The "Cherry Bomb"- Fin Attachment

[qquake2k]

Looks Like we might have a winner! I like the design and Simon approves. Thanks for helping guys! :wink:

Here is a few screenshots and the .ork file.

View attachment 106663
View attachment 106664
View attachment 106665

Stay Tuned! I'll have pictures of the actual build today.

Alex

I have to say, I like this better than your original design. I like the assymmetrical fins.

 

[patelldp]

Build what you like. Plain and simple.


...But deep down don't you really want that Thor clone? ;-)

 

[Aksrockets]

For the AV bay, the 4 bulkheads I received were all airframe size (not 2x airframe size, 2x coupler size like I ordered). 2 of them needed to be sanded down to fit the coupler.
I don't have a lathe or anything fancy but I do have a drill and sandpaper.




This worked better then I thought it would...
Took them both down to size in about 2 minutes each. Very pleased with this method.

Alex

 

[qquake2k]

You made a handheld lathe! Excellent! :clap:

 

[Aksrockets]

Got a little bored during Spanish class and sketched out some paint scheme ideas.


Alex

 

[MasonH]

Funny, I do the same thing during my precalculus class after school...hopefully I get parts for MY scratch build soonish.

 

[qquake2k]

Got a little bored during Spanish class and sketched out some paint scheme ideas.
View attachment 106695

Alex

You need to get yourself some colored pencils. Si.

 

[rheil]

Though now I'm pondering building a Dual deploy Kraken for L3 cert this summer at Hellfire... but a 4" 58mm won't fly an L. So now I'm pondering upscaling to a 8" 75mm Kraken. That'll make a cool build for Hellfire I think ;-)

I like your final plan, nice work!

 

[MasonH]

Level 3 needs an M motor...?

 

[rheil]

Right, temporary lapse in memory.... M

 

[Aksrockets]

You need to get yourself some colored pencils. Si.

I tried to army crawl out the door and over to the kindergarten but I was caught before then.

Captain, Ive seen you using programs to design paint schemes. What do you use?

Though now I'm pondering building a Dual deploy Kraken for L3 cert this summer at Hellfire... but a 4" 58mm won't fly an L. So now I'm pondering upscaling to a 8" 75mm Kraken. That'll make a cool build for Hellfire I think ;-)

I like your final plan, nice work!

That would be cool, but whoa slow down! IIRC you just got your L1 in October.
Thanks!

Alex

 

[thobin]

Humm? I think I liked your original fin set but the new one is cool too. You need to look into the Archetype recovery system for you dual deploy. I have Top Flight making me some new parts to go along with my new set up. I been thinking that dual deploy needs to be simplified and updated. My new set up has cut a few Oz off the weight of the AV bay, half the linkage and only one separation point. Are you going to build a ejection baffle? Or is it going to be electronic only? I'm really liking your choice of the 54mm, you really have a lot of options, AT 427 or CTI on up. I had been thinking all my HPR builds will be at least 54mm from now on for sometime. All you need is a good adapter and you have all the 38mm too.



TA

 

[qquake2k]

I tried to army crawl out the door and over to the kindergarten but I was caught before then.

Captain, Ive seen you using programs to design paint schemes. What do you use?

Alex

I use an OLD version of Photoshop, 6.0. I create an "empty" file in Open Rocket by deleting all the internals, including the nose cone shoulder and fin tabs. I save that as a PDF. I open the PDF in Photoshop, crop it, and erase the CP/CG graphics, and the body tube lines across the fins. I save that as a JPEG.

 

[qquake2k]

Once I have the "empty" JPEG, I can fill in the spaces with color using Photoshop's paint bucket tool. In this case, I had to add some lines for the different sections of color. I understand that Rocksim has a colorizing feature, but I've been too cheap so far to purchase the program. There may be other simpler ways of doing this, but it's been working for me.

 

[Aksrockets]

Once I have the "empty" JPEG, I can fill in the spaces with color using Photoshop's paint bucket tool. In this case, I had to add some lines for the different sections of color. I understand that Rocksim has a colorizing feature, but I've been too cheap so far to purchase the program. There may be other simpler ways of doing this, but it's been working for me.

Thanks Captain! I've always wondered what you've used.
I downloaded the 1st image and started playing around.


Thanks! I feel like you guys are doing all the work for me!

Alex

 

[stealth6]

I like #2.

Here's an idea taking those elements and tweaking another way:


BTW, I also increased the size of the fins a tiny bit - they looked just a tad small to my eye.
But remember, this is only an idea - it's YOUR eye that it needs to look right to. And I for one think you've got a pretty good eye.

s6

 

[qquake2k]

Thanks Captain! I've always wondered what you've used.
I downloaded the 1st image and started playing around.
View attachment 106759

Thanks! I feel like you guys are doing all the work for me!

Alex

I like the second one best. Not that you were asking...

 

[qquake2k]

I like #2.

Here's an idea taking those elements and tweaking another way:
View attachment 106763

BTW, I also increased the size of the fins a tiny bit - they looked just a tad small to my eye.
But remember, this is only an idea - it's YOUR eye that it needs to look right to. And I for one think you've got a pretty good eye.

s6

I like this paint scheme, but it would be a masking nightmare for me.

 

[Aksrockets]

I like #2.

Here's an idea taking those elements and tweaking another way:
View attachment 106763

BTW, I also increased the size of the fins a tiny bit - they looked just a tad small to my eye.
But remember, this is only an idea - it's YOUR eye that it needs to look right to. And I for one think you've got a pretty good eye.

s6

Ho-ly YES!
That looks fantastic. I might try to combine both the designs.

Thanks for the ideas!

Alex

 

[Aksrockets]

Did a lot of work on the AV bay today.
The two couplers I recieved were both too short for an AV bay. This will be a slightly high stress flight and I dont want anything 'wiggling' during the boost. On quicker K motors it'll break M1. I glued the two couplers using a 1.75in switch band. This will be later reinforced internally with fiberglass.
I drilled holes in the bulkheads for my 1/4 in hardware.
Here is my marking guide I used to drill precisely mark the places to drill.


Drilled 3/32in 'pilot' holes


All holes drilled out to 1/4in

I hate those little ugly splinters you get from drilling into plywood.... :eyeroll: I need a faster drill and sharper bits.

U bolt attached.


Doesn't look to bad so far!


Hope these images work for you guys. I'm trying something different.

I'll work on the sled later. That shouldn't be to hard.

Alex

 

[Aksrockets]

Thanks for the ideas, S6. I made a few modifications.
Masking is going to be hell.



Alex

 

[stealth6]

Masking is going to be hell.

View attachment 106827

Alex

Yeah it will. But it will also be worth it - I like your mods.

s6

 

[qquake2k]

I hate those little ugly splinters you get from drilling into plywood.... :eyeroll: I need a faster drill and sharper bits.

I use pilot point drill bits, and don't drill all the way through from one side. I drill through just until the very tip pokes out the other side, flip the piece over, and finish from there. I get much cleaner holes that way. You can also try drilling all the way through with a smaller bit, then drill from both sides with the bigger bit.

https://www.homedepot.com/h_d1/N-5y...eyword=pilot+point&storeId=10051#.UMPqBYM72bI

https://www.dewalt.com/tool-parts/d...al-purpose-pilot-point-drill-bits-dw1909.aspx

 

[stealth6]

Also, always clamp your piece down tight on some scrap wood. If the backside of the piece you are drilling is reinforced like this, you will get clean holes with no (or significantly less) splintering and tear out. Don't "drill into air".

And yes, sharper bits make a difference too.

s6

 

[o1d_dude]

This (#53 & #54)

Brad point drill bits. Clamp and drill through the plywood into a wooden "backstop" for best results. Doesn't mean it will be perfect tho.

 

[thobin]

+1 on the brad point bit with backstop. Biggest mistake people make is they push the bit to fast, let the bit cut the wood out of the way not mash it out of the way.

Looking good BTW you going to be done and bring it to the next launch.



TA

 

[grouch]

Take a scrap piece of ply wood and spray some 3M77 on it and stick the bulkhead to it. Drill your holes then pry the two apart. Holes with no splinters.

 

[Aksrockets]

Thanks for the tips guys! I'll try some out today when I drill the holes for my CR U-Bolt.

Looking good BTW you going to be done and bring it to the next launch.

We'll see. If I don't finish it, I'll bring it anyway if you want to see it.

You can also try drilling all the way through with a smaller bit, then drill from both sides with the bigger bit.

That's exactly what I did. What you see in the pics is where I went too fast. Not all of them are that bad.

Thanks for the advice.

Alex

 

[Aksrockets]

Cut the upper tube to size (24in)


It's gonna be a big one!
This is her next to my 2in DS


Alex

 

[Aksrockets]

I cut out the altimeter sled and layed out the AV bay tonight.
What wire do you guys use for your altimeter bays? I have lots of taken apart Cat5 wire that I use for igniters. Would this work?
I am uploading photos with my phone for the first time. I will re-upload.them tomorrow if they do not work.

Alex