How to make a hotwire

How to make a hotwire

Post by Philip Doolittl » Fri, 25 Dec 1998 04:00:00



    Thanks to those who posted about the gobing NC. Now that I have a
way to create the correct curvature, on to the next question.  In order
to the the NC  I want for a serious upscale (on the cheap) I'm probably
gonna have to make it.  Seen many pages on turning glued up foam blocks
(more tips welcome).  The problem I have is the hotwire.  Does anyone
have any electrical schematics?

Philip

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How to make a hotwire

Post by Andy Schecte » Fri, 25 Dec 1998 04:00:00



Quote:
> ............................Seen many pages on turning glued up foam blocks
> (more tips welcome).  The problem I have is the hotwire.  Does anyone
> have any electrical schematics?

Aircraft Spruce and Specialty Co. (1-800-824-1930) sells an inexpensive hotwire kit
for about $20. Basically a transformer and a dimmer (to vary the voltage, and
therefore, heat). You make your own wooden frame for the wire itself. They also sell
the nichrome wire.
--

-Andy

 
 
 

How to make a hotwire

Post by David P. Anderso » Fri, 25 Dec 1998 04:00:00


Philip:

You don't need any fancy schematics.  Use an old guitar string, from a
steel string guitar and a automotive battery charger (set at 2 amps).  The
string to use is either of the 2 highest pitch ones, i.e., the ones without
the copper colored windings.  I did this last weekend.  My wife and I
modeled a mountain for snow village houses to sit on out of a piece of
expanded polystyrene block measuring 2 feet x 3 feet x 4 feet.  Of course,
I saved the largest scraps for nosecones!

 
 
 

How to make a hotwire

Post by Rocketwr » Fri, 25 Dec 1998 04:00:00


Quote:
>Aircraft Spruce and Specialty Co. (1-800-824-1930) sells an inexpensive
>hotwire kit
>for about $20. Basically a transformer and a dimmer (to vary the voltage, and
>therefore, heat). You make your own wooden frame for the wire itself. They
>also sell
>the nichrome wire.
>--

>-Andy

This is one slick tool Andy has. I used it to shape my nosecone for my Arcon
project and we also used it to make the 14" diameter nosecone on Andys 5X scale
up of the Fat Boy. It also has adlustable heat settings.

Ray Halm
Prefect / Secretary
Tripoli Western NewYork #85

My Photo Archives     http://members.aol.com/rocketwrks/rckt/photo1.htm

 
 
 

How to make a hotwire

Post by bob fortun » Fri, 25 Dec 1998 04:00:00


Quote:

> Philip:

> You don't need any fancy schematics.  Use an old guitar string, from a
> steel string guitar and a automotive battery charger (set at 2 amps).  The
> string to use is either of the 2 highest pitch ones, i.e., the ones without
> the copper colored windings.  I did this last weekend.  My wife and I
> modeled a mountain for snow village houses to sit on out of a piece of
> expanded polystyrene block measuring 2 feet x 3 feet x 4 feet.  Of course,
> I saved the largest scraps for nosecones!

Hey David,

Just wondering if the hot wire could be used with a template.  From
seeing the construction pictures on Ray Halm's site and watching the
video tape "RocketTime", hosted by Andy Schecter, it looks like the hot
wire is used just to define the rough shape then it's turned on a lathe
of sorts to get the final shape.  Instead, I wonder if the wire holder
could follow a strong template (1/4" masonite) which was set in a jig of
sorts. Make one pass following the template precisely, turn the NC a 10
or 15 degrees and ride the template again.  Repeat this all the way
around the rocket and it seems the shape would have to be precisely
defined as long as the NC and template did not move and the hot wire was
properly guided along the template.  Some sanding and it's done. Then
again it might be a bit lumpy and require a *lot* of sanding, I dunno.
Says a lot for spinning it up on a lathe if one had a lathe.

Remember, this is coming someone who has never used a hot wire before so
I don't know beans about it. Just thinking out loud in preparation for
making a 6.56" NC of my own.

Bob Fortune