DIY hotwire cutter for styrofoam shaping

[woodsy089]

touching it would not kill you. would heart tho

[969ripper]

absolutely brilliant idea on an AC power to DC power source alternative! i've been adapting rheostats or converting clunky DC regulators that restrict movement. Question: can one reuse old piano wire or guitar string for the hotwire or is nichrome the only way to go? Thanks for the tip

[kicsiildo]

what amps and volts is this set to?

[ChuckerSea]

Very nice. Never thought about the battery charger.

[andyoaryoga]

i have a question :

1 : is it DIY hot wire ?

2 : after you turned it off, is the jolts / heat still there ? or they instantly dissapear ?

sorry for my english bro

[IThrowYellowSnow]

you can use a 6v battery..

[davonizdashit]

what kind of battery charger a car bettery charger?



[devildog2155]

Nice project! Thanks for the info.

[mattthescooterer]

i am making a hot wire cutter about 3ft long. How many amps do you think i need

[chicagolandband]

way ghetto. LOVE IT!

[a4d2d0]

you can make one of these with copper wire and a 9V battery

[PtrOBrn]

can you use a hotwire to cut spongy foam... more like the stuff used for seat cushions?

[5555deere]

@PtrOBrn no you would want to use a thing such as a EZE foam cutter

[MrICE003]

can i use copper wire and can i juz use some batteries in series?

[Flyntendo]

I've tried this, but it is much more convenient just to strech the wire across a de-bladed coping saw.

[pr4wn5tar]

now thats a shabby piece of crap

[lblmer]

Most excellent.

[nickkingdomhearts2]

its like a marshmallow xD

[sylvanenergy]

you do know you can achieve perfect cuts if the wire is guided on either side, or you can use longer wires hell you can even us ribbons of stainless steel. you don't have to butcher the foam up well if you do it nice it will be much easier for you to fill thats for damn sure.

[rtljmc]

thats polystyrene not styrofoam

[rakeliou]

Hi sgraber, I just saw you videos and I found them really interesting. I'm a student from The Netherlands and I'm working with a team on a car project. Our next goal is to make a mock-up, but we have only 10 weeks left. So I was wondering how much time it took you to build the outer shape and if there are other techniques out there that are faster but still nice as your model. Your reply will be much appreciated. Also if you know about sites or other media that can help us it would be helpful

[Craydon]

What do you do after you've shaped the foam? Cover in plastic?

[mataharitu]

i think guitar string can work too..what do u think?

[lotuselanplus2s]

I presume that you coat the styrofoam with something before you glass it,since the resin will destroy the foam,i'm going to be trying to make motorcycle fuel tanks in GF but in one piece with no seams,if i can find a foam that the resin wont dissolve it could be glassed in one piece and then the foam melted out with acetone,

[sciencoking]

yes, this is incredibly useful... The quickest and cleanest way to cut styrofoam i know...

[dacarls]

You can buy "Beadalon" stainless steel beading wire, 7-strand stainless steel, .0018 inch, at any beading shop, or sewing goods store (Jo-Ann Fabrics). Works great at 50 volts AC. Gotta heat up and burn off the nylon coating first. $5 for 30 feet. Apparently one cannot buy .0012 anymore from Hobbytown or other modelling supplies.

[SuperHardcoreguy]

Are guitar strings made of nichrome?? I live in Montreal and i can't find a store that sells nichrome wire. I calles at at least 5 different electronic store and the dont have any of those...

[06metzp]

Well folks, a metal coat hanger at 12v 10A doesn't work! Does make some pretty (but smelly) smoke though... :O

I'll check out the charger later to see if it's ok because I really don't want to buy my brother a new one. :O :O :O

[Ahoudijk]

I tried the guitar string at 12V. This is ok until about 30 cm of wire. If it gets longer, the resistance becomes too high. You would need a 24V transformer. A possibility is to use a dimmer to regulate the temperature.

[toro275]

I have no idea which of those two is the most resistant. You should get yourself an electric meter so you can measure the resistance. If you worry about blowing the transformer you should put an ajustable resistance in your circuit, compare it to a dimmer for the lights in your house. that way you can regulate the amps going through your circuit. You can buy those at a local electric store, they don't cost much.

[LTF85199]

What would you say is more responsible for heating: Volts or Amps?

[toro275]

amps offcourse, else the innerstate electricity lines would be on fire, with 100 000 volts on them :)! 5 or 6 amps going trough your wire should be enough. measure the resistance of the wire and then calculate the amount of volts u need to get 5 or 6 amps trough the wire.

[LTF85199]

thx, I am planning to buy this after trying Guitar Strings for foam Hot Wire cutting, I am using a 12v 4.5A AC transformer. Guitar String worked, but it is slow, I am hoping this wire would get hotter and cut faster, any suggestions. Under the spring tension will it break easier than guitar string or burn out?

[LTF85199]

Nichrome wire I meant to say.

[toro275]

nichrome wire is perfect for the job :)! and ur 12v 4.5A transforme should do just fine. Remember that it's resistance will grow when u use a longer wire, so you'll maybe need more Voltage to get the same amount of amps when you want a longer cutter.

the wire will only snap if you heat it so hard that it glows red. If that happens u need to lower the amps going trough by lowering the voltage over the wire. but since your transformer is limited to 4.5 Amps there should be no problem.

[LTF85199]

Thank you, "since your transformer is limited to 4.5 Amps there should be no problem" I don't know about limiting, It probably is rated to withstand up to 4.5 Amps before it burns out, this is also one of the thing I am concerned : burning out the transformer. Comparing from a guitar string will nicrome wire give you greater resistance bring down amps or will it increase it? I am never totally understood electrical flow.

[SuperHardcoreguy]

Amps

[bennydirty]

Mam takie coś do cięcia skrzydeł w modelach. Drut oporowy wziąłem z żelazka i podłączyłem do transformatora. Tylko że za długi drut nie ciągnie równomiernie. Mój ma 60 cm.

[LTF85199]

can I use regular copper wire for the hot wire?

[BrutusDecimus]

i doubt it

[edsjuice]

once you fibreglass the polystyrene it becomes as tough as steel and the styrene absorbs impact

[Mohoemaids]

Styrene? I work with that chemical in liquid form. I know Goodyear buys a lot of it, and it's used to make styrafoam, as well as rubber components, but never heard anyone use it by it's real name. just a pointless comment i had to make.

[edsjuice]

thank you i appreciate your pointless comment (accurate). E

[Mohoemaids]

your welcome. Allah will see you get 72 virgins Allah Akbar!

[MikeldigraSkyStrider]

Does nichrome need DC or AC to heat up?

[slacker3442]

Either one. I don't think it matters.

[Superjadi]

you need DC

[nerdboy19]

Well, I't should matter if you are using alternating current or dirrect current, you know, like lamps inside, they are the same as a hot wire foam cutter, just smaller and warmer, and then run perfectly on AC powers, so i should see the problem in using AC as well as DC, but anyway, not many people own a AC powersuply, and most have some sort of an DC suply, like an old PSU from a pc or something :)

[bouchardp2]

The two works, since the nichrome wire works as a resistance (nichrome is used to make light bulbs)

[panzuman]

tungsten is used in lightbulbs nichrome gets to hot

[comokate]

Ummmm....did you realize you can pick up an electric foam cutter at JoAnne Fabrics ( in the styrofoam isle)for less than 20 bucks ?? ( and if you use a 40% off coupon which comes out weekly in their mailing list) you can pick it up for much less.

[canadianmaple09]

Wow, that has to be the best-looking car I've ever seen. You'll be able to pick up a lot of chicks with that one dude!

[ponchoyo]

Hi, how much does it cost to make a custom car like yours? Just the body i mean. And how long does it take ot make one?

[venom1316]

it maybe lightweight and fuel economy. but the question is, will the people inside that car will be safe after a crash?

[gupnup]

lol do u acually thing hes making a styrofoam car???

[JKT84]

Yes he's going to make a car out styrofoam guys. The lightweight design gives it tremendous fuel economy and repairs are cheap as hell.

[gangstapenguin]

Bwahahaha x3

[Lexicon1971]

Its big...but nice job

[harpersteven]

are you using AC or DC?

[pbdude725]

AC(lightning bolt)DC of course

[stomp999]

nice man thx

[iamskintly]

way to big and bulky

[j0xIWsNt]

i wonder if it can cut a finger off..

[sgraber]

I think it will just burn the flesh, not cut through the bone. I think the fumes would be more dangerous.

[SuckMeLuckyCharms]

@sgraber I burnt my hand on one, It just hurts like hell. I still have the scar D:

[stevecoterell9]

@j0xIWsNt make one and try it - let us know mate

[IThrowYellowSnow]

@j0xIWsNt its 10amps.. touch it and die

[bob3104558]

Its just a mold!! then he will fiberglass over it. He has a huge website showing how he did it all. BTW GREAT car man!!

[sgraber]

Thanks Bob. Of course you're absolutely right. You can look at the video responses posted above or search my username sgraber to see more videos. I've actually pretty much finished the car and it is street legal. Very quick and very fun.

[murloxjki]

what the fuck dude?! are you making a styrofoam CAR......

[MAPteam93]

why using all this wood?

[jfcuyf]

cool

[farmerrayford]

Very very nice sir... I must say that is impressive.

I wish I knew more about that awesome technique.

Thanks for sharing with us.

[wasaki101]

Where do you get nichrome wire?

[sgraber]

I the wire down at the local hobby store. It's used in making wings and other items for model airplanes. I just figured out that I could use the car charger to supply the voltage to heat the wire.

[zatarraseagull]

Do you remember the gauge of the wire? They sell it online in different thicknesses.

[alliancesigns]

what car is it?

[LongIslandEddie]

I have a video which converts my tig welder into a hot wire for bending acrylic or polyplastic. Battery charger? great power supply! Nice demo video...

[sgraber]

The styrofoam stage was an intermediate process. I made a mold and then created bodywork out of fiberglass from the mold. Now I can make as many bodies as I want from the molds.

[neutron7]

are you making a styrofoam car? wont the engine heat melt it?

[teh4klift]

Really cool. Great for scratch modelers.