Idle hands lead to... unleashing the Kraken...

[snrkl]

After a painting mishap on my Other build that will require 1-2 days before I can sand and retry, I'm bored.

I decided..

I have some BT60 - what am I waiting for?!

So I've started a scratch Kraken build.




I've emailed Pemberton Tech to find out about Australian shipping, so I can send them some money because I truly believe in supporting awesome designs and products like this... (I vote with my wallet...) but in the mean time...

UNLEASH THE KRAKEN!

😜

 

[snrkl]

Ok. Fins filled, sanded, edged with CA and ready for priming tomorrow.

I've also glued 2 x1mm laser cut ply CRs together for each the fire and aft CRs on the MMT. Roughed up, Used wood glue and clamped for 30mins.



Tomorrow I prime the fins and assemble the MMT. Once the fin finish is acceptable, I'll glue the MMT in and prep, prime and paint the BT.

I'm thinking blue and orange. Those being my colours and all... 😜

 

[snrkl]

Ok. Haven't updated this in a while.

Fins painted inside

BT and NC painted.



I painted the outside of the tube fins today. Despite a wipe down, the masking tape must have left a few little spots of sticky residue on the outside of the tube. I've got a little line of pin pricks in the paint where the paint went phobic. I'll have to see if I can fix with the second coat - maybe a little sanding and respraying is in order. Not too bad, just not perfection!

Still to do: paint the launch lugs, finish the fin tubes then glue it all together and get recovery bits sorted.

Then weigh the whole thing and calculate CG/CP locations and figure out if/how much. NC weight is needed.

If I'm quick, I might just get to launch this at the QRS launch day this weekend.

 

[snrkl]

I've decided the fins are good enough.

I'm now racing to get it all assembled to hopefully fly its maiden voyage this weekend.

 

[woferry]

Curious, you paint the fins (and the airframe, presumably?) before gluing the parts together? I assume you sand-off the paint where you do the attach, or do you mask this area off before painting?

I'm getting ready to start a scratch-built tube-fin rocket, I had planned to glue the fins on first and then paint, but now I'm wondering.

 

[snrkl]

Well let me start by saying I masked the contact areas before painting.

And had second thoughts right before I painted that I hadn't masked enough, so I added some.

The correct answer was somewhere between my first and second mask.



This was what I ended up with and once glued, it's going to leave unpainted areas of the airframe visible.

I've spent enough time on this one and want to fly it in 3 days so I'm proceeding as is.

I'm planning on building another of these, so I'll adjust on the next one to get it somewhere in the middle. Either that or I'll paint the inside of the fins then glue and paint the outside afterwards now I'm confident with the rolled paper masks.

Also, in addition to masking the contact points, I'm mechanically preparing the surfaces for bonding with several sharp #11 blades to cross score the surfaces.

 

[snrkl]

Curious, you paint the fins (and the airframe, presumably?) before gluing the parts together? I assume you sand-off the paint where you do the attach, or do you mask this area off before painting?

I'm getting ready to start a scratch-built tube-fin rocket, I had planned to glue the fins on first and then paint, but now I'm wondering.

Also, it's only a problem on this rocket if you want a different colour on the inside of the tube.

My other build thread (My Take on an LPR Saturn) I Pre painted, but that's because I wanted very different colours (alternating black/white) and figured this would be easier.

 

[snrkl]

Launch lugs are done and glued.

It's kinda cool, with the kraken canards, it looks like a gun sight!

 

[snrkl]

Reminder folks:

The stuff you use to remove an epoxy drip is the SAME STUFF THAT STRIPS PAINT!! (Acetone...)





I have no idea what I was thinking...

#sigh

 

[snrkl]

Looks like I could be doing a final touch up spray if time and weather permits...

☹️

 

[snrkl]

One fin, two fin...

 

[Banzai88]

Reminder folks:

The stuff you use to remove an epoxy drip is the SAME STUFF THAT STRIPS PAINT!! (Acetone...)

View attachment 321678



View attachment 321679

I have no idea what I was thinking...

#sigh

I know your pain. I use denatured alcohol to remove epoxy drips. A little less active on paint.

 

[snrkl]

All done.

Just need to select and attach recovery hardware and hopefully fly it this weekend...

 

[snrkl]

I caved and used some spray in a cup with a brush to paint the unmasked overlaps and touched up the acetone snafu...

 

[snrkl]

Successful maiden flight at a very wet QRS Launch event on an Estes D12-5...


Kraken D12-5
Max altitude198.4 m
Date11/06/2017 10:35 AM
ModeRocket
Duration56 secs
NotesEstes D12-5
Thrust time1.90 secs
Max speed243.6 kph
Peak accel12.79 Gs
Avg accel3.61 Gs
Ejection delay6.10 secs
Coast-Apogee4.25 secs
Apogee-Eject1.85 secs
Ejection altitude191.4 m
Initial descent3.8 m/s
Landing speed3.2 m/s

 

[snrkl]

https://youtu.be/cLhVryQhawE

Short video of the launch.

 

[snrkl]

Better pic courtesy of @digit over at the AusRocketry forum.

 

[neil_w]

Well done, that came out really nice.

 

[dcullen]

I've admired the Kraken for a while now. Was reading through your thread, and I was like, BT60 - yeah - I've got that. 24mm motor mount parts: check. Plenty of new blades: check. BT60 nose cone: DRAT. But just a sec, I do have a 3D printer and I've built some model for BT70 and BT80 ogives, so I'm just a rescale away. Loaded up Onshape and rescale ad the BT80 ogive. Hey, what if I include the canards on the model? Oh Yeah - Kraken nose. Thinking about using reflective film to finish the inside of the tubes.

 

[snrkl]

I've admired the Kraken for a while now. Was reading through your thread, and I was like, BT60 - yeah - I've got that. 24mm motor mount parts: check. Plenty of new blades: check. BT60 nose cone: DRAT. But just a sec, I do have a 3D printer and I've built some model for BT70 and BT80 ogives, so I'm just a rescale away. Loaded up Onshape and rescale ad the BT80 ogive. Hey, what if I include the canards on the model? Oh Yeah - Kraken nose. Thinking about using reflective film to finish the inside of the tubes.
View attachment 321985

Nice - I'm glad I spurred some action in others!!

Oh, and my special order of two cans of this just arrived today, so I guess I'll have to build another...

 

[snrkl]

I'm also thinking about doing a down scale...

Or two.... or more.

Maybe I can have and 18mm, 24mm and the 40mm...

The mind boggles...