6" Diameter Smokin Rockets X-15 Build & L3 Certification
- Thread starter KenECoyote
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Rschub
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More story! 
Me and my rocket:
Let's talk about nose weight.
This X-15 rocket requires nose weight. It's pretty much a given if you have a short rocket with a lot of fin area forward. If the body tube length was doubled (or tripled), then maybe it wouldn't need it, but then it wouldn't look like an X-15.
Using Rocksim, I determined that, for a K1100T motor, I'd need about 3# in the nose (including the eyebolt and quicklink) to get the Cg 1.5 calibers ahead of the Cp, which in my experience was good.
Despite my first flight being a cato, reviewing the footage carefully, I saw that it had a stable boost off the rail and a stable coast (electronics and recovery were good too).
For my next planned flight with an L motor, my sims showed that I'd need to add about 2# more and for an M motor, about another 2#. Given I wasn't planning on flying M motors much at my local field, I came up with a system to have removable lead weight pucks (each puck is about 2lbs).
The puck above has the funny hole drilled because, while I originally planned on making the eyebolt in the nose removable, I had used strong thread lock on the eyebolt coupler and found that I simply couldn't remove the eyebolt, so I had to make a hole that would fit over it. After sliding the puck over the eyebolt, I would rotate it and then I used screws through the nose for the first puck. These would be removable if needed, but I might leave it in.
For the 2nd "M" puck, I used one 1/4" bolt across the sides. to secure it, I tried a few things including initially using threaded tee nuts and cutting the head down.
Adjusting for the curve of the nose cone (tricky task!):
When I was done, I didn't like how much they stuck out and eventually just cut off the heads of the tee nuts and I also cut a slot into the shaft of the bolt (which was now just like all-thread).
To top things off, I added a screw pin shackle to the base of the eyebolt and used wire to secure it so the pin wouldn't come loose (sorry, a bit hard to see in this pic). I also used a very large quick link.
This was an extra security measure in case the lead pucks would stress the screws and bolt during heavy acceleration. If the weights came loose, it would be a disaster, so I made sure to have back up safeties here. In the end, the anchored weights took the M motor boost fine.
A pic of showing the side bolt and bottom screws on the finished nose:
This X-15 rocket requires nose weight. It's pretty much a given if you have a short rocket with a lot of fin area forward. If the body tube length was doubled (or tripled), then maybe it wouldn't need it, but then it wouldn't look like an X-15.
Using Rocksim, I determined that, for a K1100T motor, I'd need about 3# in the nose (including the eyebolt and quicklink) to get the Cg 1.5 calibers ahead of the Cp, which in my experience was good.
Despite my first flight being a cato, reviewing the footage carefully, I saw that it had a stable boost off the rail and a stable coast (electronics and recovery were good too).
For my next planned flight with an L motor, my sims showed that I'd need to add about 2# more and for an M motor, about another 2#. Given I wasn't planning on flying M motors much at my local field, I came up with a system to have removable lead weight pucks (each puck is about 2lbs).
The puck above has the funny hole drilled because, while I originally planned on making the eyebolt in the nose removable, I had used strong thread lock on the eyebolt coupler and found that I simply couldn't remove the eyebolt, so I had to make a hole that would fit over it. After sliding the puck over the eyebolt, I would rotate it and then I used screws through the nose for the first puck. These would be removable if needed, but I might leave it in.
For the 2nd "M" puck, I used one 1/4" bolt across the sides. to secure it, I tried a few things including initially using threaded tee nuts and cutting the head down.
Adjusting for the curve of the nose cone (tricky task!):
When I was done, I didn't like how much they stuck out and eventually just cut off the heads of the tee nuts and I also cut a slot into the shaft of the bolt (which was now just like all-thread).
To top things off, I added a screw pin shackle to the base of the eyebolt and used wire to secure it so the pin wouldn't come loose (sorry, a bit hard to see in this pic). I also used a very large quick link.
This was an extra security measure in case the lead pucks would stress the screws and bolt during heavy acceleration. If the weights came loose, it would be a disaster, so I made sure to have back up safeties here. In the end, the anchored weights took the M motor boost fine.
A pic of showing the side bolt and bottom screws on the finished nose:
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"X-E Beast"
Trivia #1: When submitting my X-15 as a BFR flight for LDRS 42, I named it "X-E Beast" as a play on X-15 and "Sexy" ("Sexy Beast"
).
After the cato, I thought "Xtra Effort" may be more fitting!
Now that I finished the repairs, it was time to add some sexy to this beast!
Trivia #2: I had purchased 6" X-15 stickers from StickerShock back around 2015 since I was planning on eventually buying the kit and Stickershock had a "Buy 2 get 3rd Free" sale. I had been looking for the 6" kit ever since and only found it last year.
The stickers were dug up and some of the top masking layer was getting old and either dry or the tacky adhesive was coming off, but luckily the vinyl stickers themselves were still good.
The trickiest part was applying the large USAF on the wings, so I started there. I traced it onto paper and used that to determine placement. Initially I used some soapy water, but it was messy and wasn't necessary, so I stopped shortly after. Also I thought the residue may react with any clear coating I would apply later.
I somewhat rushed through the stickers and some weren't aligned perfectly, but I felt that it wouldn't be noticeable.
Trivia #3: For some reason, many/most of the X-15 stickers and even at least one of the Estes kits have the cockpit decal shown as a teardrop shape. The real plane had it more like rectangles, so I made my own using chrome vinyl sticker sheets.
With the stickers done, I first tested and then applied a gloss clear coat. I think the Rustoleum clear coats react badly with other gloss colors (possibly due to reactions from the different gloss elements), but it went great over the flat black. I wanted a clear coat to better seal the stickers (good thing because the rocket later got dragged upside down across a dirt field for a very long time before I got to it).
