Build Thread - Wildman Jr. Two-Stage

[kjhambrick]

@Antares JS --

I love your Silver and Gold paint theme !

I suppose the same warning about multiple coats does not apply to the gold paint ?

Sorry if I missed it, what brand is the gold paint ?

-- kjh

p.s. thanks for the Lab Rat Rocketry Pull-Pin tip !

 

[Antares JS]

@Antares JS --

I love your Silver and Gold paint theme !

I suppose the same warning about multiple coats does not apply to the gold paint ?

Sorry if I missed it, what brand is the gold paint ?

-- kjh

p.s. thanks for the Lab Rat Rocketry Pull-Pin tip !

Both the silver and gold are Rustoleum "Bright Coat Metallic Finish." The warning about multiple coats does not seem to apply to the gold. Someone who knows more about paint would have to tell you why that is.

 

[Banzai88]

Both the silver and gold are Rustoleum "Bright Coat Metallic Finish." The warning about multiple coats does not seem to apply to the gold. Someone who knows more about paint would have to tell you why that is.

Might have something to do with how the solids float on the solvents and binder when layed down wet, and that the solvents from a second coat may reactivate the lower layer and cause solvent evaporation issues.

May also have to do with what the silver pigment actually is, in that the first layer, once dry, may not provide a good mechanical or chemical surface for subsequent coats.

Or both. Or neither.

In any case, nice build. I hope it all works out perfectly on launch!

 

[Antares JS]

After a couple of false starts, paint, phase 2.

 

[311stylie]

Love that paint job! I would love to something similar but now that I run trackers/GPS in almost everything the metallic paints are a no go. I did just recently do a conical transition piece in silver since no electronics there. I love that metallic look.

 

[Antares JS]

Love that paint job! I would love to something similar but now that I run trackers/GPS in almost everything the metallic paints are a no go. I did just recently do a conical transition piece in silver since no electronics there. I love that metallic look.

My Level 3 uses the same paint and the Eggfinder works just fine in it.

 

[311stylie]

Interesting. I've always heard that metallic paints attenuate the signals. I might have to experiment and test that. Good to know!

 

[Antares JS]

Interesting. I've always heard that metallic paints attenuate the signals. I might have to experiment and test that. Good to know!

That can be true, but is not always. Like you said, test it and make sure.

 

[Antares JS]

Epoxy for eye bolts and charge wells, and epoxied the bulkhead into the nose coupler. The eyebolt will also be the bolt holding down the GPS sled inside the nose.

 

[Buckeye]

Interesting. I've always heard that metallic paints attenuate the signals. I might have to experiment and test that. Good to know!

No problem for me with metallic paints, either.

I think this is one of those TRF legends that may have happened one time 25 years ago, but never again. One poster in particular repeats this warning over and over.

 

[Antares JS]

Spent some time with a set of metallic paint markers today.

 

[NTP2]

Spent some time with a set of metallic paint markers today.

View attachment 647269

View attachment 647270

I did that yesterday, except I used paint brush’s, I like the hand made in a garage look they gave (at least when I use them!)

Ps and I have worse hand writing!

 

[Desfossr]

I’ve been following your build as I have a Wildman Jr. and am considering getting the 2nd stage upgrade. One thing I’ve been trying to understand is the wire routing for the sustainer starter. If I understand correctly, the Ematch wires are connected to the appropriate channel on the altimeter in the sustainer. From there, they travel out the aft end of the electronics bay, through the sustainer body and into the conduit. Upon exiting the conduit, they make the 180 degree turn and the Ematch head is placed into the motor as usual. That all makes sense. Where I scratch my head is that those wires are passing freely through the same section of airframe that contains the drouge chute and recovery harness. What keeps the wires from fouling the recovery gear? My apologies if I am missing something obvious. I’ve never done a two stage with electronics and really want to understand all aspects before I dive in.

 

[LGM-25C]

What keeps the wires from fouling the recovery gear? My apologies if I am missing something obvious.

You can tape it to the side and you put the break wire just under the ebay.

 

[Antares JS]

You can tape it to the side and you put the break wire just under the ebay.

Pretty much this.

 

[Antares JS]

Took the paint markers to the booster.

 

[Antares JS]

I did all the deployment/separation testing today.

Stage separation, booster parachute deployment, stage 2 ignition, and stage 2 main parachute all succeeded on the first try.

Stage 2 drogue failed on the first attempt because I did a bit too good a job rejoining the cut stage 2 igniter wire by twisting and taping it together. The wire did not come apart when the rocket separated. I twisted the wires together a little more loosely, giving it only two twists instead of five, and the second attempt was successful.

Tomorrow, I will be doing an electronics test to make sure the settings I have programmed on my Raven3 work the way I expect. After successfully completing that test, the Immaculate will be declared ready for flight.



I also mixed some Procast and dipped some 7' MJG's to make the stage 2 igniters.

 

[Antares JS]

Altimeter configuration testing has been successfully completed. The behavior was exactly as expected and all three e-matches lit at the intended timing.

Immaculate is ready for launch day.

 

[Antares JS]

After getting accurate weights and running sims last night, also using the bare minimum motors because of the fact that LDRS is likely to have a cloud deck the entire time, it looks like the first flight attempt is going to have an H550 in the booster and a Loki G94 Ice Blue in the sustainer, for a predicted altitude of just under 3000 feet. I'm assuming at this time that Loki Blue lights easily like Blue Thunder does. If anyone can tell me otherwise, warn me now.

 

[Antares JS]

WARNING: I just discovered that Kozmo Slim retainers, like I have in my upper stage, do not fit Loki motors. The aft end of the motor sticks out too far for the retaining ring to fit.

I reran my sims, and a G61W or G67R should work for the upper stage, but I was hoping not to have to try using them since Aerotech white and red propellant are known for being harder to ignite.

I have an H73J that I will use if the cloud deck turns out to not be much to worry about.

 

[Antares JS]

...Only to find that the head of an MJG firewire will not fit through the nozzle of a G61W.

I'm glad I thought to check all these little issues.

 

[NTP2]

...Only to find that the head of an MJG firewire will not fit through the nozzle of a G61W.

I'm glad I thought to check all these little issues.

Smarter than me, I’ll be building my first reload on site!

 

[Antares JS]

FFS. The H73J also has too small of a throat.

The smallest motor I have with a throat big enough for the e-match is an H219, but combining that with the H550 will send it to over 4500 feet. Normally I wouldn't have such an issue with it but we are trying to keep this flight low.

Assuming a cloud deck, I am going to knock the booster down to an H283ST. That brings the altitude to about 3400 feet.

I'm going to need to track down a slimmer upper stage igniter solution after LDRS.

 

[waltr]

I make thin igniters using 'wire wrap' wire and 40 ga Nichrome wire (easy to heat with 1S or 2S LiPo) dipped in Procast on 2nd stage motor.

For harder to light propellants, I paint a little Procast in the 'slot' on hole in the propellant before assembling motor to enhance motor lighting.

Biggest issue I have had is a long delay between Igniter firing and motor coming up to pressure. Best way around this is Lots of speed at booster burn-out. 100fps is minimum and prefer over 200fps.

 

[Antares JS]

Well, it's really just issue after issue trying to get this thing flown.

I was trying to prep it on Saturday morning at LDRS since it was the only day it wasn't going to rain, only to find I couldn't get the H219 far enough into the slim motor retainer in the upper stage to install the locking ring.

Even if not for that issue, I'm not sure I would have flown it as the wind and cloud decks were all over the place. It might be good when you brought your rocket out to the pad, but lower clouds and higher winds may have rolled in by the time they hit the button.

I checked when I got back and my upper stage igniters will fit into a G80, so my current plan is to build a low-profile 38-29mm adapter for the upper stage, put an H283 in the booster and a G80 in the upper stage, which will keep the altitude to only 2200 feet, and fly it at MDRA's Central Sod Farm on June 29-30.

 

[Kane]

Sorry you weren't able to get your launch in at LDRS. I was there too and was only able to get two launches in on Saturday. Winds were way too high for my 10k flight.
Regardless, I was able to get the sustainer shake down flight of my ARO-B two-stage in the air (sustainer only, no booster).
My plan has been to fly the sustainer only for a few flights, then try full stack with no air-start (dummy motor in the sustainer, but with the separation charge and air-start charge armed), then fly the full stack with air start. I seem to recall seeing this build up recommended by Jim Jarvis on a thread somewhere.
Curious if you've flown your sustainer only or if you're going straight to the two-stage

 

[Antares JS]

Curious if you've flown your sustainer only or if you're going straight to the two-stage

I'm just going straight to the two stage. The airstart is the only thing I'm not very familiar with pulling off. The altimeter is my Raven 3 that I've used for dual deploy flights for over six years and have already used it to control an event outside of dual deploy. I don't see much point in doing a shakedown of the sustainer by itself.

Also, with inflation straining everyone's budgets and the costs of AP motors outpacing inflation, I don't want to spend motors outside of doing an all-up flight. I've already ground tested the entire system, and I don't really have any interest in spending a motor to do a flight with a dummy sustainer only to see that it would have worked if I had a sustainer motor in the rocket.

That said, I have tried to make it as likely to work the first time as possible by using a fast super thunder motor in the booster and a blue thunder motor in the sustainer, since blue thunder is known for lighting easily.

 

[Antares JS]

I checked when I got back and my upper stage igniters will fit into a G80, so my current plan is to build a low-profile 38-29mm adapter for the upper stage, put an H283 in the booster and a G80 in the upper stage, which will keep the altitude to only 2200 feet, and fly it at MDRA's Central Sod Farm on June 29-30 August 24-25.

Launch delayed until August. I'm going to be out of town for work during both the June and July launches at the Sod Farm.