6" X15 build thread, or something like that.

[dlb]

About a year ago I purchased a 6in all fiberglass X15 from Ken a performance Hobby's. Upon getting at home and doing an overview, I decided to reduce weight by eliminating the fiberglass fins and converting it over to carbon fiber/ Kevlar waferboard. Just this option alone will reduce the total weight by almost 7 pounds. Picture below are some of the new fins framed out in Hardwood. Over the next few weeks I'll keep on adding pictures as I move along. I'm going to be doing heavy modifications to this kit. One of those modifications will be headend deploy.

It's been a while since I've done a build thread so I'll probably be slow and methodical.

 

[Speaknoevil]

Although not fiberglass, went a similar direction on my 6" X-15 from Hangar-11. Removed tons of weight from the back end plus many more mods for dual deploy, camera bay, etc.
https://www.rocketryforum.com/threads/finally-done-hangar-11-6-dia-x-15.143762/#post-1748366

 

[mbeels]

Wow, that is a tremendous weight reduction! Any idea what the final weight is expected to be?

 

[dlb]

About 20 lb with all the weight shifted forward

 

[SDramstad]

Where did you get the kevlar waferboard?

 

[rharshberger]

Where did you get the kevlar waferboard?

Kevlar or Nomex Honeycomb?

 

[SDramstad]

Kevlar or Nomex Honeycomb?

That stuff is way too expensive. I never heard of nomex waferboard. Hoping for a cheaper alternative

 

[Speaknoevil]

That stuff is way too expensive. I never heard of nomex waferboard. Hoping for a cheaper alternative

You might look at Rohacell. It is what I used on my X-15 build referenced in post #2 above. https://cstsales.com/Rohacell_31_IG.html

 

[dhbarr]

That stuff is way too expensive. I never heard of nomex waferboard. Hoping for a cheaper alternative

They sell radiator protectors for dirt racing that look like they could be made to serve

 

[dlb]

I bought my carbon fiber / Kevlar at air Fest two years ago. Got a piece that was 3 foot by 2 foot for 50 bucks. Such a deal.

 

[dlb]

Side wings and rear side fins are ready. The weight is lifted off the fins. The upper and lower fins will be completed in a later phase oh, and will be truly wedge-shaped.

 

[dlb]

Motor mount assembly.
75 mm motor.
34 in Long to get myself some room on both sides after assembly.


Added shock cord mounting even though I'll probably never use it. Most likely use the 75mm motors eye bolt instead. Used carbon fiber filament to reinforce all centering rings. Tail cone and arrow pack motor retainer glue on at the very end.

 

[dlb]

Installed motor mount.
Everybody lines up perfectly.

 

[SDramstad]

Nice, looking good.

 

[dlb]

Well after waiting for a few days to receive some Rotozip 3 1/2 inch cutting discs. 4 blades wide was the perfect cutting with. Zip right through those guys and now my honeycomb fins will fit. Next glue in the forward wings and figure out the cut area on the shrakes.

 

[dlb]

Well after a short break I'm back to working on my 6 in fiberglass X-15.
working on probably the hardest part is whole entire project, the shrakes and the cutouts within the shrakes. Got the wings cut out and they fit perfectly. Next is cutting out the rear angle fin area and that's going to be a little more difficult.

 

[dlb]

Pretty warmed a little rain so it's time. I rough sanded the entire airframe then attached one side have my X-15, both fins but the shrake is still loose, just in place to hold the fins. Make sure I had a proper 15 degree angle on the rear fin. The shrake when I first started was very taunt but after making the cuts in it it became more flexible oh, but you have to be careful at that point.

 

[Greg Furtman]

Pretty warmed a little rain so it's time. I rough sanded the entire airframe then attached one side have my X-15, both fins but the shrake is still loose, just in place to hold the fins. Make sure I had a proper 15 degree angle on the rear fin. The shrake when I first started was very taunt but after making the cuts in it it became more flexible oh, but you have to be careful at that point.

What's the shrake made of? Yellow poplar?

 

[dlb]

fiberglass with a jel coat

 

[dlb]

My X-15 continuation.
All side fins are glued in and their shrakes are glued on. More carbon fiber laced epoxy at the fins meet the airframe joint. You notice the Shrake Point have been cut off that's because they're going to go on the nose cone area.When Everything is dried and fully set I'm going to fill a shrakes with foam. The top and bottom rudder's are really going to be v-shaped , that's where I'm going to head now. Finish up the back end of the body so I can get a good weight and then continue on to the nose cone area, for added weight balancing. I also ordered some more US Composites epoxy.

So far it weighs 11.9 lb without the nose cone area.

 

[dlb]

Foam filled the Shrakes. lots of oozing the easy to clean off. Cleaned off the extra was a standard pocket knife.
Time to start working on the upper and lower rudders. They will be wedge-shaped.

 

[dlb]

okay, now I'm going to deal with the idea that the kits that you buy always have a single flat fin or we'll call it Rutter. I decided not to do that and go with the traditional wedge shape design. I'm using the carbon fiber plate in the center for stiffness and going all the way through to the motor tube. The rest is 1/8" aircraft plywood. I'm just outlining it right now and going for the fit to see what it looks like. when I'm done this thing will be Bulletproof.

 

[dlb]

Just finished up the lower rudder.
Epoxy and foam filled and trimmed.
And try her on for size.
Next is a lot of hand sanding oh, not really looking for it but it's required

 

[dlb]

Starting to work on the nose cone area.
First off, adding shock cord and 4 pounds of BB's into the nose cone. Topped off with some 635 US Composites epoxy.

 

[dlb]

Time to assemble the rack and start priming the surface. And get ready for a whole bunch of sanding.

 

[dlb]

After a whole series of priming and sanding I am now ready to start with the first coat of black. I came to the realization black really shows imperfections. So more sanding is required to try to remove some of those imperfections.

 

[dlb]

While waiting for the black paint to harden and cure , I decided it's time to finish off the nose cone. I foam filled the tips of the shrakes that are now mounted to the nose cone. After the foam cured, I cut off the excess and sanded it down. The foam that I use is US Composites 4 lb foam version. this stuff is like a brick when it's hardened, but still very light in weight.

 

[dlb]

The priming of the nose cone and finishing off painting it black.
Did I mention sanding, hahaha

 

[dlb]

time to come up with a coupler / avionics Bay. I'm only going to use roughly about half of the coupler for the avionics Bay. the other part will help with the drogue Chute and shock cord.
I use the remaining piece that I cut off the nose cone shoulder that I cut off previously. I cut it down and inserted it inside the coupler on one end.
End plates use u-bolts with four 4/20 threaded rods holding it all together.
top it off with three-quarter inch PVC pipe ends, for use of the charges. Each one will hold up to 4 grams. Way more than I need

 

[dlb]

Next up is applying the decals that I got from stickershock. All except the window sticker oh, I didn't like that one, seem to be way too big. So I cut windows out of 2in aluminum tape and I have to admit they came out pretty good.
then I'll have to apply a clear coat over top of them.
I'm pretty happy and I have an X-15 on my hands.
I also need to finish up the AV Bay my adding altimeter mounting boards oh, I'm still thinking about how I want to do it.