, I had to go almost to the edge of the field but I found it without any problem or apparent damage. I carefully began carrying it back to the return desk. The whole way, wind gusts seemed as if they would tear it from my hands. I turned it in and the motor was checked and it was deemed to have been a qualified flight. It was right at about a minute or so but I do not recall the exact time. I fully expected to be superseded and the day went on but I did not care since I had accomplished my goal of qualifying.


As the day wore on, I saw more and more glider flights. A good many shredded but others stayed in the air much longer than mine. None of those with the staying power, however, ever made it back to the return desk. To my amazement, I took first place. My flight was respectable, but not outstanding. What saved me was that all of the superior flights drifted so far they were never recovered, even though hours were spent looking for some of them.

Wow! Really good build thread of a complex model. Great job!

Just out of curiosity what was the most commom type of R/G at the competition, Swing wing, T slide, pop elevator...?

JPVegh said:

Wow! Really good build thread of a complex model. Great job!

Just out of curiosity what was the most commom type of R/G at the competition, Swing wing, T slide, pop elevator...?

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Without a doubt, the most common I saw had hings held aft during boost and allowed to slide forward at burnout. All of the ones that beat my time were of such a design as were all the shreds.

Mine was the only swing wing I saw.

JAL3 said:

Without a doubt, the most common I saw had hings held aft during boost and allowed to slide forward at burnout. All of the ones that beat my time were of such a design as were all the shreds.

Mine was the only swing wing I saw.

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I thought that might be the case. I attempted to fly my C t-slider this saturday but I had a problem with it binding on the rod. I will do a little redesign and try again at the next launch.

While I was extremely happy with the performance of this rocket on its last outing, I did regret the unfinished look and resolved at that time to do something about it. Partially, this is because I just do not like the raw look. Also, the rawness made it more difficult to track in the air.

I know that paint adds weight which is bad for competition rockets. I will never be a serious competitor but I didn't want to overly handicap myself so I decided to use magic marker.

I started by using a black Sharpie on the wings. I got all of the top surface of both wings done along with 3/4 of the bottom surface before the Sharpied died.

I had a smaller, finer tipped Sharpie on hand and managed to get the vertical stabilizer done as well.

I didn't see this thread back in '11 when you flew, so I'm glad you brought it back! A truly impressive build, especially for having little glider experience. Most people start with sliders, and I have never flown anything but. I've always been a little intimidated by the swing wings.

I know that this is probably already done, but typically, glider guys also put a lighter (red, orange, etc.) on top so that it contrasts with the ground after landing. All black on top is easier to see than bare balsa, but not as much as a brighter color. You can also add strips of mylar tape for that shiny glint.

As for your "I won because the other guys didn't get theirs back," that's what we call "flying the field," though the term also encompasses the weather conditions. If there are trees/obstructions/high wind, the first priority is getting a model back.

Oh, and a quick suggestion with the burn string/rubber band. I used to just wrap the string like that until it got caught in the grain of a tail. You can imagine the results. Now I use small hooks made from 1/32" music wire. I've attached a picture showing where they are on the one of my slide wings. Basically anywhere you need to make a corner in the string, place a hook. Especially for a C-RG, the added weight is negligible, but the reliability increase is definitely there.

The 3D image of the hooks shows how I mount them to the boom. You never want to press anything into the boom (pylon and fins are OK) except perhaps at the very front and very back. These hooks have two legs on them to glue to the sides of the boom. A wrap of thread with some CA helps tremendously.

TheAviator said:

I didn't see this thread back in '11 when you flew, so I'm glad you brought it back! A truly impressive build, especially for having little glider experience. Most people start with sliders, and I have never flown anything but. I've always been a little intimidated by the swing wings.

I know that this is probably already done, but typically, glider guys also put a lighter (red, orange, etc.) on top so that it contrasts with the ground after landing. All black on top is easier to see than bare balsa, but not as much as a brighter color. You can also add strips of mylar tape for that shiny glint.

As for your "I won because the other guys didn't get theirs back," that's what we call "flying the field," though the term also encompasses the weather conditions. If there are trees/obstructions/high wind, the first priority is getting a model back.

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You're right that this is done but I did keep those colors in mind. Just haven't posted yet.

I'm familiar with "flying the field" but cannot claim that much forethought. I had one glider that was possible for this competition and flew it. The weather just cooperated with me this time. At this competition, I had much higher hopes for my copter. It didn't even place.

TheAviator said:

Oh, and a quick suggestion with the burn string/rubber band. I used to just wrap the string like that until it got caught in the grain of a tail. You can imagine the results. Now I use small hooks made from 1/32" music wire. I've attached a picture showing where they are on the one of my slide wings. Basically anywhere you need to make a corner in the string, place a hook. Especially for a C-RG, the added weight is negligible, but the reliability increase is definitely there.

The 3D image of the hooks shows how I mount them to the boom. You never want to press anything into the boom (pylon and fins are OK) except perhaps at the very front and very back. These hooks have two legs on them to glue to the sides of the boom. A wrap of thread with some CA helps tremendously.

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Thanks for the suggestion. I will keep it in mind when next I build a glider.

When I re-stocked my Sharpie supply, finished the wing surfaces with the black. Strictly speaking, that was done with a HUGE Magic Marker. The horizontal stabs and wing hubs were done with red. I did the boom in green and also the pod pylon. The pod itself was blackened (this time with a real Sharpie) and the nose cone got red.

She's still no beauty queen but I like the appearance much better now and I think it will be easier to track.

Nice looking John. Congratulations on the victory! You'll surely be able to see it a good deal easier with the dark colors.

foamy said:

Nice looking John. Congratulations on the victory! You'll surely be able to see it a good deal easier with the dark colors.

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Thanks!

Thank youcfor a great build:gavel: I just read it and found it very informative.

I could never get swing wings to go up straight. They always flew in an arch.

majordude said:

I could never get swing wings to go up straight. They always flew in an arch.

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Try a Switchblade. They go up straight as an arrow. I've built lots of them in all different sizes. No looping.

[video=youtube;KzGHnP9iCpo]https://www.youtube.com/watch?v=KzGHnP9iCpo[/video]