Bill Kielb

Haha, I'm bisquing a full load of mugs as we speak.  It's 18x23 and I think I've got around 60 mugs in there.  I need to get a couple new shelves for it, the ones that came with it were well beaten with lowfire glaze and cracked/broken, and the shelves from my old kiln are too small.  No big deal, the shelves for this one are 40 bucks a piece.  
Other than that, the elements seem to be fine so far.  The bottom element is out of it's channel, and seems too small, I pinned it as best I could but it won.  New elements are on my list but will have to wait a bit, 200 bucks for a complete replace.
The good news is, it's getting hot and anything else that comes up will be a whole lot easier to handle than crawling in my crawlspace and running wire.

Yes, I'm very sore... Mostly shoulders and knees.  The knees are all bruised up from crawling, didnt think to get some knee pads til I was far too gone for it to matter.  My wife is already tired of hearing my groaning haha

For folks happy to be rolling in the mud, or rolling mud,  you wouldn’t think they wouldn't be so sensitive to the great outdoors and it’s inhabitants.
looks like these electric quotes are going higher.  Here is to hard working trade people everywhere!
LOL

PID loop tuning is a bit of an art and understanding the thermodynamic lag within a system is helpful. There are several ways to approach this and there has been two basic formulaic approaches  over many years. Many devices with pid control provide auto tune functions. Often a stand alone pid auto tune can be used to develop data that otherwise is tedious to do manually.
an effective article published by Omega engineering is here: https://www.omega.com/temperature/z/pdf/z115-117.pdf
it is generally viewed by those not accustomed to working with these processes as tedious and difficult.
Good PID loop tuners are still hard to find in the real world.
an interesting observation: the Bartlett controller currently in many kilns has an option for SSRs in their gen 700 and above controllers. Their relay cycle time I believe is once every 200 milliseconds. Early on in this thread I asked if these were zero crossing and if so, this along with some reasonable time addded for delays likely establishes the bare minimum switching time.
Tuning a pid is not necessarily how fast your switching loop is,  or how fast you can turn something physically on and off, it is more about the thermodynamics  and thermal inertia of the entire system.
ultimately no matter the method, we do not want significant overshoot, oscillation or excess undershoot.

@High Bridge Pottery With a cycle time of 2s my controller switches on about 11,000 times in a 13 hour firing.  I'm not sure what "a lot" means to you.  I'm not worried about the number of switching cycles - as long as I keep my SSR cool - it will have a long life.
If you're switching using a mechanical relay or contactor, I would set the cycle time to at least 10s.  I'm not sure about 60s... I'd have to test that.  By experience, my kiln drops a F degree per second when not being heated at 2000 degrees or more.  Setting a cycle time of 60s means the temp swing could be 30-40 degrees or more.  I want to be more precise than this.  I think a 3  degree swing is acceptable.

Full body tyvek coveralls with a hood, respirator and goggles.  We don't really have dangerous spiders where I live, more likely to find a coyote or bear under there than a black widow

Aaah, memories! Our first home had a low crawlspace - get between joists to roll from front to back.
The word "swell" reminds me - suggest long shirtsleeves and pants, both secured with rubber bands (plural), and pants tucked in socks, collar fully buttoned up, and look look look before entering. I find both black widows an' fiddlers (brown recluse) in the oddest places, e.g. in the garage/studio, right where I'd put my hand; tucked up in the garbage can hand hold; outside the front door, between knee and forehead level. 

Nice holder!
Just catching up on custom orders for mugs and underglazed stuff. Also working through fixing an existing Bristol glaze for the studio . Arrrrgh dislike these glaze recipes  but almost done, I think.
After spraying countless ornaments  and now these little mugs, cups, treasure boxes I think  I need a throwing break from this stuff! Took a picture of myself spraying and I do not appear to be excited. LOL
 

Running conduit under the house today, WHAT A CHORE.  24 inches of clearance and I'm a big 220lb 6'2" monster so not a whole lot of room to work.  Hopefully this pays off in the next few weeks and I'll be firing an electric kiln!!!
Wire arrives via UPS sometime next week and I can run the wire and call the inspector if everything goes swell.  Fingers crossed I did everything OK, it looks good anyway.

Nice holder!
Just catching up on custom orders for mugs and underglazed stuff. Also working through fixing an existing Bristol glaze for the studio . Arrrrgh dislike these glaze recipes  but almost done, I think.
After spraying countless ornaments  and now these little mugs, cups, treasure boxes I think  I need a throwing break from this stuff! Took a picture of myself spraying and I do not appear to be excited. LOL
 

Nice holder!
Just catching up on custom orders for mugs and underglazed stuff. Also working through fixing an existing Bristol glaze for the studio . Arrrrgh dislike these glaze recipes  but almost done, I think.
After spraying countless ornaments  and now these little mugs, cups, treasure boxes I think  I need a throwing break from this stuff! Took a picture of myself spraying and I do not appear to be excited. LOL
 

I have been out of touch with pottery for a very long time. Just getting back into it, a lot to try and remember but this is my first project I'm working on.

Nice holder!
Just catching up on custom orders for mugs and underglazed stuff. Also working through fixing an existing Bristol glaze for the studio . Arrrrgh dislike these glaze recipes  but almost done, I think.
After spraying countless ornaments  and now these little mugs, cups, treasure boxes I think  I need a throwing break from this stuff! Took a picture of myself spraying and I do not appear to be excited. LOL
 

I'm glad you came here to collaborate, this is a great place do it!  As you know, one of the main reasons developers choose to make their software open source is to draw on the knowledge and abilities of a community to make the project better, the same can be said of the hardware in this case.  I'm excited that this has the potential to turn my manual old 75 dollar kiln into something I can control as well as a newer 2500 dollar kiln.  I'll be doing this project eventually and without you coming here, sharing, and being humble and open to criticism, it just wouldn't happen.  So thank you!  And thank you to everyone else who has contributed here!

Nice holder!
Just catching up on custom orders for mugs and underglazed stuff. Also working through fixing an existing Bristol glaze for the studio . Arrrrgh dislike these glaze recipes  but almost done, I think.
After spraying countless ornaments  and now these little mugs, cups, treasure boxes I think  I need a throwing break from this stuff! Took a picture of myself spraying and I do not appear to be excited. LOL
 

Good thread, good info, still a nice project but there are many things in the world more complicated than googling and reading tables and trying your best to understand the basis.
As a last note, SSR’s fail quickly under short circuit. Much quicker than a circuit breaker will trip and often quicker than a standard fuse will protect. The manufactures provide the appropriate amps squared seconds rating  to protect their device. I should have been more clear, the fuse is intended to protect the SSR and all manufactures provide data and the appropriate fuse to use so your SSR will have a long useful life.
I definitely did not intend the SSR protection to fall into the machine protection required line of thinking. They are different and I should have been clearer.
 

As  I said this is still a nice project
and it is not worth the time to talk about why extension cords are not used as a single conductor or whether a fuse is way faster than your breaker and highly suggested by SSR folks or why mounting the heat sink outside was necessary when designed for direct mount  with a saddle for the SSR and thermal calculations that clearly show this in not desireable, or why we didn’t criticize the raw hole drilled for the wires without grommet or any number of things in a beta stage project. That anyone would seek to defend these issues without saying simply it’s  not a finished project is a bit troubling in my view.
again it’s a nice project and if you produce it for others you need to step up your game a whole bunch, none of that will fly as code or be approved for many reasons, none of which entail reading a chart and not understanding the application of or the proper way to derate things.
I am not here to argue the obvious, it is not code or UL or CSA or FM,  and won’t be in its present form. So last thing to say It’s in a great stage and has performed well. Hats off to your hard work and wonderful success, I believe it’s important to encourage, but the reality of needing to now make it industry standard and as safe as practical is your next step in your own development.
just my opinion so take it for what it’s worth but I have a lifetime of working through these types of issues.

Single SSR and the power disabled by relay is the norm. Actually it’s common to see the existing relays stay in place and feed the SSR. The relays are driven by a safety output so once the program is run they are latched closed for the entire firing and the SSR’s are switched on and off by the controller. Often the existing relays are safety looped through a lid switch as well.
the end result: lid closed + no controller errors + program start pulls in all the regular relays which then provide power to the elements and SSR’s. As long as no errors and the lid is closed these relays stay closed and the computer controller is free to cycle the SSRs to heat the kiln. 
SSRs often fail shorted as much as open so it is absolutely necessary to have another way to disconnect them from the load. A new device design often has a main contactor that disconnects all power incorporated into its safety loop design. SSRs are heat and overload sensitive so it is absolutely necessary to heatsink them to 2C/W or less and install fast blow fuse protection properly sized to the SSR.
interesting tidbits on SSRs, they are starting to make them with current sensors built in. The relevance? An SSR controlled kiln with these could also display the amperage of each element as it is operating. Really cool diagnostic tool!

Engineering alert!
Just a crazy add here and this has happened to several folks drilling holes in flat clock faces. Our best theory thusfar: It turns out clay acts like many materials with stress developing as  result of the drilled hole. I had a friend that made clock faces, very flat and often thin for their overall size. On several occasions the faces split completely in half during the glaze firing (Like 1/2" apart as the stress ejected each half). This can be common and present itself in flat faced items and likely presents itself similar to the stress and strain we find on other drilled materials. Our solution was to thicken the slab in the area of the bored hole one to two diameters larger than the hole …….. (reinforce with a washer over it, how original we are!))
The hard lesson: always chamfer and smooth any hole cut in the clay so as not to provide an easy path for the material to begin cracking. The forces around it will be real and will appear, so always do your best. Kind of like concrete shrinkage cracks developing at an inside corner.
Kind of geeky but good clay construction practice likely will help avoid disappointment later. Nice to see everyone has a favorite way to chamfer these.
 
 

Engineering alert!
Just a crazy add here and this has happened to several folks drilling holes in flat clock faces. Our best theory thusfar: It turns out clay acts like many materials with stress developing as  result of the drilled hole. I had a friend that made clock faces, very flat and often thin for their overall size. On several occasions the faces split completely in half during the glaze firing (Like 1/2" apart as the stress ejected each half). This can be common and present itself in flat faced items and likely presents itself similar to the stress and strain we find on other drilled materials. Our solution was to thicken the slab in the area of the bored hole one to two diameters larger than the hole …….. (reinforce with a washer over it, how original we are!))
The hard lesson: always chamfer and smooth any hole cut in the clay so as not to provide an easy path for the material to begin cracking. The forces around it will be real and will appear, so always do your best. Kind of like concrete shrinkage cracks developing at an inside corner.
Kind of geeky but good clay construction practice likely will help avoid disappointment later. Nice to see everyone has a favorite way to chamfer these.
 
 

Engineering alert!
Just a crazy add here and this has happened to several folks drilling holes in flat clock faces. Our best theory thusfar: It turns out clay acts like many materials with stress developing as  result of the drilled hole. I had a friend that made clock faces, very flat and often thin for their overall size. On several occasions the faces split completely in half during the glaze firing (Like 1/2" apart as the stress ejected each half). This can be common and present itself in flat faced items and likely presents itself similar to the stress and strain we find on other drilled materials. Our solution was to thicken the slab in the area of the bored hole one to two diameters larger than the hole …….. (reinforce with a washer over it, how original we are!))
The hard lesson: always chamfer and smooth any hole cut in the clay so as not to provide an easy path for the material to begin cracking. The forces around it will be real and will appear, so always do your best. Kind of like concrete shrinkage cracks developing at an inside corner.
Kind of geeky but good clay construction practice likely will help avoid disappointment later. Nice to see everyone has a favorite way to chamfer these.
 
 

Great question. I was fortunate enough to take my work bench on the road to build a bench for a friend which went to sofa and sold  successfully for at least four figures. Loved her art and glad it sold! Feel good about the bench as it had to support at least three hundred pounds without deflection to crack any of her tiles. Fun project and success always makes the labor part forgettable. Picture of it going to its new owner attached.
December project (s)
Complete a couple glaze formulations to work well over heavy underglaze on  low expansion porcelain.  Test are going well and should be able to publish after the first of the year.
Additional December project was to get at least four basic throwing videos done for newbies in the studio. Three done so far so we will just keep plugging along.
last project was to begin creating a glaze workshop for the resident artist at the studio. Just beginning this one and have outlined it. Thus far I like the direction and content.
 

Yep. It's a small kiln, so I just have one set of witness cones.  In this case, 5,6,7 on the center shelf.  In past firings, I've watched these to determine when to shut down (or move on to the next part of the schedule). This time I did not get the chance because the kiln sitter flipped before I thought it would.  Next time.
 

I personally see an interesting similarity yet contrast in the top one and bottom right. They have matching glazes yet different offsetting contrast and the diversity in the texture yet similar textural design would make me want to display them together.

Hi Tom, sure.....
^10 - flashing slips - soda - front / back