"The Last Defender": BaddAzz Defender build thread

I'm lucky to have one of the last kits from BaddAzz rocketry - Defender MkIII. It's a 54mm fiberglass rocket with 38mm motor mount and the coolest nose cone and fins I've ever seen.

This is how the kit looks like:



This will be a very slow build thread, so that I get to enjoy every minute of it

It is easy to build. You don't need no stinkin instructions.

Im subscribed, the kits from badazz rocketry are just magnificint.


Alexander Solis

TRA - Level 1
Mariah 54 - CTI RedLightning- I-100 - 6,345 Feet

azzie said:

I'm lucky to have one of the last kits from BaddAzz rocketry - Defender MkIII. It's a 54mm fiberglass rocket with 38mm motor mount and the coolest nose cone and fins I've ever seen.

This is how the kit looks like:

View attachment 187948 View attachment 187949 View attachment 187950

This will be a very slow build thread, so that I get to enjoy every minute of it

Click to expand...

Materials selection looks superb, I must admit I am extremely impressed with the kit. Most definitely looking forward to the build.

Gutted I never got one of his kits this side of the pond.

I have one in my build pile. I have built the other and it goes together smoothly.

Attached shock cord to the airframe.

Forward centering ring had holes for tying the shock cord. Unfortunately, they were too small for the shock cord to go through.



So I took two small screws and pushed them through the Kevlar shock cord. It looked like this, with square nuts on top:



Then I drilled two holes in the airframe, and used these two screws to attach shock cord to the inside of the airframe. Smeared the place with epoxy and tied the nuts. Now it ain't going anywhere.

Definitely an overkill, but it was quick and easy to do.


-Alex

Hmm. I got mine fed through with a trick using masking tape to hold the frayed ends.

Centering ring is made of aluminum and has four pre-drilled, threaded holes. Airframe has four holes as well.

I pushed the centering ring into the airframe, aligned the holes, and fixed it with four screws: three short screws and a longer screw with a rail button on it.



To prevent screws from ever coming out, I put some epoxy on their ends.

Sanded the fins with 60-grit paper.



You will never guess what these plastic pieces are for:



They go through the fin tabs and hold fins in place, like this:




-Alex

azzie said:

They go through the fin tabs and hold fins in place, like this:
View attachment 188313

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Very clever! I never did figure out what those were for. I used an external jig to hold the fins at right angles instead.

JohnCoker said:

Very clever! I never did figure out what those were for.

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John - that's a nice jig!

With fins and wedges in place, Defender looks like this:



I really like the fact that wedges hold fins perpendicular to the airframe. I thought of aligning the fins with a fin guide, but it is absolutely unnecessary:

Reading this thread just makes me more and more sad I cooked my MkII on the pad the first time I tried to launch. Wonder if vendors still have a couple in stock...

Mixed some Aeropoxy and made internal fillets, one at a time:



-Alex

Be sure to apply epoxy to the motor mount in the area where the fin tabs are. You dont want what happened to my rocket where the fins shredded the body tube.

I dont know if you plan to fly past the speed of sound, but it is something to consider.


Alexander Solis

TRA - Level 1
Mariah 54 - CTI RedLightning- I-100 - 6,345 Feet

Just an FYI (but you're probably better than me). Make sure to check the CP vs CG on this craft. I always do... except for the time I didn't... which happened to be this model. Instead of the Defender, it became the Offender! One busted windshield later...
Good work! Look forward to seeing it painted!
Ken

I have to say I am jealous of your background lol. Loving the rocket and good work on the build.


Alexander Solis

TRA - Level 1
Mariah 54 - CTI RedLightning- I-100 - 6,345 Feet

Be sure to apply epoxy to the motor mount in the area where the fin tabs are. You dont want what happened to my rocket where the fins shredded the body tube.

Click to expand...

I'm not sure I follow... Motor mount pushed fin tabs through the airframe?

Make sure to check the CP vs CG on this craft

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Absolutely! I have a RockSim file and once everything is put together, I'll override the weight & CG and run simulations. I hope OpenRocket can figure out CP correctly, given that the fins have openings in them.

I regret I did not weigh all the parts before epoxying them together. It would be easy to simulate different configurations (with/without AV-bay, electronics, one/two chutes, etc) if I did not have to weight and override for every configuration.

In another words epoxy the fin tabs to motor mount. If the tabs are not glued in place they can bend if fin flutter is present and thus bend the tubing and destroy it. Filament wound fiberglass is stronger than blue tube, but I would not risk it.

This is an awesome rocket and good work.


Alexander Solis

TRA - Level 1
Mariah 54 - CTI RedLightning- I-100 - 6,345 Feet

SinfulDarkLord said:

In another words epoxy the fin tabs to motor mount.

Click to expand...

Thank you - I get it now. The reason I got confused the first time is because this rocket..... does not have motor mount! The motor is held by aluminum centering ring and motor retainer - no tube!

On one hand it's a nice touch - less weight; on there other hand you are right, there's less fin support; also it looks like aluminum parts scratch the casing a bit when inserted/taken out.

Masked the fins for making fin fillets:

Today, the scenery changes from photo studio (kitchen) to well-ventilated laboratory (bathroom)

Fill fin fillets with Aeropoxy, line with foil. Press one dowel, twist, move left right:



Repeat with second dowel:



Leave for 24 hours and repeat for the next pair of fins...

I am really excited to see this build. I am also building this one, but not keeping your pace. It's like my rocket came with instructions after all!

Major Tom said:

I am really excited to see this build. I am also building this one, but not keeping your pace. It's like my rocket came with instructions after all!

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Thank you for kind words! I'm hoping to fly in on Nov 8 - single deployment as I can't make avionics this quick. Wind is forecast at 10mph, perhaps I'll load up the upper section to keep the altitude below 1,500ft. Then I'll have all winter to finish it up

All fin fillets are finished:



Adding motor retainer is a no-brainer. Insert and tighten four screws. As usual I epoxied the ends of the screws to prevent them from coming out.



And, of course, I could not resist from loading a J-something and taking a picture:



Sustainer is complete!

That is one wicked aft end of a rocket. Good work.


Alexander Solis

TRA - Level 1
Mariah 54 - CTI RedLightning- I-100 - 6,345 Feet

Making a nose cone takes about five minutes:



Step one:



Step two:



and it's done.

That is one cool nose cone. Is it made out of plastic?


Alexander Solis

TRA - Level 1
Mariah 54 - CTI RedLightning- I-100 - 6,345 Feet

SinfulDarkLord said:

That is one cool nose cone. Is it made out of plastic?

Click to expand...

UHMW, which means it's really hard to get paint to stick.

They are still available on his site, but page says $34, but when you go to cart it says $40, plus S&H???