Can anyone point me in the right direction to find a schematic diagram for automatic temperature control on a home made electric shop oven? Inside furnace dimension about 6x6x6 inches plus premolded insulation. My heat source is a discarded 1500-watt 230 volt spiral wound element from a domestic stove. My cost = $0. I would like to operate at about 1000-deg F for burnout on lost wax investment molds. The best control would be ramp up to around 250-deg F and hold 30 minutes for the preliminary melt out, then go up to 1000 deg for one hour final burnout. Furnace is already constructed and works great on manual control using one type "K" TC and a hand held readout, but of course this requires hands-on attention. TIA Dave
Home made electric oven for lost wax meltout
Jan 05, 2006
5 Replies
David, my first thought would be to look for a "process controller" on ebay. I am not sure if this one would work, but check it out this auction (Omega CN8500):
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Here's a manual for them:
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i
You can find PID controllers that take a type K thermocouple on ebay for under $50. You'll also need a relay. Read the specs on the controllers--some of them allow the ramp-up you need.
Try a ceramics shop and ask about cones. There are varoious wax cones that melt at different temperatures and trigger a relay when they melt.
Tom
Try here:
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They sell inexpensive furnace controllers for just your application.
To my knowledge, this is not hot enough. I have read, that it must be glowing red (dull red) to get the sooth out. But I may be wrong.
Nick
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