What affordable material for parallels?

I can't complain. It cost me over $1500 for my wife to make the first $3 bead. After that it got pretty cheap, until,,,,you add in 4 torches, 2 work benches, 2 more kilns, a ventilation system, oxygen generator , extra propane & oxygen tanks, heating and cooling the work area and about 500 lbs of glass at $1 to $10 a lb. Keeping the little woman happy, PRICELESS. All else there is Mastercard.
 
Hah! I DID notice that the 'kiln sitter' seems to have been missing: https://www.theceramicshop.com/store/category/39/197/kiln-sitter/ (parts 1 and 2 here?).

It seems to be a mechanism for turning the machine 'off' when it gets too hot, but it seems I can 'set' it up to be always-on without it (by gently keeping the piece in place). I think I might end up just replacing a lot of the electrical to this eventually though, so I can just use the hole for the thermocouple.
 
This thread is drifting, but I don't understand the huge expenses for these kilns. My build is underway, but my plan for temperature control is a bog standard EGT sensor tied to a $20 PID controller.

But, I guess the wife wouldn't be happy with a kiln built up from a rusty 55-gallon barrel.
 
Shotgun said:
This thread is drifting, but I don't understand the huge expenses for these kilns. My build is underway, but my plan for temperature control is a bog standard EGT sensor tied to a $20 PID controller.

But, I guess the wife wouldn't be happy with a kiln built up from a rusty 55-gallon barrel.
Click to expand...

Drifting, as my threads tend to :) I also don't get the expense of heat-treating ovens, I don't know why a decent sized one tends to be $1500! Its particularly absurd when you consider that the kiln part itself is pretty inexpensive, as you can see that pottery kilns of those sizes are cheap.

It seems they are really proud of their ramp/soak PID controllers. The chinese ones tend to go for ~$100 instead of $20, but they add the ability to program in a multi-segment heat-treat. I picked up this kit:
www.ebay.com

Professional Ramp Soak Temperature Controller Kiln SSR Kit Ceramic Thermocouple for sale online | eBay

Find many great new & used options and get the best deals for Professional Ramp Soak Temperature Controller Kiln SSR Kit Ceramic Thermocouple at the best online prices at eBay! Free shipping for many products!
www.ebay.com

to put in mine, but I likely could have been perfectly happy with the $20 PID controller.
 
If I wanted that much control, I would have bought an Arduino. The SCR is just acting as a relay for the big power and any old SCR will do. All the Arduino would have to do is send a signal to energize the relay.

They charge a lot more for the kits with high temp probes, but any of the $5 EGT gauges will do the same thing. It is just thermocouple wire, and the only thing different about the "high temp" one is the insulating material. EGT probes use the fiberglass insulation and are good to at least 2000F. I'm using the wire from a probe that got broken off.

You're also paying more for the special probe "extension". Not sure what the point of sticking the probe into the center of the space is. If there is ten degrees difference across that space, something is seriously amiss. If you have to be THAT exact, run the temp up to within 20 degrees of the target, wait ten minutes, then bring it up. My probe will be sticking out 1/4" at max, and I'll probably create a small divot in the side for it to sit in (so that it doesn't get broken off).

Caveat: I'm designing my furnace for aluminum casting, typically maxing out at 1200F, with maybe an occasional foray to 1700F for some experiments in case hardening.
 
Shotgun said:
If I wanted that much control, I would have bought an Arduino. The SCR is just acting as a relay for the big power and any old SCR will do. All the Arduino would have to do is send a signal to energize the relay.

They charge a lot more for the kits with high temp probes, but any of the $5 EGT gauges will do the same thing. It is just thermocouple wire, and the only thing different about the "high temp" one is the insulating material. EGT probes use the fiberglass insulation and are good to at least 2000F. I'm using the wire from a probe that got broken off.

You're also paying more for the special probe "extension". Not sure what the point of sticking the probe into the center of the space is. If there is ten degrees difference across that space, something is seriously amiss. If you have to be THAT exact, run the temp up to within 20 degrees of the target, wait ten minutes, then bring it up. My probe will be sticking out 1/4" at max, and I'll probably create a small divot in the side for it to sit in (so that it doesn't get broken off).

Caveat: I'm designing my furnace for aluminum casting, typically maxing out at 1200F, with maybe an occasional foray to 1700F for some experiments in case hardening.
Click to expand...
I hadn't thought about using EGT probes! Oh well, I ended up over paying for what I'm doing. I wouldn't mind doing an arduino, but I kind of appreciate the 'finished case' look of it. Arduinos are great for prototyping, but I find that I end up busting my setup 'in production' :)

Interesting to hear that Aluminum casting is only 1200! Maybe I'll do a touch of that in this kiln too! I figure most of what this is going to be doing is maxing out around 1800F for heat treating air/oil treatable steel, but I hadn't thought about aluminum casting!
 
Shootymacshootface said:
I made my first set from aluminum, just to get going on my mill.
Is there something wrong with cast iron? It's cheap, stiff, and easy to machine. Just don't drop it.
Some of the best straight edges are made out of cast iron, right?
Click to expand...
Cast iron is cheap?
Where?
 
I agree on the Arduino. Not for production. That's why I went with the Chinesium PID controller. Cost is about the same, and it is probably a scaled down Arduino in a plastic box (plus I got the SCR for the same price).

BTW, 1800F will also give you the ability to melt brass.
 
MrWhoopee said:
Here's a link to some commercial heat treaters nearby. No affiliation

Heat Treatment Company - Thermal Modification Technologies

Serving the Pacific Northwest and beyond, TMT is a full-service heat treater, offering a wide range of capabilities.
www.thermalmodtech.com www.thermalmodtech.com
Click to expand...
I looked around for a couple, though I didn't find that one in particular. The couple I called were absurdly expensive, particularly if you couldn't fill a whole 'tray' at once.
 
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