Giant Leap Vertical Assault build thread.

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Bat-mite

Rocketeer in MD
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Last night I started the build of my Giant Leap Vertical Assault. Here is the beginning of the promised build thread.

First, the parts:
IMG_0358[1].jpg IMG_0360[1].jpg

FIRST NIGHT

Step one is to J.B. Weld the tailcone and aft centering ring onto the motor tube...
IMG_0362[1].jpg IMG_0363[1].jpg

...being careful not to get any adhesive inside the motor tube.
IMG_0364[1].jpg

SECOND NIGHT
I already had an assembled 54mm to 38mm motor adapter from my earlier, shredded rocket, seen here beside the motor tube assembly.
Pencil mark on the motor tube is where the top of the fin can will be.
IMG_0365[1].jpg IMG_0366[1].jpg

Used 30-minute epoxy to adhere the fin can to the motor tube, and top it off with the forward centering ring, also 30-minute epoxy.
IMG_0367[1].jpg IMG_0368[1].jpg

And that's where I am right now. Once my epoxy has set, I will assemble the Fireball Zipper Stopper, epoxy the lower shock cord to the motor tube, and slide the slotted booster tube over the motor tube assembly and into the tailcone.
 
Thanks for the build thread, keep it up!!! Definitely not as much fun to do as it is to read. I voted FOR this thread, although not an extremely complex build it is nice to see a builder's perspective of a kit, how the parts actually work together, and sometimes interesting and useful deviations from the instructions.
Good luck, looking forward to the launch pictures/report. :pop:
 
Last post for DAY 2.

Here is the assembled Fireball.
IMG_0369[1].jpg

I laid out the parts to measure the aft shock cord so that the Fireball would be at the right location on deployment.
IMG_0371[1].jpg

I cut the cord to the right length, glues it to the motor tube with 5-minute epoxy, and duct taped it into place. After assembly, I will leave the duct tape on as it doesn't hurt anything.
IMG_0372[1].jpg

Attached the booster tube to the motor tube/fin can assembly using 30-minute epoxy. This gave me time to mix up a big batch and use a generous amount. Couldn't get this to upload with a vertical orientation.
IMG_0373[1].jpg

But because of the 30-minute set-up time, I had lots of drips to wipe away with alcohol.
IMG_0374[1].jpg

Finally, here is the Fireball sticking out of the top of the booster.
IMG_0375[1].jpg

Tomorrow night is date night with the wife :horse:, so I probably will not build anything or post anything. Check back late Saturday night.
 
Subscribed. Is the Fireball a 'chute protector? It looks Kevlar. I think I will look it up.
 
Subscribed. Is the Fireball a 'chute protector? It looks Kevlar. I think I will look it up.

It's a zipper stopper. It is a foam rubber ball covered in a Kevlar sleeve. Prevents the aft shock cord from ripping down the side of the rocket if you get an accidental drogue deployment during acceleration (pre- or post-apogee). You still need to protect your chute, as it is between the Fireball and the aft deployment charge.
 
this "fireball" concept is new to me. Thanks for the build thread! great pictures!
 
It's a zipper stopper. It is a foam rubber ball covered in a Kevlar sleeve. Prevents the aft shock cord from ripping down the side of the rocket if you get an accidental drogue deployment during acceleration (pre- or post-apogee). You still need to protect your chute, as it is between the Fireball and the aft deployment charge.
Oh ok, it makes sense.
 
THIRD NIGHT

Went to a launch Saturday. Today (Sunday) played in church band, then cut the grass, then chased after my kids on bikes. Really wiped out tonight. But here I am with an update.

Tonight was an AV bay build. Started with laying out the parts:
IMG_0376[1].jpg

I replaced the curled metal eyebolts that GLR gives you with some forged eyebolts from Grainger.
IMG_0377[1].jpg

I used the threaded rods to center the bulkheads, then attached the eyebolts.
IMG_0378[1].jpg IMG_0379[1].jpg

Here is the threaded bay with the brass sleeves on the allthreads. The sled is next to the unit. Then I CA-glued the bulkhead halves together around the joint.
IMG_0380[1].jpg

Next I tacked the sled onto the brass sleeves with a little CA glue.
IMG_0382[1].jpg

Finally I epoxied the brass sleeves to the sled with 30-minute epoxy.
IMG_0383[1].jpg IMG_0384[1].jpg

Still to go:
  1. Epoxy the coupler to the upper stage.
  2. Attach the conformal launch rails.
  3. Decide what to do about tracking. To modify the nose cone or not to modify the nose cone.
  4. Assemble the recovery electronics.
  5. Fill the spirals.
  6. Do fillets on the fins.
  7. Sand and paint and sand and paint and sand and paint...

Hopefully I get #1 and #2 done tomorrow.
 
FOURTH NIGHT

Tonight was devoted to two things: 1) epoxying the AV bay coupler into the payload tube; and 2) applying the conformal rail guides.

In the middle of my build session, my main camera ran out of battery. I had to switch to a cheaper camera mid-stream, and so some of the pictures in the latter portion of this post are a little blurry. Sorry about that.

Epoxying the AV Bay Coupler to the Payload Tube
Before I epoxied anything, I assembled my AV bay in the coupler to make sure it fit.
IMG_0386.jpg

Please note that the GLR Almost-Ready-to-Fly kits use a "slide in" principal for their phenolic AV bays. Instead of having a bay that is riveted to the upper and lower stages with a band around the middle, you actually epoxy the bay into the upper stage. Then, using your forward recovery harness, you slide the upper half of your sled assembly down the payload tube until it stops with the outer bulkhead resting on the coupler. Then you just add the washers and wingnuts, tighten securely, and you're done.

Not a bad system, actually.

I marked the coupler with multiple pencil marks at the 3" point from one end. It is way easier to make multiple small marks than trying to draw a circle around the circumference. After all, the coupler is going to go in straight, and there is no exactitude required!
IMG_0385.jpg

I then used 30-minute epoxy on the coupler to slide it into the payload tube (or upper stage). I used ample amounts of rubbing alcohol to remove all traces of epoxy on the payload tube and the extended portion of the coupler. That way, there will be no issue sliding the coupler into the booster (or lower stage).
IMG_0388.jpg

Installing the Rail Guides
The kit comes with Acme conformal rail guides, and all references to Wile E. Coyote aside, they seem to do the job.

First, I used an aluminum angle bracket to draw a straight line between two of my fins. I used a little masking tape to hold it temporarily in place.
IMG_0389.jpg IMG_0390.jpg

I traced the line several times with pencil and got a good line.
100_3720.jpg

Then I measured, according to the manual, two marks 11" and 32" from the end of the tailcone, making absolutely sure the pencil line was going straight through the center of the rail guides. I placed a guide with its aft end touching each of the lines. Once I was sure they were straight, I traced their outline with the pencil, shown below.
100_3721.jpg 100_3722.jpg

I removed the guides, and then roughed up the inner surface of the guides, and also the rectangles on the booster tube where they were to go. I applied some J.B. Weld to the inside of the guides and smoothed it out with a popsicle stick, then placed them into the rectangles that I drew on the rocket. To hold them in place while curing, I added a little masking tape.
100_3723.jpg 100_3724.jpg

Tomorrow I have a weird work day, and thus may not be able to build anything. Not sure if I will do fillets and spirals next, or assemble my electronics on the sled.
 
Does MDRA allow aluminum rail guides?


Sent from my iPhone using Rocketry Forum
 
Just curious. Some clubs don't like them because they supposedly chew up the aluminum launch rails.
 
In all honesty, I'd be more comfortable with traditional rail buttons. I'm not big on the idea of the rail guides being capable of being ripped off the side of the airframe. But with the Fireball and the one-piece fin can, I can see why they went with external guides. It would be extremely difficult to mount pem nuts inside the booster; maybe impossible.
 
Still with me? Okay, I got a little bit more done tonight. I spent an hour doing work around the house, including moving all of my rocket stuff to a different area of the house. So I was tired.

FIFTH NIGHT
Tonight, I hoped to get at least one fillet done. Fortunately, I was able to do two.

Do to the one-piece fin can, fillets are not a structural requirement for this rocket. However, I would like it to look nice on the pad, so I opted to do them. Unfortunately, I AM TERRIBLE AT FILLETS!

The instructions recommend using 6-minute epoxy and baby powder to make a Bondo-like material. For my first VA, I used real Bondo. It was okay, but not great, as many have pointed out.

This time I used epoxy clay from Apogee. As you can see, the area between the fin can and the slotted booster tube is wide and deep.
IMG_0393[1].jpg IMG_0392[1].jpg

I taped off my fillet area (not shown), and used my (gloved) finger to apply the clay. I pulled the tape, then used alcohol swabs to smooth things down. But I know I am looking at a lot of sanding.
IMG_0394[1].jpg IMG_0395[1].jpg IMG_0396[1].jpg IMG_0397[1].jpg

Hoping to do fillet #3 tomorrow night.
 
SIXTH NIGHT

I decided to take a break from filleting (is that a word?) to wire up my recovery system. I didn't take any "in progress" photos, but here are a few of the finished product.

I am using a Missile Works RRC2+ altimeter, and a wiring kit and switch from Doghouse Rocketry.

Here is the altimeter side. Orange = Drogue, White = Main, Brown = Switch
IMG_0399[1].jpg

Here is the Drogue end, with charge well and terminal block.
IMG_0400[1].jpg

Ditto for the main. And YES, I need to putty up the wiring hole in each bulkhead.
IMG_0401[1].jpg

A closer shot of the altimeter wiring.
IMG_0402[1].jpg

And the battery holder is on the other side. That way it won't get stuck on my switch as the bay slides down the upper tube after loading.
IMG_0403[1].jpg

Wow! I've got to be at least halfway done. Still to go, hopefully in this order:
  1. Third fillet.
  2. Modify nose cone to hold tracking device.
  3. Modify nose cone for shear pin breakage.
  4. Fill spirals.
  5. Sand and paint and sand and paint and sand and paint and sand and paint....

BTW, the painting color scheme will be the same as before--yellow nose and fin can (my son's favorite color is yellow), and metallic blue for the airframe (my daughter's favorite color is blue).

If anyone is still following this, don't be afraid to post something. Questions? Criticisms? Praise? (Okay, well, I can ask, can't I?)
 
I have a Vertical Assault. I love that rocket. Just flies well and always works recovery-wise.
 
If you ever want to know if people are reading your thread, check the sub-forum where it's listed. "High Power Rocketry" shows how many "views" and "replies"you have gotten since you started it.
838 and counting.
Using epoxy clay for fillets is a tough way to go, especially on a cardboard rocket. Sanding them down will probably cut through the glassine coat on your body tube, causing a "hairy" problem. A search on fillets here will give you lots of alternatives, but my favorite is "Titebond" Molding & Trim glue:

https://www.grainger.com/product/3K...3KRU9&ef_id=U45wyAAAAZXRxFjq:20140725174326:s

I know it"s a little late for this build, but if you plan to build more paper rockets, give it a try.
 
Doesn't this rocket have a plastic fincan? Will Titebond Molding and Trim glue bond to plastic? I'm thinking no but I could be wrong.
 
Doesn't this rocket have a plastic fincan? Will Titebond Molding and Trim glue bond to plastic? I'm thinking no but I could be wrong.


the plastic fin can is inside the BT. the BT is slotted and fitted over the plastic part.
 
True, but you are still applying the fillets to both the tube and the fin can.

So, Wayco, does TiteBond stick to plastic?

It says it's wood glue, but also mentions that it's "formulated for trim, crown molding, baseboards, window casings and other applications". Some crown moldings and window casings are plastic, but most of them don't launch into the air unless there is a tornado involved.... Since this application is for cosmetic reasons, why not try it and find out?
I use "Future" floor wax over my decals instead of clear paint, when it gets scratched, I just add another coat. This could work the same way, but I'm thinking it's flexible enough, it wouldn't crack. Anyway, you already have fillets on this rocket, try it on your next build.
 
SEVENTH NIGHT

Nose cone mods, a fillet, and some body tube spirals.

First, the nose cone. I got a BRB900, and after much internal debating, decided it really needs to be in the nose. Also decided that, since I don't own any cool tools and I am not particularly "handy," I needed to find an easy way to do it.

But first -- the screw hole for the nose cone eyebolt is too small.
IMG_0404[1].jpg

So I drilled out to 5/16".
IMG_0405[1].jpg

That allows the eyebolt to fit.
IMG_0406[1].jpg

Next I had to cut a door in my nose cone to serve two purposes: 1) so that I could tighten the eyebolt; 2) so that I could house my BRB900 transmitter in foam in side the nose cone.

To do that, I measured and cut a 1.5" X 3.5" template out of paper.
IMG_0485[1].jpg

I spot-taped the template on the nose cone, and traced the rectangle with a Sharpie.
IMG_0486[1].jpg

I then cut out the rectangle with a matter knife, trying to bevel it so that the door could not fall back inside the cone. (Thanks to timro and Apogee for this idea.) Unfortunately, that's where things started going screwy. My cuts were not straight, and I ended up with a weird design.
IMG_0487[1].jpg

However, I did get the eyebolt in place and tightened.
IMG_0488[1].jpg

I surrounded my BRB900 in some foam rubber and shoved it in, to get a good fit.
IMG_0489[1].jpg

Sadly, a lot of bad things happened. First, the door that I cut out started to lose its arc, i.e., get flatter and less curved. It would no longer fit back into place. When I placed tape over it, it was no longer able to fit into the body tube; the tape got scraped off by the tube. So I think I am going to go with masking tape across the opening. If anyone has any comments or suggestions or warnings about this, please share them. I think if I rotate my foam so that it is facing to the closed side of the nose, and make sure it is well packed, the BRB would not be able to get out even if all the tape came off.
IMG_0495[1].jpg

I did get a nice, snug fit that way. And I tell you, that nose cone fits so tightly into the upper tube that I don't think I'll need shear pins. I bought some, and a #2-56 tap; but when I pull the nose cone out, it is so tight that it makes an audible pop.
IMG_0494[1].jpg

See next post. Too many pictures.
 
I finished the third fillet, and since I had some clay already mixed, started filling some spirals.
IMG_0496[1].jpg IMG_0497[1].jpg

Once all the spirals are filled, it will be time to sand and paint. Hopefully I have this thing ready for launch at the August 16 MDRA meet.

I will post when the spirals are finished, i.e., pre-paint. Then again when the paint is done. Then one last time with my recovery system in place. Thanks for sticking with me.
 
looking great! those nose cone doors look tricky. I cant wait to see this thing finished! Its a very neat rocket and yours is coming out wonderfully!
 
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