Heat Treat Oven - WIP

I was considering a door with a section that extends inside but it just was not worth the time to do it. This is why I made my hinges adjustable so o could get a nice perfect fit. Funny think is I adjusted the door and fired up the oven and once hot I looked down and there was a gap at the top of the door. So I re adjusted and been perfect ever since.
 
I am planning on a flip down door as well, with slotted holes in the mount to the frame so it can be adjusted. I don't plan on any fancy bushings, but it should work for me. :p
 
kdogmcg said:
I am planning on a flip down door as well, with slotted holes in the mount to the frame so it can be adjusted. I don't plan on any fancy bushings, but it should work for me. :p
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One thing to consider with the flip down vs swinging right or left: When you are reaching into the oven to pull out knives you will have to clear the heat of the door. If you have long tongs this is a non issue but I seem to always be grabbing them out with pliers! I built mine swinging open from the right and I have to make sure the door is full 180 degree open so the radiant heat off the door bricks don't singe my hands- especially at stainless temperatures.
 
Roger. I have a long pair, and I wear a leather apron and gloves, mostly just because I make that look GOOOOD.
 
Hate to resurrect a thread, but I've been seriously thinking about rebuilding my old heat treat oven, as it's just about to fall apart, and I really like several aspects of this build.

Just curious how everything has been holding up over the last year and some change? Any design changes that you'd make if you had to do it over again?
 
I am actually very happy with my oven still, it has held up great. I had been very disappointed with the TAP controller. It would never hold a very accurate temp swing. It would swing from around -10 deg to a + 10 deg over set temp. I contacted them quite a few times in the beginning and did not get much of anywhere. I asked for access to the programing as a developer but was turned down. There was a locked advanced feature that thy gave me the code for. But that gave me very little control, was basically for setting the type of TC and max temp. I kept emailing them asking them things like "does your controller incorporate fuzzy logic". I was told no it does not. I emailed them some advise on perhaps a future software update and did not hear much back.

Then just a few weeks ago i was frustrated because I did an update and it now says evenheat on the screen and my advanced password did not work. Also my temp swing went up to -5 or -10 deg to a + 15 to 20 deg. So i send them an email complaining about everything that was bugging me about there control and how I hoped for changes with the update. I got an email back that included a "bata" update that thy said has fuzzy logic. I installed it and now magically my advanced password works. My big issue in the past was the SSR's would not shut off, it would just over shoot and then stay on. It was like is was preventing the SSR,s from cycling more then x amount per x seconds. Well with this new update i now have a lot of things to change in the advanced menu. One of them is relay type, and what do you know, mine was set on relay not SSR. after switching that and with there new improvements to the control algorithm my problem is gone. I can now hold temp with just a few deg swing. I'm now just waiting for a calibration function.

So as it sits now I'm very happy with my oven, i love the remote access on my phone or table to my oven. It allows me to keep an eye on it from the house without having to go check on it all the time. i also can wright heat treat schedules remotely. But i am going to replace my TC with a longer one. I have found a little issue which has to do with how much TC is exposed in the oven. i ct mine off so just about a inch is exposed inside. This has the problem of not having enough inside the oven to counter the cooling rate of the TC going out through the bricks and into the terminal block. This is one reason i let my oven soak for so long befor heat treating a blade. I can tell when i open the oven that the tc is to short because the tip is a different color then the stainless bade holder that's right next to it. I have to let to oven soak for around an hr till the TC and the oven are the same color. This can be solved by extending the TC in quite a bit more and then bending it out of the way. Im sure there is a formula for the amount of exposed surface area required for accurate readings. What i would have done now is drill the TC hole either further back or closer to the door and then turned the TC 90deg. Then bend the tc to a 90deg so it laid along the wall parallel to the floor for at least 3 inches.
 
JTknives said:
These also showed up. Thy are the coil support rods for the roof.

Photo%20Jul%2027%2C%2011%2027%2040.jpg
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What kind of rods are these? Very nice oven. Thanks
 
I too am interested to know what these Roda are. I'm building my HT oven at the moment 9n weekends when I get the time and the control box is ready.
Didn't want to mess with making those routes along the side walls and was thinking of mounting my elements on ceramic rods along the side walls. Some more info on the ones you used would be really helpful.
Thanks.
 
Kosa_PL said:
JT: Mostly my concern about US made kilns are - Energy efficency.
With better insulation you save energy and have lower energy bill...
And also kiln need to be properly made to meet Work Safety regulations. (Otherwise in EU you will not get insurance for a workshop)

Also why US kilns are made like this?
- Because it's cheap.
Ask industrial kiln makers what they think about them :)
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@Kosa_PL , forget about energy bill ................... additional layer of insulation over brick improve heat uniformity in oven . . . . .
 
JTknives said:
But i am going to replace my TC with a longer one.
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I have a long TC in my oven. I believe its a 12" TC. So about 10" long within the oven itself. The tip is placed right above the ceramic rack that holds the blades up when heat treating. Its working great as far as temperature goes, but the longer TC does droop from the heat, and I was actually thinking about going to a smaller one because of this reason. I might try and use kanthol pinned to the roof of the kiln to hold it up and stop it from drooping down.

Thats unfortunate about the tap controller. I was thinking about getting one eventually for my oven, but now I am not sure. These issues would be apparent on all Evenheat kilns using the Tap controller as well, right?

Also, as a developer myself, I love the fact that you asked for the source!
 
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I absolutely love the TAP controller now. It has come along way from where it was when I got it. I highly recommend it as an oven controller.
 
When wiring up the tap controller. Could you do it as per the schematic? Does the
relay 11801.200 take the place of the SSR's?
 
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I never hooked the gas up to the alarm as I normally give the oven a good 1-2hrs of soak at temp before the first blade goes in. Also I don't always use gas shielding as most orders are only a handful of blades. If the blade needs a long soak like D2 then it gets foil. I would have to look at the schematic again to see how thy say to do it. I kinda just went off on my own and wired it how i wanted to. I have been SUPER happy with this oven and do not regret getting the tap. Thy have now turned on the 2nd TC input for duel zone control which is a cool feature. I would most likely just use it to read the temp at the rear. I vaguely remember the board having 3 TC inputs which would be nice to show front, middle and end temps.
 
Thanks for the reply. I'm thinking of installing a tap controller now instead of a normal ramp soak pid. I haven't bought any SSR's yet. I was looking at the schematic. So you recommend using the relays or the SSR's? Where is the best place to buy the Tap controller?
 
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