Oven kit 220v Proto-Form
Proto-Form oven kit requires the purchase of our plans.
Introducing our new “Fast Heat” modular heating elements for the Proto-Form machines. These new elements offer the exact same performance but with a faster warm up and much lower cost than the previous Cal-rod based kits. They will retrofit easily into the existing design and come with necessary high temp wire, jumper strips and terminals, as well as instructions on CD. The Cal-rod kits will be discontinued and the plans will be revised for the next printing.
The “Fast Heat” elements consist of a special coiled resistance wire mounted directly onto a ceramic fiber board.
These new elements are modular “Tiles” measuring 6 x 24 inches and putting out 1200 watts each on 240 volts. Its best to think of each tile as replacing one pair of the old tubular elements. For example, the 2 x 4 ft. machine will use 8 tiles instead of 16 individual tubular elements. These elements are then connected to each other with tinned copper jumper strips to simplify the wiring.
The Proto-Form oven kits consist of 4,6,or 8 heating tiles (depending on size plus the necessary high temperature 8 gauge wire and set screw terminals. These elements are supplied in kit form with pre-cut ceramic fiber board, nichrome heating coil and hardware. You must use the supplied template and drill the mounting holes, then stretch the coil and fasten to the board with the hardware provided. Adjacent tiles are connected with the pre-punched jumper strips.
Frequently Asked Questions
“Cal-Rod” tubular style vs coiled wire elements.
Do these work as well as the old Cal-Rod based oven kits?
These are functionally identical but they heat up faster and are much cheaper. They fit in the same place with the same heat output and power consumption.
How long does a coiled Nichrome element last?
Not really sure!,.. I’ve been selling this type of coiled element for my Hobby-Vac machines since 1996 with no reported failures yet. How long does a toaster last, I’ve got one that’s 20 years old? If assembled carefully with no nicks in the wire and not subjected to repeated movement or vibration, they last very long and are cheap to replace.
Are these elements safe?
Not if you touch them, but neither is an open flame or burner on your stove. The oven box is grounded so a broken wire will trip a breaker if it touches something metal. Treat it like you would any appliance. Use common sense, don’t modify the design and follow the instructions carefully.
Are they more work to install?
About the same as the old oven kits, you will spend more time assembling the elements, but the oven box is much easier to make. No special skills required, just follow instructions.
They look kind of cheap, why didn’t you use something cool like Quartz tubes or ceramic panel elements?
The short answer is cost vs benefit. A coiled resistance element is far cheaper than all other options and if designed correctly, functions the same. Remember, ALL electric heaters have the same nichrome wire hidden inside somewhere.
Can I just use “Hardi-backer” cement board from Home Depot?
The ceramic fiber board in these kits can handle 1800 degrees and direct contact with the heating coil. Tile backer boards look similar but are cement based and only rated for a few hundred degrees. They won’t burn but they will crack!