quick experimental temperature controller for my uds

Discussion in 'Other Builds' started by smokerpaul, May 12, 2013.

  1. hi guys

    this is my quickly made up controller using bits from the deepest darkest recesses of my shed and some cheap stuff i needed from ebay(£12 controller,£3 switches,£1.50 fan) the controller is 12 volt and came from china it was supplied with a k type thermocouple, the food storage box was raided from the kitchen (she was not pleased) i have not bothered to use a solid state relay yet  but i may include one on the next version and also incorporate an alarm into the system 


    the tiny pid controller fitted next to the 2 switches (top) on/off(bottom) is fan disable. the box was very brittle to cut and kept snapping bits off and i cracked it quite badly hence the sticky tape. the fan switch is to turn off the fan when i lift the lid on the smoker and i will turn the fan back on again when the temperature is stable   

    k type thermocouple that was included with controller

    12v cigarette lighter plug

    a brass water tank fitting and a 3/4 inch flexi hose i have another brass fitting to go in the uds drum for the other end of the pipe to fit on to 

    powered up, it is a 80 mm fan and it is capable of moving 24 cfm but as i am making it push air down a 6ft long 3/4 inch pipe that amount is drastically reduced to approx 8 cfm and hopefully it will be about right for the uds

    the controller manual listed settings for the P.I.D.  that are suitable for use on smokers they are  

    P 1.2

    I  300

    D 70

    hope that helps anyone setting up one for themselves

    i will be giving it a trial run this week so fingers crossed it will work ok
  2. wade

    wade Master of the Pit OTBS Member SMF Premier Member

    Hi Paul - That looks very promising.

    To get it to work efficiently you may also need to play with the air flow over the coals as well. My first couple of attempts with my IQ110 were somewhat disappointing as I had not sufficiently focussed the air flow through the fire. I did not take photos of my IQ110 in use but I have found a good blog that shows in pictures what needs to be done to achieve effective control of the heat.


    You need to make sure that ALL of the air flow from the fan is directed through the coals and so masking off other routes for the air to flow around the coals is critical. Making sure that the air from the blower is the only air to go through the coals is also just as important. I used a similar setup to the picture above and I also used aluminium tape to block up all other air holes, gaps and vents.

    It is also much easier to control the temperature as it is going up rather than to bring it down when it gets too hot. Therefore I found the most effective method is to place only a couple of lit briquettes in the basket and then cover them with unlit briquettes. Put on the lid and fire up the control unit and let it blow on the lit coals until the desired temperature is reached and maintained.

    I know you are not using a Weber but in the UDS you will probably have to adapt these same principles in order to get it to work as you hope. I cannot stress enough though NOT to start off with a full basket of lit coals and to hope that the unit will be able to control them, as it will almost certainly fail - or at best result in very unstable temperatures.

    Looking forward to hearing how the trial run goes [​IMG]

    Last edited: May 13, 2013
  3. hi wade 

    i have been looking on the web and people using ique 110, bbq guru and other units on a uds have the inlet  fitted just below the level of the bottom of the basket so i am just going to change  one of the existing vent fittings over to a straight inlet and i think i will attach the controller directly to the fitting without the pipe and see how it goes.  i am going to the market again tomorrow to pick up another shoulder and do a full on practice run on pulled pork before going to santapod i will use the maverick and also my fluke pyrometer (which records high and low temps) during the cook to monitor what goes on, i will try to do the whole cook at 225f  it will be interesting with the new basket as well !!. i just hope the sore thumbs were worth it lol

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