forget the spring - make it like an old skool bow saw, using loops of twine / string / rope. then get a piece of wood between the loopage and wind the tension up windlass style. tension can be adjusted turn at a time while in use
Using a variac straight off the mains power makes this an electrocution hazard. Better to run a low voltage transformer off the variac so it cant go over around 40v and is isolated from the mains.
Burt Rutan just uses a wing nut on the end of the wire and a u shape. He states it's for light weight and ease of use. He also adjusts the wire after warming to correct cutting temp due to heat stretch.
Just a thing I noticed: When un-bowing the chord with the spring, do it while putting tension on the spring, and taking tension out of the hotwire, or else, u might tear the hotwire, with the added tension of un-bowing. In other words, press with yout foot against the wood-end near the spring ("spring-proximal wood-end"), pull an the opposite chord´s end thus stretching the spring, and un-bow it while holding the spring-distal wood-end stable.
You can always tell who's the engineer, he's the one that over engineers the project. Surfboard shapers have been using hot wire cutters for decades and the bow of choice is the simply C shape bow with the cutting wire and a spring attached to take-up the slack. Classic KISS: Keep It Simple Stupid.
forget the spring - make it like an old skool bow saw, using loops of twine / string / rope. then get a piece of wood between the loopage and wind the tension up windlass style. tension can be adjusted turn at a time while in use
also it's easy to slacken for storage
Using a variac straight off the mains power makes this an electrocution hazard. Better to run a low voltage transformer off the variac so it cant go over around 40v and is isolated from the mains.
Really high-quality guide, thanks for including all the specific parts used.
Good Foam Hotwire Carving101, I would also add, do any hotwire work outdoors.
Outdoors is good. Or in my case I have a good window fan for sucking out fumes.
I have to turn the fan off though to record videos. Sigh.
Why not just use the nichrome wire from the space heater you got the power cord from? Is there a benefit in using stainless wire I’m missing?
WOW!!! GREAT IDEAS, LEON!! THANKS, FOR SHARING!!!
Add a turnbuckle to the tension cable or easier adjustments, and relieving tension for storage.
Burt Rutan just uses a wing nut on the end of the wire and a u shape. He states it's for light weight and ease of use. He also adjusts the wire after warming to correct cutting temp due to heat stretch.
Thankyou
What I have questions are how to make the power supply.
Just a thing I noticed: When un-bowing the chord with the spring, do it while putting tension on the spring, and taking tension out of the hotwire, or else, u might tear the hotwire, with the added tension of un-bowing. In other words, press with yout foot against the wood-end near the spring ("spring-proximal wood-end"), pull an the opposite chord´s end thus stretching the spring, and un-bow it while holding the spring-distal wood-end stable.
Dynamometer+ long spring would be good
Why not use an appropriate turnbuckle... to set and relax the tension.
A turnbuckle would work great. I was using what I had on hand to reduce costs.
How many amps are you running?
You can always tell who's the engineer, he's the one that over engineers the project. Surfboard shapers have been using hot wire cutters for decades and the bow of choice is the simply C shape bow with the cutting wire and a spring attached to take-up the slack. Classic KISS: Keep It Simple Stupid.
Toooooo much pounds pounds pounds … not basics knowledge!
Waste of time...!