Power source for foam cutter

Reply

  #1  
Old 12-28-19, 02:09 PM
D
Member
Thread Starter
Join Date: Nov 2019
Posts: 9
Received 0 Votes on 0 Posts
Power source for foam cutter

i built a foam cutter and have been using a schumacher battery charger plugged into a reostat as my power source for several years. trying a different schumacher this morning, i get no power until the reostat is like halfway and then the battery charger comes on full. no good. the thought occurred, can i use a common power adapter for electronic devices like a laptop instead? i have one that puts out 2.6 amps dc. i would run the schumacher at 2 amps and check it down to about 1/3 power. can i do the same with an adaptor?
thank you!
 
  #2  
Old 12-28-19, 02:17 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 60,936
Received 1,351 Votes on 1,249 Posts
I doubt a laptop charger would work. A desktop supply may work. You might be able to use the high amperage 5v section. Otherwise you could try the 12v section.

I ran my foam cutter on a 10A 12v transformer and a variac.
You need low voltage and high current.
 
  #3  
Old 12-28-19, 02:35 PM
D
Member
Thread Starter
Join Date: Nov 2019
Posts: 9
Received 0 Votes on 0 Posts
what size where your foam cutters?
 
  #4  
Old 12-28-19, 02:57 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 60,936
Received 1,351 Votes on 1,249 Posts
I have no idea what size it is...... it's big.
 
  #5  
Old 12-28-19, 05:20 PM
J
Member
Join Date: Sep 2002
Location: welland ontario
Posts: 7,734
Received 300 Votes on 257 Posts
The problem with most electronic power supplies is they have a regulator inside to maintain the proper voltage output.
What you need is a cheap unregulated supply. Something with an AC output instead of a DC output would probably be better.
 
  #6  
Old 12-28-19, 05:21 PM
D
Member
Thread Starter
Join Date: Nov 2019
Posts: 9
Received 0 Votes on 0 Posts
cool.
laptop adaptor did not work. heard a little knocking sound where the wires attach to the cutter..
do you think a variable speed lionel train transformer would work?
i'm forced to do the macgyver thing...
 
  #7  
Old 12-29-19, 02:16 AM
A
Member
Join Date: Aug 2015
Location: USA
Posts: 624
Received 23 Votes on 22 Posts
might read up on it a little more to see what you need, wire length and gauge will play a big role in how much voltage and amperage is needed many will use a dimmer so they can regulate it some but the thicker the wire the more amperage is needed to reach temp and the longer the wire the more voltage is required to overcome resistance of the wire the site below should help you determine what size transformer you would need.
https://www.jacobs-online.biz/wire-x..._selection.htm
 
  #8  
Old 12-29-19, 07:15 AM
T
Member
Join Date: Oct 2005
Location: USA
Posts: 1,693
Received 47 Votes on 46 Posts
Allan is correct; u need to measure the load resistance to start any design. I might consider either a 6 or 12volt lead acid battery as the power source, if this is for a short term use.
 
  #9  
Old 12-29-19, 07:18 AM
J
Member
Join Date: Sep 2002
Location: welland ontario
Posts: 7,734
Received 300 Votes on 257 Posts
If the train supply has enough power it would likely work.
 
  #10  
Old 12-29-19, 10:19 AM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 60,936
Received 1,351 Votes on 1,249 Posts
The problem with this setup is that the cutting wire appears as a short to most power supplies. That's what happened to your laptop supply. Many train transformers were around 90 watts so that may work.
 
  #11  
Old 12-29-19, 10:39 AM
J
Member
Join Date: Sep 2002
Location: welland ontario
Posts: 7,734
Received 300 Votes on 257 Posts
I used to use a variac. Start at zero volts and turn up until wire was proper temp. After a few cuts the I knew the settings for each length of cutting wire.
Lionel trains function on AC. The Lionel transformer is probably just a small variac.
 
  #12  
Old 12-29-19, 09:56 PM
D
Member
Thread Starter
Join Date: Nov 2019
Posts: 9
Received 0 Votes on 0 Posts
wow folks. thanks for all the replies.
great link alan.
ya'll were right about the lionel transformer.
my housemate is a train hobbyist.
he gave me 100 watt american flyer transformer from around 1950.
did the trick on a very low setting through a reostat on low.
too much power without a reostat for my 3 and 4 inch long cutting wires.
 
  #13  
Old 12-29-19, 10:35 PM
J
Member
Join Date: Sep 2002
Location: welland ontario
Posts: 7,734
Received 300 Votes on 257 Posts
3-4 inches is some small cutting. I was using 2 and 3 foot wires for cutting airplane wings and parts etc.
 
  #14  
Old 12-30-19, 10:09 AM
D
Member
Thread Starter
Join Date: Nov 2019
Posts: 9
Received 0 Votes on 0 Posts
was that free-form cutting joed? i imagine you had to be paying close attention...lol
i need to cut channels in a strip of foam and also cut the strips.
it's for attaching glass keys to a glass marimba.


 
  #15  
Old 12-30-19, 11:14 AM
J
Member
Join Date: Sep 2002
Location: welland ontario
Posts: 7,734
Received 300 Votes on 257 Posts
No free form cutting. A template was attached to each end of the piece of foam being cut and the wire rode the template at each end cutting. It took a bit of practice. Go too slow or stop and the wire burnt a groove. Go to fast and the wire cooled too much or bowed in the center.

Here is a video that shows it almost exactly how I did it. The guy mentions fishing line. That is also what we used, wire braided fishing line.

https://www.youtube.com/watch?v=-sd0c7Y1XqE
 
 

Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: