X-15 (3D printed parts + BT-80 body tubes + plywood fins)

[BABAR]

Next goal is to redesign the motor mounts so that I can use a larger variety of motors.

was apogee not high enough on the 2 motor D12-3 cluster? Are you wanting to go UP to either 24mm E or 29 mm motors? Adapting DOWN doesn’t require any rocket redesign, just 24-18 motor adapters, these are easy enough to make, the Estes ones are decent and I think reasonably priced last time I checked. Would this fly on two C5-3s ?

You also have the option of the Q-Jet 24 mm Es.

If it ain’t broke…..

 

[BigMacDaddy]

Just got done watching the Vido looks like you're getting close to a release date on the parts.
This is going to make a great kit, hope to be able to get a couples.

Thank you -- yes, hoping to release the kit this coming week.

 

[BigMacDaddy]

Looks great

Here’s a nifty antizipper trick

Blaine's Kevlar Anti-Zipper using Foam Ear Plug

Hello all, In the "totally over engineered LPR department"... I just wanted to share my Kevlar Anti-Zipper using a Foam Ear Plug. Producing motorsports television, I have an over abundance of foam ear plugs so, to put them to good use... please see description below pictures... 1. I...

www.rocketryforum.com

Cool -- thanks for sharing this. I put a piece of duct tape on the Kevlar where it lined up with the edge of body tube.

 

[BigMacDaddy]

Since you video many of your rocket launches, one thing that may help you on mismatching motors is, prior to count down, name the rocket and the motors.

Had you said, “This is the X-15 on a cluster of two D12-0s, 3,2,…… wait a minute, that can’t be right”


There is probably a reason they do this at sanctioned NAR and I presume TRIPOLI launches, at least all the vids I have seen.

Also nice info for those who watch your videos.

That mix-up was much more dumb than that -- I loaded them when I was doing test fitting and measuring CG. Just grabbed the first motors that were near me.... Fast forward to a couple of months later as I am loading multiple rockets to launch and I thought I had loaded D12-5 motors in there so if I was giving the count down I would have said "on a pair of D12-5s".

I need to use more check lists.

I used to update the description of the videos after the launch once I unloaded the spent motors and parachute etc... but not Youtube does not use descriptions (or thumbnails) for videos they classify as shorts. Annoying.

 

[BigMacDaddy]

was apogee not high enough on the 2 motor D12-3 cluster? Are you wanting to go UP to either 24mm E or 29 mm motors? Adapting DOWN doesn’t require any rocket redesign, just 24-18 motor adapters, these are easy enough to make, the Estes ones are decent and I think reasonably priced last time I checked. Would this fly on two C5-3s ?

You also have the option of the Q-Jet 24 mm Es.

If it ain’t broke…..

Actually I am quite happy with the launch and D12-3 is good for me with this rocket.

However, want to provide more flexibility when I turn these rockets into kits so using motor mount tubes w/ motor blocks to provide more flexibility.

Without the tube it is quite a bit more difficult to use adapters. I might setup my next build for E12-4s and adapt down to D12-3s.

 

[ksaves2]

Interesting project as it reflects the early XLR11 motored X-15s. The big mother XLR-99 motor wasn't ready yet for the early tests. The interesting caveat as the motors were throttleable and that hadn't been done often up to that time. Kurt

 

[burkefj]

What is the weight of your nose cone complete with cockpit?

 

[burkefj]

Interesting project as it reflects the early XLR11 motored X-15s. The big mother XLR-99 motor wasn't ready yet for the early tests. The interesting caveat as the motors were throttleable and that hadn't been done often up to that time. Kurt

Sort of, on the dual motor and ealier XLR-99 version the tunnels didn't go back as far on the boat tail, he's more modeled the X-15A-2 with extended tunnels..The modified A-2 was also 29" longer than the other two birds which helps CG, I prefer this version in any case...and is what i use on my R/C version. For dual motors you should trim the side tunnels back. For the A-2 long tunnels but should have the ball tank at the base of the stab.. likewise the a2 version with the full tunnels should have rounded Windows as those were installed to prevent cracking at the high speeds and not have the semi-rectangular windows like on the other two aircraft.

 

[BigMacDaddy]

Sort of, on the dual motor and ealier XLR-99 version the tunnels didn't go back as far on the boat tail, he's more modeled the X-15A-2 with extended tunnels..The modified A-2 was also 29" longer than the other two birds which helps CG, I prefer this version in any case...and is what i use on my R/C version. For dual motors you should trim the side tunnels back. For the A-2 long tunnels but should have the ball tank at the base of the stab.. likewise the a2 version with the full tunnels should have rounded Windows as those were installed to prevent cracking at the high speeds and not have the semi-rectangular windows like on the other two aircraft.


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Thanks Ron -- yes, I started with the A-2 but then when I realized I was going to need 2x 24mm engines I oriented them vertically based on the XLR11 motor setup. I am actually working on modifying the retainer cap to better simulate the look of the XLR11 tail.

There seem to be a bunch of variations on this design but cannot find reliable pictures of all the different versions. (and this is from a Russian document to TIFWIW).

 

[BigMacDaddy]

Interesting diagram...

Prelude to the High Frontier: Early Space Vehicles

In the closing months of World War II, Henry “Hap” Arnold, Commanding General of the Army Air Forces (AAF), persuaded Caltech’s eminent aeronautics Professor Theodore von Kármán to lead a team of American scientists to Europe and Asia....

link.springer.com

 

[BigMacDaddy]

What is the weight of your nose cone complete with cockpit?

5.4oz

 

[burkefj]

Thanks Ron -- yes, I started with the A-2 but then when I realized I was going to need 2x 24mm engines I oriented them vertically based on the XLR11 motor setup. I am actually working on modifying the retainer cap to better simulate the look of the XLR11 tail.

There seem to be a bunch of variations on this design but cannot find reliable pictures of all the different versions. (and this is from a Russian document to TIFWIW).

View attachment 570948

Rely on the photos, and there will never was an X-15A terminology used. Just X-15 or X-15A2 The top model in the Russian drawing was an early proposal it was never an actual aircraft, the serj and A3 were just proposals as well. That Soviet drawing doesn't show the A2 version being longer either which is incorrect.

 

[BigMacDaddy]

Ok, quite a bit of redesigning things today to create multiple prototypes with the same basic structure.

First I created the option to extend the side pods to the rear of the rocket with separate extensions. These extra little parts are actually H2O2 tanks in the real thing. Then I made two engine / motor options. The vertically aligned pair of 24mm engines or a single 29mm engine in the middle.

I also designed retainer caps inspired by the models of the two engine configurations (ah also inserts for the rear of those pods). Need to get those relatively large engines in there so cannot make things exactly like the real thing.



I am also considering 3D printing the top and bottom wedge fins instead of building out of plywood. Any thoughts on this? I think the 3D printed parts are a bit lighter and certainly easier to finish but they plywood might be a bit stronger.

Also added the helium tank optional add-on part (still needs a bit of tweaking).

 

[burkefj]

Looks good.

 

[Richard N]

Yes on 3D printed wedge fins. Sturdier and easier to finish.

 

[BigMacDaddy]

Design is finalized (well as much as 3D printed designs are ever "final"). Printing these fairings is proving to be a pain...

Wound up with lots of parts and a few different variants.

• X-15 w/ 2x 24mm cluster, tall ventral wedge fin, and short fairings (blue parts).
• X-15A-2 w/ 1x 29mm engine, short ventral wedge fit, Helium Ball, and extended fairings (green parts).
• Yellow parts are universal as are the plywood fins.

 

[NOLA_BAR]

That’s interesting. I did not realize the short ventral fin was a flight configuration. I knew it had to drop part of the lower fin before landing.

That dual 24mm is sending a lot of hot material into a single BT-50 tube. Might be better to keep them separate, or into a heavy wall 29mm.

 

[Tobor]

You keep coming up with fantastic rockets. The 29mm X-15, Tao Zero, TB3 and R-360 are among my favorites. But, I have too many kits atm, according to the Mrs. One day I'll just have to go into stealth mode purchasing.....

 

[KenECoyote]

That’s interesting. I did not realize the short ventral fin was a flight configuration. I knew it had to drop part of the lower fin before landing.

That dual 24mm is sending a lot of hot material into a single BT-50 tube. Might be better to keep them separate, or into a heavy wall 29mm.

How about one D12-3 and one D12-5 so the ejection isn't at the same time and the longer delay one serves like a back up?

 

[BigMacDaddy]

That’s interesting. I did not realize the short ventral fin was a flight configuration. I knew it had to drop part of the lower fin before landing.

That dual 24mm is sending a lot of hot material into a single BT-50 tube. Might be better to keep them separate, or into a heavy wall 29mm.

Apparently 129/199 flights were done without the bottom rudder and every picture we see of them on the ground or landing no longer has the rudder even if it had it in flight (since they eject it prior to landing). I finally found measurements of the wedge fins and rudder and scaled parts accordingly so should be accurate to scale. I had to fudge the details on the backs a bit since the actual wedge fins were open on the bottom and you can see the rudder mechanism.

The setup allows the options for heavy wall 29mm tube as the stuffer tube (also need to do that if you want to swap between cluster and 29mm engine). However, I have done this on a couple of rockets and have not had a problem yet w/ BT-50 tubes (although I have not launched any rockets dozens of times). Could definitely double up the BT-50 tube with an outer tube or tape or wood glue and Kraft paper wrapped layers. I have also sometimes swabbed the inside of tubes that were going to take ejection abuse with wood glue to help protect them.

 

[BigMacDaddy]

You keep coming up with fantastic rockets. The 29mm X-15, Tao Zero, TB3 and R-360 are among my favorites. But, I have too many kits atm, according to the Mrs. One day I'll just have to go into stealth mode purchasing.....

Thanks very much!

Trying to do different models or change up details, motor configuration, size, price, etc.. for models that already exist in some form.

 

[BigMacDaddy]

How about one D12-3 and one D12-5 so the ejection isn't at the same time and the longer delay one serves like a back up?

Just don't use D12-0s.... As I already found out that does not mean no ejection charge...

 

[KenECoyote]

Just don't use D12-0s.... As I already found out that does not mean no ejection charge...

YES. It was an early lesson for me that D12-0 meant "0 seconds" delay before ejection (used for boosting and igniting 2-stage sustainers).

The Estes motors without an ejection are labeled with "-PT" and called "plugged".

 

[burkefj]

You also have a third option of the xlr-99 motor, no extended ventral, standard length and without tank on the rear top or the strake extensions, many flights were done this way...

Frank

 

[BigMacDaddy]

You also have a third option of the xlr-99 motor, no extended ventral, standard length and without tank on the rear top or the strake extensions, many flights were done this way...

Frank

Thanks Frank -- yes, if folks get the 29mm version they can just leave off the fairing extensions and He ball to leave it as an X-15. Most people looking to do this are probably getting the combo set with all the parts so they can swap 2x 24mm cluster and 29mm motor options.

 

[BigMacDaddy]

You also have a third option of the xlr-99 motor, no extended ventral, standard length and without tank on the rear top or the strake extensions, many flights were done this way...

Frank

By any chance do you have data on the diameter and length of the external fuel tanks on the X-15A-2?

I cannot find those dimensions...

Nevermind - I measured from pictures. Right on the money for BT-60 tubes. 9" long + nosecone and rear cap.

 

[burkefj]

By any chance do you have data on the diameter and length of the external fuel tanks on the X-15A-2?

I cannot find those dimensions...

Nevermind - I measured from pictures. Right on the money for BT-60 tubes. 9" long + nosecone and rear cap.

That would be great if you could do the nose and end for that at least for display purposes

 

[NOLA_BAR]

Sent a PM about getting a combo kit, but just checked FB and it looks like you sold out. If you do a second run put me down for a 29mm/24mm combo. Looks like a hit!

 

[BigMacDaddy]

Sent a PM about getting a combo kit, but just checked FB and it looks like you sold out. If you do a second run put me down for a 29mm/24mm combo. Looks like a hit!

Sorry -- I had a draft private message that I did not send but sent it now. I had one kit set aside for you (you were the last order).

Thanks for the support!

-Rob

 

[BigMacDaddy]

That would be great if you could do the nose and end for that at least for display purposes

I think @KenECoyote might experiment with launching with the external tanks (maybe with them moved back to the rear of plane). I am sending him some prototype external tank parts.