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Glassing a nose cone

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ActingLikeAKid

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Yes. I know that there are fiberglass nose cones available. But...
1. I don't feel like dropping the coin on them right now
2. This is for a launch in just under a week and I don't want to spend $$$$ on shipping
3. I already have everything I need to glass the cone...

So here's what happened. I was putting primer on my Mega Vector Force project and the top tube fell; the nose cone cracked open like a $@!#!@$# Easter egg.
IMG_5173.jpg
The design is that the nose cone and top body tube are glued together; they all slide over the Eggfinder sled and get screwed into the transition.
Anyway, as you can see, the 3d-printed ABS nose cone cracked. It could have been a weak spot in the printing. It could have been dropped/whacked at some point (I have small kids). And it could be that it just hit something on the way down just perfectly. Doesn't matter. Point is, if it happened once it could happen again and I don't want the nose cone cracking on landing (or worse, under thrust).

My plan is to double-wrap this thing with fiberglass. (because if it's worth doing, it's worth overdoing).
Wrap 1: 2oz glass, 1" wide ribbon. I start at the top, overlapping around 1/4" . Wrap 2: Cut out something that looks like this:
wrap.png
...the goal being that each "leaf" overlaps a little as it curves down over the nose cone.

Has anyone glassed a softer/lighter material nose cone? Tips/suggestions are muchly appreciated.

(I was going to dive in tonight -- like I said, launch in under 7 days -- but it struck me that it's late, I'm tired, and I'm saying things like "muchly appreciated", so now is probably not the best time to do precision fiberglass layup.)

Oh, and yeah. I realize there's going to be a TON of sanding to make this thing anything close to round/smooth. I don't think I know anyone with a lathe, so this will be a lot of careful sanding to try to re-round it.
 

Incongruent

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What if you spread epoxy (possibly mixed with chopped fiber or something) on the interior of the cone? How much clearance is there between the nose cone wall and the electronics sled?
 

rharshberger

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Being its ABS iirc Acetone could be used to weld the cone back together, MEK will work as well and Plastruct Plastic Weld. Tack the two pieces together with a couple of dots of CA, then use a brush to wick a bit of acetone/mek into the joint, the solvent are thin enough to penetrate through the joint entirely.
 

ActingLikeAKid

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Thanks for the suggestions!
Unfortunately...
-can't do anything to the inside- the cone is already glued in place:(
-I tacked it in place with 5 min epoxy (which seems to have held pretty well) but I'm worried that fixing this without strengthening the whole thing would just set me up for doing this again.
 

BDB

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I glassed a transition this winter. It was a pain in the butt, but it can be done. I used the transition generator on payloadbay.com to make a template, and then I cut a curved piece of 2 oz glass. I'm sure you could do something similar--just create a 29 mm-->0.1 mm transition.
 
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ActingLikeAKid

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That's what I was thinking at first... the (limited) stretchiness of the cloth ought to lay down on the curve.
 

ActingLikeAKid

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After trying various iterations and making a huge mess (an epoxy-less mess, but still) I determined that:

All methods were going to be bad - there is no easy way to do this.
The best bad method was laying tapered strips down, overlapping them.
The NC is curing now, we'll see what happens when everything hardens up.
 

soopirV

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I haven't tried this, but that explains why most cones I've seen are filament-wound, difficult to get a 2D sheet to conform?
 

ActingLikeAKid

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I haven't tried this, but that explains why most cones I've seen are filament-wound, difficult to get a 2D sheet to conform?
I would think so, yes. Sadly, though, I don't have the patience for manually filament-winding the cone manually, and don't have equipment to do so.
 
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