Hi,where can I find nichrome wire in house ?not in shop.

 

Nichrome wire is often used in toasters. It is used in some space heaters. It is used in most hair dryers.

 

Nichrome wire is often used in toasters. It is used in some space heaters. It is used in most hair dryers.

How can I identify whether it is nichrome wire or not?

 

If it is shaped like a spring, is on a ceramic support, and heats up, it's nichrome.

However it is dangerous on many counts to play with nichrome wire, including burns, fire, and electrocution so I'd leave it alone if you don't even know what you are looking for.

 

If it is shaped like a spring, is on a ceramic support, and heats up, it's nichrome.

However it is dangerous on many counts to play with nichrome wire, including burns, fire, and electrocution so I'd leave it alone if you don't even know what you are looking for.

I wanna make foam cutter.so I need nichrome wire

 

I wanna make foam cutter.so I need nichrome wire

You will need to buy some. That will be much cheaper than destroying an appliance, and in any caseit is very unlikely that you will find sufficient reusable wire in them. The wire will be the wrong gauge, coiled in a way you will not be able to undo, or kinked around an insulator.

 

What kind of cuts do you need to make? I made a foam cutter using some welding wire and a welder. The pieces I was cutting were 4' by 8'. Using a 9' length of welding wire and my welder I was able to cut straight lines using a frame I built. However, the wire sagged when heated, so I had to make a spring arm to take up the slack when heated but relax when cooled.

If you're looking for a special shape cutter you can always use an old Weller soldering iron. Remove the tip and make your own tip to the shape you need. Then you need a steady hand or some kind of guide.

 

I wanna make foam cutter.so I need nichrome wire

Why does every one think that? Most all foams don't need or work well when the wire is red hot. And red hot is the only advantage of nichrome or Kanthal. Plain smooth unwound guitar strings work just fine for foam cutters.

https://www.instructables.com/Guitar-String-Hot-Wire-Cutter/

 

I agree that a stainless steel wire is just fine in most cases. Red hot is nice for some applications. I had a wire cutter for acrylic that vaporized the acrylic without melting. Worked great but made a heck of an odor of methylmethacrylate monomer. Recommend doing that outdoors. Don't bother trying with polycarbonate - does not vaporize like acrylic. Red hot inset required but it sure speeds sup the cut rate. Red hot makes a mess on some foams.

 

Why does every one think that? Most all foams don't need or work well when the wire is red hot.

The one I made used solid core (not flux core) steel welding wire. It didn't get red hot. It got too hot to touch, but never red hot. And it cut nicely.

The thing I've experienced with cutting foam using a knife was the little balls of foam that would break loose. I was never able to get clean cuts using anything other than a hot wire. And NiChrome doesn't need to be red hot to cut foam. Hot enough is hot enough. Red hot is not necessary. At least that's been my experience.

 

I don't see it mentioned in this thread so here goes: Please use a transformer to isolate your foam cutter from the power lines, and a fuse on the primary is a pretty good idea to protect your transformer in case of accidental shorting of the secondary. It is best to copy a successful design using wire of the same type and the same voltage across the wire. This will save you a lot of time experimenting, maybe save on materials cost, and assure success.

https://www.instructables.com/5-DIY-Hot-Wire-Styrofoam-Cutter/

If you have looked around you have probably seen many of the read-made foam cutters available from about US $3 and up.

 

Can I use other wire for foam cutting instead of nichrome wire ?

 

Yes, you can use other wire. Just as an example and as mentioned guitar string wire.

I am in the US Cleveland, Ohio suburbs and if I want Nichrome wire I just go to a chart, look up diameter verse resistance and buy it from McMaster Carr supply. Then too since I have no clue as to your location I can't make a suggestion as to nichrome wire, guitar strings or for that matter anything else or where to buy it. Dick gave a good link in post #11.

Ron

 

Tom, I made a foam cutter and was cutting very thick foam, it worked ok for short cuts but long ones cooled the wire and was a stringy mess. I used an old computer power supply converted into a bench power supply and tried different gauges and volts to see what worked best. Wire tension was important on making a cutter yourself or the wire bows as you "cut" the foam. A rheostat is a must to control the power.
If I was to do it again, I would buy the foam cutting pen/knife. Oh Ni-chrome wire is used for those e-cigs vapor things and you may be able to buy a length you need from a smoke shop. The big shops make their own coils for modified units and have it on hand. I bought a whole box on Amazon of 6 different gauges and used about 1' from each roll testing which gauge worked best on the material. I should have bought the foam pen/knife.
I cut some braided automotive wire wrap for a classic car harness and used my solder gun with a piece of 14 gauge copper wire flattened in the middle as a blade. It worked better than the foam wire cutter I made, smoother edges and cut through all the weave effortlessly.
Cheers.

 

Tom, I made a foam cutter and was cutting very thick foam, it worked ok for short cuts but long ones cooled the wire and was a stringy mess. I used an old computer power supply

I think if you do some deep research you'll find that the problem you had was due to your choice of power supply. DC will work but not as good as AC. All of the industrial and store bought hobby cutters use AC, many people just use a 24V HVAC control transformer. But what Dick said is very important, what ever is used needs to have a transformer for mains isolation.

 

I used a 9 foot length of welding wire to cut 8 foot sheets of 2 inch foam. Cutting through the entire 8 feet would take about 5 seconds at whatever voltage my welder put out. Off hand I don't know what that voltage is - it's probably 24 volts. And I don't know how much current I was drawing, I only know the welder handled it nicely. I don't know how hot the wire got, I only know it cut straight and cleanly. The only issue I had was with the wire becoming slack when hot. That's why I put a hinged arm on the operator end. The arm had a spring to keep tension on the wire, but if the spring tension wasn't enough I could just put a little extra pressure on the arm by hand. I just had to be sure not to touch the hot wire.

 

Yes, you can use other wire. Just as an example and as mentioned guitar string wire.

I am in the US Cleveland, Ohio suburbs and if I want Nichrome wire I just go to a chart, look up diameter verse resistance and buy it from McMaster Carr supply. Then too since I have no clue as to your location I can't make a suggestion as to nichrome wire, guitar strings or for that matter anything else or where to buy it. Dick gave a good link in post #11.

Ron

Cheap thin steel wire will work, but it will expand as it heats and so you do need a spring to keep it tight. As streel wire sizes seem to be odd numbers. About #17 will be a good choice between drawing too much current or stretching too much.

 

Cheap thin steel wire will work, but it will expand as it heats and so you do need a spring to keep it tight. As streel wire sizes seem to be odd numbers. About #17 will be a good choice between drawing too much current or stretching too much.

I can certainly agree with that. As pointed out earlier guitar strings using steel and nickel should work out fine with spring loading. I also saw mention of welding wire and assume tungsten. There is no shortage of materials which should work. The thread startercan choose whatever trips his or her trigger.

Ron

 

The last time I checked, guitar strings cost a whole lot more than even nichrome wire. There is also fairly cheap stainless steel wire used for lashing things, which is also available. The qualityof wire used should depend on how long you need the setup to work. For a one-off project almost any kind can be used. Production tooling will demand better.

 

The last time I checked, guitar strings cost a whole lot more than even nichrome wire.

Guitar strings are a whole lot cheaper than anything else if you know a guitarist or if you ask for the used scraps at a guitar store. The used strings may not be perfectly in tune when used in the heater but they cut foam pretty well.