Madcow 4" Phoenix "Build...Tear...Rebuild" Thread

[Handeman]

Here are some pictures of how I set up my JLCR for the Phoenix.

View attachment 549273 View attachment 549278

View attachment 549279

Most people end up with some added weight in the nose cone so as to improves the rocket's stability.
With the added weight the Phoenix will tend to descend quickly, nose cone first, when you use a JLCR.
Once the nose cone takes the lead, the open body tube almost acts like a drag chute. My rocket comes
down straight as an arrow; Body Tube-----Harness-----Nose Cone-->

The JLCR tether and the chute are rigged so that the chute won't push out from under the elastic band.
The tether is attached ahead of the chute and the chute's harness loop so that the chute goes
"up & away" from the JLCR. This way you won't get any entanglement.

That's a 50" Top Flight chute in the pictures.

That is interesting. I've never wrapped the shock cord with the chute when using a JLCR. Never thought of doing that. My JLCR is tethered to the anchor point of the chute and just wrapped around the chute. In my Callisto, the rocket leads everything down, fin first, the nose cone falls below the chute and the JLCR and chute act like a drogue chute and is the last thing down.

This has always worked for me, but I will definitely keep in mind putting the JLCR band around the shock cord also.

Thanks...

 

[user 30299]

That is interesting. I've never wrapped the shock cord with the chute when using a JLCR. Never thought of doing that. My JLCR is tethered to the anchor point of the chute and just wrapped around the chute. In my Callisto, the rocket leads everything down, fin first, the nose cone falls below the chute and the JLCR and chute act like a drogue chute and is the last thing down.

This has always worked for me, but I will definitely keep in mind putting the JLCR band around the shock cord also.

Thanks...

If you have no JLCR issues on the Callisto with your current setup, then you may want to let it be. It's on those screamin' straight
descents that I found my tether & chute arrangement made the JLCR work 100% of the time; no early chute deployment and no
entanglement.

I was working with a university student that was using a chute release on a MD rocket. He kept having these scary close calls and
early deployment issues on a rocket that had a straight descent. Issues went away once he tried my arrangement. His rocket came
down fins first so we just flipped the chute and tether arrangement 180-degrees from what I did on the Phoenix.

To bring this all back around to this thread, the Phoenix body tube has never run into the chute once it's released
and starts to inflate. The body starts to swing out and misses the chute. But I think you want a strong harness
when using the JLCR. I can't "quantify it", but it looks like there is one heck of a "snap" on the harness when the
chute abruptly stops the momentum on the fast-moving body tube. It's a heart stopper for sure.

I'm using a 7/16" (or 1/2"?) Kevlar harness from OneBadHawk. Zero failures on the harness, and lots of flights.

 

[KenECoyote]

If you have no JLCR issues on the Callisto with your current setup, then you may want to let it be. It's on those screamin' straight
descents that I found my tether & chute arrangement made the JLCR work 100% of the time; no early chute deployment and no
entanglement.

I was working with a university student that was using a chute release on a MD rocket. He kept having these scary close calls and
early deployment issues on a rocket that had a straight descent. Issues went away once he tried my arrangement. His rocket came
down fins first so we just flipped the chute and tether arrangement 180-degrees from what I did on the Phoenix.

To bring this all back around to this thread, the Phoenix body tube has never run into the chute once it's released
and starts to inflate. The body starts to swing out and misses the chute. But I think you want a strong harness
when using the JLCR. I can't "quantify it", but it looks like there is one heck of a "snap" on the harness when the
chute abruptly stops the momentum on the fast-moving body tube. It's a heart stopper for sure.

I'm using a 7/16" (or 1/2"?) Kevlar harness from OneBadHawk. Zero failures on the harness, and lots of flights.

Thanks! Great info and yesterday I was thinking over switching out the nylon harness to some longer kevlar. I have a OBH 11/32" harness set that I was considering if going DD and actually had just ordered some of his 7/16" kevlar.

For the JLCR, I can't recall where I saw this, but someone was using a piece of folded flexible plastic (like the type from those frustrating-to-open product clam shells). It's used as a type of spring to push the JLCR away and I think he said he's had 100% success with it. I'll be trying this next launch.

 

[Handeman]

To bring this all back around to this thread, the Phoenix body tube has never run into the chute once it's released
and starts to inflate. The body starts to swing out and misses the chute. But I think you want a strong harness
when using the JLCR. I can't "quantify it", but it looks like there is one heck of a "snap" on the harness when the
chute abruptly stops the momentum on the fast-moving body tube. It's a heart stopper for sure.

The "snap" is very common. I see it multiple times each launch. It is most common on drogueless DD flights where the rocket is separated, but coming in ballistic with the nosecone/payload dragging the fin can down. Those usually get a double snap, once when the payload section hits the end of the stopped chute and a bigger one when the booster hits the end. The longer the shock cords, the harder the "snap".

Unfortunately, most times this happens everyone congratulates the flier and tells them "nice flight" so I doubt it will ever go away.

BTW, I once saw that happen on a 110 lbs. L3 fight. When the booster hit the end of the cord, it tore the shock cord anchor out of the 3/4 plywood CR and the booster section never even slowed down as it fell free and crashed.

 

[user 30299]

BTW, I once saw that happen on a 110 lbs. L3 fight. When the booster hit the end of the cord, it tore the shock cord anchor out of the 3/4 plywood CR and the booster section never even slowed down as it fell free and crashed.

Now don't go telling stories like that. Poor KenECoyote won't want to fly his Phoenix now . . . .

 

[KenECoyote]

Now don't go telling stories like that. Poor KenECoyote won't want to fly his Phoenix now . . . .

Nah, it takes a lot to scare me.

Plus I find that crossing my fingers is a good preventative measure.

 

[jmasterj]

For the JLCR, I can't recall where I saw this, but someone was using a piece of folded flexible plastic (like the type from those frustrating-to-open product clam shells). It's used as a type of spring to push the JLCR away and I think he said he's had 100% success with it. I'll be trying this next launch.

Latest issue of Sport Rocketry.

Edit: couldn't get the word "issue" to mind.

 

[KenECoyote]

Quick update...

I used Rocketpoxy for the first time and that stuff is dang thick! (Cold temps at home likely didn't help...I did put the two jars in a warm area for an hour, but I got impatient.)

I laid it on thick and heavy and then smoothed with a finger dipped in alcohol. Came out pretty nicely and I still need to sand and use filler, but may apply a primer first.

I've also been trying to plan out how to add the mid fin root accents found on the actual Phoenix:

I figured it would be a good transition to the thick rear fin fillets and also provide some strength... plus I think it looks cool!

However, it's proving to be quite a brain buster figuring out how to make 8 of them in such an unusual shape.

 

[KenECoyote]

I decided to use triangular wood stock, but the only ones I found readily available was in balsa and I wasn't up for making it myself out of basswood, etc. So balsa it is! Plus it should be fine epoxied on and maybe with a thin epoxy coating.

Additionally, the triangular stock doesn't sit completely flush against both the bt and fin since the bt is curved, so it needs to be further sanded or trimmed.

As a first attempt, I used an Xacto hand saw just to see and it was very hard to saw the triangular stock sideways at an angle, but the result wasn't too bad and maybe usable with a bit of filler.



I think I've figured out a better way which I'll try later. (Involves a miter saw, tape and extra pieces of stock and would allow me to trim a 2-4 at once... we'll see.)

 

[KenECoyote]

Time for an update!

The fin root accents (FRAs) were proving to be quite a pickle.

The problem for me was the steep angle of the cuts needed and I needed it done consistently. I thought of making some jig (including hot gluing some angle stock to my miter saw or cutoff grinder base), but that seemed a bit too troublesome as well.

After a lot of brainstorming and trial, I decided to try my scroll saw and mostly free hand it. I used to love scrollsawing many years back, so I had some experience.

An example of one of my past scrollsaw projects in keeping with the bird/"phoenix" theme:

 

[KenECoyote]

My scrolling... I used a piece of angle aluminum to hold the stock at the correct angle for cutting.

note that it's a bad idea to place a cold soda on a metal tool base in a humid basement in the summer

I still need to final sand, but I think they came out very well!

Oh, I'll also need to cut the backs a sliver to fit better to the body tube. I may just use a hobby knife since other tools (bandsaw, table saw, etc.) seem to be overkill and also dangerous given how I only need an angled sliver off the back of 1/2" balsa triangular stock, which is soft).

 

[KenECoyote]

Ok, decided to just do it!

I said screw the sliver and I'll just use heavy amount for glue to fill the gaps during and after. I also plan to coat these FRAs with epoxy after to further strengthen the balsa as well as the fin to bt connection.

Stii, I had to whittle a bit of the corner edge off because some of the fins had a small bead of epoxy.


I then laid the wood glue on very thick where it faces the body tube and thinner where it joins the fins.

No pics of the glue... it was messy and I got glue all over my hands...both sides.

Here it is glued and waiting to dry.

I also made sure to have a reference pic there to ensure I was putting them on correctly.

Til next exciting episode!

 

[Hobie1dog]

keep the pictures coming

 

[KenECoyote]

keep the pictures coming

Thanks for support hobie!

 

[T-Rex]

Threads like this make me wish I had taken more photos when I was active duty. They would be very helpful now.
Looking good so far Mr Coyote, keep it coming!

 

[KenECoyote]

Thanks T-Rex!

 

[KenECoyote]

So weather today in NY was unusually beautiful ... which was a bit sad because the Phoenix still wasn't ready for paint yet.

Still, there's hope that I can paint it soon, so I tackled more of the FRAs (Fin Root Accents).

I first applied a few heavy rounds of wood glue to fill the gap between the FRAs and the bt.


However, after drying there were still some spots with bubbles and gaps.

So I figured, no more short cuts...time to get out the heavy stuff...Rocketpoxy fillets!

First I masked off the areas around where the fillets would go. Regular tape on the FRAs and blue tape on the bt.


I find it helpful to use a masking tape dispenser alongside the area to be taped so you can get the right length each time.

 

[KenECoyote]

Then I mixed the Rocketpoxy and applied with a chopstick (free with Chinese takeout ).


Looks pretty good and I was able to do all 8 of them at once. I made sure to save the rail button side for last since by then the epoxy starts getting thick and harder to work with (usually resulting in fillets that don't look as good as the rest).


I did a bit of smoothing touch-up with alcohol before it hardened.

 

[KenECoyote]

Now... do you recall what the FRAs are constructed from? Balsa!

Given that balsa is soft, I wanted to harden it (even though this triangle stock seemed firmer than balsa fin stock).

Initially I considered epoxy brushed on, CA, even wood glue, but after some quick web research, I decided on epoxy thinned with alcohol and brushed on.

I used 30 minute epoxy so that there would be more time to get soaked in.

Went on easy peasy.

BTW The balancing cup of thinned epoxy is an "Instagram shot" for photo purposes and I would definitely suggest you don't do that!

Now I'll let it dry overnight and maybe I'll be able to give it a primer coat tomorrow if the weather is good...


Regardless, life is good when you're building rockets.

 

[KenECoyote]

So after hunting down some Rusto Filler Primer (my preferred base paint) at Walmart last night...it snowed.

Well, at least it was pretty!

Still, I was determined, so I brushed the snow off my patio table and brought out my trusty cardboard. I was a bit hesitant given the high humidity, but it was sunny and it's just a Primer coat anyway.

Note that a Chinese takeout soup container makes a good plug for the front of the 4" bt to prevent paint spray.

 

[KenECoyote]

So I'll continue with priming and then start filling spirals and sanding.

For a while now I've waffled a lot on the color scheme. I like the all white, but I launch on a black dirt farm and that dirt can create quite a mess on white paint. The gray however is a bit blah. Meanwhile some of the custom paints just don't look right to me.

We'll see where I end up.

 

[KenECoyote]

I did pick up a unique "grayish" paint a while back for this. It's Rust-Oleum French Blue, but looks like a shade of gray. It does look good to me and seems to catch my eye.

Test spray:

It's Satin too!

Right now I'm thinking of this scheme, which definitely pops and if I don't like it, I can later paint the fins to match the body...

 

[KenECoyote]

Time for an update!

So I went a bit overboard with the CWF filler...



This is the first time I've used so much! Sanding it indoors (since it's winter in NY) was a bit unpleasant as well. I found myself covered with so much gray dust that I ended up just wearing gray sweatpants and a gray hoodie lol!

I only did half of the rocket before I ran out of my sanding sponges and besides, I couldn't take it any longer! I decided to continue sanding it later.

Well, weather was looking kinda good (albeit still cold around the 30Fs and windy) and on a whim I decided to see how the sanded half looks painted. It's really hard to tell how well it's sanded in this shape.

 

[KenECoyote]

On goes the first coat of Semi-gloss White and viola - it's like one of those infomercials!



I personally think it's looking awesome and it turned out as well as I had hoped; however, it's still not done since I need to sand the other half and also do some touch ups and additional coats, but it's getting there!

"Sturdy Birdy"

 

[KenECoyote]

Some updates!

I masked off the fins and tried that blue gray color for the body.


The color IRL is more gray when wet.

However, outside when dried looks a bit too blue to me.

"It's a boy!"

I tried adding some color bands to see how it looks.

Better...


Here's what it looks like indoors.

The color indoors was more of what I was looking for. I'll try it with blue bands to see what that looks like, but if it's still too blue, I may respray it back to white.

(Side note: The two color scheme may make it easier to track and see if there is rotation, which is a plus.)

Any thoughts or opinions?

 

[KenECoyote]

Just tried the blue bands and I like it much better.



Trivia: Brown bands on a AIM-54 Phoenix missile signifies a live missile while blue signifies inert.

 

[Hobie1dog]

 

[KenECoyote]

Thanks Hobie!

 

[KenECoyote]

Added the infamous "most rockets are missing it" silver band!



Tried shiny chrome vinyl for the first time. Didn't seem to stretch the same as regular vinyl though, so I don't know if it's good for large areas. May test it on a Fat Cats 3" F104 Starfighter.

 

[KenECoyote]

I wasn't happy with the yellow vinyl I used for the upper bands. It was some vinyl roll found at a Dollar General that was pretty cheap and some of the paint underneath showed through as shadows, so I picked up some quality stuff (Micheals clearance!) and replaced those bands. Much better!


After that, I started applying the supplied decals. Many were cracked after the sheet was crumpled from shipping and the damage wasn't noticeable until they're wet and separated.