Which Should I Consider? PID Temp Controller or the Ranco 111000...

[Nikfits]

I really want to build a Flue Cure Chamber out of the fridge I have (metal Interior), but may not be able to this year. Unless, I find used parts out of appliances. I've heard I can do both with the fridge having a metal interior. The fact of the matter is that I've got $68.00 to put in it right now. Some of the items will be easy to get later (crock pot, etc.).

The main thing I'm wanting to know is your opinion of which would be better to get...
PID Controller or the Ranco 111000?

With the thought of using it for both. Kilning and Flue Cure.

May seem like a dumb question? But some dumb questions need to be asked - eh?

Thanks in advance for your input.

Gary

 

[Jitterbugdude]

I've never used a PID Controller but I have used a Ranco Controller for about 4 years now. I highly recommend it. I use it for my kiln and for my Flue Cure Chamber.

 

[leverhead]

I've used my Ranco for both flue-curing and kilning, it's simple to use and is rugged. I haven't used a PID controller, Amax would have to give his opinion for that. For flue-curing a ramp function would be nice, the Ranco doesn't have that. For kilning you're just holding one temperature, the Ranco does that very well.

 

[Nikfits]

Then the Ranco it is. Thanks much for your help guys. Me being a beginner, it may be a good idea learning without a ramp function. Then later, enjoy the benefit of a ramp function.

Thank you both.

 

[Chicken]

once you get it built depending on how much bacca you grow,

you'll like it a lot, i have a '' walk in kiln ''

it's pretty big,,,and this year i may '' expand ''

 

[Knucklehead]

Then the Ranco it is. Thanks much for your help guys. Me being a beginner, it may be a good idea learning without a ramp function. Then later, enjoy the benefit of a ramp function.

Thank you both.

A water heater thermostat will also get you by until you get ready to flue cure or step up to a ramp feature. I think they go for about $16.00. Precise control isn't necessary for kilning.

 

[Nikfits]

A water heater thermostat will also get you by until you get ready to flue cure or step up to a ramp feature. I think they go for about $16.00. Precise control isn't necessary for kilning.

I'm thinking that while I have the money to get it. I should go ahead and do it with the Ranco. That way later, when I get up enough to go with the next step (Flue Curing), then I'll already have one of the required pieces. I think the next higher priced item is the squirrel cage blower motor. The heater, I think will be easier to obtain than that piece, unless I get lucky with finding a squirrel cage somewhere. And in the whole process, learn some hands on experience.

I have seen two kilns listed on Craigslist so far. They were for pottery though. And I think would consume lots of power. I've never seen one up close. Though I wouldn't use one for Baccy (not enough space and may cook em to a black color, lol). I'm curious about the parts on them. I would have tried to get them. However, they were a good drive away from where I am. Does anyone have an opinion on these? For the Parts...

Thanks for all the feedback.

 

[leverhead]

Don't bother with the pottery kiln! The heat source is open coils or open flame, the moisture involved with either flue-curing or kilning would ruin the fire brick. I used two 500W electric charcoal starters, they were $20-25 each at Wally Mart. Depending on the size of your fridge, you might look at old window unit A/C's for blowers. Read up on the flue-curing threads, find out what not to try.

 

[Markx]

When using PID controllers it's important to know that they are all about the tunig. You must familiarize yourself with the inner workings of the Proportional Integral Differential model. Most of the units will not work properly out of the box or only do so in systems that have a high thermal inertia (in other words applications that heat up and cool very slowly, like a big shamber or a large crockpot). In such applications the actions of the controller around the setpoint have a very limited effect on maintaining the temperature, the controller can act totally absurdly and still be able to maintain the rough setpoint. A bit better units have an autotuning option, but it is only useful in establishing the rough baseline for the PID parameters. The fine tuning has to be done by hand and using trial and error method (or a sophisticated guide model ). Another very important point is that a well calibrated PID controller is not universal....in fact the tuning parameter values are absurdly connected to the particular setup that it has been calibrated to. Change anything (sensor location, chamber dimensions, heating element placement or wattage, thermal insulation etc.) and you have to start the calibration all over. Yet another point to bring out is that a PID will assume that a system heats up and cools in exactly the same manner (following the same curve of temp vs time) . This is more or less true for sytems with high thermal inertia, but consider a system that is small, has a powerful heater and is thermally well insulated. In such a case the temperature is rising very quickly when the heater is on, but will fall very slowly due to the good thermal insulation when the heater is off. In such a case the heating and cooling curves are completely different, but a PID controller does not understand that. So you can either calibrate it to behave reasonably on heating or on cooling, but not on both cases. So long story short....use the simplest on/off type controllers when building a thermal control for your cureing chamber and forget about PID or prepare youself for a long battle with mathematical models and thermodynamic calculus

 

[Brown Thumb]

When using PID controllers it's important to know that they are all about the tunig. You must familiarize yourself with the inner workings of the Proportional Integral Differential model. Most of the units will not work properly out of the box or only do so in systems that have a high thermal inertia (in other words applications that heat up and cool very slowly, like a big shamber or a large crockpot). In such applications the actions of the controller around the setpoint have a very limited effect on maintaining the temperature, the controller can act totally absurdly and still be able to maintain the rough setpoint. A bit better units have an autotuning option, but it is only useful in establishing the rough baseline for the PID parameters. The fine tuning has to be done by hand and using trial and error method (or a sophisticated guide model ). Another very important point is that a well calibrated PID controller is not universal....in fact the tuning parameter values are absurdly connected to the particular setup that it has been calibrated to. Change anything (sensor location, chamber dimensions, heating element placement or wattage, thermal insulation etc.) and you have to start the calibration all over. Yet another point to bring out is that a PID will assume that a system heats up and cools in exactly the same manner (following the same curve of temp vs time) . This is more or less true for sytems with high thermal inertia, but consider a system that is small, has a powerful heater and is thermally well insulated. In such a case the temperature is rising very quickly when the heater is on, but will fall very slowly due to the good thermal insulation when the heater is off. In such a case the heating and cooling curves are completely different, but a PID controller does not understand that. So you can either calibrate it to behave reasonably on heating or on cooling, but not on both cases. So long story short....use the simplest on/off type controllers when building a thermal control for your cureing chamber and forget about PID or prepare youself for a long battle with mathematical models and thermodynamic calculus

Amen.

 

[deluxestogie]

For flue-curing, the controller is exclusively ramping the temp up. For kilning, a 5-8ºF error in the temp control is no problem. That's why a water heater thermostat (thermodisc) for controlling a kiln works perfectly well.

Bob

 

[AmaxB]

For flue curing you must understand the process -it is all about heat, time, and moisture. A pid can work fine so can other methods. Do not confuse Kilning with Flue Curing they are different worlds. Ramping is a plus but if you have the ability to know your true temp. and moisture the cure can be done with or without automated ramp.
There is no cooling until the cure has finished.

Some one had said to read through last years threads - a good idea.... but understanding only comes with hands on plus a bit of pain.
There are a ton of varying aspects like, variety of tobacco, how ripe, time, temp, humidity, chamber, heat type, and on and on. These all change from load to load.
If you press on be sure your chamber will not leak moisture or heat and you have a good method of controlling them or suffer loss.
Keeping the air circulating is a big help too.

The best to you.