My 3'x3'x6' Oven project.

[CarWiz]

Oh yeah, I see that now. Duh! I wonder why they bother. The PID needs setup anyway with the alarm temps even if you go auto. It's just confusing to some of us.

[JTW37]

I also have built an oven the size you are thinking. Just a couple of thoughts after using mine for the past year. You mentioned about gage of steel inside of oven. Be careful and not go to thin as I've had problem's with expanding and contracting. It was causing dust particles (I think from the insulation) to be scattered in my curring powder. Used several seam sealers and they all got brittle and cracked and I was right back where I started. I think I finally have that problem solved. Mine is 28 gage, way to thin, but is okay for now.

Also, the casters you are looking at, what is the load capacity? I have some heavy duty, as my oven is quite heavy, once you get it all together. Got my wheels from HF.

I have ran across a bumper that made me wish I had built a 7 ft high oven. Mine has 2 inch walls and it just fit inside to cure. 7 ft would have been better.

I also have my k type thermo inside a pipe with a cap on the end to read temp and it runs pretty close to the temp of parts for cure times. I have 8150 watts and it takes around 30 minutes to heat, unless it's heavy/thick parts.

Hope this added info helps out as with the other guys. Lot to mull over.

[BottleFed70]

Buy the thermocouples with a threaded end. That's how mine came. I just drilled a hole in the sheetmetal and used a wrench to gently thread it in.

It's easier to install, has a better responce time that a sensor inside a pipe, and is quite durable looking.

[JTW37]

The whole idea to the thermocouple inside the pipe, is to give you a more accurate reading of the part temp and not the oven temp. My oven temp will read as much as 15 or 20 degrees more then my thermocouple. But as the thermocouple reaches the set temp, so does the oven temp. No short time or wrong temp cures. Part temp is what I'm after. Powder will flow early, but the part may not have reached the temp to cure it correctly.

[Kyrasis6]

ok guys, I'm getting ready to order a temp controller, SSRs, and 6" thermocouple I want to order them all from the same place. Anybody have other suggestions other than Auberins? So far I havn't found anywhere else that sells all three and can beat their prices.

[JTW37]

This guy always has PID's (normally with thermocouple) and SSR's. The link below already has a bid (E-bay), but he has a bunch more and some are Buy It Now items. check it out. He goes by Coldfusionx. You should be able to find what you need.

http://cgi.ebay.com/ws/eBayISAPI.dll...BSI%26otn%3D12

[blackcamaros]

Originally Posted by JTW37

The whole idea to the thermocouple inside the pipe, is to give you a more accurate reading of the part temp and not the oven temp. My oven temp will read as much as 15 or 20 degrees more then my thermocouple. But as the thermocouple reaches the set temp, so does the oven temp. No short time or wrong temp cures. Part temp is what I'm after. Powder will flow early, but the part may not have reached the temp to cure it correctly.

Could you elaborate on this? So you basically have a pipe with a cap on the end protruding into the oven and the thermocouple is inside that?

[JTW37]

Yep, that's pretty much it. An older German fella show me this. He deals with temps on a daily basis, that have to be within 5 deg of the required temp. With this setup, he knows that he is pretty accurate. He deals with colors for plastics. I have used this for over a year and so far it has been good. The pipe is only big enough )inside diameter) to slide the thermo couple into it.

As an example, Today, my Son and I did a batch of items. My oven temp was 400 and the temp showing on the PID was at 380. If my curring temp is 400, I wait until the PID reads that temp, not the oven temp. Powders flow out good and so far no problems. Here's who mine is.

[Kyrasis6]

lol, now you have me confused. I understand the concept of putting the thermocouple in the pipe, but when do you put the parts in? Do you measure the oven temp with an IR gun and put the parts in at 400 deg then don't start timing the parts until the thermocouple reaches 400 deg?

Since I plan on running batches of smaller parts and batches of larger parts should I have two mounting locations for the thermocouple? One with a thicker walled tube for larger parts and one with a thinner walled tube for smaller parts?

[asallwey]

Sounds like that would work great if the average item thickness was similar to the pipe.

But what do you do if you want to do a 2nd batch right away, do you cool the pipe?