Talon 6

[troj]

Now it's back to that nifty av bay!

First up is getting the nuts onto the allthread. One of the joys of cutting allthread is the effect it has on the threads. Kent did a nice job of taking a grinder to the ends and getting rid of those nasty bits that seem to be flesh hunters. The threads were close, but I couldn't quite get a nut on the ends. So, a trip downstairs and run the ends through a 1/4-20 die, and voila! Nice, clean threads. It took me longer to get downstairs and find the die than it did to clean them up -- they were that close. Mine are never that close, when I do the cutting!

Now, one of the joys of this av bay is that it uses lock nuts (nuts with nylon inserts) on one end. I love these, and when I build my own bay, I use them -- I buy the buggers by the box.

The challenge is holding the allthread while you thread that locknut on. I haven't found a way, yet, to hold the allthread without destroying the thread. So, I use two nuts jammed together.

This av bay uses wing nuts on the "open" end, so what I did was run the wingnut on, then the nut that goes on the inside of the "closed" end. I used a wrench and jammed these together.



This gives me something to grip while I use a wrench to tighten the nut with the insert. So, the allthread gets a washer, then through the bulkhead sandwich, another washer, and finally that lock nut. Then the wrench to tighten it all down. Repeat with the other piece of allthread.



Finally, pop the wingnuts loose, snug down the inside nut one last time, and that part is done.

Next, slip it into the coupler, pop on the other bulkhead, put on washers, spin down the wingnuts, and it's done!



That's as far as I can get with the av bay until a couple more parts arrive. Those shipped out yesterday, so I expect them on Thursday or Friday.

-Kevin

[freddiejojo]

Mental Note: Secret Santas are forever to send Jon coal....

Okay, back to work! Bouncing around a bit, because, well, that's what I do.

First up is assembly of the piston. Never used a piston in a rocket before, but I know the mechanics of it. This one consists of a short piece of coupler tubing with a bulkhead and Kevlar. The Kevlar gets passed through a hole in the piston, then tied off on both sides, so that the piston can't move around on the cord. Shoving 1/2" Kevlar through a small hole is enough fun -- doing it when the Kevlar has been folded over on itself and sewn, to form loops, makes it even more fun. I cheated -- I enlarged the hole a smidge.

You see tape. That's there to keep the bulkhead in place at the bottom of the coupler, as well as keep epoxy from running out all over the place.

Attachment 88869

-Kevin

Kevin,

Make sure you get that piston secured so it doesn't blow past the shokcord knots. Words of experience.

Kent/GLR

[freddiejojo]

Kevin,

I'm surprised the threads in the one all-thread gave you difficulty. I check everyone before they go out.

Sorry,

Kent/GLR

[atxcple]

Mental Note: Secret Santas are forever to send Jon coal....

Bouncing around a bit, because, well, that's what I do.


-Kevin

NO NO NO This is too nice a project to bounce like the others....

[troj]

I'm surprised the threads in the one all-thread gave you difficulty. I check everyone before they go out.

No need to apologize at all, Kent! I expect it when I get cut pieces of allthread, and these are very close. I didn't mind, and I have the die, because I need it when I cut my own. Literally took me less than 30 seconds to clean up the threads.

-Kevin

[cwbullet]

Thank the inverter of a die kit.

[CarVac]

Whenever I cut allthread I just put a nut on before cutting it.

[troj]

Make sure you get that piston secured so it doesn't blow past the shokcord knots. Words of experience.

That would be.....unpleasant.

-Kevin

[troj]

After spending a few hours helping dad with technology issues, and acquiring incendiary devices to share with the kids tonight, it's time for a bit more building!

First up is the piston from earlier today -- the first batch of epoxy was from the inside. That's set far enough to remove the tape and apply more from the top. This is to make sure there's a good solid bond between the bulkhead and the piston body, as well as make sure there are no gaps that hot gasses can escape through.



Yet more of that nifty blue tape!

Here, it's being used to keep the Kevlar from getting epoxy on it.

-Kevin

[troj]

Next we turn to the nosecone, which gets a small bulkhead installed near the tip, which the recovery system is attached to. I started by putting some epoxy on the perimeter of the bulkhead, pushing it into place, then working to apply a fillet around the edge.

To say this was "fun" would be an understatement -- the epoxy I'm using for this has the consistency of thick molasses on a cold winter night. Plus it's sticky. Really, really, really sticky. In addition, I'm working inside the nosecone about 2 feet, so it's not easy to do, regardless.



The picture shows a bit of a gap on one edge. This means the epoxy has slumped down in a bit. I'll come back later and apply more, especially in that spot, to make sure there's a good, solid joint. If this fails, the nosecone goes into freefall which I put in the "bad thing" category!

-Kevin

[Pantherjon]

Nice progress!


Send on the coal! Then I wont need to turn on the furnace this winter, I have a fireplace! Tho I doubt the neighbors would like me burning coal to stay warm, but....

[o1d_dude]

Whenever I cut allthread I just put a nut on before cutting it.

This is what I do as well.

A little clean up with a file after the cut and Bob's yer uncle.

[troj]

There won't be any progress for the next couple of weeks -- I have some other committments that are going to take up my free time. I'll resume building when I get those taken care of.

-Kevin

[chadrog]

There won't be any progress for the next couple of weeks -- I have some other committments that are going to take up my free time. I'll resume building when I get those taken care of.

-Kevin

I'm sure you won't have to dig too deep to find the thread when you get back to it.

[atxcple]

There won't be any progress for the next couple of weeks -- I have some other committments that are going to take up my free time. I'll resume building when I get those taken care of.

-Kevin

Your turn to BOD sit Robin and Stu...

[cwbullet]

There won't be any progress for the next couple of weeks -- I have some other committments that are going to take up my free time. I'll resume building when I get those taken care of.

-Kevin

The dreaded pause. Oh darn. It will be worth the wait. Thanks for sharing.

[The Rocket Kid]

darn it was just getting interesting guess it'll be worth the wait

[G2Rockets]

There won't be any progress for the next couple of weeks -- I have some other committments that are going to take up my free time. I'll resume building when I get those taken care of.

-Kevin

Kevin,
Since you don't have time to work on it, I think you should bring it over to my house for safe keeping.

[Sailorbill]

Kevin,
Since you don't have time to work on it, I think you should bring it over to my house for safe keeping.

Yep I am sure Carmen would have it finished before Kevin returned from LDRS.

[troj]

Yep I am sure Carmen would have it finished before Kevin returned from LDRS.

Nah, I know for certain she has a big rocket she hasn't even started

[G2Rockets]

Nah, I know for certain she has a big rocket she hasn't even started

And she keeps blaming me for not being able to start it.
She can order shock cord just as easily as I can.

[blackbrandt]

Oh well, this truly tells me that I can't try and pass off rocketeers as very smart or intelligent.

[troj]

Okay, we're home from LDRS, and while I was away, the box with the last parts arrived.

Don't ask me exactly what they are -- I'm going on 2 hours of sleep after being up from 22.5 hours (I'm too old for that nonsense!), so I'm not exactly the most focused right now.

The first picture shows how it arrived, which is done to show how well packaged everything Kent touches is. The second shows the individual parts separated.



I'm reasonably certain that these components are used to build the bay the receiver from the modular av bay that I showed in an earlier post. I'll figure that out after some serious sleep, and post some pictures once I get building again -- building this on minimal sleep wouldn't be prudent.

-Kevin

[atxcple]

I know what color scheme you can use for it …. That U>>G>>L>>Y Hawaiian shirt would make a great wrap.

[blackbrandt]

Ouch

[troj]

After some actual sleep, time to work a bit on the Talon!

Remember those parts that showed up while we were on our LDRS trip? They're used to make the housing for the av bay. This collection of bits gets epoxied inside the tube, and is the receiver that the modular av bay slips into. The Kevlar bridles are used as the attachment points for the recovery system.

Kent did something interesting -- the recovery is attached to doubled up 3/4" centering rings, and the "outside" ring on each is a bit smaller than the "inside" ring. The difference isn't much, but it's enough to make sure there's epoxy fillets holding the "inside" ring into the tube, as well as making a solid bond between the "outside" ring and the tube. I cringe to think of what it would take to pull this thing out!

The process begins by epoxying the rings together, and epoxying one of the ring stacks onto the tube. The other stack will get epoxied on later -- its alignment is critical, or the av bay retaining screws won't all line up. More on that when I get to that step.



BTW, if you want to see what kind of a construction/design artist Kent is, take a look at one of his latest projects.

-Kevin

[troj]

Progress on the av bay receiver continues.

The first step is to install (or attempt to, when you've gotten epoxy in the threads of a threaded insert.... Thank goodness for 1/4-20 taps) the av bay into its receiver. This allows for finding the proper alignment of the second collar assembly, at which point a mark is made, to allow things to line up properly later.



Next, we remove the av bay and set it aside, then head outside to mix up epoxy and epoxy the collar ring in place, using the alignment mark made in the previous step to line things up.



You know it's hot outside when AeroPoxy ES6209 has the consistency of syrup, instead of molasses on a cold January day! The upside is that the epoxy is pretty well on its way to a cure in a couple hours.

-Kevin

[atxcple]

i know what you mean i just glued up a N2501 with gorrilla glue. that last grain was getting a little tough to push.

[troj]

A bit more progress. Today's effort entails the first steps of epoxying the av bay receiver into the upper tube. This one is a bit tricky, as you have to first slide the receiver 18.5 inches into the tube, then make a mark around the centering rings. Remove the receiver, apply epoxy to the spots in between the marks, then slide the receiver back in.

Since I'll have to pour fillets in around this later, I used thickened ES6209 -- the epoxy is already pretty thick, but in the heat, it's getting more runny than usual, and I need to make sure it stays put. So I mixed in some fumed silica. I then applied some inside the tube as well as around the centering rings, then slid the receiver in. It's now laying on its side in the sun, while the epoxy cures.



After the epoxy sets up sufficiently, I'll start moving on to the next steps.

-Kevin

[troj]

While the av bay receiver is curing, it's on to other assembly steps. In this case, the bonding of the motor mount into the tail cone.

There are two bonds at this point -- JB Weld to hold the Slimline into the tailcone (you want a Slimline for this rocket -- it fits flush to the bottom of the tailcone, leaving nothing exposed to muck up the rocket's lines), and epoxy to bond the bottom rings into the tailcone.

First, the Slimline gets scuffed up with sandpaper. Easier said than done -- that anodizing is tough! I started with 100 grit by hand, and that wasn't doing much, so I resorted to 80 grit on a palm sander, and that did some, but not a lot. But, it should be sufficient.

Then, slather a generous layer of JB Weld into the bottom of the tailcone and a generous coating of thickened ES6209 into the upper portion where the centering ring goes, slid it in, line things up properly, and let it cure!



-Kevin