Talon 6

[jimbo]

We will, and we'll try not to have too many jokes in your name.

-Kevin

Don't be fibbin' to me Kevin....yes you will.

[troj]

Don't be fibbin' to me Kevin....yes you will.

Yeah, but we've got Pat to pick on, too. And there's a whole lotta material there....

We'll save some good zingers for ya, though!

-Kevin

[freddiejojo]

Dear Mr. Bullet,

I think I can give you a pretty close idea what the full-up weight of Kevin's T6 will end up. Kevin requested 1/8" g10 for his fins which is pretty heavy. On my very first T6, I used .093 g10 with CF tip to tip on top ( 20oz worth). I used phenolic tubes with a total of 10oz of glass lay-up in three layers ( 6, 3 and 3/4 oz). His is going to be dual-deploy, mine are always apogee deployment having the booster and upper section come down on separate chutes. With two Adept altimeters and a Jim Amos (Missileworks) WRC2, TAC9b and a 84" chute lifted by an Aerotech M1315, we had a pad weight of 43.5lbs resulting in an altitude of 8,739 feet in March of 2001.

Kevin is a neat builder (doesn't slop on the epoxy) so I would not be surprised to see him come in around the weight I mentioned -1lb or +3lbs. Not bad for the size of a design.

Kent/GLR

[cwbullet]

Kent thanks. Great kit. I am ogling the kit on every post.

[troj]

Some minor progress today -- this has been a multi-day, a little at a time thing of foaming the area between the av-bay receiver and the main tube.

One of the keys is to mix small batches and let it expand, rather than mixing a great gob and dumping it all in at once -- the latter will give you cracked tubes and a complete mess.

Part of it, also, is understanding that each brand/type of expanding foam is different. I have a gallon I bought from someone which is a brand-unknown. It expands less than other foams I've used, but it also expands more slowly.

Here are a couple down-the-tube pics that show that the foam didn't come pouring out of anywhere, which is a good thing!



And finally, we discover that the Talon has an outie!



Next, I need to finalize how I want to do the switches for the electronics. I've been chatting a bit with Kent about how he likes to do it. I need to decide what I want to do, and I need to do so before I fiberglass this tube.

-Kevin

[troj]

On the arming switches, I've made a decision -- I have some of Adrian's Featherweight Screw Switches on order. I'll mount those on the sled such that I can reach them through the vent holes in the airframe.

Of course, that begs the question -- how to line up the darned vent holes? There are those who are good at measuring and marking, and getting it just right. And then there's me. I can get it within an inch, but that doesn't work.

So, my plan is to assemble the altimeter sled, then attach a block of foam, or some clay, to the board and slid it into place. I'll then poke a screwdriver through the hole, making a dimple in the foam or clay. Then, when I pull the sled back out, it'll show me where the arming screw needs to go. Should work well, I think.

I'll post pics when I do so.

-Kevin

[freddiejojo]

Mr. Skillet,

Banging great idea. I'm keeping that one.

Kent/GLR

[SinfulDarkLord]

This Talon 6 is inspiring me to get one. One day perhaps. Awesome rocket.

[UPscaler]

So, my plan is to assemble the altimeter sled, then attach a block of foam, or some clay, to the board and slid it into place. I'll then poke a screwdriver through the hole, making a dimple in the foam or clay. Then, when I pull the sled back out, it'll show me where the arming screw needs to go. Should work well, I think.

I'll post pics when I do so.

-Kevin

That should do it! Another way is to get a dowel that will fit through the vent hole, dip it in ink, and make a mark through the vent hole where the switches will go. Either way, it works!



Braden

[DM1975]

I like the clay idea. I generally just measure and get fairly close, but I am always just a bit off.

[troj]

Banging great idea. I'm keeping that one.

Glad to be giving you something back, Kent! Goodness knows I've gotten some new ideas about how to do things from this kit!

-Kevin

[G2Rockets]

Kevin,
I am having a problem with visualizing the size of some of the components... What size kevlar is being used? Is it sewn completely?

John

[troj]

I am having a problem with visualizing the size of some of the components... What size kevlar is being used? Is it sewn completely?

The only place the harnesses are not sewn is where I tied knots above and below the piston, and where I'll tie the Kevlar on to the delta links. Everything else is sewn, and sewn quite robustly. I don't have the harnesses in front of me to measure, but I'd estimate an 8" length thoroughly stitched at each point.

Drive to Bellevue and I'll let you see it, to help with that scale issue.

-Kevin

[troj]

New parts!

The new Delta links, plus another Y-harness to provide a redundant recovery system attachment point for the booster.



I'll get these attached later today, then progress a bit more on the build.

-Kevin

[freddiejojo]

Dear Mr. G2,

I don't want to step on Kevin's feet, but I will try to fill in some gaps. All the tubular Kelvar used in the entire kit is 1/2". The length mounted on the motor mount tube is 14 feet long. Kevin will begin by finding the center of the length and threading each end down opposite sides of the mmt assembly. At the top he will take one end and first loop it around a ubolt (let's call it the port side) and then thread that same end through a provided adjacent opening, continuing on going through a second opening (in the mid c-ring) and finishing at the very bottom c-ring assembly where he will be using an "anchor knot to attach onto the mounted u-bolt. Now go back up to the top and do the same routine with the opposite end going down the starboard side. That very bottom assembly where he will tie off on is half-way down into the tailcone. Obviously, it won't take fourteen feet to do that, but the excess makes for a nice attachement point for the twenty-five foot sewn GLR 1/2 Kevlar shokloop. But because I'm manic, Kevin will also take the just received "Y" harness and attach the two "arms" of the Y to the same upper ubolts and utilize the loop on the "leg" in conjunction with the extra length of the 14' Kevlar to connect the 25' Kevlar shok loop which he can either attach to the upper av-bay (as described next) or simply to a parachute and have the booster come down on one chute and the upper section on a second chute. But I'm pretty sure he is going to do "high/low" deployment so we will continue.

Now jump up to the av-bay in the upper airframe. On both sides of the assembly are two ubolts with a "Y" harness mounted on each. Odds are Kevin will be connecting the twenty-five foot booster shok-loop to the aft side and there will be a fifteen foot shokloop connected to the upper side "Y" harness to the nosecone.

Kevin could, if he wishes, attach his parachutes directly to one of the appropriate ubolts. But the kit comes with two, 3' x 1/2" Kevlar Shokloops. The first one slides onto the twenty-five foot shokloop one third of the way down from the upper ariframe attachment. To prevent it from sliding, Kevin will be doing nothing more than tie one simple overhand (granny) knot over the three foot loop end, locking it into place. From the opposite end of the three foot loop, he will be connecting his parachute. The same proceedure will happen on the top shokcord connection as well.

Why the three foot loops coming off the main shokloops? My first rocket kit in 1994 from Ross at Magnum (yea!) was made by a company called "Cluster R" and was a four inch Sandhawk. They used an attachment method similar to this explaining it was a way to get the parachute away from the mass of the rocket quickly reducing the chance of fouling with the rocket. Does it work? All I can tell you is it hasn't failed me yet.

Please say tuned to Kevin's build. Some of the neatest methods in his contruction are yet to come. Just wait until he gets to the nosecone.

Kent/GLR

[atxcple]

Please say tuned to Kevin's build. Some of the neatest methods in his contruction are yet to come. Just wait until he gets to the nosecone.

Kent/GLR

KEVIN That’s the pointy thingy....... not the bucket your probably sitting on

[G2Rockets]

KEVIN That’s the pointy thingy....... not the bucket your probably sitting on

[troj]

Oh, Quicklinks, how I love thee!



This picture shows the Kevlar properly tied to the deltas, and the "tail" then wrapped in tape to keep it safely out of the way.



Here we see the deltas attached to the U-bolts. I then used a box end wrench to make sure the links are nice and tight, as getting at them would be non-trivial!

As an aside, a comment about the delta links I received from Giant Leap... Years ago, a rigger buddy of mine was telling me a bit about quick links, and the fact that like any such material, they're not all created equal. He gave me a tip which he uses when rummaging through bins at hardware stores, to find which links are good, and which are questionable, or possibly junk.

His trick? Look for the French writing -- if it says "Maillon rapide" on the side, that helps identify the ones that are truly load rated.

Guess what the ones I got from GLR are marked? Yup! The French writing is on there. Quality links.

Now, back to the build! Next up, I need to scuff up the shoulder of the nosecone a bit, get some epoxy mixed, and get the lower section assembled. When I show those pictures, I'll also post a pick of the nifty Y-harness that I got from Kent, as well.

-Kevin

[freddiejojo]

Dear Mr. Skillet,

I hope I can survive this forum build; I was expecting you to say the links had "shucks-strong" in redneck on the side.

Kent/GLR

[kruland]

This picture shows the Kevlar properly tied to the deltas, and the "tail" then wrapped in tape to keep it safely out of the way.

<img src="http://www.rocketryforum.com/attachment.php?attachmentid=91845"/>

Kevin,

What knot is this?

Kevin

[troj]

What knot is this?

It's the one I tied!

It's an anchor knot, which is what the instructions specify. They're even good enough to give a nice diagram on how to tie it!

-Kevin

[DM1975]

Was hard to tell on that flat Kevlar. I wanted to ask too. Almost looked like a cow hitch with a stopper or some other contraption of a hitch knot.

[troj]

Today, I started working on the venting for the av bay. I have a pair of Featherweight screw switches I'm going to use, so I need to holes through which to access them. The kit comes with a brass sleeve for one of them; I have more brass tubing with which to make a sleeve for the other.

The first order of business is to install part of the av bay, so that I can see exactly where the sled will line up -- it doesn't do me any good if the holes go straight into the side of it. Ideally, they come out just a bit above, so I can easily mount the switches.

The problem? When I foamed the area between the av bay receiver and the tube, one of the threaded inserts filled with foam. You can see it in the top left of this picture.



The foam is pretty dense, plus the hole is entirely filled, so it's not possible to just run a screw in and force it to compress. So, out comes the 1/4-20 tap, and I ran that down into the hole, to clean it out. The challenge is leverage, since there's so little room to work. To fix that, I put a short bolt (one of the ones for holding in the av bay fit perfectly!) through the handle for the tap, and that gave me just enough to grip.



