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

jus_rockets said:

If you want extra assurance you can always put a locking nut on top of it

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Yuupp, good idea. Also the NC isn't exposed to anything until main deploy, that's usually so close to the ground there isn't that much time for it to unscrew.

I don't use them on my av-bay, but I know others do & they seem to work just fine.


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I cut my vent band in half, wasn't going to use it at all, but it fits so nice decided to keep it, but smaller.

Often overlooked is pre-fitting the parts. If you have been doing glass awhile ya probably figured that one out. Take some time to try each end of coupler into fincan, then payload. Many times it will work a specific orientation better that the other. Sometimes one end of payload works better for NC fit than the other.

My vent band definitely goes one edge best to fincan & the other to payload. Same for coupler.

Make sure to mark them so ya can tell later.

I could barely see the joint when I finally got the Vent band oriented after much twisting to fit. I knocked off a high spot or two with sandpaper to get the final result. It was worth it.

After getting the V-band in place, I marked the coupler NC & Aft for future reference. Being a black rocket, a lead pencil seemed to work best for seeing my marks, till I get some "key" marks on it.
I want this stuff to fit right when it's time to glue.

I will place the V-band closer to the payload end so more coupler is in the fincan, where it's needed, since the other end[payload] will be permanently attached during flight. This also gives another 1.5in of room in the already short payload.

Here's your Adapter:

Using 2 CR's
Section of coupler [75mm/3in.]
54mm motor tubing
3/8 Kevlar for recovery attachment.


Kevlar Y-harness is glued on motor tube just like any Wildman build. In this case just wrapped with tape after gluing for appearances.

Charlie O from Carolina Composites made this one for me & I'm thinking most of it's carbon, cause it's very light weight. He can describe what he did later.

Basically as you see in my mock up, just glue a tailcone retainer on MM tube and center CR on each end of coupler. Of course you must fit it as in any retainer & encapsulate the Kevlar harness in epoxy as I will, in this build.

The tailcone handles all the thrust stress as it fits to rear of airframe. Screw from railbutton holds adapter in place and prevents ejection charge from blowing it out of place.

Thanks Mike!


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First time you use it, drill through the railbutton hole into adapter coupler.

Screw railbutton through airframe into adapter, to hold in place.

If you are using a tower, space a couple of #8 set screw around airframe into adapter.

If ya want to use it in multiple rockets. Rotate it a bit and drill new hole/holes and mark for which rockets.

Very light & slick set up.


Last inch of my airframe is unpainted. I use foil tape to hold 75 motors inplace & it would pull the paint off.

Here are a few more Jim.



Mike

Mike....
Didn't you get over 10,000 something with that 54mm Jart on a 2grain?

Was that altimeter an Adept if I remember right.
Finally see if i remember what ya told me at the launch...

Jart hits apogee...NC pops off, out comes streamer....at 500[or whatever] little chute cannon fires & out comes main.

How tiny were charges & what contained In?

It was a fantastic utilization of space & it looked good too! LOl

Ps will have to do the "Pirate Group Launch" for a charitable cause, again next year! Twas a bit of look'n, but we got'em all back & had plenty 'O' fun.

Jim,

I got just short of 10,000', 9,864' on a 54mm 2 grain I-100 red about 9 second long burn CTI. (got a J 244 white coming for Thunderstruck)

Yep it was an Adept 22.

Yes at apogee there was a charge on top of the bulkhead on the 38mm chute cannon that blew off the nose cone which pulled the streamer that was rubber banded to the outside of the cannon tube.

At 700' the main charge blew inside the cannon tube blowing the 24" main out.

Charges where .5 gram of ffffg, poured into a corner cutoff of a plastic baggy & wraped up in tin foil. The baggy is there just to insulate the chage from the foil.

As for space, I believe I used it all. I don't think an ant would be able to move inside that thing.

Your right I think we'll had a bunch of fun with the launch, glad we got em all came back from 14,000 too. ARGGGG

I get mine at copperstate

I go the cheap rout and use a coupler nut from lowes and a forged eye bolt. If you cut off the threads on the eye bolt to about half an inch, then epoxy the bolt into the coupler nut it works about the same, just a bit longer.

FWIW I use blue loctite on the threads of the stuff I eventually need to unfasten.

I use the same technique for pretty much all of my nosecone bulkheads and all of my homebuilt av bays. (threaded rod through the middle, with a ghetto eye-nut on either end) and haven't had anything come undone yet.

Green Jello said:

CJ.....you cut down the length of the body tubes. What do you use to do this? Band saw?

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In this case, a chop saw with mason blade, but I have done it many times with just a hack saw and taking my time. The old Estes tube method, wrap a piece of paper around tube, to get a nice straight line. Tape to line and take your time with the cut. Sand a bit here & there to square it up.


My local hardware store [True Value] had the Eye nuts. Yuup..I've done the coupler nut and cut down eyebolt too. When ya find eye nuts cheap....I bought 4 for future use.

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Now all time boring, time consuming stuff, to prep for gluing. It will all become clear as I progress.

All sanding I use 80 grit floor sanding paper. This stuff is wet/dry and a sheet will do the entire build. I got it at Sherwin Williams, it's on a roll, sold by the foot. Best stuff there is [IMO]. Rental places for tools usually have it as well as most commercial stores. 2nd best is a belt sander belt cut into sections. That lasts a fairly long time also.

Sand the entire motor mount tube, it's just easier than figuring where stuff will be attached.
Sand CR's to fit, mine needed it, but that's what BUILDING rockets is all about, don't complain, just make stuff fit!
Sand CR's & tube till all the shine is off.

Place a CR on each end of MM tube, insert into airframe and mark where slots are. I used a mechanical pencil with the lead out a ways to reach in. Use a light touch, I broke the lead several times. If ya got a better way to do this.....I would like to hear it? A box cutter blade works on green glass, but not on the black so well.

So far leads the only thing I can see on black tubes, unless they are sanded.Then a Sharpie shows up So I went over my slot lines with sharpie.

I did the above to make placement of Y-harness & notching the top CR correctly.Ya could just lay the cord over a CR and mark to file, but I got this stuff, I'm getting old & use anything that helps.LOL

I made this from an old 8in CR & a compass. The lines with small circles are for 3fin rockets, 4 plain lines 4 fin [obviously] and LL for railbuttons or launch lugs. The hole in center allows me to bolt on a CR, to hold tube in place for marking to cut slots or visual fin alignment when gluing fins on. It will work for 29mm up to 7.5 tubes. After all the lines were drawn I clear coated it for posterity.

So I place Cr on end of tube, center my slot marks on the guide.

Mark for 2 lines opposite each other for Kevlar slots.


File slots in CR for recovery gear. Top CR only.

Place tails of 3/8 Kevlar over MM tube and slide notched CR into place. Make sure you miss slot positions or be in trouble later. You want 6-7inches of overhang.

Make sure when doing this to stretch out you Kevlar so there are no twists in it.


When finished stuff excess Kevlar into MM to keep it out of the way during gluing.


As ya can see, nice neat install, missing slots on both sides.

Set aside more to do before gluing. Have to fit retainer on other end.

Yes there is an overhand knot tied in other end to give me small loop to attach the shock cord.

Here's the tricky part if you want to do Black external fillets & are not painting. Just going with all black.
You don't want sanding marks all over the fin & tube, just where the fillet is going. Normally I'd be painting the rocket & it wouldn't matter. Here since I'm leaving it black , must be very careful, so some of my steps are out of normal order.

I want to tape fins and tube to protect from sanding marks so first I must decide how big to do fillets.
I'll use a 1in. diameter section of PVC to pull them smooth...so

Using a magic marker, coat an edge of PVC & rub it back in forth in the V-groove. [after first placing MM back into airframe and inserting fins, mine all fit, so no sanding needed in slots]
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EDIT: I HAVE NOW DISCOVERED SILVER SHARPIES......MAKES SEEING YOUR MARKS ON BLACK TUBING VERY EASY!!!! GET ONE BEFORE YOU START YOUR BUILD.

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It is really hard to see marks on black tube & fins, but they are there. Took several coatings & several passes to see it.

Click on images to enlarge & you can then see.

I then remove fins. Place them together to make sanding SOOO much simpler. Do a set a one time.

Finally tape them down to edge of table, so I can use my one finger as a guide on side of table while sanding.

This keeps the edge of paper straight & you are less likely to damage edge of tape.

Now I have a nice straight sanded edge for super neat fillets that will Fit EXACTLY.

Coming along nicely, Jim. Makes me wish I had bought one, just couldn't justify it when there is already an Intimidator 3 in the fleet.

I will post some pictures tomorrow of my addition to the "Glueless Nosecone." Basically, I am going to machine a shoulder for the metal tip, threaded for 1/4-20. This should help center the allthread. In my mock-up with the 4" Broken Arrow cone tonight, It was frustrating trying to keep the tip straight.

More tomorrow, meanwhile, keep up the great build thread!

There is a lot of extra prep to do if keeping your rocket black, so lets do the tube now.

TIP:
I'm going to inject the internal fillets, as I always have. To do so you must first drill hole to inject. You will find when drilling you get splinters that want to unravel on the inside & fuzzies that must be sanded out of the hole. You must also drill holes close enough to slot, to insure the exterior fillet covers them. I will eliminate these pests by simply filing a 1/2 hole, just large enough to get my trimmed syringe tip into.

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First tape off the lines from marker to sand for fillets.

Carefully sand area needed.

File out hole for injecting, no need to worry, will be covered by fillet. I just did one on each slot for this size.

I had my syringe handy to file holes to correct size. Since ya got to tinker with this build to get it right, might as well go all the way.

There is a lot of prep on this.....but worth it in the end. Now I'll finish all slots & fins.That will take a couple hours.

patelldp said:

Coming along nicely, Jim. Makes me wish I had bought one, just couldn't justify it when there is already an Intimidator 3 in the fleet.

I will post some pictures tomorrow of my addition to the "Glueless Nosecone." Basically, I am going to machine a shoulder for the metal tip, threaded for 1/4-20. This should help center the allthread. In my mock-up with the 4" Broken Arrow cone tonight, It was frustrating trying to keep the tip straight.

More tomorrow, meanwhile, keep up the great build thread!

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sounds very interesting, can't wait to see how you mod it.

Time to start gluing stuff!

I always seem to have left over glue when mixing small amounts, so I try to have extra things to glue ready.

After sanding the end of MM tube for the Aero-pac tailcone retainer, I also got the 2 sets of Av-bay lids ready.

Sand one side of each set.[ a large & small, combined make 1 lid or end cap.]


Lightly coat interior of retainer with JB Weld & thin coat on tube.
Insert MM with a twisting motion, slowly to distribute epoxy.

Carefully wipe any excess out of MM tube with rag & denatured alcohol. Set aside to cure.

You need Eye-bolt +2 nuts for this.

After sanding 1 side of each BP....

Spread a small amount of glue on 1 each Large bp....sanded side!

Place nut on eyebolt [to keep BP's square when tightened down later]

Stack large on bolt, then small, glue sides facing each other. Twist a bit to distribute glue evenly.

Add the second set same way..... DO NOT glue all 4 together!

Tighten down the second nut to hold in place during cure. Do not over-tighten, just snug, finger tight...ya don't want to squish out all the glue.

Ya can use 2 eye bolts if your not comfortable using 1 & fear gluing them all together
. Later I will stack them all, when drilling holes for tie rods, this keeps all in alignment when drilling.

blackjack2564 said:

Hey I'm out of that, my source in Uthornasia ran out.
Could I borrow some of yours Brad?:dark:

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Sorry all my unobtainium is set aside for my Dynacomm Black Widow kit...

UncleVanya said:

Sorry all my unobtainium is set aside for my Dynacomm Black Widow kit...

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"Hoarder"

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Installing the tailcone retainer and first CR, is crucial for a tight fit when motor is in place and cone is tightened. Ya don't want an ugly gap & hence non functioning thrust ring.

There is a lip on tailcone that fits inside the airframe & act as a thrust ring. There is no room for error. I place 2 CR's [each end]on MM tube, screw on cap and slide into position.

Unscrew the cap, should leave MM tube properly positioned.[unless your is a loose fit, then be real careful]
Tap the CR with screwdriver into position....i.e....you should just barely see the ring at end of all 3 slots. Then try screwing on cap again to be sure fit is tight to airframe. Adjust if needed.

Remember the CR's must be tight to fin when injection glue or they will leak, so if CR is behind slot there is no way fin will be tight against it. The edge MUST be peaking out a bit.

Now the tricky part.....just a drop or 2 of CA to hold that ring in place. Be CAREFUL don't glue the CR to airframe. Just on CR to mm tube.

If ya did it correctly, you will have a perfect fit of tailcone and the CR is in position to start stacking fins. I tried using measurements supplied with Aero-Pac, was only off 1/16 on one side. Just enough the retainer would not seat tight & had to bust loose the CR and start over, that's why I came up with this.

Green Jello said:

That's this model number, right?

https://www.wildmanrocketry.com/ProductDetail.aspx?product=1623

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Yes

After CA sets remove Motor mount assembly from fincan.

Remember those slot lines I drew on the MM? Here's where they are needed.
I always number slots, fins & lines on MM tube, when it comes time to glue, it will always fit perfectly. There is nothing perfect in all of the parts, and this takes that into account. Hand fitting stuff, building a rocket, not just slapping it together.

If your CR is loose, ya might need an extra set of hands.

Stack the numbered fins in their positions around the MM and slide CR down tight on top. Tack in position between fins,ya don't want CA running down, gluing fin on tube.[don't ask me]

Wait till CA sets, then remove fins, CR might be a tad crooked, that's OK & why we hand fitted. At least the CR is tight to fin, so glue won't leak when injected.

TIP:................

When injecting glue for internal fillets, the CR's must be tight and act like a small dam. No glue can leak under root after tacking fins in, & around the front and rear of fin, where it contacts the CR's. That's why all this precise fitting. There will be a small amount of chopped carbon fibers added, much like re-bar in concrete, to the epoxy while mixing.

First time is a bit much for some, after that the 2nd becomes a breeze and ya wonder why you haven't done this on all builds. Keeps the integrity of airframe intact, and has been used successfully all the way up to 12inch airframes & "O" motors.......so it does work!

Upper finset.

Gap between slots is 1.25in. { at least on mine. you should measure yours}

So measure from outside edge of CR & mark MM tube 1 1/4 in.
Wrap paper around tube [ala Estes ] and draw circle around MM.

Slide next CR on MM tube.
I wrapped a layer or 2 of tape around the line to have a lip for the CR to hang on while I tacked it with CA. & keep it perfectly straight. [forgot to take pic of that]

After CA sets, slide assembly into airframe ,& check fit.
You should now see 3CR's poking out the edge of slots.
If not go back and adjust.

Ready now for Upper Finset:

A bit tricky here cause the upper CR has the notches and holds the Kevlar.


Do same as lower set. Place all numbered fins into position, make sure your Kevlar tails are set & slide notched CR over all to hold in place.
Try to adjust for space next to fins for Kevlar.

Hold CR in place & tack with CA. Hold till set

I stuck all my fins in to admire, after the long afternoon.

I could build this thing in 2 days as some know, but thought since there were so many sold & a bunch of new guys, I could help them build a better rocket their first time out. I know it's a bit boring for you guys that have seen it before. BUT there are a couple of firsts......black on black.......tailcone retainer.......glue-less NC ...I've incorporated into the build, just to keep ya entertained!