X-15 coming soon

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Astronaut Chesseball

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Just watched the two new videos. Part 12 is straightforward. I've actually been waiting to do the fillets on the wings and fairings to see how Tim did it. I was surprised to see him using a piping bag. What do you guys think about that technique? I'm kind of liking it. Having practiced with Rocketpoxy on my DBRM, I think it will work great with this. I don't know how Tim mixed it up, but I wonder if I could even put the two parts in the bag and just use that to mix it, rather in a bowl or paper plate. It would save a messy step.

Curious to hear what others think.
I watched the video also and like Tim's piping bag technique this would of saved me serious time on this step. I would mix the RP in a clear plastic cup then transfer into the bag. I like to mix the epoxy real good and need the bottom & side walls of a sturdy cup rather then mixing on a plastic bag that might tear. I noticed he went ultra thin on the vacuum rails then followed with rubbing alcohol. Either way I'm going to implement this technique on my next X-15 build.
 

markschnell

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@Astronaut Chesseball I noticed how thin he went. I almost thought he went too thin on the wing joints, but then again, he knows a whole lot more than me.

Good thought on not mixing in the bag. That stuff is expensive. I wouldn't want to risk losing any of it. Although, I use ziploc freezer bags all the time to marinate meat for grilling and I squeeze it all around vigorously and it doesn't break. We used them to make homemade ice cream with the kids (a fun, gimmicky kind of deal) and they hold up to that too. I'll have to think about it before committing the expensive rocketpoxy.

P.S. I always thought your screen name was Astronaut Cheeseball, and I looked closer and I see it's Chesseball. What's the significance of that? Just curious. :)
 

Astronaut Chesseball

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P.S. I always thought your screen name was Astronaut Cheeseball, and I looked closer and I see it's Chesseball. What's the significance of that? Just curious. :)
[/QUOTE]

Your the first to catch this nice job :clapping:...it's a [sic] hence the P-2 avatar photo.
 

AfterBurners

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I watched the video also and like Tim's piping bag technique this would of saved me serious time on this step. I would mix the RP in a clear plastic cup then transfer into the bag. I like to mix the epoxy real good and need the bottom & side walls of a sturdy cup rather then mixing on a plastic bag that might tear. I noticed he went ultra thin on the vacuum rails then followed with rubbing alcohol. Either way I'm going to implement this technique on my next X-15 build.
Good technique, but I would imagine you could also use a medium CA if you wanted too? I gotta get back to my pizza. Have a good night !
 
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AfterBurners

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He mentions a engine retainer and how it will throw the CG off. I'm doubting something that weighs very little will do that, but if you plan in advance just add a little more nose weight. There is a RS file for this kit so just build accordingly. Why does he attach two shock cords to the nose cone. The Kevlar and the one with the D link??
 
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Astronaut Chesseball

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He mentions a engine retainer and how it will throw the CG off. I'm something that weighs very little will do that, but if you plan in advance just add a little more nose weight. There is a RS file for this kit so just build accordingly. Why does he attach two shock cords to the nose cone. The Kevlar and the one with the D link??
Elastic and Kevlar® Shock Cords - This is a unique rocket. Because of the extra weight in the nose cone, a normal kevlar shock cord could increase the chances of a zipper. It is hard for the nose to slow down because it has so much momentum compared to a lightweight nose cone. So to absorb that excess energy, we've included a elastic shock cord as well. The two cords are not tied together end-to-end. They are strung in parallel to each other (side-by-side). The Kevlar is much longer than the elastic cord, so that allows the elastic to stretch fully and use up the energy of deployment. The Kevlar then acts as extra insurance in case the elastic cord degrades over time and loses its strechiness and strength. You'll want both in this kit.
 

AfterBurners

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Elastic and Kevlar® Shock Cords - This is a unique rocket. Because of the extra weight in the nose cone, a normal kevlar shock cord could increase the chances of a zipper. It is hard for the nose to slow down because it has so much momentum compared to a lightweight nose cone. So to absorb that excess energy, we've included a elastic shock cord as well. The two cords are not tied together end-to-end. They are strung in parallel to each other (side-by-side). The Kevlar is much longer than the elastic cord, so that allows the elastic to stretch fully and use up the energy of deployment. The Kevlar then acts as extra insurance in case the elastic cord degrades over time and loses its strechiness and strength. You'll want both in this kit.
Thank you for the explanation and definitely well thought out design.
 

AfterBurners

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I think another option if the nose cone is heavy and the elastic does eventually break I would be have the two pieces come down separately of each other. My concern especially with a nose cone that is heavy is having it come back and ding up the body of the rocket when it's ejected. I also like the way the lines are sewn on the parachute (across from each other) and not corner to corner. Well thought out and you guys get much kudos for doing that. Now I would definitely consider buying your chutes and even the kit just for that reason, because someone in charge took the time to do it right!!!! This is what I mean. After years and years in this hobby someone figured it out! This is the only reason why I never purchased flat chutes from anyone because no one out there took the time to correct this flaw. Well done!!!!!
 
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AfterBurners

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AfterBurners

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I'm putting this together now, but no build thread since Apogee has their series of build videos ongoing for this.
Some observations:
1. The most challenging aspect of the build are the vacu-form fairings. Specifically getting them to properly contour to the body tube. I watched video #4 several times and followed it and the instructions religiously, but still the fairings are not cooperating. The front of the fairing flares up and away from the tube so that if you try to push it down the rest of the fairing deforms. I wound up pushing the center down just to get the front flush with the tube. Perhaps my building skills, or lack thereof, are not up to the task. Two tubes of Tamiya contouring putty are on order as we speak.
2. LOTS of nose clay is included.
3. A big, beautiful 30" nylon chute is also included.
4. Two heavy cardboard fairing and fin/wing alignment jigs are included. Makes alignment very easy.
5. The upper and lower rudders are made of laser cut heavy fiberboard with slot and tab assembly.
6. This has an unusual double shock cord attachment method. I've only seen this on some NCR kits.
7. The quick link is supposed to attach to the nose cone eye loop but at full open it's still too narrow to slip on.
Don't want to shave the eye loop for fear of making it even weaker.
8. The plastic on the back end of the fairings is very thin and splits easily. Use short strokes to trim as per the video.
9. The fairings also have to be slotted. Much more difficult than slotting a body tube since you cannot use an angle tool. They do supply a slotting jig, but it's an adventure. ;)
I would expect some first run glitches. I'm sure Apogee will be correcting these very shortly.

View attachment 437597

Ready for a coat of CWF
View attachment 437598

No cigar.
View attachment 437599

Hope this helps you builders.
Laters.
what about papering the wings? I wonder if that would help and the clay nose weight maybe use BBs instead and use a film of epoxy to secure and fill the rest of the nose cone with 2 part foam epoxy? I think that would really secure things up. I would also add a retainer although they recommended using tape to secure the motor. Of course keeping track of the added weight and measuring out the epoxy and running it through RS I those additions / changes would be pretty good. Cut back on the actual weight itself (BBs) and calculate the extra epoxy and foam. Also add in the weight of the retainer to keep CG and CP in check.
 

AfterBurners

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Opened up my apogee package just now. I got a couple amazing looking kits!
View attachment 436749View attachment 436750
Also the apogee body tubes and parts I ordered are top notch quality! I recently got an NCR F-117 and now this X-15 from apogee and they are both super top notch kits for just over $100. IDK which to build first! Either way its been an awesome year for new products. Too many to list here. Here's to hoping all the kit makers keep up the good work!
I picked up the NCR F-117 too...nice kit for sure
 

AfterBurners

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That's expensive, but seems reasonable for what you're getting. I was certainly prepared for the price to be higher. I look forward to the first build thread!
I think you are right that it is expensive, but there's a lot of nice features that come with the kit. Laser cut wing alignment jigs, a nice rocket stand and a well made nylon chute. IDK I can't pull the trigger on this kit. I mean I look at a Madcow Bomarc or Jayhawk for around basically the same price range that comes with lite ply parts and heavy walled tubing. I understand the X-15 needed to be designed in such a way to make sure the CG and CP are correct, but maybe if it was a 3" kit with heavy walled tubes or plywood wings, that would be really cool because then you can launch it on high power motors. I feel that you are pushing it with even the Hobby line 29 motors. Don't get me wrong it's a nice kit and well designed, but as I said not in that big of a hurry to pull the trigger on it. I feel the same way about the Dynastar kits that are sold @ Apogee. Great looking kits, but for the type of parts / materials I just would like to see more. For instance card stock rings vs fiber or lite ply. Maybe thicker MMT or a nylon chute? These additions would probably make it worth to pay a premium price for a kit. Just my two cents.:)
 

afadeev

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I think you are right that it is expensive, but there's a lot of nice features that come with the kit. [...] I just would like to see more. For instance card stock rings vs fiber or lite ply. Maybe thicker MMT or a nylon chute? These additions would probably make it worth to pay a premium price for a kit. Just my two cents.:)
First of all, I got the kit, but haven't gotten around to building it yet (have other high-/mid-/low-power builds in flight).

I just took another look at the parts, and other than the blow-molded wings, I have zero concerns about kit's structural integrity.
The nose cone looks beefy and large, and will absolutely take as much epoxy + BB's mix into it as you have on hand. I am yet to damage any of my paper MMT + paper centering rings rockets, even though I stuff larger than specified APCP motors into all of them.
X-15 flies on 29mm motors, and claims to hit 2K on G53FJ, of which I have four on hand. You bet I will stick one up its flamy end later this summer! I will need to sim the stability with larger motors, but 3-4K on an H-motor should be reasonably safe as well. Basically, anything short of approaching super-sonic speeds, which will definitely shred the plastic wings.

Overall, this kit has all the hallmarks of something that will be selling for $300-500+ on eBay in a few years, once it goes out of production.
Just saying...
 
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AfterBurners

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First of all, I got the kit, but haven't gotten around to building it yet (have other high-/mid-/low-power builds in flight).

I just took another look at the parts, and other than the blow-molded wings, I have zero concerns about kit's structural integrity.
The nose cone looks beefy and large, and will absolutely take as much epoxy + BB's mix into it as you have on hand. I am yet to damage any of my paper MMT + paper centering rings rockets, even though I stuff larger than specified APCP motors into all of them.
X-15 flies on 29mm motors, and claims to hit 2K on G53FJ, of which I have four on hand. You bet I will stick one up its flamy end later this summer! I will need to sim the stability with larger motors, but 3-4K on an H-motor should be reasonably safe as well. Basically, anything short of approaching super-sonic speeds, which will definitely shred the plastic wings.

Overall, this kit has all the hallmarks of something that will be selling for $300-500+ on eBay in a few years, once it goes out of production.
Just saying...
Good points and well taken, but a high power motor? They even stated it's not designed for that, but up it's fanny it shall go. :p As I mentioned I think having maybe heavy walled tubes including the MMT I think I would stuff maybe an H in it just for kicks and giggles. If you plan on going with an H I would use the JLCR so you can get it back along with whatever motor you are planning on using. If you do decide on doing it an onboard would be nice...I'd like to see video of the flight.
 

Astronaut Chesseball

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First of all, I got the kit, but haven't gotten around to building it yet (have other high-/mid-/low-power builds in flight).

I just took another look at the parts, and other than the blow-molded wings, I have zero concerns about kit's structural integrity.
The nose cone looks beefy and large, and will absolutely take as much epoxy + BB's mix into it as you have on hand. I am yet to damage any of my paper MMT + paper centering rings rockets, even though I stuff larger than specified APCP motors into all of them.
X-15 flies on 29mm motors, and claims to hit 2K on G53FJ, of which I have four on hand. You bet I will stick one up its flamy end later this summer! I will need to sim the stability with larger motors, but 3-4K on an H-motor should be reasonably safe as well. Basically, anything short of approaching super-sonic speeds, which will definitely shred the plastic wings.

Overall, this kit has all the hallmarks of something that will be selling for $300-500+ on eBay in a few years, once it goes out of production.
Just saying...
Excellent points and I would agree about other X-15 kits costing 3 times as much in the past. The next closet kit in scale next to the Apogee X-15 was Paul Clarks 1:20 back in the 90's. If you wanted anything close in scale this was your only options in a kit. For a mid power rocket you will be hard pressed to find anything else on the market that comes close to the Apogee X-15.

 

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