Viola!
At this point, I decided to try to do the second test flight on Sunday.
Trivia #1: When submitting my X-15 as a BFR flight for LDRS 42, I named it "X-E Beast" as a play on X-15 and "Sexy" ("Sexy Beast"
).After the cato, I thought "Xtra Effort" may be more fitting!
Now that I finished the repairs, it was time to add some sexy to this beast!
Trivia #2: I had purchased 6" X-15 stickers from StickerShock back around 2015 since I was planning on eventually buying the kit and Stickershock had a "Buy 2 get 3rd Free" sale. I had been looking for the 6" kit ever since and only found it last year.
The stickers were dug up and some of the top masking layer was getting old and either dry or the tacky adhesive was coming off, but luckily the vinyl stickers themselves were still good.
The trickiest part was applying the large USAF on the wings, so I started there. I traced it onto paper and used that to determine placement. Initially I used some soapy water, but it was messy and wasn't necessary, so I stopped shortly after. Also I thought the residue may react with any clear coating I would apply later.
I somewhat rushed through the stickers and some weren't aligned perfectly, but I felt that it wouldn't be noticeable.
Trivia #3: For some reason, many/most of the X-15 stickers and even at least one of the Estes kits have the cockpit decal shown as a teardrop shape. The real plane had it more like rectangles, so I made my own using chrome vinyl sticker sheets.
With the stickers done, I first tested and then applied a gloss clear coat. I think the Rustoleum clear coats react badly with other gloss colors (possibly due to reactions from the different gloss elements), but it went great over the flat black. I wanted a clear coat to better seal the stickers (good thing because the rocket later got dragged upside down across a dirt field for a very long time before I got to it).
Viola!
At this point, I decided to try to do the second test flight on Sunday.
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Launch Is Scrubbed! (but that's ok)
So I bring my nice shiny, sexy "beast of a rocket" to the June 2, Sunday launch for Rick to review and to have a second flight test on an L motor.
Rick seemed amazed at my repair and loved the rocket!
I told him that I was going to do another test flight and he told me not to bother. He said that the first flight, despite the cato, actually "checked all the boxes" (stable boost and coast, electronics worked, and recovered fine under chute).
I thought that made a lot of sense given there's always something that can go wrong with a flight (into the river or tree, drift away, etc.) and then there wouldn't be any more chances given LDRS was a few days away. If he was happy, I was happy!
There was one concern I had above the rest and I wanted to check this with him:
Me: "Rick, if the main deploys at apogee, is it a failure?"
Rick: "Nope!"
Golden.
If there are any gray areas on judging or concerns you have, talk with your L3CC/TAP first.
So I bring my nice shiny, sexy "beast of a rocket" to the June 2, Sunday launch for Rick to review and to have a second flight test on an L motor.
Rick seemed amazed at my repair and loved the rocket!
I told him that I was going to do another test flight and he told me not to bother. He said that the first flight, despite the cato, actually "checked all the boxes" (stable boost and coast, electronics worked, and recovered fine under chute).
I thought that made a lot of sense given there's always something that can go wrong with a flight (into the river or tree, drift away, etc.) and then there wouldn't be any more chances given LDRS was a few days away. If he was happy, I was happy!
There was one concern I had above the rest and I wanted to check this with him:
Me: "Rick, if the main deploys at apogee, is it a failure?"
Rick: "Nope!"
Golden.
If there are any gray areas on judging or concerns you have, talk with your L3CC/TAP first.
Some Additional Notes:
- Issue of the V2 HED Cannon main chute deployed at apogee:
- I thought this one over and felt that the dowels I had inside the body tube were a bit short/left a gap and so the rear bay lid was not resting on it. This allowed the main shear pins to flex and stress under boost. To fix this, I used epoxy putty to fill in any gaps and did the same for the X-15.
- I also took further caution with not too much primary bp charge on the drogue side (Rick's thought).
- To address Brian's thought that the nose was going too fast and the drogue chute yanked out the bay, I doubled the drogue line length, placed the drogue chute closer to the forward end and reefed the drogue chute.
- Why I didn't launch Saturday:
- Originally I was planning to attend LDRS by myself and stay at Country Charm campgrounds, which simplified things. As LDRS got closer, my family decided to come along, which I thought was awesome, however, it was no longer simple since I had to gather camping gear for 4 people.
- After my cato, I told my wife that I'd be very busy and asked her to do all the packing for the camping. As LDRS drew near, my wife's work exploded and suddenly she had no time to help, so I ended up spending most of Saturday gathering, cleaning, and packing everything for the trip myself... it was insane!
- End of April, I saw a TRF thread noting that Additive Aerospace was now selling RunCam 6 and shrouds for it. I had never had video on my rockets before, so I picked one up along with shrouds for the V2 (7.5") and the X-15 (6").
- It didn't keep recording on with my first try on the X-15 cato (my fault), but worked at LDRS when it counted!
- For the X-15, I placed it under the nose since I've always felt that the canopy bulge at top can make the rocket veer and I felt that the camera on the underside would balance that out well!
- It didn't keep recording on with my first try on the X-15 cato (my fault), but worked at LDRS when it counted!
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- Joined
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Wow, thats some horrific printing.
I print my caps vertically so you get a nice smooth surface.
It seemed fine to me based on other 3D printed items I've purchased. Back when I used to 3D print things, I made them at the highest resolution, however I understand that isn't usually practical for sellers printing a lot of things quickly.Wow, thats some horrific printing.
I thought it looked great after I painted it black.
- Joined
- Jun 4, 2018
- Messages
- 1,352
- Reaction score
- 1,019
Doubt they are printing that high of volume. I do like to coat mine in a light coat of epoxy and then sand down, gives a real nice finish to paint on.
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