More power supplies

I've used an old computer power supply, also a Weller soldering gun. Take the heavy wire out and run your power wires from the gun to the cutting end like Fritz has shown. Also I've used heavy copper wire, 10 gauge, with the soldering gun to carve foam.

One thing Fritz didn't mention. The fumes are toxic so make sure you have plenty of ventilation. Also keep a fire extinguisher or other means of putting out a fire. It will catch fire if your wire gets red hot. You don't want to burn your railroad room and house down or have to remove that black soot from the wall and ceiling. 

Carve safely.

Bernd

Good Point about the Fumes

Always cut foam in a ventilated area.  Resist inhaling the fumes. 

I like the solder gun to carve idea.  I gotta try it!

Also the size of my wire:  when  it get red hot...it melts and connection stops immediately.  But it doesnt hurt to be ready if it does flare. 

Thanks for the comments!

fritz

Incorrect Power Supply Design

This to say the least this is a bad design for the power supply.  If what I see is 120 volts of power supplying the transformer it should not be in a plastic food container. It needs to be in a UL listed metal or plastic electrical box or enclosure to contain any sparks or shorts that may lead to a fire. Containing the 120 volts in an electrical box complies with the National Electrical Codes when working with voltages over 50. Please keep safety in mind when designing these types of power supplies.  If this were to cause a fire and loss of property an insurance company could deny payment.

Doug (Licensed Electrician)

Point Well Taken

Thank you Doug,

I was hoping an electrician would weigh in sooner or later.

This IS very important I know.  But as I said in my original post, a fuse and indicator light could be added as well.

I never run this thing longer than what it takes to make a cut.  You should NOT leave it on, nor should you leave it on and walk away.

I only have heated up my plastic wham-bamm container once with the longest trimming session the other night.  So yes it can get warm.  And this only takes about 2 minutes or less.  A metal container would probably be better for long term useage.

Beware guys, but it works great...and I will never use it again after all my base foam is cut. 

fritz

Fritz - That Zip lock container is unsafe

Your basic design is good and appears to do what you want done.

But I have to agree with Doug. I did go to night school for 2 years to get a education in electronics and when you work with Transformers weather they are step down or step up they can get very hot especially when used as you are using it. That little Zip Lock Vacuumed formed container will and I say WILL get hot melt and burst into flames.

If you go to Lowes or any big box Hardware and lumber store go to the electrical department and pick up an electrical box that will withstand the heat your transformer puts out.

Please don't think I'm putting you or your Cutter down I'm truly only concerned for your safety. Please consider acquiring a proper container.

Thanks for reading.

Dan

Power Supply Design

Seriously...this is a dangerous setup. Don't try this at home kids.

Doug

OK - probably a dumb question

OK - probably a dumb question - why?

When you can get a trouble free cutter for $19.95 (and up) why spend so much time and money and have to worry about fire and all the mentioned problems?  

I know, just to see if you can do it.  

Here ya go

a foam cutter for $9.95 from Woodland Scenics.

http://www.buy.com/pr/product.aspx?sku=218239011&sellerid=31454812

Even cheaper, but does it have the right capacity to do what you want? If not you might want to build your own or you can get a bigger one.

http://www.amazon.com/wire-Styrofoam-Cutter-12-inch/dp/B0019VR9KI

Price: $9.95 to $69.99. Information Priceless.

Bernd

Guidance in Box Selection at BigBox store . . .

Thanks DOUG ​for sayin' it! Yeah, this is a "hobby", but I've had this sort of thing "get away from me" before and kicked myself for not doing the "dumb stuff" (like fuses/Circuit Breakers, pilot lights, insulated handles -elec & thermal, etc., etc., etc.). "But it's just a HOBBY . . . " and I make my own [expletive deleted] tools!" Terrific! ​GOOD hobbyists DO! REALLY GOOD hobbyists are experienced with Murphy's Law, too. Come ON, FOLKS! This might be "hobby" stuff, and the SCALE of our trains and scenery might be reduced, but it's REAL "FULL SIZE" poisonous smoke coming off that foam cutter, and while your wife might holler at you for "stinkin up the place" when you use it, she's only getting the 0.1% concentration of what you're trying to see through.

I met fellow hobbyist a my gym a year ago and he was wearing one of those small, "belt-strap" type oxygen bottles when I climbed on the rowing machine next to him. Since we're in NJ, I knew it wasn't an "altitude" issue, so I casually inquired. He was a cabinet maker, and kept working one night late on a project for his daughter out in the garage. He was spraying some high volatility finish on a really beautiful china closet and woke up the next morning in a hospital bed inside an oxygen tent. His wife said that she became alarmed when she woke up at 300am and he wasn't in bed. It seems that she found him, flat on his back, out in the shop, where he'd been for about four hours after he passed out from the fumes, then hit his head as he went over backwards. Thankfully, no concussion, but his pulmonologist said he'd be "wearing supplemental oxygen" for the rest of his life, as his lungs were about 80% shot.

Oh, yeah - this comment was about ELECTRICAL issues. Well, just consider the above as "introductory" material.

FIRST- DOUG is CORRECT when he mentions that the fire insurance adjuster ​will deny a claim​ if it is found that a fire is caused by equipment or wiring "NOT COMPLIANT WITH CURRENT CODE REQUIREMENTS".

​SO DOUG ​or any other Licensed Electrician out there — PLEASE HELP!!! ​What size of a "box" should be used for this project? ​And for those of us who would like to understand how this box-size selection process is done (for "future" projects) ​please cite the current NEC section reference. 

THANKS!

​One other thing — a FIRE EXTINGUISHER is a FANTASTIC idea - but what most people will get, and even be ADVISED to get, will be a ​DRY CHEMICAL​ type. If you do, just don't EVER USE IT! ​The ​MESS ​that it makes (yes, while effectively saving your house!) will come close to motivating you to trashing your whole layout and starting over!

My recommendation (I'm a certified industrial safety inspector for a major utility company) is a CO2 (i.e., Carbon Dioxide) fire extinguisher which will do just as quick a job and won't leave the powder all over the place that a dry chemical job does. The "dry chemical" is extremely fine, and will get inside just about anything within ten feet of the application point. ​IT'S A CERTIFIED KILLER OF ANY ELECTRONICS IT TOUCHES, AND WILL GUM UP ANY FINE MACHINERY IT GETS INTO!!!

​ONE CAUTIONARY NOTE: CO2 is NOT oxygen, ​so if you discharge this type of fire extinguisher indoors, you should leave the room​ IMMEDIATELY, and ventilate thoroughly to expel this HEAVIER THAN "AIR" gas. You'll have saved your layout AND your house, AND will be able to get back to work in a half-hour or less! (Just don't forget to have it re-charged!)

Let's < < THINK and have < < FUN with this HOBBY!!!

Just remember that HOSPITAL, AMBULANCE, and ER time comes OFF your BUILDING/RUNNING time!

Rick

Hot knives

I have a shipping business and we use a variety of different foams for cushioning and isolation. This might be a little pricey for individuals but it is by far the best and most durable foam cutter that I have used. It has a 3" blade and I believe you can get up to 5-1/2" blades. 

It heats almost instantaneously and can cut straight and curved easily and quickly. The blade is very strong and I have used it sidewards to cut out ditches and wide spots. 

Being the biz owner I get to take it home to play with whenever I need it. It certainly is making my all foam base 8'x17' layout go quickly. 

This is far better than any of the craft store hot knives or the hand held wire models. I do still use my Woodland Scenics handheld for more intricate cuts. 

I have bought chinese copies off the internet that worked pretty good for awhile but the original hot knife lasts for years with nearly daily use. 

http://psiservices.com/pack/store/hot-knife/

http://www.demandproducts.com/item.php?l1=&sku=GROUPHKT

I figure we're all adults so you should be able to figure out your own safety needs without my caveats.