Page 1 of 3 123 LastLast
Results 1 to 10 of 23

Thread: Tempering Oven Build -WIP

  1. #1
    Join Date
    Oct 2006
    Location
    Tokyo Japan
    Posts
    15,582

    Tempering Oven Build -WIP

    OK, I'm on to building the Tempering Oven

    Attachment 11007
    I found a donor hot plate thing, it draws 1200 watts max, so should do nicely, it was $12 delivered to my door, I promptly cut it up in to pieces

    I took two bricks, and stagger jointed the edges together, then I carved out a depression for the hot plate to sit in, with two holes going right through the bricks for the wiring.

    Attachment 11005
    I then built up a mock up of an oven around this hotplate thing, hooked it up and let it rip!

    It took about 8 minutes to get to 600C...........

    Attachment 11006
    I slid one top brick aside to take a look see, yep, it's hot!

    The one problem I'm seeing is the temp control on this unit is not very good, I ran it through a good dozen cycles and the low point where the heater kicks back on and the high point where it kicks off is about 80C different........ not so good.

    I need to hit a temp between 540-570C for 62 minutes, according to the steel maker.

    I guess I'l try to find some kind of controller that is more sensitive?

    Any ideas guys?
    Last edited by Stuart Ablett; 07-25-2007 at 11:25 AM.
    The pessimist complains about the wind; the optimist expects it to change; the realist adjusts the sails.
    William Arthur Ward

  2. #2
    Join Date
    Oct 2006
    Location
    The Heart of Dixie
    Posts
    4,265
    Where is your thermostate? In the oven of outside of it? That could make a difference.
    God grant me the senility to forget the people I never liked anyway,
    the good fortune to run into the ones I do,
    and the eyesight to tell the difference.


    Kudzu Craft Lightweight Skin on frame Kayaks.
    Custom built boats and Kits

  3. #3
    Join Date
    Oct 2006
    Location
    Tokyo Japan
    Posts
    15,582
    I don't really think it is a "Thermostat" as it is the knob you see on the control panel thing with the red light on it. There are a set of contact point there, by adjusting the knob, the distance between the points vary, and the temp that it kicks on or off does too.

    I know to keep it right on a certain temp, I need something that is in the oven, I guess that is what I'm looking for, something I'd wire into the circuit somehow, that would have a relay in it.......?

    The pessimist complains about the wind; the optimist expects it to change; the realist adjusts the sails.
    William Arthur Ward

  4. #4
    Join Date
    Oct 2006
    Location
    The Heart of Dixie
    Posts
    4,265
    Just had an idea. A rheostat, if you can find one. Or some other way to control the current to the element. Temperature is then related to the amount of current. Not the time it is on and off. Should be more stable. Assuming you can find a control of some type.
    God grant me the senility to forget the people I never liked anyway,
    the good fortune to run into the ones I do,
    and the eyesight to tell the difference.


    Kudzu Craft Lightweight Skin on frame Kayaks.
    Custom built boats and Kits

  5. #5
    Alan DuBoff is offline Former Member (by the member's request)
    Join Date
    Nov 2006
    Posts
    711
    Stu,

    You can get a ceramic probe that will work, from a clay supply store. They should have those down around the art area near Ochanomizu, or thereabouts. I mostly remember stationary and other art though, but there must be a city for clay supplies somewhere...

    You can order one from Clay Planet in Santa Clara.

  6. #6
    Join Date
    Oct 2006
    Location
    Tokyo Japan
    Posts
    15,582
    Thanks Alan, but I'd need more than just the probe, I'd need something to turn on and off the heat, right?

    This is where I got to this morning........

    Attachment 11015
    That is the basic shape, all stagger jointed together, lots of work, and lots of white dust everywhere!

    Attachment 11016
    I put the heating element on the top, I figured it would not matter much, and it would take a lot less abuse up there, I very much doubt it will make much of a difference on the heating up part.....

    Here it is with the top removed......
    Attachment 11017
    ...... I wired the heating element into the two blocks, I'll have to get some high temp joint cement or something to fill in those holes, a bit of heat could come out of them!

    Now I got to build a frame for it, then I'll crank it up and see how it goes.

    Cheers!
    The pessimist complains about the wind; the optimist expects it to change; the realist adjusts the sails.
    William Arthur Ward

  7. #7
    Alan DuBoff is offline Former Member (by the member's request)
    Join Date
    Nov 2006
    Posts
    711
    Quote Originally Posted by Stuart Ablett View Post
    Thanks Alan, but I'd need more than just the probe, I'd need something to turn on and off the heat, right?
    You mean you want not only the ability to monitor the temp, but to control it for you also? I think that would be an elaborate setup. For the most part, you can keep propane at a constant rate, so if you get the forge to a specific temp, it should hold pretty good, at least mine did when I measured and heated it for forging brass (around 1300F deg.).

    What your problem most likely will be is keeping the temp. low enough so that you can stay in the range you've listed, which seemed to be similar to the brass figure I put in above. I don't have a conversion table so not sure how much 540C-570C is, but I think it's about 2x the figure, so you should be around 1100 degrees.

    You will most likely have a difficult time getting your burner down that low.

    Did you put a flare on it? If so, you may need to adjust it so that you can turn the flame down low enough, there's a fine area that you must adjust that will allow low vs. high flames. Ideally you want to be able to use an idle loop as I installed on my forge, but in order for it to work correctly, the flare needs to be adjusted, otherwise the flame will go out when it's low.

  8. #8
    Join Date
    Oct 2006
    Location
    Tokyo Japan
    Posts
    15,582
    Alan!!

    This tempering oven is "Electric"

    Cheers!
    The pessimist complains about the wind; the optimist expects it to change; the realist adjusts the sails.
    William Arthur Ward

  9. #9
    Alan DuBoff is offline Former Member (by the member's request)
    Join Date
    Nov 2006
    Posts
    711
    Stu,

    I see that this is not your forge, it's another brick box...

    Get a hot plate with a temp gauge on it!

  10. #10
    Join Date
    Oct 2006
    Location
    Tokyo Japan
    Posts
    15,582
    The hot plate does have a temp thing on it, but the sensor, or rely on it has an 80C range, so it if turns on at 530C it goes to 620C before it turns off.

    I'm hoping that this will not matter much, as once the steel is up to temperature, it will not effect things much, the time from power on to power off is less than a minute....

    This is what I got done today........

    Attachment 11067
    The frame on this one is much like the frame on the other forge.

    Attachment 11068
    I'm doing a test run here, letting it run full chat, to see how hot it does get....

    Attachment 11069
    It was still climbing, but the high heat wires were starting to smoke where the come out of the oven, so I shut it down.

    Attachment 11070
    I opened the door to take a cook see, yep, I could make toast in there no problem

    Attachment 11071
    Ready to give the 62 minute temper routine tonight, I ran out of time today.

    Wish me luck!
    The pessimist complains about the wind; the optimist expects it to change; the realist adjusts the sails.
    William Arthur Ward

Similar Threads

  1. New CNC Build - Day 5
    By Carol Reed in forum New Systems and Builds
    Replies: 80
    Last Post: 08-19-2015, 07:00 AM
  2. ES Build
    By Dave Black in forum All Things Musical
    Replies: 26
    Last Post: 09-22-2014, 04:09 AM
  3. Cover for toaster oven
    By Roger Tulk in forum Flatwork Project Showcase
    Replies: 2
    Last Post: 08-05-2014, 12:52 AM
  4. How to build this....
    By Sam Smith in forum General Woodworking Q&A
    Replies: 16
    Last Post: 11-05-2011, 01:57 PM
  5. Somebody Build This!
    By Dave Richards in forum Designs, Plans and Sketches
    Replies: 20
    Last Post: 01-26-2008, 01:21 PM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •