Making the Mighty Goliath Hotwire Machine!

Complete instructions for the making of the Mighty Goliath Hotwire Machine. Materials and directions are shown in each step, image notes. See my other instructables for sample work, signs, etc. Creativeman.

Step 1: Additional Instruments Made With Same Technique

I have made several instruments like this, namely to use in a class I plan to hold. I think it is a viable art form and is relatively unknown to the general and artistic community. People find it hard to believe you can get such detail in the lettering. Try it, I think you will like it. Disclaimer: IF YOU DON'T UNDERSTAND THE ELECTRICAL WIRING, DO NOT ATTEMPT! GET QUALIFIED ELECTRICIAN TO HELP. I have used one of these machines for 15 years with no problems, not even a broken wire. So if things don't seem to be working right, you have probably done something wrong. A few additional tips: Try to keep temperature as low as possible. You want to melt the foam, not burn it. Use only with adequate ventilation. Some people may be sensitive to the vapors produced. Use care around the wire! It is hot and will burn you. Don't let young children play with it. It is not a toy.

Step 2: Pieces of Project Needed to Constuct Instrument.

Most pieces of the instrument assembled together for this instructable. The transformer, dimmer control and wires will be added in the next view. View image notes for a complete explanation of the various parts.

Step 3:

Electrical components needed for the machine. All items are listed in the image notes.
Costs: Electrical cord: $1.25; Transformer: $6.90; Dimmer switch: $4.99 (push on/off type); Nichrome wire: I bought 100 feet for $2.50! Wood parts probably add a dollor or so to costs, same with various mounting screws/hardware. So for between $10 and $20 dollars you can have your own hotwire machine. I have seen these on the web for much more money. This machine will accomplish the same thing. I have made larger machines to be able to cut larger pieces of styrofoam, or EPS foam. I just changed the length of wire, the transformer and the sizes of the wood components, obviously.

Step 4: One Example of a Dimmer Control

In this picture, an inline lamp dimming switch is shown. It seems to work ok, although has not been tested over time. This type of control is quite a bit more expensive than dimmer switches used in other models.

Step 5: Closer Look at Arm Assembly

This is a close up of one arm made for the blue machine. All are similar. These two pieces are made of common pine lumber, 3/4 inch thick. The arm it self is about 8 inches long by 3/4 by 1/4in. Pieces are glued and screwed for strenght.

Step 6: Apparatus for Testing Various Components and Wiring Details

This is a helpful item to test transformers, switches, wiring, etc. before final assembly.

Step 7: Details for Mounting Dimmer Switch.

Shown in the pictures are the milling or routing of a depression for mounting the dimmer. Placement of dimmer and knob are shown.

Step 8: Bottom Mounting Piece Details

In this shot, details of the bottom wire mounting piece are shown. A 1/8 inch hole is drilled in the end of the wood piece to accept a 8-32x1in. machine screw. To this screw, the power wire from the transformer and the hotwire itself will be attached. In the center of the bottom mount, a 1/2 inch hole is drilled with a forstner bit. A 1x6in. wood screw with washer is used to attach the piece to the table. By moving the mounting piece slightly in any direction, hotwire can be adjusted to be plumb in two directions and give right angles when slicing through the foam.

Step 9: Top Arm Details

Here, the top arm has been drilled to accept the machine screw as shown. The hole is 1/8 in, and the machine screw is an 8-32x1in.

Step 10: Cutting Stencil for Painting on Name

A stencil is made by selecting the fonts used on the word processor, printing the words out in duplicate, and then cutting the stencil with a craft knife, or scalpel.

Step 11: Making Design Decisions

Shown are various instruments being tested for color combinations, placement of components, lettering choices, and so on. See image notes for more details.