Which controller?

[gmsisco]

Which controller would be best for my Sugar Creek knife kiln and what else will I need? Right now it has a finite (I think that's the word) switch and a digital temp display.

[jackwrabbit]

I think that is called an "infinite switch" controller and is, IFIIK, not very useful for heat treating blades (which is what I'm guessing you want to do with the kiln).

I got the JLD634 Ramp/Soak PID Temperature Controller for the knife kiln I'm building. You will also need a SSR (Solid State Relay) and heat sink, a K-type thermocouple (or you might can use the thermocouple from the digital temp. display you have now). Plus some wire (still trying to find out what is the right kind myself, anyone know what kind to use for both the controller to relay and relay to element?) and a box to put it in if it won't fit in the control box you have.

Did I miss anything?

Also, anyone know what screws are needed to attach the SSR to the heatsink; I'm having trouble finding one that will fit.

Jack

[richiem]

Wire -- controller to relay, any light gauge color-coded wire; I used "bell wire" from the hardware store. It's big enough to not be fragile, small enough to be easy to connect.

line to SSR to element to line, appropriately heavy gauge for the current of the element; use at least 16 gauge and 12 gauge wouldn't be inappropriate for a really big heater, say over 2kW. Make sure the SSR's rated current is at least 5 times the rated current of the heater, and definitely use a heatsink.

Power = voltage X current So if you know any two, you can find the third... Nice thing about heaters is that they're purely resistive, so you don't have to consider voltage or current phase angles in the calculation

SSR mounting screws -- two ways: 1) re-tap the holes in the heatsink for regular screws, say 8-32; or 2) get the right metric screws at a hardware store that has metric screws in stock -- lots of them do these days.