Finessing Filament Fiberglass...

...Nosecones... So I've been working on my Wildchild. The new filament wound nosecones are sweet, but are not attached to the coupler.

Of course, with my severe case of Obsessive Compulsive Disorder(s), I couldn't just epoxy it on and be done. The NC hung over the tube, so before permanently attaching it to the coupler, I sanded it. And sanded. And sanded. It's getting better. Sanded some more. Sand, sand, sand. Check? Looking much better. Yup, still square. 400 grit on top of a piece of glass, BTW. Sand, sand.

I am sanding the base, not the circumference. Its getting shorter, not thinner.

Sand, sand, sand.

Nearly perfect.

Enough, I quit!

(......sand some more)

Yea, I'm nuts.






This rocket is going to lawn dart on it first launch, isn't it?

`

This is what's up...so far...

I'm just slightly obsessively compulsed (or is that compulsively obsessed?) - I had the same issue with my WildChild and started to do the same thing. But I gave up halfway there, talking myself down with a healthy dose of "it's good enough".

Here's mine:


PLEASE be careful breathing around all that fibreglass dust - wear a mask!

s6

well the only person you need to satisfy is you... but unless you're trying for the extreme absolute alt or fps, it probably will not be affect the flight noticeably . I heard it said that the chances of damage related to how much time effort is invested in making it look good...spend too much time on it and you'll lose it.
rex

I actually went a different route and added a couple wraps of fiberglass on the fore end of the tube and tapered it down. It came out looking acceptable.

Yup, still at it... (but, yes, I am working on other rockets at the same time, sorta)

I have gotten it to the point that I can no longer sand down the 'length' of the nose cone. It is almost flush with the tube, on one side.

"Ha-ha, he sanded it crooked!"

Actually, no. I've been checking by rolling it, the tip is near perfect for runout. No perceptible wobble.

I found, somewhat on accident, that when I set down the NC, it always rolled to the same side.

Upon using my electron microscope (kidding) I saw that it had a 'heavy side' where it is just a bit thicker wall. I'm guessing that's where the extra epoxy may have settled after the winding process (?)

The thin, or 'light side' is obviously what became flush with the BT first...

McKailas Dad said:

I saw that it had a 'heavy side' where it is just a bit thicker wall. I'm guessing that's where the extra epoxy may have settled after the winding process (?)

Click to expand...

Doubt it....they are wound on a mandrel,then immediately heat cured. Epoxy is not the 2 part stuff we use, rather it's industrial grade heat cure. It can sit for weeks and won't harden till heat application.

I suspect the culprit is the grinding process that occurs after it's cured. That's why there is always a metal or epoxy tip. Ya can't grind it to an accurate point.

You're not sanding epoxy per se...you are sanding the tow itself, that's what makes it so difficult. A much faster way is to use 60-80 grit to Hawg it off and use 100-125 to get the sanding marks out. It will speed up the process 100 fold. Been there-done that.

It's the price we pay for cheap fiberglass parts. Yeah it could be tweaked to closer tolerance's but that would drive the price up considerably. The smaller the part, the more obvious it seems. There is always the alternative.... going back to a molded one.:wink: