Hey guys, Let me start off with saying I'm no electrician. Short of changing an electircal outlet I can't do much. So I tackled the hotwire thinking it would be a quick project. I tried the Instructables.com one with the transformer/dimmer switch. Tried a harbor frieght battery charger. Tried a foam cutter with a lengthened blade. Tried a soldering iron with modified bit. And all I've gotten to show for it is a slight tingling under my scalp a couple of times. Not sure if my bow is gounding the electricity (or if that's even possible). So now I've had a block of glued Home depot foam with rocker templates sitting in my garage for 2 months and a wife quickly losing patience with the mess. Any advice, or preferably hotwires, for me?
(www.acp-composites.com)& (www.hotwirefoamfactory.com)
I got the Instructables DYI hotwire to work without any fuss but I am a contractor by trade.
Good luck,
transformer/dimmer switch. harbor frieght battery charger foam cutter with a lengthened blade. soldering iron with modified bit
You must be kidding?
Just think of all the time and money you could have saved doing it right the first time?
You buy a variac and thats it.
I've made 100's of blanks if not close to a 1,000 with a variac. I need a blank no problem!
10 minutes and you done.
No wonder you wife is losing patience!
Surfding
If you take the two outputs from your dc source and hook them on a length of wire it should heat up. Matching the gauge and type of wire to your power level and length of wire is probably the problem.
surfding. is that what variacs look like these days? LOL, the one I use must be a ''vintage'' piece. It looks about the same age as a well-used Skil 100.
Sounds like you're skimpin' on the ni-chrome wire eh? If that's the case, you'll never get it to work. I threw mine together with a solid state battery charger with 6/12V setting ($5 fleamarket special) and some 22ga ni-chrome I got on ebay. Works perfect on the 6v setting, and I added a momentary switch on the bow for control.
It's really as simple as MD says -hook it up to both terminals and it will heat the wire (or burn it or trip your breaker). If you want to give it a try with some of this wire I've got left, PM me with how much you need and I'll throw it in the mail for ya.
Very cool of you to offer the wire although I think that was the one thing I got right. 26gauge Nichrome from amazon.com. Is it possible the battery charger has a breaker in it to keep it from heating the wire? Or maybe the bow is grounding it? Suppose I should just suck it up and by the variac but since none of the other ones worked I wasn’t really looking forward to another $50 down the drain. Any chance the terminals on the bow aren’t conducting the current? Questions questons I know, maybe I just need new bow plans.
Wire's not heating, slight tingling....
Is your bow conducting?
What's this about ''terminals''? Alligator clips on end of supply wires are about as fancy as you need to get.
The terminals are just the bolts that the wire is wound around at each end of the bow. I attach the clips from the charger to them and plug it in but nothing no heating nothing. I’ll try to post a pic of the bow when I get home hopefully that will clarify it. The battery charger seemed like the simplest way to go. I was pretty surprised that didn’t work.
Asked the same question (almost) myself in the thread Hotwire Wanted. Much of the same has been listed here in this thread. Check the archives. You can either buy it or build it. Mcding
I'm in North County. I have a hot wire rig complete with old school Variac. The only money you need to spend now is for the 6 pac of Stone Pale Ale you are going to buy me when I hot wire your blanks.
Is your block of foam less than 24" wide?
What type of glue did you use?
What are your rocker templates made of?
Do you want stringers?
I work lots of odd hours but I'm sure we can work something out within the next month. Once you see my hot wire rig you will be able to make your own using all the stuff you already paid for. We've cut several blanks using a 12 volt battery charger. Send me a PM
Have a great day
Ray
There ya go....
See stingray, will hotwire for beer! Take your ''parts'' and I'd bet he can figure out your system difficulty too.
I use single strand steel leader wire from a fihing shop. This helped issues I had with the wire not getting hot (not enough resistance) and being too weak.
Hi Mike: Doesn't really matter the age or method as long as it gets the job done! Here's some things that helped me simplify things when I had my larger shop:
http://www.hpalloy.com/alloys/descriptions/INCONEL625.html Is the wire that I use.
$104 buck cheap I have 2 of these. One to cut rocker profiles and one to split for stringers. The one I posted is only $49. Greg Lohr was using a simple variac when he showed us how 4 years ago at Cerritos College after the Clark Shut Down and we were al scrambling for blanks that's when I bought a few truck loads of XPS and a few semis of EPS. We made as many as 25 blanks a day at on time including stringers and glue up. Inconel wire is what you will find on the Hot Wire CNC machine. One of my bows has the same InconeI wire for over a year. I bought 300 feet of it. It will last my life time. I have some real good tools for making blanks. It takes minutes to pop one out. It's a no brainer. My 13 year daugther can make them. I had the neighbor kid making 10 a day after school for a over a year. I thought this method of making blanks died a long time ago. Brings back memories! There's no money in blanks. However there a necessary evil.
Here's of photo of the Variacs I have.
Ebay is a better source that Harbor Freight! I'm not lying. Really!
Surfding
Hello bfrenck,
I got your PM's...We just have to work around my odd hours....
We're working with white 1# EPS foam ? Right ???
Ray
Ray,
I believei t is 1#. It's just the styrofoam insulation with the blue wrap on it from home depot. Feels light I can tell you that.
Hey all. For anyone using variacs: Is it overkill to use a 20A variac? Or is it okay since it’s metered? Just snooping around ebay and I see lots of higher amperage variacs.
Thanks.
I OWN TWO 20 AMP VARIACS. THEY HAVE MADE A LOT OF BLANKS.
THEY ARE METERED SO I DON’T UNDERSTAND YOUR QUESTION?
Lets say that the Variac that Surfding posted is a 1985 Corvette.....
...Well....
...the one I'm using is more like a 1963 Nash Rambler.....mine has a 10 amp fuse if that matters....on / off switch is broken......Free, free, free.....
Works great......The blank got cut...No problem...Thanks for the Stone Ale...taste so good.....
Ray
In my opinion it is overkill to use a variac at all.
I've nailed an extra 3 feet of cutting wire to the wall. Then I checked what the best length for the cutting wire is so that i has the right temperature for the given power source. Lets say it is 3 feet.
My big cutting bow is 2 feet so I put an extra foot in series with the wire on the wall (aligator clips)
My small cutting bow for railbands etc is 1 feet, so I put 2 extra feet with the wire on the wall in series.
You can even make marks on the wall for the various "settings" you use.
Erwin