Hot wire cutter

[whateg01]

I made and have used a hot wire cutter to cut foam stuff for a couple of years now. I've used it sporadically, but it does the job. When I made it, I read several recommendations for using guitar wire and it seems to work, but it also seems very fragile. If I'm cutting fast enough not to burn the foam, it breaks the wire. If I cut slow enough to not put substantial tension on the wire, it burns the foam. There seems to be a very small window where it just works. Does nichrome wire act this way? I am thinking that maybe, since it's meant to get hot, it might not break as easily when heated. THoughts?

Dave

 

[skruft]

I suggest, contact companies that make those tools or look at their websites.

 

[shawhite]

I suggest, contact companies that make those tools or look at their websites.

Yeah because why would you come on a tool forum and talk about tools.

 

[Larryjones]

I've used shrink wrappers, and they will burn the wire but there is an adjustment to turn the current down. I would try a lamp dimmer on yours and see if you could find a setting that would work.

 

[balrog]

Lots of info here:

http://jacobs-online.biz/index.htm

 

[whateg01]

Lots of info here:

http://jacobs-online.biz/index.htm

Thanks! I don't think I've run across that page before. I've been on a few, but all of them were suggesting guitar wire, which is where I started. I see on one of the linked pages there, that nichrome wire is in fact stronger and shouldn't break like I've experienced. I guess that confirms it, and I guess I should get some ordered!

Dave

 

[gungatim]

I used to work on weldotron's, replacing the heating wire was a semi-weekly ritual. IIRC, the best luck we had was with the nichrome wire with a graphite coating on it. we also had a spray we would use regularly that had graphite in it. this was a hemhorroid ointment line and the tear strip in the plastic always gummed it up more than the regular shrink wrap...if that helps...

how big is your styro cutter? I have a smaller hand held one brand new in the pkg someone gave me, never used it, it's yours for the cost of postage if you want it...it looks like it came from walmart so it may not be of much use to you.

 

[whateg01]

...how big is your styro cutter? I have a smaller hand held one brand new in the pkg someone gave me, never used it, it's yours for the cost of postage if you want it...it looks like it came from walmart so it may not be of much use to you.

I made it with an opening of about 6" and a throat depth of around 15", IIRC. I'd like to put this on my plasma table and the size I currently have is a bit long. My plasma table's working size is about 30" square, so I may have to remake it anyway to get the most out of the table.

Dave

 

[mikegt4]

Hot wire cutters are used for building experimental (home built) aircraft. A quick search will find a lot of info.

 

[whateg01]

Hot wire cutters are used for building experimental (home built) aircraft. A quick search will find a lot of info.

That was where I got started and where I found people using guitar wire. There is a lot of info out there in that area on lasers, too. I don't think I'm ready to take that leap yet, though.

Dave

 

[Milton Shaw]

I have gapped a few pair of wire cutters by cutting wire that was hot that I thought was cold. I would make sure it's not carrying any voltage or current like a neutral wire could and not show a voltage. I know this is not the type of wire he is using but thought it was appropriate to mention this also.

 

[whateg01]

I have gapped a few pair of wire cutters by cutting wire that was hot that I thought was cold. I would make sure it's not carrying any voltage or current like a neutral wire could and not show a voltage. I know this is not the type of wire he is using but thought it was appropriate to mention this also.

As an electronics tech, formerly an ET2, I have seen my share of those situations. Unfortunately, I've been a part of those situations at least once. There's a gal at work who once had a faulty power cord. The end of the cord that plugged into the equipment was making intermittent connection, so she was going to cut it in half and throw it away. Forgot that the other end was still plugged in. That got her attention. We've never let her live that down. (Or the time she blew up my oscope by pumping 500W of pulsed power into it.)

Dave

 

[ovrrdrive]

He doesn't say what kind of wire he used but you might gain some ideas from this vid... Love this channel.

 

[Guster]

Nichrome wire and other alternatives are very expensive here but I found some thin(0.25mm or 0.3mm) stainless MIG wire on a roll for about 1/20th of the cost and has been working well enough so far. I sometimes cut asymmetric wings and hydrofoil sections as much as 3' wide cut at a time and made my powersupply for my cutter using a light dimmer and transformer to adjust it to that Goldilocks zone where it is "not too hot, not too cold, just right"

One modification to my bow is a stiff tensioning spring that allows for a little give in the wire and also take up the slack as needed. This has reduced breakages quite a bit. Also a good indicator of your cutting speed as too much drag in the wire won't give you a decent profile or dimension given that the trailing wire is not cutting in line with the given profile. This can be quite noticeable over 3' of cut in a complex 3d part.

 

[TLCObsession]

Rene wire works great for foam cutting.

 

[whateg01]

Damn...

Typical applications
After burner parts
Turbine castings
Bolts
Other fasteners

Well, I guess that means that it'll take the heat. I hadn't made it to that page on the Jacobs-online site yet, but did now. Looks like for foam cutting, this is the cat's meow! A little more expensive, but in the quantities needed for the home shop, I don't think it's a problem.