Build Thread

This is the build thread for my darkstar jr.

I am planning a maiden flight on an Aerotech 38/360 H178 Dark Matter. Openrocket says it should hit about 3300 feet at 400mph. Pulling 20 g's. So that should be a fun launch.

Already been talking with mark, so just a teaser of the final decals:



Printed nose cone flame wrap, and Greek Vinyl decals.


I have already built the av-bays:

Parts list for coupler av-bay (all hardware is 1/4*20):
1) 1" bolt
2) wingnuts
4) hex nuts
2) 12 inch all-thread rods
2) bulkheads for ID of coupler
2) bulkheads for ID of airframe
1) coupler for airframe with switch band


Safety first!


Now, on to the build!


So, I start out with a layout of all of the parts.



I now pair up an airframe and a coupler bulkhead:



I now feed a bolt through the center hole (sorry, picture somehow got deleted)


These are now epoxied together:



Continued in next post.

Alright, so after I ran the bolt through that hole, I test fit the bulkhead pair into the coupler:



Any excess is removed with the trusty dremel and a drum sander:




I repeat this for the other pair.



I then insert the bolt through all 4 bulkheads, and clamp them together with a bolt:



This is clamped to my drilling area:



I then mark the top bulkhead 1/2 inch from the edge, then mark it 1/2 inch on the opposite side, for drilling locations:

Alright, so now, this whole kit-and-kaboodle is clamped to my drilling area. I did not get pictures of the next stage as it is kinda hard to hold an iPad, use a drill, and accurately drill a hole in G10. But, anyway, when I finish drilling, I have this:


(the outboard holes are 1/4+a few 64ths of an inch)


Now, I test fit one of the all threads through the outboard holes.



It fits well, so I throw a hex nut on there:


And another, to lock the all-thread in place:



Repeating for the other all-thread, I get this:

Now, I have a little problem here:


If you don't see the problem, this photo should show it:


And this should show even the blind how badly I screwed up:

Stick a walkie talkie radio in there, and you have a perfect rocketeers cellphone!


I ended up fixing this by cutting off the excess with my dremel carbide wheel.

YEAH BUDDY LETS GO! :grin:

(just remember who named it for you!)

Yes, you did come up with Misled Priorities, forgot to mention that. So mason, shouldn't it be "Thanks to facebook"? You said AKS and you were discussing it on FB...

blackbrandt said:

Yes, you did come up with Misled Priorities, forgot to mention that. So mason, shouldn't it be "Thanks to facebook"? You said AKS and you were discussing it on FB...

Click to expand...

Nope, he and I were discussing something different, a group project. Maybe some other time the project will come to light.

As for your problem, I must have no eyes at all because it seems fine for me. What am I missing?

Wait, it was just the extra allthread?

The allthread were 5 inches too long for the av-bay, so I cut them off with my carbide wheel.

Gotcha. Looks good so far, BB. Keep it up and ask questions if you need it!

Oh, and something that is really making me nervous. I am borrowing the Dr Rocket casing for the flight, and learned that the casing is a special LDRS pattern that cannot be replaced...

:y::y::y::y::y::y::y::y::y::y::y::y:

your pics are all fubar...

Hmm, let's see what I could do about that...

somewhat better.

blackbrandt said:

Oh, and something that is really making me nervous. I am borrowing the Dr Rocket casing for the flight, and learned that the casing is a special LDRS pattern that cannot be replaced...

Click to expand...

Is this for your J1 cert flight? Want my opinion? Don't borrow that case. You have to buy a motor anyway right? So why not just buy a CTI H400 Vmax and get the case for free? Then you don't have to worry about losing or catoing someone else's junk and at the end of the day, you have a sweet little 2 grain 38mm case all your own. Now buy a spacer and you can fly 18 different CTI 38mm motors from G to H. I have a 2 grain case and my only complaint is I don't get to use it enough.

Nice job on the build btw.

Nope, not a cert flight, I am a Tripoli member, and he is just signing the flight card for me.


