CJ's "HOW TO BUILD A DARKSTAR 3 OR ANY GLASS KIT BUILD" STARTS

CarVac said:

It might, but what of it? G10 is heat resistant.

Click to expand...

What he said, actually I lay the charge flat to BP when ready to fly. There are many doing this with wood BP's [including myself, it's never been a problem so far.

Interesting using finger tips for the BP charge. I skip 'em and just use tape. Lay a 1.5" x 3" strip of masking on the scale, sticky side up, add my BP in a pile in the center of the first 1.5x1.5" area (i.e. half of the strip), lay the match head in the center of the pile, fold the unencumbered half on top of the encumbered half and seal the edges like a black powder ravioli. Then fold the two "sides" in to make the package 0.5x1.5 and run a piece of tape around the assembly, about 1/2" down from the end so that there's 1" of tape holding the BP package together and 1/2" of tape to "double seal" the end where the match leads go in.

The big advantage is that I don't end up with epoxy on my fingers the next time I use the gloves. :lol:

blackjack2564 said:

THAT ONE WON'T WORK...... IT CHIPS RIGHT OFF....NOTHING STICKS TO POLYPROPYLENE OTHER THAN TAPE.....AT LEAST WITH WHAT I'VE TRIED SO FAR.LOL

Click to expand...

Sharpie?

blackjack2564 said:

Yes..just good old masking tape.

Click to expand...

That is amazing. So not even high temp masking tape: https://www.tapecase.com/sd/tapes-die-cuts/1070/1/1/0.0/masking-tape-high-temp.aspx

JordanT said:

Looking at your wiring, it seems to be all solid conductor. I had several of my solid core connections break (over time) at solder joints and I'm seriously considering stranded for the next build to avoid that failure mode.

Click to expand...

He wires the e-match leads directly to the altimeter. New wires each flight

Tom and Jim taught me this technique using the e-match directly wired and it in my mind makes less room for error by having less connections for error or short.

cwbullet said:

Tom and Jim taught me this technique using the e-match directly wired and it in my mind makes less room for error by having less connections for error or short.

Click to expand...

I have done it both ways. The one downside to direct wire that I have seen is that it offers no strain relief if something happens and the charge is snagged on something and pulls the terminal block. It's a pretty small issue but one I have seen in practice once or twice.

Good point. I always try to leave slack.

cwbullet said:

Good point. I always try to leave slack.

Click to expand...

I think another option that might help that I have tried is to loop around the base of the eyebolt so that if something tugs at the wire it has to pull there first.

blackjack2564 said:

You'll like it. Doesn't get hard like clay over time, & very cheap. Tommy from Adept showed me this trick. He comes to our launches. If you have a problem bay....stick some on the inside also, I do that on my high flying minimums.

Click to expand...

Silly putty works well also.

UncleVanya said:

I think another option that might help that I have tried is to loop around the base of the eyebolt so that if something tugs at the wire it has to pull there first.

Click to expand...

This is exactly how do it, but I also leave slack so it does not break the wire when I assemble the av bay.

I have used silly putty and concur it works. Both it and the adhesive putty can get messy in high temperatures.

View attachment 111706

blackjack2564 said:

Here's the whole shebang laid out and ready to pack.
I just wish someone had shown me all these simply every day ways, when I started. Would have saved me many a burnt chute & cord. Hope ya likey.

Click to expand...

What is that green chute? Rocketchutes.com?

Green Jello said:

View attachment 111706

What is that green chute? Rocketchutes.com?

Click to expand...

Looks like Top Flite to me. But I guess we should get it from the source.

If there was a prize for the most helpful/thorough build thread ever this one would definitely be in the running. More than even the basic construction techniques I think all of the finishing and setup tips here really add to the pool of knowledge on TRF. Thanks for all your time and effort to shine the light Jim!

cwbullet said:

This is exactly how do it, but I also leave slack so it does not break the wire when I assemble the av bay.

I have used silly putty and concur it works. Both it and the adhesive putty can get messy in high temperatures.

Click to expand...

The stuff I use most often is actually a fire resistant putty used in commercial applications - it holds up fine in every situation I have used it in.

Green Jello said:

View attachment 111706

What is that green chute? Rocketchutes.com?

Click to expand...

It's a 50in. Topflight

beezwax said:

If there was a prize for the most helpful/thorough build thread ever this one would definitely be in the running. More than even the basic construction techniques I think all of the finishing and setup tips here really add to the pool of knowledge on TRF. Thanks for all your time and effort to shine the light Jim!

Click to expand...

Thanks..it started as just a build thread. As I got farther along, I realized that there were so many of these sold to first-time buyers of fiberglass, I decided to make it the tell-all of builds.

Every little trick & short-cut I learned in my many years, so it could be found in one place for future reference. How many times have you seen the same questions asked over & over as the years go by. Not that it's bad, just new folks coming along all the time. Answers in this thread & that or re-typing answers to already asked question from the past.
Now I can just refer back to this thread in the future. I will probably ask that it be cleaned up by a moderator[ meaning the first several pages not pertaining to build be eliminated] & placed somewhere as a sticky.

Not that this is the "end all" of builds. But pretty much covers everything to some extent.

I've been sanding and painting last couple days, waiting for the RRC3 beta & LCD to come in so I can mount it for the "Black Pearl's" maiden flight!

Will document fight readiness & the rest of stuff with pic then.

Decided to go with a "Pyrate" theme. Mostly black with yellow fin tips & accents. Maybe a bit of red highlights, skull & bones & Black Pearl in "pieces of eight font" from Pirates of the Caribbean.
If ya run into me at a launch somewhere & throw down the "challenge". I'll give ya one of the skull & bones stickers for your rocket, to show "YOU TRIED" to out-run the Pearl..LOL A tradition just started at MWP with the Pirates Drag Race.

"ye lilly livered, bilge water drink'n skoundrals!" Aaarrgg.....

I love the name.

blackjack2564 said:

Impossible to get good photo's of this step due to black on black, so I use a previous build pic to explain.

You want the 3 rivet locations BETWEEN the vent holes, so there is NO turbulence from rivets, screwing up altimeter readings.
Rivet locations are 1.5in from edge of payload, drill holes with 5/32 bit. Not all rivets are same, some have tiny ridge on them making a tight fit. You may have to ream your holes with bit to get rivets in.
Drill first hole, insert rivet, then move to next location, do the same & so on.
Do NOT try to drill all holes first, this rarely if ever works. Do them one at a time, inserting rivet as you go.

To do this on the black tube I wrap a piece of tape around payload, to mark on.
First I mark the 3 positions where vent holes are, using lines on coupler.[pulled out of payload enough to see lines, not shown in pic]
Then double mark those lines so they cannot be confused with rivet locations lines.[next]

Then rotate the coupler with lines BETWEEN previously drawn set, and transfer marks to tape.
These will be the rivet locations, drilled 1.5 in from edge of tube.

Finally drill into joints between sections, just enough to be seen through a couple of coats of paint.[ I use a smaller bit for this,1/8] These are your"key" marks to aid putting it all together during rocket prep for flight.
As you can see I got such a nice tight fit, you can barely see all the joints, when pushed together. It takes a bit of extra time to pre-fit all this, but if you give a rats a$$ about it.....well worth the effort.

There ya have it......perfect fitting Av-bay.

Click to expand...

Another noob question. In this, the "rivets" are shear pins, correct? Also, where do you get those black ones?

Green Jello said:

Another noob question. In this, the "rivets" are shear pins, correct? Also, where do you get those black ones?

Click to expand...

No, they are actual automotive rivets. I get mine from Lowes, but they seemed to stop carrying them.

Green Jello said:

Another noob question. In this, the "rivets" are shear pins, correct? Also, where do you get those black ones?

Click to expand...

These are what you're looking for:

https://www.apogeerockets.com/Building_Supplies/Misc._Hardware/Removable_Plastic_Rivets

https://rocketrywarehouse.com/product_info.php?products_id=171

They're available in larger quantities for a cheaper per item cost from many tool/hardware stores, McMaster-Carr etc. I bought a large pack from Zoro Tools a while back. Pay attention to the specs though, as they come in different sizes depending on what wall thickness you wish to secure.

I'll let Jim answer how he does it, but here's how I use them:

The upper "payload" airframe and the AV bay are to stay permanently attached for the whole flight. These are what the rivets are for. They are removable so as to allow you to properly setup and arm the AV bay prior to flight. But once you place the AV bay in the payload airframe, it stays there.

So, at apogee the aiframe splits with the fincan seperating from the AV bay (shear pins may or may not be used at this point). The nose cone, payload airframe, and AV bay stay together, with the nose cone being held in by shear pins, and the AV bay being held in with rivets. At mains deployment, the nose cone is ejected (breaking the shear pins). So now you have three assemblies - the fincan, the AV Bay/payload airframe (held together with rivets), and the nose cone.

The rivets are meant to NOT break, and the shear pins ARE supposed to.

On the ground after the flight, you can pull the rivets and take the AV bay out.

Hope this makes sense, s6

When you join any two sections of your rocket you have three options:

1) A permanent connection that you cannot open later, such as an epoxy joint.
2) A connection that remains secure throughout the entire flight, but which you are able to open pre/post flight (to access an Av-bay for example) such as the removable rivets being discussed...other folks simply use machine screws and some variety of a backing nut to secure these transitions.
3) A connection that you wish to release or open at some stage in the flight, the simplest example of this being a friction fit nosecone...it's connected to the airframe during boost and coast, then is pushed out by the ejection gases. But you can get in trouble with simple friction fittings, for example drag separation causing your connection to pull apart before you want it to, or expanding air volume in an unvented airframe pushing them apart. Shear pins are a more certain way to control the separation timing for this type of connection, because they are strong enough to prevent the joint from falling apart or dragging open early, but are designed to break (shear) open when you want them to from the force of the ejection gases.

Exactly which type of connection you want to use at any given joint depends on the design of your rocket....stealth6 describes a very typical dual-deployment design.

All of the above answers are good..... if your gonna fly rocket for awhile ya need to know about this site, [almost] ANY thing you want can be found here:https://www.mcmaster.com/#push-rivets/=kypcl8


As stated Rivets are rivets. [for holding things together semi-permanently, they can be removed & re-used for many, many flights]

Shear pins are shear pins. [used once, they break/shear as designed. new ones used for every flight]
I haven't got into shearpins yet as I am still waiting for my NC to arrive.

You don't mix the two.
They come in packs of 50 or 100, by far the cheapest way to buy.

Edit: some folks use RIVETS to hold a nose cone on a payload, that is NOT for dual-deploy. Such as carrying experiments or an altimeter that is read altitude only. In this case the rocket uses motor eject for parachute deployment. They want a solid hold, but yet removable & re-usable. Shear pins are not for this[generally, got to cover my butt here]

I think this is where your confusion comes from.

For our use here.... it is:
Dual Deployment..........................
Shear pins in NC
Rivets or screws to hold av-bay on payload.

Forget everything else you are reading..... call/write them for their explanation, we can't speak for them. I don't get Apogee's explanation nor do I care. That's not the way any of us I know use them. For transportation, common sense tells ya to leave them in & just pull the upper-half apart with av-bay still attached....otherwise all your gear can fall out.
Like I say many times......"there are many ways to do this, none right or wrong" I just think the description here is one of the most no-nonsense...common sense approaches.
Judging by how many folks use it, that speaks for itself.

These are the ones I use below.

Hmm yeah sorry if I made things more confusing instead of less, I was just linking to a couple rocketry retailers that stock these rivets. I didn't actually read the description on the Apogee site, I'm not sure what they're talking about with transportation to/from the range.

blackjack2564 said:

You want the 3 rivet locations BETWEEN the vent holes, so there is NO turbulence from rivets, screwing up altimeter readings.

Click to expand...

How should these line up with the fins below? Rivet in line with fins? Vent holes in line with fins? All three on different lines? Doesn't matter at all?

Green Jello said:

How should these line up with the fins below? Rivet in line with fins? Vent holes in line with fins? All three on different lines? Doesn't matter at all?

Click to expand...

My guess on this one...probably doesn't mater because the fins are below the vent holes. Looking forward to what more experienced flyers have to say though...

Also, a question for Jim--you said that we can get anything at McMaster-Carr. I've looked in vain for a bulk source of the nylon rail buttons, hoping thayt they are some industrial product. Besides our rocketry vendors (who I do support with kit and motor purchases), are there other places to get these?

Green Jello said:

How should these line up with the fins below? Rivet in line with fins? Vent holes in line with fins? All three on different lines? Doesn't matter at all?

Click to expand...

On my Blackhawk, I have the rivets for the AV-Bay aligned with the fins. While the vent holes halfway inbetween the fins, my guess is it does not matter.