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Mad City Flyers 09-25-2016 08:11 PM

Wildman V2 Build
1 Attachment(s)
Next project for the Mad City Flyers is a 4" Wildman V2 with a 54mm motor mount!

As we have learned, no BAR's collection is complete without a V2. We wanted to build a fiberglass V2 and the Wildman kit seemed the best value for money. The included AV Bay sweetened the deal and our order was placed!

The AV bay includes aluminum bulkheads and the coupler tube, but no hardware. A quick trip to the local True Value netted us the eye bolts, 1/4" all-thread, nuts, washers and aluminum tube for the sled.

The downloaded instructions are clear enough for someone who has already built a few high power rockets. The included pictures help out greatly!

Mad City Flyers 09-25-2016 08:20 PM

V2 motor mount
2 Attachment(s)
After laying out all the parts and measuring the motor mount it is clear that the innards of the V2 will be pretty tightly packed.

The 54mm motor mount will hold a 1280 case, but when using the AV bay there is very little space left between the eye bolt and the top of the forward closure on the motor.

As you can see in the pic below the motor mount is built using an Aeropak retainer and a single centering ring. I epoxied a 1/2" nylon strap along the full length. I've started using this nylon strap for recovery on my HP rockets. I cut it off about a foot above the top of the booster section and use a heavy duty awl and polyester thread to stick a loop into the end. This way the drogue chute recovery strap can be removable just like the payload section. This lets me swap between rockets and saves money.


Mad City Flyers 09-25-2016 08:30 PM

V2 Fins
7 Attachment(s)
Fin attachment is pretty straight forward:
  • Roughed up all surfaces with 80 grit sandpaper
  • RocketPoxy for root edge attachment to motor mount
  • Fin jig is a simple wooden straight edge clipped to the fin tails with binder clips
  • Devcon 5 minute epoxy for internal fillets

Although the Devcon quickset epoxy syringes are a little pricey I really like the ease of using them for internal fillets.


Mad City Flyers 09-25-2016 08:41 PM

V2 AV Bay
5 Attachment(s)
AV Bay is also a fairly straightforward build. The only negative is that the vent band is not centered at the midpoint of the coupler. This is because the nose cone only sits on the AV bay about 2 inches. The downside is that this AV bay could not be used in a different 4" diameter rocket.

I've been using the DogHouse Rocketry charge canisters. I really like the simple circuit run through the mounting screws rather than having to also mount a wiring block on the bulkhead.

I also purchased the 9V battery mount, and rotary switch along with required wires/connectors from DogHouse Rocketry.

Altimeter will be a PerfectFlite Stratologger CF. I've had very good luck with the StratologgerCF this summer and like it's ease of use.


Mad City Flyers 09-25-2016 08:56 PM

V2 Fin Finishing
4 Attachment(s)
Finished the fins with external fillets using the RocketPoxy. As this epoxy is already thickened I did not add anything more to it like phenolic microballons or fiberglass.

I have to say that my feeling are mixed about the RocketPoxy for external fillets. The tape edges were not as clean as I usually get with the Great Planes 30 minute epoxy thickened with West Systems fiberglass and phenolic microballons. The only downside was a lot of sanding to get very clean and smooth edges.

External fillets:
  • Roughened inside edges with 80 grit sandpaper
  • Taped off the edges with standard painters tape.
  • Mixed the RocketPoxy 1:1 and let it sit for about 10 minutes prior to pouring into the fin joint.
  • Used a 1/2" piece of PVC soaked in rubbing alcohol to smooth the fillets followed by a gloved finger dipped in rubbing alcohol.
  • Let the epoxy set for about 5-10 minutes before pulling up the tape and smoothing again with a gloved finger dipped in rubbing alcohol.
  • After letting the epoxy set overnight - lots of sanding with 150 followed by 320 grit sandpaper.
  • Cleaned the fillets with a rubbing alcohol soaked paper towel and then applied a somewhat thick layer of Elmers Carpenters wood filler.
  • Wood filler was allowed to set overnight and then sanded hard to remove almost everything but a nice cleaner over layer that filled all the minor imperfections.

Almost ready for paint!


Mad City Flyers 09-25-2016 09:05 PM

V2 Launch Rail Guides
7 Attachment(s)
As I noted earlier the interior space of this V2 is really tight. To minimize the chance of snagging any of the recovery gear on a rail button bolt I decided to go with Acme Conformal Rail Guides from Giant Leap Rocketry.

I of course read all of the warnings about ensuring that the guides are fixed well to the exterior and aligned perfectly.

Conformal Rail Guides:
  • Found the perfect midpoint and alignment for the guides.
  • Etched the back of the guides and sanded the rocket body wall to rough it up.
  • Taped off the boundaries for the guides to minimize glue spill and ease the alignment.
  • Used JB Weld Steel 1:1
  • Used two straight edges (ruler and yard stick) to brace the guides to ensure a straight line.


Mad City Flyers 09-25-2016 09:17 PM

V2 Ready for Paint
3 Attachment(s)
Paint prep consisted of lots and lots of sanding......

320 grit 3M paper and a ton of elbow grease until all surfaces were nice and smooth.

Cleaned up with a wipe down with rubbing alcohol soaked paper towels followed by a gentle wipe down with a tack cloth.

Chose 2 coats of PlastiKote sandable primer followed by wet sanding with 320 and then 1000 grit sandpaper.

Plan is to paint the post war White Sands #2 Yellow and Black roll pattern. Decided to try painting the entire rocket the gloss yellow and then tape it off for the gloss black.

Here's where we got this weekend:


Mad City Flyers 10-16-2016 01:42 PM

V2 Finished
1 Attachment(s)
Finishing turned out to be a bit of a PIA. I learned a hard lesson about Laquer vs Enamel paints.

I started the finish coats using a Valspar Laquer paint because the yellow seemed a better match for what I saw online for the US White Sands Missile Range V2.

Problem was that even after 3 days of dry time the paint was not hard enough to avoid scarring by the tape I used for masking. I tried a different masking approach which was to use electrical tape for the edges and then 3M painters masking tape for filling in the larger areas.

When I removed the tape it was a horror show of ridges and discoloration. UGGGGHHH.

So back to the drawing board. Let the finish dry for another 3 days and then wet sanded with 600 to 1500 grit paper to knock down the ugly ridges and prep for repainting.

Went back to Rustoleum gloss enamel for the yellow and black with much better results. I guess the lesson learned is to DFWWW.

Last steps will be:
  • load with the J415W motor and case, recovery harness, AV Bay, drogue and main chute to determine the Cg point. I'm guessing that a little nose weight will be required. This will be done by adding steel shot and enough Rocket Poxy to cover it to the nose with the 1/4" all thread in place.
  • drill sheer pin holes (3)
  • ejection charge test

Still on timeline for Midwest Power 14



Mad City Flyers 10-23-2016 09:11 PM

Ejection Charge Test
Had a nice day to test the altimeter triggered ejection charge in the backyard.

Ejection Charge Test Video

1.5 grams of Goex FFFFg black powder

Two nylon screw shear pins.

I think this bird is ready for first flight!

Mad City Flyers 11-16-2016 12:05 AM

First flight at MWP 14
Fantastic weather in Princeton, IL at MWP 14 allowed for great launches. Nate and I made it down on Saturday and launched the V2, X-15 and our Binder Design Stealth.

V2 - J415w - 6565ft

X-15 - J500MG - 2000ft estimate

Stealth - J575FJ - 3292ft

V2 came down a little hard due to an undersized parachute. Damage is to a couple of the fillets that cracked. Will give me something to fix over the winter.


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