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Foam Cutting Power Supply - Train Transformer

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Foam Cutting Power Supply - Train Transformer

Old 10-20-2005, 09:57 PM
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Jim_Purcha
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Default Foam Cutting Power Supply - Train Transformer

Has anyone used a model train power supply/transformer as a power source for foam wing cutting? If so, what was the output amperage and voltage? Thanks for your help.
Old 10-21-2005, 12:18 AM
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majortom-RCU
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Default RE: Foam Cutting Power Supply - Train Transformer

I tried a couple model train transformers, and could not get enough heat out of them. I'm currently using a Variac, bought used from electronics surplus store; still a bit expensive, but gives very precise control of heat for good control of cuts. I've heard people say they like automotive battery chargers. I kinda like AC for heat, because I can tell how much heat I'm getting by the hum in the wire. You don't need a lot of heat, so if I hear a loud hum I turn the knob back close to zero and come up very gradually with the wire resting on a piece of test foam. As soon as it starts just slowly cutting through, that's the setting I use.

Be careful with this stuff, because you can easily feed enough voltage to melt the wire--potential fire hazard!

I tried the wall dimmer switch, but that was a little too coarse in the way of control; I now use the dimmer switch as my on/off switch to the Variac, and reduce the voltage to the Variac to give me even better adjustment to the cutting wire.
Old 10-21-2005, 05:53 AM
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Default RE: Foam Cutting Power Supply - Train Transformer

Check out this link: http://www.nsrca.org/technical/tip_t...wer_supply.htm

A very good power supply that provides a degree of safety from electrical shock.
Old 10-21-2005, 06:54 AM
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Jim_Purcha
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Default RE: Foam Cutting Power Supply - Train Transformer

I was going to build this unit. but the costs for parts ran into $100.00 before the case which is nolonger available. Your'll in Katy, Texas. The fabrication shop I work for supplies components to a few companies in Texas, I've been to around NW Houston area and Katy. Katy seems like a nice place to live. Where do you fly from? Space City RC or NW Houston Aeromodelers. I been to both and met quite a few flyers there. We're nice people.
Old 10-21-2005, 10:23 AM
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Default RE: Foam Cutting Power Supply - Train Transformer

jpurcha

I'm a little surprised at the parts cost you mention (Canadian $ ?) - I built one of these a couple of years ago for around $50. My son uses it to cut wings for C/L combat planes - the thing gets lots of use and has not demonstrated any weakness. I'd still choose it for $100 (and I have a big Variac).

I'm southeast of Katy proper - an area called Cinco Ranch. I generally fly at Scobee Memorial Field (in George Bush Park). Next time you're in the area, give me a call.
Old 10-21-2005, 05:18 PM
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Jim_Purcha
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Default RE: Foam Cutting Power Supply - Train Transformer

When you add in the additional cost of not having any chemicals to etch the circuit board, the cost to make the board. The mark up on the Canadian prices are at least 50% greater than the US price. I might bite the bullet and make one. It still cheaper than having a foam wing cut at $30.00 a piece + shipping and handling.

Might be in the Houston area next month.
Old 10-22-2005, 08:12 PM
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Default RE: Foam Cutting Power Supply - Train Transformer

I bought a variac off of e-bay for around $65 US. (it was the second one I bought - the first one at $45 burnt out the first time I plugged it in).
Old 10-22-2005, 08:41 PM
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Default RE: Foam Cutting Power Supply - Train Transformer

I am curious as to the problems with power from a train transformer. I bought an old style transformer on ebay for $5.00. I am using it routinely to cut foam and find no problem at all. There is ample power to cut in the lengths of wire I normally use. I use 3/32 music wire. One setup is only 7" long. The other is 2 feet long. I still have ample power to make too much heat for the application. Admittedly, I am not trying to cut long wing blanks, but I still believe that I can generate enough heat to do that job too. Is the key the guage of the wire being used?
Old 03-31-2009, 04:03 PM
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icerinkdad
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Default RE: Foam Cutting Power Supply - Train Transformer

No problems at all as far as I can see with most older larger train transformers. The new ones are a bit small and can overheat. I use a auto battery charger from Sears (honey I want to be sure you can get your car started...) and a home made 36" bow with .012 or .015 control line seven strand flying line. To get an idea how well it works go to youtube and type in foam wing cutting. That should take you to an 8 minute segment of the foam cutting video that my son sells for me on his web site. It really is easy to cut your own wings by hand.
Bob
Old 04-08-2009, 03:52 AM
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Default RE: Foam Cutting Power Supply - Train Transformer

Train transformer on a nichrome wire bow works fine here.
Old 04-08-2009, 09:29 AM
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jib
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Default RE: Foam Cutting Power Supply - Train Transformer

Cool. New life for the old ZW.

