Kijiji score - nice little kiln and a bunch of other cool stuff too

Discussion in 'Foundry tools and flasks' started by Tobho Mott, Oct 11, 2018.

  1. crazybillybob

    crazybillybob Silver Banner Member

  2. I've used four of the controllers pictured here in various projects with no issues:
    https://www.aliexpress.com/item/PID...lgo_pvid=72dd7350-cf45-4832-949a-16aade6761e9

    They are a knock off of a reputable unit made by a Japanese company: Rex and called a REX C100 and seem to be very common. All of the ones I bought were thermocouple input and limited to 400 deg C but there were two software options to change to unlock the full temperature range.

    They typically have a set of mechanical relay contacts you can use to drive a solid state relay or in my case a 40 Amp TRIAC. The sellers have learned which acronyms and buzzwords people want to hear and claim it has an internal solid state relay not the actual solenoid mechanical relay.
     
  3. I bought 40 amp SSR's for a 30 amp kiln load. Resistance of Nichrome wire goes up with temperature. Inrush popped the SSR (and there is no reset). by the time I'd figured it out (and started 1/2 the coil at a time) I had popped three of them. Fortunately they were only about $10.
     
  4. The only time I blew one, was a 1000A welding unit, I had the brainwave of making a capacitor discharge spot welder: it worked great on small stuff until I tried to weld a couple of copper two cent coins together and heard a faint splat. As far as the 40 Amp units go I was switching less than 10 Amps so they never missed a beat with constant switching.
     
  5. Al2O3

    Al2O3 Administrator Staff Member Banner Member

    Tobho Mott, my advice would be: decide what you want to control before you select a PiD. Do you just want to control temperature at a set point or do you want to be able to program a temperature schedule with ramps, times, and multiple set points for each? If you just want set point control, you don't need a ramp and soak type controller. A simple PiD will only require that you turn it on and use the up and down arrow to set temperature.....that's it. If you want to be able to program a temperature schedule to burn out an investment, cure refractory, or heat treat something, you should by a PiD with step control....but they will require more key strokes and programming to do the simple functions. You can still do heat schedules with the simple controller but you have to manually change the temperature after time instead of just programming it and walking away. Some heat schedules I've used are 24hrs in duration and I prefer to program (and program is a strong word for what it really is) instead of baby sit a machine.

    My melting furnace just has a simple set point control because I primarily just melt with it.....no reason to program anything accept maybe changing the set point to a holding temperature after the melt has been achieved. My large furnace has a ramp and soak PiD because with the electric heating module installed, it has a larger interior space (14" ID by 28" tall) to accommodate things to heat treat, burn out etc.

    Not counting the two installed in my furnaces, I have four spare PiD controllers in my shop now comprising three different brands. I didn't pay more than $10 for any of them accept the first one I bought because I didn't know any better. Three came with an 40 amp SSR, heat sink, and K type TC. They all have the same terminal location for each input/output and for the most part function the same. However, they all have different temperature ranges from 400c to 2600c. As Mark says, some of these can programmed.....if you know how. Which brings up a point that may be important to you.

    Does the PiD have a manual that you can read and understand? Several of mine are in Hanzi or Kanji depending upon depending upon country of origin. Several have English instructions. They all pretty much work the same. If it's simple set point, just wire per schematic and arrow up or down, just as long as you're sure that's what you are getting.

    The link RTSquirell posted has one of the most complete descriptions I have seen on eBay...which should instill confidence.
    The AliExpress link for $6 that Mark posted has a 400c temp set point limit and may only have Chinese instructions, so figuring out how to change that may be a problem.

    I've fiddled around with a number of them and with that familiarity have found they all pretty much the same.

    Beyond that, you just need input/output voltage compatibility. Here are a couple links to a simple PiD and a Ramp and Soak PiD. This source also imports and resells. They ask premium over what they can be bought for direct but you know what you are getting. More importantly, scroll down and click the links to tutorials and download the manuals for free.

    https://www.auberins.com/index.php?main_page=index&cPath=1
    https://www.auberins.com/index.php?main_page=product_info&cPath=1&products_id=4

    Here's their full line. You can see different features typical to PiD control schemes.

    https://www.auberins.com/index.php?main_page=index&cPath=1

    Best,
    Kelly
     
  6. Tobho Mott

    Tobho Mott Gold Banner Member

    Wow, thanks for all the info guys! I'm gonna a take my time.and.go through it all carefully

    And I am pretty sure I will be fine with a set the temp and walk away until the temp needs changing type deal.

    Thanks again,

    Jeff
     
  7. Kelly is correct: the REX C100 knock off manuals are just about useless, not only that, they are not a precise copy of the original quality RKC brand unit so the original English language REX C100 manual is of limited use. That said, they have a series of configuration bytes defined in the manual to set things like the particular type of thermocouple connected. As I recall you have to set one location bit to unlock the controller (operator proof locking) and then set another bit to change the upper temp limit from 400 deg C to 1500 deg C.

    They are very cheap (the original would be about $200+) and very popular, so there's plenty of discussion on how to set them up, like this video for example:


    I left a comment on this video a while ago as a note to myself: You have to set the LCK value to 1000 and at that point the hidden menu is accessible and the upper limit can be changed. I was able to change "RKC" and "Berme" branded units.
     
    Last edited: Oct 13, 2018
  8. Al2O3

    Al2O3 Administrator Staff Member Banner Member

    I have one of the Berme 400c units. Also TDWK but they are already high range. I may have to try that Mark. I forgot about good ole YouTube. There's seems to be a how-to for everything.

    Best,
    Kelly
     
    Mark's castings likes this.

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