Patrol Cruiser Excalibur - 4" Upscale

[hornet driver]

I was biting my toenails with the anxiety!

Nimble little manx is'nt he?

 

[krusty]

mmmmmmmmmmm

Weeee!!!!!

Krusty

 

[hornet driver]

I did'nt put two and two together !!---BIG---I like it! At least bigger than I thought--very cool!!

 

[qquake2k]

Nimble little manx is'nt he?

It's amazing what you can do when you're anxious...

 

[thobin]

Very nice!

TA

 

[krusty]

After three attempts, I have a nose cone

I started by laying up each half of the nose cone mold. With four layers of glass in each half, the mold was closed. Using a long stick with a paintbrush taped to the end, strips of cloth were used to bond the seam.

This was then set aside to cure for 24 hours.



Once mostly cured, the bolts holding the mold were removed and the two halves were split apart.



Excess glass was then trimmed from around the end of the shoulder and the flash removed from the seam.

The nose cone was then left for a further 24 hours to finish curing.

Now fully cured, the shoulder was sanded down to allow the nose cone to fit correctly in the body tube and the voids were filled with bog.



Krusty

 

[Aksrockets]

BRAVO!
Excellent work. How much does she weigh? The few that I've made have been as light or much lighter then a plastic one.

op:

Alex

 

[krusty]

BRAVO!
Excellent work. How much does she weigh? The few that I've made have been as light or much lighter then a plastic one.

op:

Alex

Thank you

The original nose cone (that I made the mold from) weighs in at 217g

The original is from a Mega Der Red Max kit.

The glass reproduction is 223g - pretty close!! But that doesn't include bulkheads etc.

I will have to add nose weight, so having it a bit heavier is ok.

Krusty

 

[krusty]

Over the last two nights I've been working on the motor mount tube.

I would have liked to have had access via the rear of the rocket to apply internal fillets but I figured that I had no way to glue on the external tubes to the motor mount - at least the ones hidden by the shroud at the back.

So I went ahead and glued them in place first. I will inject some expanding foam inside the fin can instead.

The first thing I needed to do was to get the Aeropack retainer to fit the blue tube. I originally intended on using a cardboard motor mount, so I purchased a cardboard compatible retainer which is now way too tight. So I put it on the lathe and turned down the inside.



I have a perfect fit!

The next step was to start building up the back end of the motor mount with the additional tubes. Since the tubes aren't an exact fit, there's a gap between each one. I've used a set of guide rings to keep everything aligned correctly.



Once the epoxy was cured, the rings were removed



And a dry fit to see how it's all looking



Krusty

 

[krusty]

Since the rear-end of the body tube is larger due to the shroud, I went ahead and ordered some 1/2" stand-offs from Dog House Rocketry today. They'll take a couple of weeks to arrive from the US but they look neat and I'm not in a hurry

I also have to figure out recovery on this sucker. I'm thinking a MAD in the nose cone at the moment.... Ah.. Options.. options!!

Krusty

 

[qquake2k]

Holy cow, Krusty, you got mad skillz!

 

[krusty]

Well, work has started again on the Excalibur!

When I left off I was at the point where I could dry fit the fins and cockpit. The engine mount was done.

Over the last few evenings I've fitted the launch lugs & engine mount. I had originally intended on using a 1/2" stand-off but in the end I've decided to use standard launch lugs - just extended out a little.



Lunch lugs have been drilled through the body tube with a washer and nut to secure in place. I've added a dob of epoxy over the nuts to make sure they remain secured. Once the engine mount is in place, I'll have no way to access them.

Next up, engine mount! No photos of this - step, but I slipped the engine mount into place with a temporary centering ring at the top, since I wanted to be able to remove it once the epoxy had cured. As I had cut the fin slots, this is where I injected the epoxy.

With the engine mount in place & epoxy cured, I moved on to fitting the fins. Nothing exciting here - fins were eye-balled since a 4" rocket just won't fit into my fin jig

With the fins in place, I added internal fillets - this... this was no easy task! I ended up drilling a couple of small holes along the fin root and injecting epoxy with a syringe.

Once the internal fillets were done, I foamed the rear end -



Foam. Horrid, messy stuff - but my fins aren't going anywhere now!

Krusty

 

[krusty]

With the fins in place and the rear end foam cured, I moved onto the centering ring.

Centering ring installed with Kevlar strap dropped through engine mount.

I used a length of 90mm tube to push the centering ring into place.

And with epoxy poured on top.


The centering ring is quite a way down!

Krusty

 

[qquake2k]

Glad you're back at it. This is such a cool design!

 

[accpool]

Are you using the same beer for scale, it's probably warm by now. Love the design, you are an artist.

 

[krusty]

Are you using the same beer for scale, it's probably warm by now. Love the design, you are an artist.

LOL Yup, same beer! It's my standard 'beer for scale' - and I've had it some time, so it's definitely warm - and probably stale, too!

Krusty