After that, I was able to install the plate with the all-thread for the sled, and secure it with 1/4-20 screws. This gave me a reference line, with which I could verify hole locations.

First hole drilled, and the brass tube slid it, to verify it lines up where we want it. Looks good, so far!



I repeated the same thing on the other side, then roughed up the tubes, epoxied them into place, then cut and sanded them flush with the surface of the tube. One more bit done!

This tube still needs fillets on the inside, along where the av bay receiver is mounted into the tube. Applying epoxy 18 - 20 inches down inside a tube is always a good time....

-Kevin

[cwbullet]

It's the one I tied!

It's an anchor knot, which is what the instructions specify. They're even good enough to give a nice diagram on how to tie it!

Awesome link. It shows my two favorite knots. The bowline and anchor are awesome rocketry knots.

[troj]

Next up are proper fillets around the av bay receiver, to make sure it doesn't pop loose. As you will recall, the centering rings on each end are actually a double-stack of 3/4" rings, with the "outer" ring being just a small amount (I'm guessing 1/16") smaller than the "inner" ring. This is to allow a solid fillet to be formed, without creating a lip inside the tube that causes problems with getting the av bay plates to seat.



The red arrows are pointing to the small gap that needs to be filled with epoxy.

The challenge here is that I'm working 18" in from the end of the tube on one end, and about 22" or 25" in from the end on the other. How to get epoxy in there, without getting it all over?

That's easy, with the right tools!



This nifty little gizmo is nothing more than a catheter tip syringe with a length of aquarium airline tubing attached, and the free end of the tubing taped to a dowel. The dowel lets me control where the end of the tubing goes, and the syringe makes it easy to push the epoxy through the tube.

I'm using slightly thickened epoxy for this -- thickened a bit with fumed silica to give it more structure, but not thinned so much that it's difficult to push through the tube, or get to run into the gap.



After it's done, if you compare this picture to the first one in this post, you can see where the epoxy is filling the gap nicely, without coming up on top of the centering ring.

Once this sets for about 90 minutes (60 minute pot life at 85 degrees, 90 minutes and it'll be set enough to not move), I'll flip the tube over, and repeat the process.

-Kevin

[dixontj93060]

Good idea on the extended syringe.

[troj]

No, the Talon hasn't faded into the distance. There have just been some other things going on!

Today was the "fun" stage, where I did final assembly of the lower section. There are multiple bonding points here, the first of which is the tailcone into the tube. Since the tailcone has gelcoat, which is very smooth, there's not much for the epoxy to "grab". To resolve that, I took the Dremel and put numerous quasi-diagonal gouges into the gelcoat, to give it some "tooth" for the epoxy to grab.



I then used an applicator to put a thin coat of epoxy on the centering ring that goes at the bottom of the coupler -- it goes into the tube first, so it needed epoxy first. A corresponding thin layer where it bonds to.

Next, I used an applicator to spread a thing layer on the bonding surface of the tailcone, as well as the corresponding surface of the inside of the tube. Then, slide everything together, while keeping tension on the Kevlar so it doesn't get epoxy on it. The result? Epoxy runs!



The run is actually a good thing, as it means there's enough epoxy to form a solid bond, and the extra is getting pushed out. That gets wiped off, and the surface cleaned up, so it doesn't leave a mess.

I then used a syringe to put in a little epoxy at the top of the middle ring, then spread a layer on the top ring as well as its surface, then inserted it into the tube. The Kevlar gets stuffed down into the motor mount, to keep it from getting epoxy on it, as things cure.

The final result? One lower section, read for the next step!



-Kevin

[dixontj93060]

Kevin, are you planning on reinforcing/filling the tailcone/airframe seam? Or leave it "as is."

[troj]

Kevin, are you planning on reinforcing/filling the tailcone/airframe seam? Or leave it "as is."

Good question!

The instructions actually address this, and suggest fiberglassing over the joint. Since I plan to fiberglass the entire tube, I've intentionally held off doing so, until reaching this point -- I'll just wrap the entire thing, including an inch or two of overlap.

-Kevin

[troj]

There are points in a build where it's hard to be the excitement of a particular step. This is one of them!

Today step is brought to you by the letter Z, and entails applying fillets to the joints on the top bulkhead in the lower assembly. This is a mixture of fumed silica and epoxy, to something a little less than peanut butter consistency.

First, I mix the epoxy, then I spread a thin layer over the bonding surfaces, so it can penetrate. I then add the filler to the epoxy, mix, and apply. Pretty isn't easy, or as critical, at this point. The important part is keeping it off of the Kevlar!



After application, the rocket gets wedged up against the deck rail with a chair -- it's 100F out, and the epoxy will set fairly quickly in this heat, which is a nice feature.



Why the chair, you ask?

Because last night, I left it standing on the deck near the grill, without any support. It was calm out, so I figured there was no problem....until something happened.



Wind kicked up just long enough to knock it over such that it went down the stairs, and that happened.

So, I'll put some thickened epoxy on that, later.

-Kevin