building kilns Kiln build from scratch

[Jeryko]

Hello everyone,

I've started dabbling in pottery about three years ago, making bonsai pots. This fits with another hobby of mine, you can guess which  :).

Point is, after firing my works with some acquaintances, I've decided that my own kiln is a must in order to really progress in the craft. The problem is that I my backwater location the chances of buying a second hand one are next to none, and I can't really justify spending almost $2500 for a new one. So I came up with the idea of actually building one from scratch. Yes, I know it's hard, yes, I know it can be dangerous but I'm trying to be as smart about it as I can and mitigate all the risks as much as I can. 

I would really appreciate it if you ladies and gentlemen would be willing to part with some knowledge to help me have the best possible outcome for this project. 

Now for the tech specs:

In order to fit the nature of my work, I would need a 50x40x30cm interior.  (19.7x15.7x12 inches)

The temps needed would be around 1240°C (2264°F)

The power I can get away with as a household consumer in my location is 230V 16A ~ 3600W

This takes me to my first point: As far as internet wisdom goes, the Wattage needed for a pottery kiln is 0.6W/cm2  which would place me at a needed Wattage of around 5600W. Waaaay above what I can provide. But then I read specs for kilns produced on Germany like Nabertherm that for a 60L pottery kiln with a top temperature of 1300°C produce single phase 230V 16A models, which makes me believe I can do it.  I'm assuming that I'll need to go with more insulation and longer firing times, but it's doable. Is that accurate?

Next up, elements: luckily I have a provider for Kanthal A1 wire near me and prices are decent. Would 1.6mm  1380°C max,  0,721 Ohm/m be suitable? With this diameter I seem to be able to juggle the resistance, wattage, length and placement of elements as close to optimal, with 2 elements running in parallel. 

Thirdly the most amusing topic... Well not amusing but maybe the most complex. The controller. 

Being in IT i'm a sucker for gadgets. Usually buying them, true, but this time I'm thinking about building :). I saw a lot of projects on the web with Raspberry Pi kiln controllers. The features they provide, the adaptability and the connectivity of the systems sounds amazing. Question is: does anyone fire with something like this? How does it compare to commercial controllers that are super expensive and in the stone age as far as features go. Are they worth the trouble? An example project that stuck with me is below. But there are many more

 

Thanks for the help, and looking forward to chatting with you.

Mihai

Edited April 20, 2020 by Jeryko

[Hulk]

Hi Mihai!

I started out with a used electric two years ago. Its capacity is about seven cubic feet; it came with a brand new shelf set, fairly new elements (~15 firings) some old shelves, an assortment of posts, and glaze material. There's no controller - three switches for low, medium, high only - so takes some attention and care, for sure. I spent almost twice as much on a wheel, and another basket of money on clay, glaze materials, tools, and equipment. I am having fun!

If I were to build a kiln, for sure it would be gas fired, no question there. Have you considered gas?

The other question that comes to mind - are you considering going larger than ~2 cubic feet? That seems rather small for big pots!

Several active members here have cobbled together controllers, relays, etc. as upgrade to a manual kiln; you might find some of the threads...

[CactusPots]

In any kiln design, we always start with the shelves.  Make a commitment, there and use lots of pencil and paper.

[Stephen]

ya know I get it, I'm a thirty-five year IT guy and a gadget person so it's always fun to consider this stuff but man you could be setting yourself up for a huge distraction from your 2 passions and before you know it its been a couple of years since you made any pots. I know I do this stuff to relax after spending 8-9 hours programming all day.

If I were you before I went down the electric kiln route I would maybe take Hulk's advice and explore a propane conversion if you can score an old kiln to gut or maybe a small wood kiln. I can't remember the book off hand and my copy is buried somewhere but I think it was alternative kilns or something like that and there was a design for a 10-12cf wood fired kiln that the guy claimed could be fired with a half cord of wood. Could be fun and not IT related which for me would be appealing.

 

Just a thought.    

Edited April 21, 2020 by Stephen

[Jeryko]

11 hours ago, Hulk said:

Hi Mihai!

I started out with a used electric two years ago. Its capacity is about seven cubic feet; it came with a brand new shelf set, fairly new elements (~15 firings) some old shelves, an assortment of posts, and glaze material. There's no controller - three switches for low, medium, high only - so takes some attention and care, for sure. I spent almost twice as much on a wheel, and another basket of money on clay, glaze materials, tools, and equipment. I am having fun!

If I were to build a kiln, for sure it would be gas fired, no question there. Have you considered gas?

The other question that comes to mind - are you considering going larger than ~2 cubic feet? That seems rather small for big pots!

Several active members here have cobbled together controllers, relays, etc. as upgrade to a manual kiln; you might find some of the threads...

Heyya @Hulk. Thanks for the answer. I would love a gas fired kiln. The concept scares me a bit, but would love one. Only issue there is with management (please read the Mrs ) . She agreed to an electric one but will probably divorce me if I make what she calls 'an improvised bomb' in the backyard. Except for that, she's pretty cool :)). 

Totally get the equipment buying. I do the same for all my hobbies and then milk them for all they're worth :). 

The 2cubic ft is probably the max size for which I could squeeze out sufficient Wattage from my electric system. I'm limited to 230V and 16A. So it's gotta be electric and it's gotta be small. Good part is that I only do it for a hobby and occasionally take on a pot commission but the size should be enoughish. 

About the controller, looked through 30 pages of this forum, and a whole lot of internet. I found a couple of interesting ideas and implementations. Was wondering if I can get a little more first hand feedback as to how they behave. Most of the threads are a couple of yeas old and look quite dead. 

Hello @CactusPots. Thanks for the reply. I actually found shelves that fit my proposed kiln size :D. So i'm hoping to be able to stick to it. Did the math already, so it's just that I need confirmation about whether the power is enough or not and if the wire gage is suitable.  I'd kill for a discussion with someone who owns a Nabertherm Ecotop 60. That's the one that has 60L with only 3.6kW. There aren't really any speciffics about the model on the internet except for some basic stats. 

 

[Jeryko]

@Stephen hello! Thanks for the reply. Aaaa... Wood fired. That would be awesome sometime in the next 10 years but I don't think I can commit to that right now. Electric... sure, gas... Maybe if i get the missus onboard. Wood is out of my league at the moment. I'm pretty new to pottery as it is and I feel that adding the complexities of woof firing to the mix a bit too much to chew. 

Concerning the IT business, oddly enough, if it's not really SAP administration related (my current field)  I find it relaxing. Spent the last two days playing with an arduino and a K type thermocouple just for fun to get it to post to an IOT platform in preparation to building the actual controller. I did not expect C++ and Python to be entertaining :)) . Worked :)). 

About the book... Started looking around for The Kiln by a Mrs Olsen that I saw recommended. 

 

Edited April 21, 2020 by Jeryko

[neilestrick]

Unless you're really set on building your own, I would keep a lookout for a decent used kiln. From a time and money standpoint it would be the best way to go, even if you have to drive a bit to get it. The most difficult part is cutting the grooves in the bricks. Brick dust chews up anything it gets into, so know that any power tools you use may be sacrificed. Build the controller box so it can be wall mounted, not mounted to the kiln. Have a jumper cord coming off the kiln that plugs into the control box. The boxes I've built run about $200 for a 50 amp kiln, including everything but the controller. For a 20 amp kiln you could drop $30-40 off of that since you'd only need a small relay, outlet, etc. You can get a good 3-button kiln controller for $200.

The big questions are how much work do want to do, and how quickly do you want to be firing? Building your own electric kiln is about 10 times as much work as a small gas kiln. There are a lot of little parts needed to make it work. A control box alone uses about 20 different parts if you count wire as one part. There's also all the little terminal ends, screws, nuts and bolts, etc. I'm not trying to discourage you, I just want you to realize what you're getting into. I'm assuming you know enough about electrical systems to do it all safely? Start making a list of everything you need. It will be lengthy, and sourcing all those parts in small quantities can get expensive.

[liambesaw]

2 hours ago, Jeryko said:

Most of the threads are a couple of yeas old and look quite dead. 

That speaks loads

Do you have only 16 amps available for a reason?  That seems like a very weird amount.  If it's a 16 amp breaker in your breaker panel, you are limited to more like 12 amps of continuous duty.  And 2500 watts isn't a lot to work with, less than 2 small space heaters

I don't know how things are in your country, or if there's any sort of home insurance, but another drawback of building your own kiln, is that it won't have any sort of safety certification, and if it happens to burn down the house, you may be hosed.

Anyway, just a lot of fun stuff to consider.  LPG is not a very good explosive, maybe build a small raku kiln in the back yard first to "warm" her up to the idea of a bigger one

Google "Ian Gregory flat pack kiln" for a quick and cheap design.

 

[Bill Kielb]

3 hours ago, Jeryko said:

Heyya @Hulk. Thanks for the answer. I would love a gas fired kiln. The concept scares me a bit, but would love one. Only issue there is with management (please read the Mrs ) . She agreed to an electric one but will probably divorce me if I make what she calls 'an improvised bomb' in the backyard. Except for that, she's pretty cool :)). 

Totally get the equipment buying. I do the same for all my hobbies and then milk them for all they're worth :). 

The 2cubic ft is probably the max size for which I could squeeze out sufficient Wattage from my electric system. I'm limited to 230V and 16A. So it's gotta be electric and it's gotta be small. Good part is that I only do it for a hobby and occasionally take on a pot commission but the size should be enoughish. 

About the controller, looked through 30 pages of this forum, and a whole lot of internet. I found a couple of interesting ideas and implementations. Was wondering if I can get a little more first hand feedback as to how they behave. Most of the threads are a couple of yeas old and look quite dead. 

Hello @CactusPots. Thanks for the reply. I actually found shelves that fit my proposed kiln size :D. So i'm hoping to be able to stick to it. Did the math already, so it's just that I need confirmation about whether the power is enough or not and if the wire gage is suitable.  I'd kill for a discussion with someone who owns a Nabertherm Ecotop 60. That's the one that has 60L with only 3.6kW. There aren't really any speciffics about the model on the internet except for some basic stats. 

 

Here is my take:

Yes you can build and super insulate a kiln (compared to typical 3” brick kilns). It is most likely needed for your electrical restriction.  Fiber is certainly king with respect to having to heat a bunch of brick mass each and every firing.

Arduino or equal is fine if you have the time, lots of very nice  temperature controllers out there though for super cheap (20.00 - 50.00 usd) PID, Fuzzy logic, auto tune, and I find their type K interfaces more industrial compared to Arduino. If you are contemplating the arduino then likely  are anticipating solid state relays.  They are very doable and will actually add some capacity to your kiln. They need to be done right though, so use the manufactures cooling data and design conservatively with protection for your SSR.

I personally like using low cost PLC because it’s super easy and proven super reliable by industry but, it’s sort of old technology. Having said that even the most basic have web interface capability, standard k type inputs, data gathering, email engines, etc... without too much custom  effort.

And finally, this is a lot of design work with adaptation of available hardware so getting a used kiln to use as is, or to modify seems to me to be  something I would  seriously contemplate. 
 

Finally - finally, an economical  Raku kiln sounds really doable and fun as a warmup step.

At one time a few folks asked what does it take to design an SSR retrofit for an existing kiln, to which we made a very general video so folks could get a real feel for some of the thought that goes into just that part. You might find it interesting.

 

Edited April 21, 2020 by Bill Kielb

[Jeryko]

1 hour ago, liambesaw said:

That speaks loads

Do you have only 16 amps available for a reason?  That seems like a very weird amount.  If it's a 16 amp breaker in your breaker panel, you are limited to more like 12 amps of continuous duty.  And 2500 watts isn't a lot to work with, less than 2 small space heaters

I don't know how things are in your country, or if there's any sort of home insurance, but another drawback of building your own kiln, is that it won't have any sort of safety certification, and if it happens to burn down the house, you may be hosed.

Anyway, just a lot of fun stuff to consider.  LPG is not a very good explosive, maybe build a small raku kiln in the back yard first to "warm" her up to the idea of a bigger one

Google "Ian Gregory flat pack kiln" for a quick and cheap design.

 

Hello Liam. 

The 16Amps : Couple of reasons. First and foremost, modern contractors in Romania are cheap idiots. The ones that built the house I live in at least...  I have a 3x2.5mm copper wire cable going from a 20A breaker (easy to replace) to my detached basement (completely disconnected from the house, next to it below ground level rather than under) . According to code, the cable is rated for 20A when enclosed, 32A in the open... So 20 in my case. 

Secondly, single phase wall sockets are all rated 16A in RO.  If i hardwire I can go past 16 but with safety margins on the current cable I wouldn't really want to do that. The other option would be to replace the cable with thicker gage, but that involves an electrician and if the tubes inside the walls are not done properly and the old cable can't be used to pull in the new one, it might cost a small fortune.  

The basement situation above explains why I'm not overly concerned with fire. The whole thing is concrete below ground, detached from the house. If any mishap should happen worst thing that can burn are four car tyres and two stools :)). 

Edited April 21, 2020 by Jeryko

[liambesaw]

In that case, I would run new heavier gauge wire to the basement and make the kiln so that the power draw is not the limiting factor.   In my mind it would be easier to build an electric kiln capable of cone 10 if you have enough amperage, instead of trying to beat industry on engineering the most energy efficient kiln on the market.  

And then in the future if you end up buying a bigger kiln or find something used, you can hook it up without any power issues.  

I think everyone here has had to pay that electrician bill or do the work themselves, I don't think there's a home in the world set up to run a decently sized kiln straight from the wall.

[Jeryko]

On 4/21/2020 at 8:17 PM, neilestrick said:

Unless you're really set on building your own, I would keep a lookout for a decent used kiln. From a time and money standpoint it would be the best way to go, even if you have to drive a bit to get it. The most difficult part is cutting the grooves in the bricks. Brick dust chews up anything it gets into, so know that any power tools you use may be sacrificed. Build the controller box so it can be wall mounted, not mounted to the kiln. Have a jumper cord coming off the kiln that plugs into the control box. The boxes I've built run about $200 for a 50 amp kiln, including everything but the controller. For a 20 amp kiln you could drop $30-40 off of that since you'd only need a small relay, outlet, etc. You can get a good 3-button kiln controller for $200.

The big questions are how much work do want to do, and how quickly do you want to be firing? Building your own electric kiln is about 10 times as much work as a small gas kiln. There are a lot of little parts needed to make it work. A control box alone uses about 20 different parts if you count wire as one part. There's also all the little terminal ends, screws, nuts and bolts, etc. I'm not trying to discourage you, I just want you to realize what you're getting into. I'm assuming you know enough about electrical systems to do it all safely? Start making a list of everything you need. It will be lengthy, and sourcing all those parts in small quantities can get expensive.

Hello @neilestrick . Thanks for the reply. That's the issue. There are literally none second hand  to be had in Romania.  Two posts on the web at this time: 1000L and 850L for $7K and $5K. obviously out of scope. I've been looking every day on all the sales sites for the last five months. Nothing. Closest I can find second hand is in Austria or Germany, and that's a minimum 700 mile drive.  

About the brick cutting, haven't figured it out yet but I'll get to it. Baby steps. Concerning the work, well that doesn't frighten me one bit. I love manual labor and buying crap :). Kiln parts count :D. I'm compiling a BOM as we speak. The kiln sans electrics/controller gets me to  $400. I'll post everything once I get them all down on paper... well excel I mean. $200 sounds like what i'll be looking at for the control box as far as I can tell so far.

I'm not an electrician, but I think I know enough not to kill myself by a small margin :)). 

On 4/21/2020 at 9:31 PM, Bill Kielb said:

Here is my take:

Yes you can build and super insulate a kiln (compared to typical 3” brick kilns). It is most likely needed for your electrical restriction.  Fiber is certainly king with respect to having to heat a bunch of brick mass each and every firing.

Arduino or equal is fine if you have the time, lots of very nice  temperature controllers out there though for super cheap (20.00 - 50.00 usd) PID, Fuzzy logic, auto tune, and I find their type K interfaces more industrial compared to Arduino. If you are contemplating the Arduino then likely  are anticipating solid state relays.  They are very doable and will actually add some capacity to your kiln. They need to be done right though, so use the manufactures cooling data and design conservatively with protection for your SSR.

I personally like using low cost PLC because it’s super easy and proven super reliable by industry but, it’s sort of old technology. Having said that even the most basic have web interface capability, standard k type inputs, data gathering, email engines, etc... without too much custom  effort.

And finally, this is a lot of design work with adaptation of available hardware so getting a used kiln to use as is, or to modify seems to me to be  something I would  seriously contemplate. 
 

Finally - finally, an economical  Raku kiln sounds really doable and fun as a warmup step.

At one time a few folks asked what does it take to design an SSR retrofit for an existing kiln, to which we made a very general video so folks could get a real feel for some of the thought that goes into just that part. You might find it interesting.

 

@Bill Kielb hello Bill. That's a super helpful answer and the video is very educational. Thank you. 

The insulation I'm looking at is 3"IFB backed up by 2-3" of ceramic fiber blanket and a 4"  ceramic fiber board lid. 

I am indeed thinking of SSRs. Two of them with  copper heat sinks and a fan to tie it all together. I'm adding a PDF with my rough sketch of the wiring to the post if you have time to take a look. I didn't factor in a contactor but the SSRs in series should take the chance of the system getting  stuck on the ON position to next to 0, and lid switches should provide extra safety. If this is not enough I can always change approach.

Wow. PLC. This is a topic I have never touched, even in passing . I just know what the acronym stands for :)). 

 

23 hours ago, liambesaw said:

In that case, I would run new heavier gauge wire to the basement and make the kiln so that the power draw is not the limiting factor.   In my mind it would be easier to build an electric kiln capable of cone 10 if you have enough amperage, instead of trying to beat industry on engineering the most energy efficient kiln on the market.  

And then in the future if you end up buying a bigger kiln or find something used, you can hook it up without any power issues.  

I think everyone here has had to pay that electrician bill or do the work themselves, I don't think there's a home in the world set up to run a decently sized kiln straight from the wall.

@liambesaw you're probably right of course. The first instinct tho' is to try to make due with the wiggle room that's there :). An electrician is possible in my future :D.

If you guys are bored, here's a PDF of the wiring. Suggestions welcome, pointers on how not to die, more than welcome :)). No details of the microcontroller GPIO wiring because that feels besides the point at this time.

Have a good one! Mihai 

 

Kiln Wiring.pdf

Edited April 22, 2020 by Jeryko

[liambesaw]

17 minutes ago, Jeryko said:

Hello @neilestrick . Thanks for the reply. That's the issue. There are literally none second hand  to be had in Romania.  Two posts on the web at this time: 1000L and 850L for $7K and $5K. obviously out of scope. I've been looking every day on all the sales sites for the last five months. Nothing. Closest I can find second hand is in Austria or Germany, and that's a minimum 700 mile drive.  

About the brick cutting, haven't figured it out yet but I'll get to it. Baby steps. Concerning the work, well that doesn't frighten me one bit. I love manual labor and buying crap :). Kiln parts count :D. I'm compiling a BOM as we speak. The kiln sans electrics/controller gets me to  $400. I'll post everything once I get them all down on paper... well excel I mean. $200 sounds like what i'll be looking at for the control box as far as I can tell so far.

I'm not an electrician, but I think I know enough not to kill myself by a small margin :)). 

@Bill Kielb hello Bill. That's a super helpful answer and the video is very educational. Thank you. 

The insulation I'm looking at is 3"IFB backed up by 2-3" of ceramic fiber blanket and a 4"  ceramic fiber board lid. 

I am indeed thinking of SSRs. Two of them with  copper heat sinks and a fan to tie it all together. I'm adding a PDF with my rough sketch of the wiring to the post if you have time to take a look. I didn't factor in a contactor but the SSRs in series should take the chance of the system getting  stuck on the ON position to next to 0, and lid switches should provide extra safety. If this is not enough I can always change approach.

Wow. PLC. This is a topic I have never touched, even in passing . I just know what the acronym stands for :)). 

 

@liambesaw you're probably right of course. The first instinct tho' is to try to make due with the wiggle room that's there :). An electrician is possible in my future :D.

If you guys are bored, here's a PDF of the wiring. Suggestions welcome, pointers on how not to die, more than welcome :)). No details of the microcontroller GPIO wiring because that feels besides the point at this time.

Have a good one! Mihai 

 

Kiln Wiring.pdf 115.75 kB · 0 downloads

In your wiring diagram, I would switch to a single relay since you're not controlling them independently, unless you have chosen two for a different reason, one less thing to buy and one less thing to fail.

[Jeryko]

@liambesaw i put two for redundancy. Of one fails in closed position the whole contraption will still be turned on/off by the second one avoiding an overfire or an unforseen basement barbeque . That was the thought process. 

[Bill Kielb]

19 minutes ago, liambesaw said:

@Bill Kielb hello Bill. That's a super helpful answer and the video is very educational. Thank you. 

The insulation I'm looking at is 3"IFB backed up by 2-3" of ceramic fiber blanket and a 4"  ceramic fiber board lid. 

I am indeed thinking of SSRs. Two of them with  copper heat sinks and a fan to tie it all together. I'm adding a PDF with my rough sketch of the wiring to the post if you have time to take a look. I didn't factor in a contactor but the SSRs in series should take the chance of the system getting  stuck on the ON position to next to 0, and lid switches should provide extra safety. If this is not enough I can always change approach.

Wow. PLC. This is a topic I have never touched, even in passing . I just know what the acronym stands for :)). 

 

I would suggest using an economical mechanical switch, dual SSR are an ok idea but theoretically they will have leakage even when good. The definite purpose contactor is an industry established norm and cheap if you take screen shots of the video. Additionally no need for the copper heat sinks, although better you can get larger surface area aluminum for cheap. PM me if and when you decide and I can send you some sources that are very reasonable in price.

Heat sink pic and a PLC teaser of what we build for under 1000.00 at this point.

[Sorcery]

Hey Brother!

Great Advice here!

700miles ain't too far!

I just drilled some brick to hold a flue wall in my gas joint. Reckon you can do the same to groove bricks. 

Drill 2 holes thru the entire brick, about 2-7mm of the face then saw cut out the top one to expose the channel to the kiln interior. Save the dust!

Sorce

[ojb]

Hi Mihai,

Just wanted to check how you're getting on with this project? I'm planning to build an efficient ceramics kiln for my partner that's pretty similar to yours. My planned specs are: 30cm x 30cm x 40cm, front loader, made from 50mm ceramic fibre board, backed up with 75mm ceramic fibre blanket, and with an aluminium case. We have 16 amp circuits too, so I'm looking to power the kiln at about 3000 watts / 13 amps. Aiming to get it to around 1280 degrees C. I'm shopping around for some 1.8mm Kanthal, looks quite expensive. I bought a ramp / soak PID controller from AliExpress, hopefully that works fine.

Would be very keen to hear about your progress!

Cheers
Ollie

[Jeryko]

On 5/8/2020 at 10:32 AM, ojb said:

Hi Mihai,

Just wanted to check how you're getting on with this project? I'm planning to build an efficient ceramics kiln for my partner that's pretty similar to yours. My planned specs are: 30cm x 30cm x 40cm, front loader, made from 50mm ceramic fibre board, backed up with 75mm ceramic fibre blanket, and with an aluminium case. We have 16 amp circuits too, so I'm looking to power the kiln at about 3000 watts / 13 amps. Aiming to get it to around 1280 degrees C. I'm shopping around for some 1.8mm Kanthal, looks quite expensive. I bought a ramp / soak PID controller from AliExpress, hopefully that works fine.

Would be very keen to hear about your progress!

Cheers
Ollie

Hey Ollie. Just completed the build. Turned out better than expected. Only issue is that I did end up using more amps than I previously thought to get it to temperature fast enough. I'll write the specs if ur curious. 

Thanks everyone else for the feedback and great ideas. Rpi controller rocks by the way :). 

@Sorcery holly cow. Glad to see you here dude. Haven't had time for The Nut in quite a while. 

 

The end product:

[Sorcery]

Nice feet! Not the Red ones! Lol!

Nice kiln though!

 

Sorce

[ATauer]

On 7/29/2020 at 5:20 PM, Jeryko said:

Hey Ollie. Just completed the build. Turned out better than expected. Only issue is that I did end up using more amps than I previously thought to get it to temperature fast enough. I'll write the specs if ur curious. 

Thanks everyone else for the feedback and great ideas. Rpi controller rocks by the way :). 

@Sorcery holly cow. Glad to see you here dude. Haven't had time for The Nut in quite a while. 

 

The end product:

I know this thread is a couple years old by now, surprised it isn’t archived. I was super interested, thank you for providing so much detail as you went through the process. I got a “free” Skutt KS-1227-3, basically the second biggest kiln they make, except they seem to have not very long ago discontinued the KS line, but of course what I was told, by the woman who gave it to me who knew nothing about ceramics having never touched clay (super great Mother’s Day present from the Dad, ha! She scared the hell out of me so I can only imagine how this clearly clueless husband suffered after buying a broken down kiln at a school auction and gave it to her for her gift, men, sometimes!)  was that it only needed new elements and a new cord to switch it make to its original 240 volts single phase so I could use it at home instead of the 3 phase 208 volts the school used and an obviously broken part of the kiln sitter. No big deal. Of course, after months of talking to the techs at Skutt, discovering with them each call some new thing that was missing, weird things, that make no sense someone would take them off, leading to me needing to rebuild the kiln sitter pretty much entirely as well as some heat switches using bolts so old that it took them weeks to find any in their warehouse. I’m in the process of trying to build my own electronic controller, for obvious reasons but also because I do a ton of glass casting and fusing, and you can’t use kiln sitters with that!

I tried really hard to do a Raspberry pi controller from the github creator Jbruce, but after having help from someone on Reddit about what equipment to buy, then not being able to find the new Raspberry pi anywhere for months until I finally found it online only in an expensive package with a bunch of accessories. But I’ve given up, JBruce’s kiln controller GitHub is way too confusing, his electrical diagram is wrong and is missing many things, his list of materials you will need only has about half of what you need on it, and despite watching tons of videos of putting together PIDs on youtube I cannot figure out how the damn breadboard fits into the work box I have, if I need the long breadbox part plus all the little ones that look exactly the same, because no one in the youtube videos used breadboards and the GitHub doesn’t explain anything about how they are attached/wired in, how many that came in that package of different sizes to use etc. I struggled through so many other things with that controller, and was going to do the damn programming of which he seems to have way more of than others I’ve looked at recently, even though I haven’t used python or any code since 2019 and I did bioinformatics for a while which is a lot lot different. Looking everywhere to try to figure out the breadboard thing just caused me to finally throw up my hands in defeat and decide to try and find a less advanced controller, initially thinking an Inkbird before finding out they don’t make them go high enough in temp, damn it. Now I’m on the AliExpress site someone on here mentioned which I’m super grateful for but the only problem is a lot of the PIDs sound good, and will have 32 or 50 step ramps, except it is very unclear with all of them whether there is just one program with all those segments or whether you can save multiple programs, which I would prefer, because not only do I have a couple different ceramic firing schedules but I have a bunch of different ones for glass, and it would be a pain in the butt to have to input them completely every time instead of having at least some of them saved, and if they can have 50 segments you’d think they could have more than one saved program. Seeing your post and your joy with your Raspberry pi controller is now making me rethink giving up, if you are still on here and can tell me which Raspberry Pi program you went with that was so successful maybe I’ll give it another shot. Although I would need to find out about the freaking breadboard. 

I also was incredibly impressed you succeeded in making your own electric kiln, something I have been told over and over again is not possible. The thing is I make very large scale sculptures, and have to section them for firing and spend days epoxying them and hiding the seams after so no one can tell they were sectioned. I desperately want a huge electric kiln that I could fire my sculptures in one piece. But though I am saving up I won’t be able to afford one for years and years, they are usually well over $20,000. I know your small kiln is not anywhere near the scale I’m talking about, but seeing you accomplish it has given me hope. I also wanted to mention, for all the people who are carving grooves through bricks, that I have been seeing a ton of kilns on social media in New Zealand in particular but Australia and parts of Europe, with kilns with incredibly thick ceramic blanket as the walls with very thick coils of elements attached to the blanket. It is a very interesting kiln look, they have a lot less elements in there because they are so big, and I assume also because it seems that all the insulation is ceramic blanket that they are *extremely* well insulated. If I was to make any kind of electric kiln I think I would go that route after seeing these kilns, and hearing about how they can get to cone 10 at 1220C, which is what I use to get to cone 6 in my IFB insulated American made kilns! I’m a former scientist, although biology related, not something helpful for this like engineering, but it does mean I do have a little more background than the average ceramic artist in some tech stuff. The hardest part for me would be determining all the calculations for the elements, and then being able to get the gauge and even harder coil them to the right size. Otherwise I would just be making a huge ceramic fiber box possibly train style, and just need to hire someone to weld the steel for the outside. And by then hopefully I can afford a proper electronic controller or will have successfully built one hopefully. If I could build my own, I would be able to afford it so much earlier than buying one. That much ceramic fiber blanket will be expensive but a mere fraction of what a commercial one will cost. I just hope I can figure out the elements stuff, having no background in electronics or electricity. I’ve read a lot of kiln books & the chapters on electric kilns are always the same- do not actually write about anything about how they are made, except going into deep detail about the calculations for the elements, then end by saying that you really should never build one and just buy one. So unhelpful, whereas the chapters on all the other kilns are lengthy dissertations on all the ways and designs you can build yourself and how to fire them. In about 1.5 years my plan is to move to France, hopefully to a place where I will have room in my yard/property to build a big enough studio for the kind of work I do, or if I’m lucky have a nice barn or stable to set up in, and soon after I’d like to get that big kiln, and keeps my big but smaller electric kilns as well, and have room for raku and a large pitfire, and also space to eventually build a small fast fire wood kiln and a small soda kiln, under a shelter outside probably. The only way I’d have any ability after spending the money to buy a place & move there to get the big kiln any time soon would be to build it. ‘

And I know everyone will say to me the same thing they said to you, do gas, but I already feel horribly guilty enough using propane for raku, as someone completely against fracking, plus for my large scale sculptures I prefer a true oxidation firing usually, I don’t feel I could get what I want from a gas kiln. And for reduction that’s why I’m building the smaller fast fire wood kiln and soda kilns (also wood), which are much better for the environment than gas. I’ll still probably use propane for raku and feel horrible about it, but I’m not a fan personally of doing my raku electric or with wood, so I’m kind of stuck until they hurry up and invent something to replace it! And I am entertaining gas in a way, because if I can’t get my huge electric kiln built, I will be using Ian Gregory’s flat packed kiln- not the tiny one they show on his website but the huge ones I’ve seen in paperclay books where he is firing sculptures in situ using propane and different sizes and configurations of his flat packed kiln, which is essentially a raku kiln since it is made of panels of hardware cloth covered with ceramic blanket, and clipped together using metal clips like the ones for jumper cables. He consistently got to stoneware temps or all the way up to cone 10 in that, and it would be easy for me to make, cost a little less (and the ceramic fiber could be reused in a big kiln later on if I was able to start building it), and takes up no room in storage since it packs. Flat. There might be some overall advantages to just sticking with that long term, as it wouldn’t take up a bunch of studio space and instead of assistants and hoists and forklifts moving the sculptures to the kiln, I would move the kiln to the sculptures. The biggest downsides for me are that I’d be using a lot of propane with that, instead of electricity that I would also at somepoint be installing solar panels to offset, and I don’t think he got totally consistent temperatures with it always, it is exactly like raku. I’d also be struggling to keep it well oxygenated, although the thought of maybe occasionally doing one of my large pieces in reduction does have some appeal…mostly I just have one form in my head that is huge that would look fabulous in a blue celadon. But those can also be easily faked or I can do SiC celadons which tend to work out for me. 

Sorry, I went too long. I learned a lot from this thread that I’m grateful for, like it is actually possible to build an electric kiln, even if very small. That I’m not alone in wanting to do that. And a few other tips and tricks…if you read this and can tell me or send me a DM with the github for the Raspberry pi controller you were very happy with I’d appreciate it. I’m super unhappy with the one I was trying to build and its hard to assess some of the others I’ve come across. Thanks!

[Bill Kielb]

1 hour ago, ATauer said:

If I could build my own, I would be able to afford it so much earlier than buying one.

The Bartlett controls - touch screen and old V6cf are PID based, likely without the derivative portion and are reasonably priced as well as capable of storing multiple programs including many pre maid for glass. I think the price range for the controller board is 200.00 - 400.00 so maybe something to consider. Most temperature controllers are PID based and provide lots of segments for programming and can be had in the 50.00 - 150.00 dollar range. Problem is programming is a bit of reading and learning thing. Most folks do not know how to tune a PID process, yet auto tune is available on most.

[ATauer]

4 minutes ago, Bill Kielb said:

The Bartlett controls - touch screen and old V6cf are PID based, likely without the derivative portion and are reasonably priced as well as capable of storing multiple programs including many pre maid for glass. I think the price range for the controller board is 200.00 - 400.00 so maybe something to consider. Most temperature controllers are PID based and provide lots of segments for programming and can be had in the 50.00 - 150.00 dollar range. Problem is programming is a bit of reading and learning thing. Most folks do not know how to tune a PID process, yet auto tune is available on most.

I’m having an impossible time finding any PIDs so far that save multiple programs. There are some very reasonably priced that otherwise have great qualities, and they do segments- 32 segments! 50! But they don’t save them and they don’t have more than one it appears. The tuning doesn’t worry me, what I’ve read about it it sounds pretty easy. I just want to find one that will save multiple programs. Maybe there aren’t any, and I will have to settle for putting in my firing schedules manually every single time. I have looked at the Bartlett V6cf and the price is right at some places, but it is always very unclear if they are selling the actual controller, or just the faceplate. Because most places I have enquired including at Bartlett itself they say they only sell the interface, and I would have to pay someone to build a box and put the SSR and and some kind of PID I assume and all that stuff in it, and when they quoted me how much that costs, on top of the cost for the interface, it is basically as much as the Orton standalones which are already put together and ready to plug in, although nearing 1K these days, in the fall they were a lot cheaper. And it drives me nuts because I know these things they are selling for so much money are simple PIDs, they even say they are PID based, and I know I’m smart enough I could put one together with a little help, just some background in electrical work and brushing up on my coding. I hate the idea of paying over 1K for something I know I could make for under $200. But the frustration, and the amount of time it takes up, and how much it delays me being able to use that particular kiln are things I have to consider. If it was something I knew I couldn’t figure out it wouldn’t bother me so much, I’d just find the money somewhere, but the fact that I know I can make these….

[Min]

@ATauer, there is a lot to digest in your post first post in this thread, a fair bit of hijacking going on. We do not permit sexist comments such as what you said at the end of the quote below. There is an "edit" function with every post, please feel free to use it.

3 hours ago, ATauer said:

...I can only imagine how this clearly clueless husband suffered after buying a broken down kiln at a school auction and gave it to her for her gift, men, sometimes!

Please try and keep to the topic being discussed.

edit: there is a 14 page thread on Raspberry PI controlled kilns here that you might find helpful.

Edited July 29, 2022 by Min
added a link

[Bill Kielb]

1 hour ago, ATauer said:

The tuning doesn’t worry me, what I’ve read about it it sounds pretty easy.

Tuning properly can be extremely difficult. Auto tune helps a bunch but good PID loop process folks spend a lifetime becoming good at it.

1 hour ago, ATauer said:

. I have looked at the Bartlett V6cf and the price is right at some places, but it is always very unclear if they are selling the actual controller, or just the faceplate

If it’s several hundred dollars it is a control with faceplate, circuit board, built in relays, built in PID, etc…. If you intend to use SSR or mechanical relays you would use the output of the V6cf to drive them. You will need a box, transformer, fuse holder, cord, wiring, SSR’s heat sinks etc… regardless of which controller, even a Ras pi will require all the support stuff and probably more actually

A stand alone control will still need something to turn on and off which means relays, SSR’s box to hold them etc…. I am just saying, plan this out start to finish and I think you will have a better idea of how it all will work within your design. Right now there seems to be some confusion.

The Bartlett has a PID already tuned for the typical thermodynamics of a kiln and places to store programs. The RAs pi is all your tuning -100% and you need to write the entire program as well. Economical temp controllers have a PID and auto tune, else you are going to have to tune and they still require all the support: box, interconnect wire, relays, etc…..

I think if you define this completely an easiest path will become obvious.

Edited July 29, 2022 by Bill Kielb

[Hulk]

Big, seems easier with gas.

Energy choice, local electric grid may be clean and low impact, or not.
Burning wood can be dirty- particulates, particularly - even with secondary combustion flame path design, which I don't see kilns having; I can see it being a choice, just not where I live now.
We heated with cordwood for decades, so. Now it's a switch, on the wall, forced air gas furnace.

Copying files should be simple. The Pi uses a Linux variant, so cp command (copy), or mv (move).
Try the copy first.
Command line takes some getting used to. Just try a few commands a day, it won't take long to get the hang of it...

Edited July 30, 2022 by Hulk