View Single Post
Old Apr 02, 2012, 03:42 PM
vtdiy is offline
Find More Posts by vtdiy
low tech high tech
vtdiy's Avatar
Southern Vermont
Joined Feb 2007
3,029 Posts
BTW, this data from Harry D already shows us something to answer a lot of questions often asked.

Example:

"My power supply is a 12 volt supply rated at 2 amps -- will it be adequate for a hot wire cutter?"

Calculation:

If a bow for foam requires about 1.5 watts per inch of cutting wire, and you can supply about (for conservative sake) about 75% of your rated supply in watts:

75% x 12V x 2A = 18 watts

18 watts / 1.5 watts per inch = 12 inches.

Your power supply can supply a wire cutter of about 12" in length -- this can cut 12" wing panels. (if you glue these together as required for a dihedral wing, your simple wing capacity is 24" -- or you can glue multiple panels end to end to make a wing of any length).

"Yes but I want a wire cutter that can cut a 24" panel. What do I need for a power supply for that?

Answer, well you could go with either a 4 amp 12 volt system, or a 24 volt 2 amp system, or any other combination that gives you about 48 watts output.

"Yes but what is the difference between a 48 watt system that runs on 12 volts and one that runs on 24 volts?"

Answer:

The 12 volt system will use thicker cutting wire to achieve 48 watts, while the 24 volt system will require thinner wire. Or, the 12 volt system needs a wire composition of lower resistance than the 24 volt system to achieve 48 watts. You can go with either alternative, or even a combination of the two. A calculator can help you decide which combination is best for you

Of course all of the above requires a little more user data to confirm what the useful wattage per unit length range is.
vtdiy is offline Find More Posts by vtdiy
Reply With Quote