How Do You Use A Hot Wire Foam Cutter?


So I bought a new toy for myself, namely a hot wire cutter but I didn’t really have much experience with it so I decided to do some research to find out the best way to use it safely.

There are a few steps you need to take before making your first cut.

  • Check the cabling to make sure there are no exposed wires or loose connections
  • Make sure the feet are level and the bed is stable and not wobbling
  • Check the main hot wire before plugging the unit in to make sure it’s clean and taut but not overly so
  • Wear the appropriate ppe such as mask and goggles, something for your hands too
  • Make sure the guides are in the correct position and tight
  • Set the correct temperature for the material you are going to cut
  • Test the wire using a piece of scrap material to ensure it’s not too hot

Once I had gone through the basic safety checks prior to use it was time to have some fun crafting.

How do you cut thin sheets with a hot wire cutter?

If you have a thick piece of foam that you only want a thin sheet from then you will need a taller guide to rest the foam against. Using a large rectangle of wood (even a large cube of foam can suffice) place and set the guide so the edge closest to the wire is at the right distance from the foam.

Once you are sure the angles are true (at 90 degrees) position the foam on its side so you can get a thin wide sheet as needed. Slide the foam along the makeshift wooden guide pushing it gently against the hot wire and keep pushing until a nice thin sheet has been cut from the main block.

Repeat as needed to get multiple sheets from each block

How do you cut angles with a hot wire cutter?

For this type of cut, you need to make some adjustments to the hot wire position. Firstly, after making sure the unit is off and the wire is cool, turn the screw above the hot wire to loosen the top guide and slide it closer to the main vertical support.

This action will slacken the wire so you will need to turn the wheel holding the spare wire to increase the tightness. Make sure you don’t overtighten the wire or it may snap during use. Using a tool like a protractor set the wire to the desired gradient and cut as before.

If you want a really shallow angle, something less than 45 degrees then you can get around this by clamping a guide 90 degrees to the existing guide, you may need extra tools (not supplied) for this though. Using the variation in the main support arm you may be able to get an angle as little as 30 degrees.

If you need shallower angles than 30 degrees a handheld hot wire version may be more useful.

How do you cut circles with a hot wire cutter?

If you have a jig for your wire cutter then you can cut shapes like circles and cylinders with the jig easily.

Place the jig so it will accept the wire and set the guide so it will only move back and forth and not from side to side.

Place your foam onto the nail/pin to keep it in place. Give it a small test twist to make sure it will rotate easily before you begin to cut.

Using the required diameter as a guide, move your foam into place at the right diameter and rotate the foam until you have rotated it 360 degrees, and then move it immediately away from the wire.

Helpful tips: If you want a circle that measures 6 inches across then your diameter is half that. After rotation, you will have the right size.

If you try to cut a smaller circle from your piece of foam then you may end up with a square with a circular hole, be careful when doing this as the foam may stick to the wire if you cannot remove it quickly and cleanly, it may also melt the foam you have just made deforming the shape. Use a low and slow approach to temperature and working speed.

How do you cut cones with a hot wire cutter?

Using a mixture of the above techniques but instead of moving the wire along the main support arm, you can move the whole support arm without needing to change the tension of the wire multiple times.

This flexibility means you can have a great range of cones ranging from tall princess castle types to short fat SciFi dome types.

Set the jig to cut a circle and set the main support arm at the angle you like. This will then allow you to cut near-perfect cone shapes.

How do you cut corner L shapes with a hot wire cutter?

First, you need to cut a square for the desired outside edges and then after you have decided on the width of each leg of the L shape then adjust the guide to match and then make a pass to cut the inside but only as far as the width of the intended second cut plus an extra fraction to allow for the melting cut.

Carefully but quickly, withdraw the first piece along with the first cut and guide foam into the wire for the second cut and you will have cut a smaller square out of the foam but in a way that you are left with a corner L shaped piece.

What foam is best for a hot wire cutter?

XPS foam

XPS or extruded polystyrene is a foam that comes in one solid block. It is known for being less porous and less prone to moisture ingress, but these features as well as the machinery needed, make it a slightly more expensive choice which, in some areas can be hard to source.

Usual colors are blue and pink and can come in a variety of hardnesses and textures but are all are fairly similar. The main differences are how resistant they are to crafting tools.

EPS foam

EPS or expanded polystyrene is the foam we are all familiar with. The large pieces of white foam that come with most electrical products inside a box, molded specifically to shape. EPS is made from tiny balls of styrene that are then heated and molded and/or cut into various shapes as required. Because of the versatility of using small beads to produce complex shapes it has become the industry standard as a protective medium.

Despite its cheapness and availability EPS is very hard to work with. It does cut well with a hot wire cutter but that’s where the ease of use ends. Carving and trying to texture EPS to almost impossible without resorting to heat to melt texture into it, which makes it unsuitable for fine craftwork.

It is, however, perfect for large construction pieces where you need to build up a base and don’t want to use expensive and useful XPS for the job. It can also be covered with texture materials like Sculptamold or clay to cover it.

Where can I buy a hot wire cutter?

The model I use is the VEVOR and can be found easily on Amazon here. comes with a circle cutting jig which I find very useful indeed. Check out my review article showing you it in much more detail.

What Is The Best Hot Wire Foam Cutter? (Tabletop) Reviewed

If you want the cream of the crop then you can go wrong with the Proxxon 37080. It doesn’t come with a circle cutting jig but the guide does adjust so you can cut angled or mitered edges easily.

You can find it on Amazon here.

These machines are great for cutting other materials like glass, for example, but if you prefer to keep it just for foam then check here for glass cutting tools suitable for you and your needs.

If you are on a budget or if you prefer to freehand your cuts then a handheld hot wire cutter may be more beneficial. They allow you to cut realistic terrain easily by chipping away at large foam blocks with ease.

Take a look here on Amazon.

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