Instructables
Almost ready for Halloween, but you find an empty space in your yard you just can't fill? Add a foam tombstone! I'll show you how to make your very own hot wire foam cutter for cutting the shape, how to carve out the letters, and how to paint your creation!
 
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Step 1: The HotWire Cutter

Picture of The HotWire Cutter
The first thing we'll make is the HotWire Cutter. You could try using a saw to cut the foam, but if you do that, you'll find yourself in a wonderland of statically charged snow. What you need is a Hotwire cutter! The one you'll make has a vertical wire and deep throat so you'll have no trouble carving even the most elaborate designs. You can vary most of the dimensions to fit your needs or preferences.

Materials:
- A short (about 6" long x 1.5" x 1.5") piece of wood
- A long (about 18" long x 1.5" x 1.5")piece of wood
- A plywood base (about 1' x 2')
- Thin craft wire (24-gauge or smaller, I think)
- Electrical wire
- Rubber feet
- 2 small eyelet screws
- Power supply (mine is 12VDC, 1.2A)
- Ruler

Step 2: Build the Frame

Now, we will begin to build up the frame. Start by screwing in the 6" piece into the base from the bottom. You will likely need more than one screw to keep the wood from swiveling. Next, screw the 18" wood into the top of the 6" wood. Again, more than one screw will be necessary. Try to keep the arm parallel to the base (when looking down upon your creation). Mine isn't.
xboxteen015 years ago
This is pretty cool. But not to ask a dumb question but what are the consequences of making something like this? Electrical shocks, house fires, etc. Ive never seen the plans for one before so for all i know this could be the only way to do it. Good Instructable though.
Radioactive_Legos (author)  xboxteen015 years ago
There are indeed some risks involved, but they are easily overcome. To prevent fire, just keep flammable items out of the immediate area you are working in. Also, to prevent electric shock, just don't touch the exposed wires. Overall, however, it's a pretty safe piece of equipment.
even touching the exposed wired you will only get a painful shock , nothing life threatening , though with a pace maker it's posible . more likly than not if you touch the cutter while its on you'll get burnt and not shocked , as the power wouldn't flow into you ( more resistance in you to a ground than in the wire )
ORDuckFan3 years ago
I love the idea of using a hot glue gun tip for carving the letters - we tried to use the same effect by liberal use of a sharpie pen to melt the foam, but yours is better.

For a "really" weathered look, we have tried painting the letters with a small paintbrush dipped in gasoline. You have to go very slowly and cannot do fine details - but it achieves the desired effect.
A paint brush dipped into gas will melt foam in fast. (Found that out when I was young and getting gas from dads car)
Walke2jd4 years ago
What kind of foam did you use (looks like maybe the pink insulation foam sheets?)?

Also, how do these hold up outdoors? I decorate Oct. 1st and leave it through Halloween. Any way to add laquer or some other protectant to get more life out of these?

Awesome instrucable!
jumpertoad4 years ago
who can die of a splitting headache?
zachninme5 years ago
Awesome job!
Just a suggestion: you might want to rename the instructable to just Hotwire Cutter, because this could obviously be extended to general foam cutting. (And you'll probably get more hits ;-)
Radioactive_Legos (author)  zachninme5 years ago
Thank you. I considered that, but then I forgot to change it. I have 30 keywords, though, so I don't know if hits is a problem :)
HotWire.jpg
The problem is more of someone searching for the latter, finding this, and thinking it won't work. Its just my opinion, though. I'm waiting for the tombstone-making instructable...
Radioactive_Legos (author)  zachninme5 years ago
Good point. I will likely change the name soon. Also, if my homework allows, I may post the tombstone instructable within the week.
If you change the title, you will not change the url.
Make the wire longer than you need to and you will be abl to vary temperature a bit by changing your electrical connection points. A spring or weight is recomended because your wire will stretch a good inch once it gets hot. I rigged something like this up once to cut out a scale car body for an art project. I used a guitar string (e string if I remember correctly, would try a B next time), a computer power supply, some alligator clips, scrap wood, and something heavy to maintain tension. It was fantastic.
The first time I turned it on, it bent way out of shape. Now, however, it doesn't do it as much. The weight/spring is definitely a good idea, though!
HotWire.jpg
rimar20005 years ago
I suggest you to add a spring in the lower extreme of the wire, so that when this stretch upon being heated can continue tense. Under the table, it is invisible. GOOD INSTRUCTABLE.
Radioactive_Legos (author)  rimar20005 years ago
Thanks. In my original design, I actually had a spring in the arm behind the little wood piece (labeled tensioning spring). I forgot to draw in the pivot, though...
HotWire.jpg
Padlock5 years ago
haha. you said deep throat... "The one you'll make has a vertical wire and deep throat so you'll have no trouble carving even the most elaborate designs."