Tonight, I glued on the centering rings, glued in the motor mount, and attached the fins. I had read on here it is easiest to do all of them at the same time so you can adjust the rings once they are inside the body tube to clear the fins. I got no pictures, because my dad REFUSES to let me use a camera around epoxy.

Anyway, in a stressful series of events tonight, I got everything epoxied in. Motor mount and fins. Will inject Friday, and will probably draw fillets Sunday. THIS SCHEDULE IS NOT FINAL!!

I will be receiving help with the wiring for the av-bay next week, and this will launch not this Sunday, but the next. February 24th.

What epoxy/filler are you planning on injecting with?

Alex

Personally, I would have gone with 10-32 or even 8-32 threaded rod to keep the weight a little lower, but there is certainly nothing wrong with going bigger. The build looks great, should be a cool Cert flight!

Aksrockets said:

What epoxy/filler are you planning on injecting with?

Alex

Click to expand...

Aeropoxy and chopped glass.

COrocket said:

Personally, I would have gone with 10-32 or even 8-32 threaded rod to keep the weight a little lower, but there is certainly nothing wrong with going bigger. The build looks great, should be a cool Cert flight!

Click to expand...

I used 1/4 because that is what I had handy, and also, I like to keep all hardware in a build consistent. Just something I always do. Also, this is not a cert flight.

Alright, I am going to be using the P6K for the first flight, and then I will be getting an Adept22.
I have been allowed to borrow an avionics bay for learning how the wiring works. Dang, there is a lot of wire in an av-bay!!

Here is a picture of the bay, disassembled.
View attachment 118879
Also in that pic is the 38-360 I am using for the flight.






And here is a picture of the altimeter:
Boy these things look complicated!





Sorry no progress today, got hung up in a store when my mom saw a cool piece of furniture...
I will be in TN all weekend, and I get back Sunday...

Yay! Got these emailed to me today:



I learned that we are going to our grandmother's until Friday night, so I will be bringing my rocket stuff up there. I will lay up and inject fillets, and work on the wiring while I am there.

I WILL GET PIKKERS!!

OK, this is weird...
Darkstar jr instructions say 3x5/32 holes for the av-bay.
An online port size calculator says 3 1/16 holes...


???
What do I use?

blackbrandt said:

What do I use?

Click to expand...

I was taught that you should use the port sizes recommended by your altimeter manufacturer. You have an email address and phone number for John at Transolve, so I would ask him.

G.D.

blackbrandt said:

OK, this is weird...
Darkstar jr instructions say 3x5/32 holes for the av-bay.
An online port size calculator says 3 1/16 holes...


???
What do I use?

Click to expand...

The answer is in the instructions you posted!

rcktnut said:

The answer is in the instructions you posted!

Click to expand...

Which says 1/4", which I feel is overkill on a rocket this size..

Matt, I would go with the DSJr kit directions of 3x 5/32" holes.A REAL rocket scientist made those directions!:wink:

rcktnut said:

The answer is in the instructions you posted!

Click to expand...

Yes, but that just says "one or more 1/4 inch holes".

Pantherjon said:

Which says 1/4", which I feel is overkill on a rocket this size..

Matt, I would go with the DSJr kit directions of 3x 5/32" holes.A REAL rocket scientist made those directions!:wink:

Click to expand...

Wow... I guess Crazy Jim is a rocket scientist, but should I really trust someone who made his level 3 flight in a wind so strong that the pad fell over? :wink:

Alright, I just made a Lowes run, and got a switch and about 5 feet of 22 gauge solid wire. I am going to be wiring the av-bay and injecting fillets today.

Fixed and cropped:

Thanks. Lemme throw that in there.

Did a quick fit of all of the parts, here is the pic:

Alright, I have done a lot in the past 2 hours. I injected a set of fillets, which ended up pretty well. Next set, though, I need to use less chopped FG. Here is a picture of the epoxy as I am mixing it up:
They ended up pretty good, though. I noticed I had some leftover epoxy, so I said "what the heck" and laid one external fillet.

I also went to Lowes and got wire and a switch. Here is a pic of a test mount of it:


And I got a random picture of the dog, Scout, being tormented by my sister. He is reaching for a dog bone: