Re: [CAD_CAM_EDM_DRO] Digest Number 6138
Posted by
Andrew Werby
on 2008-11-23 12:03:13 UTC
3. Re: "My new CNC testing"
Posted by: "Yahoo" yahoo@... phil_mattison
Date: Sat Nov 22, 2008 4:19 pm ((PST))
Truth is this is one of the few threads I have been following. I was very
glad to see I can make machinable wax from ordinary wax, and can't wait to
give it a try. I already tried using ordinary wax bit it suffers from the
exact problems mentioned here. I was very disappointed after all the trouble
it took to make a block of it. Damned stuff sticks to EVERYTHING.
--
Phil Mattison
[Yes, adding LDPE (Low Density Polyethylene) to white candle-wax toughens it up considerably, making it machine a lot better. But it seems like that would also make it less good for sticking things together - there are special sticky-wax formulations for that. I'd use Gorilla glue for sticking urethane foam pieces together, since it's also made from urethane.
To make your own machinable wax, melt some white candle-wax (aka paraffin in the USA) in a deep-fat fryer, preferably one with an infinite-range control (not just low, medium and high) so you can dial the temperature in precisely. Take it up to about 250F - if it starts smoking it's too hot, and can cause a fire. Then add the LDPE - that can be in the form of plastic grocery bags, but it takes a whole lot of them, or you can get LDPE in pellet form. You want the mix to be somewhere between 1/3 and 1/2 plastic to wax by weight. It gets syrupy as the plastic melts; keep stirring, but let it cool somewhat before pouring it out - the empty fat fryer can burst into flame once it's nearly empty. (Keep the lid handy to clap on if that happens). It will shrink a lot, so it's okay to use a metal baking pan as a mold; once it's cool, it will pop out cleanly.]
Andrew Werby
www.computersculpture.com
Posted by: "Yahoo" yahoo@... phil_mattison
Date: Sat Nov 22, 2008 4:19 pm ((PST))
Truth is this is one of the few threads I have been following. I was very
glad to see I can make machinable wax from ordinary wax, and can't wait to
give it a try. I already tried using ordinary wax bit it suffers from the
exact problems mentioned here. I was very disappointed after all the trouble
it took to make a block of it. Damned stuff sticks to EVERYTHING.
--
Phil Mattison
[Yes, adding LDPE (Low Density Polyethylene) to white candle-wax toughens it up considerably, making it machine a lot better. But it seems like that would also make it less good for sticking things together - there are special sticky-wax formulations for that. I'd use Gorilla glue for sticking urethane foam pieces together, since it's also made from urethane.
To make your own machinable wax, melt some white candle-wax (aka paraffin in the USA) in a deep-fat fryer, preferably one with an infinite-range control (not just low, medium and high) so you can dial the temperature in precisely. Take it up to about 250F - if it starts smoking it's too hot, and can cause a fire. Then add the LDPE - that can be in the form of plastic grocery bags, but it takes a whole lot of them, or you can get LDPE in pellet form. You want the mix to be somewhere between 1/3 and 1/2 plastic to wax by weight. It gets syrupy as the plastic melts; keep stirring, but let it cool somewhat before pouring it out - the empty fat fryer can burst into flame once it's nearly empty. (Keep the lid handy to clap on if that happens). It will shrink a lot, so it's okay to use a metal baking pan as a mold; once it's cool, it will pop out cleanly.]
Andrew Werby
www.computersculpture.com