Jack
Old 05-17-2013, 02:36 PM
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Default RE: Foam Cutting Power Supply - Train Transformer

So how many watts do I need for small jobs?
Old 05-17-2013, 05:09 PM
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Default RE: Foam Cutting Power Supply - Train Transformer

Regarding the variac...is it dangerous? I used to hear stories that it was. I have one that I have used several time and fortunately I never shocked myself. What type of output does it generate, and is it safer to put a transformer upstream?

Kurt
Old 05-17-2013, 05:31 PM
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Default RE: Foam Cutting Power Supply - Train Transformer

Kurt, I have a variac and 51"bow for cutting quickie wings, I use .010 316SS saftey tie wire. Can't tell you what the output is but it can cut a wing as slick as deer guts on a door knob. Checking with an indicator they don't vary much over .01"
Old 05-17-2013, 08:42 PM
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Default RE: Foam Cutting Power Supply - Train Transformer

American Flyer No. B4 100 watt with circuit breaker, 7 to 16 volts. I've been using this for about 50 years. Have records to prove over 440 cores cut. The total is likely over 500 cores. Mostly short bows with all kinds of nicrome, stainless steel, and guitar strings. The three bows I just went and measured are 22", 28" and 36". If the price is right, try it? Good luck, Greg
Old 05-17-2013, 08:48 PM
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Default RE: Foam Cutting Power Supply - Train Transformer

The master has spoken
Old 05-17-2013, 08:56 PM
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Default RE: Foam Cutting Power Supply - Train Transformer

Vic, You are too kind. Greg
Old 05-18-2013, 04:09 AM
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Default RE: Foam Cutting Power Supply - Train Transformer

To add some idea of what will work, the train transformer used here is a Lionel, 50 watt, 8-15 volt and will run a 44 inch bow with nichrome wire at about a 3/4 power setting.
Old 05-18-2013, 08:26 AM
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jester_s1
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Default RE: Foam Cutting Power Supply - Train Transformer

Going the inexpensive route, I have one made with a 12/24 volt radio shack transformer and a light dimmer switch. The 110 goes into the dimmer first, then the transformer. I put three leads out on my homemade project box- one common ground and two power so that I can have 12v or 24v power for different length bows rigged with 30 pound stranded fishing leader. The total cost was about $30 and some scrap wood.
Old 05-20-2013, 03:46 AM
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Default RE: Foam Cutting Power Supply - Train Transformer

Plain old Hobbico/Horizon 12v battery charger works ok with steel control line flying wire. Have also used 12v charger normally used for your full scale car with a rheostat installed in the enclosure to adjust power into the device from the wall. Some hobby batteriy chargers can also be used, Astro Flight 110d for example.

My rig draws just under 1 amp at about 8 volts as I remember.
Old 05-21-2013, 07:03 PM
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Jim_Purcha
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Default RE: Foam Cutting Power Supply - Train Transformer

I've gone this same route off of youtube videos'. It cuts foam nice. Just haven't tried in for wing cores yet. Going to make some ace 1/2 A cores from scrap foam.

Jim
ORIGINAL: jester_s1

Going the inexpensive route, I have one made with a 12/24 volt radio shack transformer and a light dimmer switch. The 110 goes into the dimmer first, then the transformer. I put three leads out on my homemade project box- one common ground and two power so that I can have 12v or 24v power for different length bows rigged with 30 pound stranded fishing leader. The total cost was about $30 and some scrap wood.
Old 05-22-2013, 05:03 AM
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Default RE: Foam Cutting Power Supply - Train Transformer

I picked up a Hammant and Morgan train transformer somewhere for the purpose of a hot wire cutter, as well as a Variac .  I was previously using a 6A car battery charger which was a bit cool.  Then I used a 10A and it was ok.  no dimmer switch or anything.  30" .015" solid wire.  I tried stainless, nichrome and steel wire.  The nichrome wasn't thick enough or something.  just didn't work right.  I haven't tried the train transformer or Variac yet, just have too many wings floating around.  Good to know it may work.  There are a lot of adjustments on it.  It has two outputs, and half wave and resistance switches too.  Seems to be 12 or 16 v and 1 A.  I will try to find time to test them out maybe.  Other more pressing projects for a while.
Old 05-24-2013, 07:15 PM
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Default RE: Foam Cutting Power Supply - Train Transformer

Can I use this with .062" (1?16") music wire to cut out foam for my retracts and etc?

http://www.yoyo.com/p/lionel-cw-80-80-watt-transformer-132942?site=CA&utm_source=Google&utm_medium=cpc_Y&utm_term=XXY-120&utm_campaign=Google&CAWELAID=1324525707&utm_content=pla&ci_sku=XXY-120&ci_gpa=pla&ci_kw={keyword}

I actually own one of these...

Brian
Old 05-24-2013, 07:56 PM
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Default RE: Foam Cutting Power Supply - Train Transformer

After having cut a bunch of wings, fuse, and other projects like a lighthouse for my daughter. The best advice I can offer is give what you have a try.
Old 05-24-2013, 10:20 PM
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Default RE: Foam Cutting Power Supply - Train Transformer

Will do. Thanks!!!

Brian

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