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Tool Tutorial

Tool Tutorial

The Kiln

The kiln is a custom made electric kiln with a programmable PID temperature controller.

Notes

Safety

  • Do not leave the building with the kiln running.
  • No overnight programs are permitted.

Common Hazards

  • Burns or fire from heat exposure, touching hot parts of the oven or workpiece
  • Smoke and fumes due to contaminants, inadequate ventilation
  • Shrapnel from rapid temperature shocks in brittle materials (e.g. glass) or wet materials (e.g. ceramic that isn't bone-dry) 
  • Damage to the interior of the kiln from heating fusible workpieces without proper technique
  • Damage to refractory (scraping against workpiece, thermal shock, slamming the door etc.)
  • Damage to the kiln heater system from prolonged operation at the max temperature
  • Pinching/crushing on the door latches

Care

  • Minimize the amount of time with heating at high temperatures to prolong life of the heating elements.
  • Shut the door gently to prolong life of the door gasket and fire bricks.

Use

Simple Ramp and Soak Program

This program ramps from room temperature (68 F) to 2000 F over 60 minutes, holds temperature at 2000 F for 30 minutes, then the program stops and cools to ambient. A plot of time vs temperature should look like this:

 
 Temperature (F)Time (minutes)
C16860
C2200030
C32000-121

image.png

Note: This is IDEAL

 

Here is the data for what actually happens:

Time After Start (Min)Temperature (F)HUR (F/min)
068N/A
60147123.38
75162510.26
9017498.26
10518466.46
12019255.26
13519813.73
1501979-0.13
image.png

Note that you can program the controller to do impossible tasks. Doing this will prevent the controller from executing commands as programmed. In this example, there were two problems:

  1. The programmed heatup rate was (2000-68)F / 60 min = 32.2 F/min, but the absolute maximum average heatup rate that the kiln can provide in this temperature range was only 23.38 F/min.
  2. The program called for soaking at 2000 F for 30 minutes, but the kiln never reached 2000 F to start the soak, so the program ran for 150 minutes (before it was shut down manually) rather than the 90 minutes it was programmed to run.
Program Explanation

Ramp: Using the program above as an example, you can program a ramp by setting the temperature for C1 and C2 as different values, then at the end of the time period set for C1, the controller will change the setpoint heating to be at temperature C2 by the end of the time set for C1.

Soak: Just as in the ramp program, once the temperature setpoint for C2 is reached the controller looks ahead to the next temperature setpoint to figure out what needs to happen next. In this example, the temperature setpoint for C3 is the same as the temperature for C2, so the controller will not adjust the temperature setpoint for 30 minutes (the time C2 is programmed to run for).

Stop: the time "-121" in C3 time comes from this equation:

C(stop) time value = - (30 * Command# + NextStep)

In this example: C3 = -(30 * 4(from C4) +1(We want the next step to be C1)) = - (120+1) = -121

 Summary:

Command typeTemperatureTime
RampC[a] =/= C[a+1]Duration of the ramp in minutes
SoakC[b] == C[b+1]Duration of the soak in minutes
StopFinal desired temperature requiring temperature control

Calculated via:

(30 * Command# + NextStep)

 

Other Example Programs

Here is a program that might be used to anneal steel (temperatures are approximate, but are used to determine timing):

 Temperature (F)Time (minutes)Explanation
C16860Ramp up to 1450 F
C2145030Hold at 1450 F
C31450630Ramp cooldown to 1000 F
C41000-151End of program

 

Normalizing steel:

 Temperature (F)Time (minutes)
C16870
C2155030
C31550-121

 

Known Heatup and Cooldown Rates:

Use these to determine program step times. 

Heatup Rates: These are the maximum possible heatup rates over timespans. In the future, we will organize these by temperature band for ease of use.

   
Time after Start (Min)Temperature (F)HUR (F/min)HUR (F/hr)
068N/AN/A
60147123.381403
75162510.26616
9017498.26496
10518466.46388
12019255.26316
13519813.73224

 

Cooldown Rates: These are the maximum possible cooldown rates over timespans. In the future, we will organize these by temperature band for ease of use.


TempCDR (F/min)CDR F/Hr
01613N/AN/A
151429-12.26-736
301291-9.2-552
451204-5.8-348
601114-6-360
751041-4.86-292
90980-4.06-244
120875-3.5

-210

 

Consumables

  • None

Tooling

  • Personal temperature measurement device, if desired. A type-K thermocouple is used for control and display purposes, which has a standard accuracy of approximately +/- 4 degrees F.

Materials

The kiln does not have active ventillation, as such, materials that produce fumes when heated are not permitted. 

Prohibited materials include but are not limited to:

  • Polymers / Plastics of any kind
  • Oil covered metals (degrease before heat treatment)
  • Zinc-bearing metal alloys - including brass, bronze, Zamak and "pot metals"
  • Radioactive metal alloys
  • Combustible materials
  • Rubber
  • Wood, paper, cardboard, MDF
  • Foam
  • Textiles or fibers
  • Wax
  • Painted, coated or varnished objects
  • Adhesives
  • Lead or lead containing materials
  • Sealed or hollow containers
  • Materials that can melt onto heating elements

Parts of the Tool

Kiln Anatomy

1.

  1. Controller
    2. 2.
  2. Breaker switches
    3. 3.
  3. Alarm lights 4.(Currently not functional)
  4. Temperature probe
    5. 5.
  5. Latches
    6. Latches 6.
  6. Viewing port

Controller Anatomy

image.png

① PV window: Displays the sensorCurrent read out,Temperature, or process value (PV).
② SV window: Displays the Temperature set value (SV) or output value (%).
③ AL1 indicator: It lights up when AL1 relay is on.
④ AL2 indicator: It lights up when AL2 relay is on.

⑤ A-M indicator: The light indicates the controller operating status.

  • When A-M
     is solid on, program is running.
  • When A-M is flashing, program is paused.
  • When A-M is off, program is stopped.

⑥ Output indicator: It is synchronized with controlControl output (terminal 7 and 8),
and the power to the load.heater.

  • When itthe Output indicator is on, the heater (oris cooler)on.
  • When the Output indicatoris off, the heater is powered.
    off.

⑦ SET key: In normal operating mode,mode keep(Display mode 1), pressing the SET key momentarily
sowill switch the display will be switched between the temperature, step number and
 step timer.timer Pressin and hold the SET key for 2s so the controller will switch tosequence.
the parameter setting mode. For details, see Figure 3 below.
⑧ A/M key: Programming key; digit shift key.
⑨ DOWN key ▼: Decreases numeric value of the setting value. Pressing and holding the DOWN key for 2 seconds will start the selected program if the controller is displaying STOP or HOLD.
⑩ UP key ▲: Increases numeric value of the setting value. Pressing and holding the UP key for 2 seconds will STOP the current program

Controller Display Modes

image.png

Display modeMode 1: normalNormal operating mode. WhenFollowing power up, the powercontroller iswill turnedbe on,placed thein Display Mode 1. The upper display window shows the measured value (PV) and the lower window shows the four-digit set value (SV).

Display modeMode 2: checkingChecking the step. Press the SET key once to change the display from mode 1 to mode 2. The upper display window shows “STEP” and the lower windows shows the current step number. Press SET key again to show the timer information. PV window shows the set time for the current step. SV window shows remaining time in minutes. Press SET key again to return to the
display mode 1.

Display modeMode 3: programmingProgramming mode. Press A/M key once to change the display from mode 1 to mode 3. As a member, you will only ever need to adjust C01/T01 values.

Do not assume that the C#/T# values are the same since the last time you ran a program.

Display mode 4: Parameter setting mode. Press and hold the SET key for 2 seconds to enter the display mode 4. The top window shows the name of a parameter and the bottom window shows its value. Use the UP and DOWN arrow key the change the value; use the SET key to save the change and go to the next parameter.

These settings are specific to the machine and must not be changed by members. If you suspect a parameter needs to change, please contact a shop tech and ask for help.

To

do

Basic
Operation

Setting Alarms

Coming soon. 

  • orderAlarms &can installbe alarmset, buzzer-lightshowever the only indication currently is a small light on the controller.
  • createAlarms aare plotinformative only - they do not impact the operation of heatingthe time to 2000F

4/18 "does it work" test

T value = time until next step

StepSet Temp (˚F)T valueCheck timeCheck tempNotes
1801510:3375 
23001510:48295213˚/15min = ~14˚/min
30-12111:03265it definitely works

4/18 "is there an alarm buzzer" test

  • AL1: Set ALM1 to 1000˚
  • AL2: Set Hy-2 to 10˚
    kiln.

Setup

AskedNote: If you wait too long while setting the kilnprogram, it reverts back to trythe todisplay rampmode towith 2k˚ in 15 minutes. The alarm relays are firing, but no alarm light or buzzer sounds, so we need to get one (or two).

StepTemp (˚F)T valueCheck timeCheck tempNotes
18015step skipped 
23001511:40300AL2 light on, no buzzer
3200018012:00550proceeding to “can we get to 2k” test
   12:03600 
   12:07661 
   12:15766 
   12:21839 
   12:27896 
   12:34958 
   12:541099AL1 light on, no buzzer
   1:251250 
   1:351284 
   1:471331 
   2:091386 
   2:111400 
   2:321454 
   2:511492 
   3:45~1570hovering around here, jumping rapidly upPV and down. the area around the kiln is warm. this is about the functional limit of this configuration.
480-121   

Forge curing schedule

There's a forge which has been lined but needs to be heat-cured.

Stoppeduserperformsstep
StepTempSET (˚F) Tif value Notes
110060ramping up 100˚/hr
220060 
330060 
440060 
550060 
660060 
770060 
880060 
990060 
10100060 
11110060 
12120030holding for 1/2 hour for 1/2“ of material
1380-121stop

The official kast-o-lite packet says to ramp down 100˚ per hour, but people online seem to skip this step.2)

Temperature test notes

TemperatureTime
250FT=0
1500FT+45min
1750FT+70min
2000FT+140min
Ramp down to 1500F+15 mins

misc notes

  • it's possible to store several simple programs; there are 30 steps total
  • it's possible to set a schedule which is impossible for the machine to achieve
  • telling people in plain english how to set alarms for each type of project is important
  • the alarms don't stop anything and are not a safety feature so much as an alert
  • it's possible to observe and change the schedule while it's in progress

To set a singleprogram: temperature:

  1. pressShut the breaker to turn the kiln and controller on. 
  2. Press and hold the UP arrow key to stop the last loaded program from running.
    1. The display should be flashing STOP
  3. Press A/M.M to enter programming mode (Display mode 3). The display should show C-1.1 for the last program that was run.
    1. Note: If step 2 was not performed, the controller will display the active step from the last program run.
  4. useSet up/downthe arrowstemperature for the first temperature setpoint as follows:
    1. Use the UP / DOWN keys to set firstthe digit,selected thendigit pressof the temperature setpoint (Setpoint in fahrenheit).
    2. Press the A/M to move onkey to nextselect digit.which digit of the temperature setpoint is being modified.
    3. Repeat steps 4.1 and 4.2 until lastthe digitdesired temperature setpoint is set.
  5. Press the SET key to save the temperature setpoint and advance to the time setpoint.
    1. Use the UP / DOWN keys to set the selected digit of the time setpoint (Setpoint in minutes).
    2. Press the A/M key to select which digit of the time setpoint is being modified.
    3. Repeat steps 5.1 and 5.2 until the desired time setpoint is set.
  6. Press the SET key to save the time setpoint and advance to the next temperature setpoint.
  7. Repeat steps 4 and 5 for all desired time and temperature setpoints.

Programs can be set and changed during operation of a program.

Run a Program

To start a program:

  1. Press and hold the down arrow button for 2 seconds.seconds to start the program.
  2. Don'tObserve touchthat anything;the waitPV display temperature begins increasing.

The controller display returns to Display mode 1 (displays temperature and temperature setpoint) after 10 seconds of inactivity. To view the current step being executed, press the SET key from Display mode 1. Pressing the SET key a fewsecond secondstime will show the programmed time (top number) of the step and itthe shouldelapsed starttime heating.(bottom

  • Younumber) can turnof the machinestep.

    off

    Stop ata theProgram

    breaker,

    To orstop toa observeprogram:

    the
      temperature
    1. Press asand it cools you can presshold the UP arrow key for 2 seconds to putstop the machineprogram.
      2. into
    2. The STOPdisplay statewill begin flashing STOP.

    • Shut

    To run a pre-created program (i.e. set the current program segment):

    Down

    1. PressOpen A/M.the Displaycircuit should show C-1breaker.
    2. PressShut AMthe again.kiln Display should show T-1door.
    3. UseClean up the up/down arrows to enter -X, where X is the step number (i.e. the negative of the step you wish to run). For instance, to run a program at step 5 you would enter -5. This tells the controller to jump to that step.
    4. Press and hold the down arrow button for 2 seconds. 
    5. Continue as with single temperature from step 4.area.

    Cleaning

    TheUp

    kiln
      will
    1. Remove resumeany personal belongings from the lastarea
      2. program when it is turned on - be sure to 

    Parameter settings as of 2025-12-02

    Lock Values

    3) Program Adjustment
    When Lock = 0, program adjustment is allowed. The operator can view the
    program steps and change the setting. When Lock = 1, 2, 3 and up, program
    steps cannot be viewed nor edited.
    4) Step Selection
    When Lock = 0 or 1, operator can check the current step number and jump to
    another step by changing the step number. When Lock = 2, 3 or up, operator is
    not allowed to check the current step number and cannot jump to other steps.

    Propose setting LOCK value 0 so program adjustment and step selection, but limited parameter changing. Ensure EP1 is NONE so no adjustment of settings. Would need to set LOCK to 808 to adjust parameters afterwards

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