8" V2 Build Series

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UPscaler

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Hey everyone! I started my build on my Composite Warehouse 8" V2. This thing is awesome. It's massive but also "small" enough to be convenient. Won't break waivers on Ls and for small fields you can even fly a K. Of course, if I decided to get real brave. It looks like the 98/15360 might juuuuuust fit.



Braden

(Stubby mode picture because it looks hilarious)
 

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pathtouch

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I'm also loving that Buildcember has some unique rockets so far! A split fin kit and now this. It's nice seeing something besides straight 3 and 4 FNC models.
 

UPscaler

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I tried a new method for internal fillets than typical for my next installment! The first set went pretty questionable. The second set came out pretty passable though!


Braden
 

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boomtube-mk2

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I'd be worried about that strange pink glow coming off of it if I were you.
 
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cautery

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Braden..... don't give up on the tube and syringe material delivery technique. You are headed in the right direction.

We used to use a similar technique to fill voids/delams in Nomex honeycomb panels used in turbine engine decks.

Just need a much larger syringe, a positive way to attach the tube to the syringe (small stainlesshose clamp would be ideal), and choose a different material for the hose, and possibly add a nozzle to the end of the hose.

A real silicone hose might be the ticket..... It would conform to and lay still in the fillet trough allowing you to simply pull withdraw as you dispense material.
Downside might be tendency to expand under pressure in tube if material is too thick.

Alternatively, for very high viscosity or general use, you could use a section of PTFE tube..... It is straight and stiff..... You could still put the tip right where you want it.....

Or you could hybridization it..... A PTFE wand of sufficient length connected to the syringe (fixed in a mount) with a flexible real silicone hose..... You can then manipulate the syringe with one finger while using the dominant hand to guide the wand along fillet area.

Just my 2/100ths of a $1 debt note.
 

UPscaler

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Blah...blah...bla.... bla ba...blha abl bl..abla.blah! Nice to see u having fun.What??? no toothpaste fillets? : }
I haven't done the externals yet! I was thinking of using general tile grout. Maybe mix a little quikrete dust in there.

Did you catch your honorable mention in there? This is the second video where I've said "and this is a trick I learned from Crazy Jim." ;)

Braden
 

UPscaler

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Braden..... don't give up on the tube and syringe material delivery technique. You are headed in the right direction.
I actually got it far more refined on the second set and the third set is looking even better. Just took a little better attachment to the syringe and a straighter tube. All is good now!

Still a little uneven on the left side but plenty durable.

Braden

1638995990506.png
 

DarthMuffin

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Are you not doing the outer interior fillets? I know they're not nearly as important as the other two sets, but I'd probably make an attempt at wiping on at least a thin fillet (am also still n00b).
 

UPscaler

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Are you not doing the outer interior fillets? I know they're not nearly as important as the other two sets, but I'd probably make an attempt at wiping on at least a thin fillet (am also still n00b).
I wasn't planning on it, as I don't want to fight the fin slots leaking and given the stubby nature of the V2, I don't want to add any more weight to the rear than I have to. It's going to get a big chute since it lands on the fins and relatively hefty external fillets. I'm not too worried about it!

Braden
 

gerbs4me

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I actually got it far more refined on the second set and the third set is looking even better. Just took a little better attachment to the syringe and a straighter tube. All is good now!

Still a little uneven on the left side but plenty durable.

Braden

View attachment 493160
Those internal fillets turned out good! I like the syringe and hose method.
 

UPscaler

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Those internal fillets turned out good! I like the syringe and hose method.
I actually stole it from a local friend of mine who does it to all his rockets. I still think I prefer the traditional injection method, but this was solid for this application given all the extra room.

Braden
 

Theory

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No worries.

Everything was sanded using 180 grit sandpaper, I explained it in the video. I always wipe things down with denatured alcohol before bonding them.


Braden

noticed you mentioned that you started using a finer grit sand paper for composite prep. defiantly believe this to be a good move. use 220 myself.
 

David Schwantz

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To each their own, I am sure that works, but myself, I prefer the coarser grit for prep. I like to use 36 grit as my final paper. I'll even go as far as to use my dremel with a perma grit bit to cross hatch the area.
 
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I wasn't planning on it, as I don't want to fight the fin slots leaking and given the stubby nature of the V2, I don't want to add any more weight to the rear than I have to. It's going to get a big chute since it lands on the fins and relatively hefty external fillets. I'm not too worried about it!

Braden
Do the exterior fillets first, then the interior fillets won't leak. Put the rear CR as the final step. Since the fins extend beyond the end of the airframe they will hit first, likely one fin if it comes in angled at all. That extra fillet won't add much weight and may save the fin can.
 

cautery

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Do the exterior fillets first, then the interior fillets won't leak. Put the rear CR as the final step. Since the fins extend beyond the end of the airframe they will hit first, likely one fin if it comes in angled at all. That extra fillet won't add much weight and may save the fin can.

Good idea.... but overall, would it not make more sense to choose a chute that reduced descent rate under the main to a velocity that would be much less likely to pop a fin?

Less weight, more stable, and achieve same "safety factor" for FC?

Rocket man for sure has a light weight, high drag canopy to fit the bill... :)

From a confirmed "weight weenie"...
 

UPscaler

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Do the exterior fillets first, then the interior fillets won't leak. Put the rear CR as the final step. Since the fins extend beyond the end of the airframe they will hit first, likely one fin if it comes in angled at all. That extra fillet won't add much weight and may save the fin can.
I was considering adding them after externals but the rocksim file doesn't give optimistic stability for the weight that is already back there, let alone adding more. Eight more CF filled fillets would be a more substantial weight increase than one would think.

Braden
 

UPscaler

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To each their own, I am sure that works, but myself, I prefer the coarser grit for prep. I like to use 36 grit as my final paper. I'll even go as far as to use my dremel with a perma grit bit to cross hatch the area.
I used to use 40 or 60 grit sandpaper on fiberglass kits. However, when I did my first minimum diameter build I wanted to ensure the strongest bond possible and learned that heavier grit sandpaper is doing more harm than good on that front. Flynfrog did a great writeup and explanation in this thread:


Braden
 
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