Building that HPR rocket... NoseCones

One of the biggest problems I have encountered in building the current minimum diameter HPR rocket is having so few choices to use in 'off the shelf' nosecones.

I had certain requirements for the rocket nosecone that included having a long shoulder length (almost two caliber's) to fit the GPS \ Transceiver, and a 4.1:1 Power Ogive to minimize shock while going through 'warp'.

As the current rocket is expected to well exceed Mach (and I couldn't use Carbon Fiber because it blocks RF), I decided to make a Mold using fiberglass, vacuum whetted with an High Temperature non-conductive epoxy.

For the design of the nosecone, I used an Excel Spreadsheet written by Kemal Payza. A fantastic bit of Excel wizardry that allows you to custom design nosecones in the tangent Ogive, Secant Ogive, Parabola, Ellipse, or Weighted average curves. The spread sheet is designed for the Lathe worker, and not only gives pictorial representation of the cone with dimensions, but a print of X-Y lathe coordinates to be used.

Once I had the cone design, I need a skilled lathe worker to make the nosecone at a reasonable price.

Enter Gordon Agnello. I contacted Gordy, and described my needs... he suggested Basswood with several coats of quality varnish. I sent Gordy the print of the nosecone, and within a couple weeks the nosecone arrived.

Perfect in every detail... and absolutely beautiful!

When the mold making process is complete... this nosecone (signed by The Sandman) will take it's rightful place on the Rocket Trophy Shelf... beautiful work Gordon. Thank you!

snipped-for-privacy@yahoo.com

Reply to
Mark
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Reply to
Jerry Irvine

See Bob's mini-Gila monster page:

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Joel. phx

Reply to
Joel Corwith

yes Mark, the sandman and his infamous RoachWerks........ shockie B)

Reply to
shockwaveriderz

Nice... didn't know it could be done that way... didnt' think of it, that's for sure. ;)

I've been experimenting with that 'expandable foam' that comes in a can... and trying to apply it to the 'lost wax' methode of mold making... seems this foam would be Ideal for nosecone making, but can't seem to find a solvent to disolve it after the mold process.

Any Ideas?

(I've tried Acetone, MEK, and Trich).

Reply to
Mark

joking.. shockie B)

Reply to
shockwaveriderz

If you do not need the nose weight, a paper cone covered with fiberglass will work well. If you do not need the volume in the cone, fill it with foam, and possibly forget the glass. A small wood bead or piece of dowel glued into the tip will give it more durablilty. Use what ever length of coupler you want for the shoulder.

Reply to
Eric Pederson

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