A while back I had put a new thermocouple into our kiln since the last one crapped out. This is not unusual. What was unusual is when the thermocouple braid shorted the controller against the 200v rail since all of the connectors inside the kiln are uninsulated. The controller was toast so I decided to build my own, not very difficult.
First I built a controller from a cheap Inkbird thermal controller with a solid state relay. It seemed to work well until it got to about 600C and then it would level off and just get hotter and hotter without giving a reading that it was above ~800C. So I tried to confirm it with a pyrometer to double check and yes, it wasn’t reading correctly. So I thought it was the thermocouple and I replaced it, no dice. I then made my own controller with a MAX6675 module. Still the same problem. This stumped me for a bit until I did some reading.
What I found was that polarity of the wires is very important. Each wire from a thermocouple has its own composition and this is important in proper application of the Seebeck effect. On a K-Type thermocouple, the wire that goes to the negative terminal is magnetic whereas the positive wire is not. The wires I had were made to the Japanese standard where the red was positive and white was negative whereas US standard has the red wire as negative. The kiln now works correctly.
The kiln in action with my prototype controller along the sideThe kiln is definitely up to temperature
Some things to note as well is that running a kiln off a cheap Chinese SSR can be a bad idea. The cheap SSR’s seem to limit the overall current, probably at the zero-crossing point where it cuts out. I used the bigger chonkier mechanical relay for this application and there are no problems. Also, turning on a heating element has a fairly large inrush current, it’s good to put some larger decoupling caps on any power supplies that might be feeding from the main AC source.
Once I’m done programming the controller to do ramps and timed cycles I may publish the code and circuit diagram so that others can make their own controller if they wish. That said, here’s a pair of electronics cats who assist by staring at me while I work.
Things are going good. Things are busier than hell and I’ve been working on a few things. Firstly, I’ve been doing woodworking as an interesting departure from what I do on a daily basis. There’s a particular sense of accomplishment in having a usable item ready to use after a few hours of work.
A little work area I’ve set up in the mezzanine of the shop.
So, I’ve also been working on more boxes for use on our products. Hopefully they look good enough and will be better than us sending things out in cardboard or some makeshift case.
A bunch of boxes for our setting masters
It should also be said that I bought a junky little 3018 pro CNC machine off amazon for laser engraving paddle gages and setting masters and whatnot. The machine initially ran like shit, the bearings on the Y axis were some of the worst garbage I’ve seen in a while. I polished the linear rod down a bit and trued up the bearing blocks so that they’re in line with the rods. This however only made it a bit better. I may buy some decent bearings at some point.
The 3018 CNC engraving a paddle gage. This one is just enough to discolor the metal, not engrave it too much. I have a larger laser coming in that will hopefully remedy this problem.
Also, I’ve taken a few more steps to completing a prototype version of my goofy digital LED clock. This was done with a 16×16 matrix of ws2812 LED’s. You can pick these up for like 15 bucks CAD. They’re an interesting display if anything.
The back end of the clock.
Obviously, the protective layer on the plastic hasn’t been removed yet. I figured that putting some translucent plastic over top of the display would make it a bit less hard on the eyes when looking directly at it.
Well, there we go. Perhaps more will occur this month.
So another year is about to close and we wind our way into winter soon enough. I’ve been pushing ahead on a few things and playing around on a couple of others.
Recently sent out a bunch of gages for a large valve manufacturer in the States. We’ve made quite a few of these over the last few years, seems to be a popular design. These represent a great deal of work to make each one so it’s always a treat to see them go out and hear nothing back. No news is good news.
Building an LED clock with a WS2812 matrix. These things can really draw a ton of current if it’s put to full white. I think this will make a nice addition to the shop. I’ve made a box with a white diffuser, this will make the clock a bit easier on the eyes.
Also trying my hand at some woodworking. I’ve been making boxes for sending our product out in custom cases rather than trying to get them done outside of house. This will allow us to make changes or add products together and have a cohesive look to everything.
Well, there’s a bunch of work going on and Rejent is now in the new place with most everything unpacked. Here’s hoping to a good winter.
Over the years I’ve posted things to this site as a bit of a reminder to myself about the kinds of things I’ve done over the years. It has now been about 15 years since I started the site and that prompted me to go through old photos, back some stuff up and reminisce about days gone by. I’m going to post a number of photos that I’ve found that are purely of interest to me but, hey, maybe somebody else might enjoy them too.
My work area circa 2008 or so. I don’t miss the 4:3 aspect ration monitors but I sure seem to have had a lot of themA panoramic view of Edmonton in the Year 2007, September to be exact. This was taken near the river bank at the Old Timer’s cabin.My first real bike that I had bought as an adult. I didn’t drive at the time so I rode this sorry bastard of a bike all over the city with me. I still have it and it works fine.The result of some layup molds I had made for an intake cover. I made the molds but the other guys did the actual hard work of laying up the fiber and making it look like a finished product.My desk at Endura. As you can see I’ve tried to set up a small electronics lab on my desk there and the area is a mess. This trend will not be going away in 2022.My first real attempt at making a functioning product. In this case it’s an inline viscometer in a form that would roughly emulate a krebs viscometer. It worked eventually…. somewhat. I truly suffered from a distinct case of hubris but it helped me force my way along to learning what I’ve learned to this day.The inside of the maintenance shop of Endura MFG. I learned so much here in my 2-3 years, more than almost any other place. Despite being bitter about the place for years, I now understand and appreciate my time here.Another picture of that inline krebs viscometer. In retrospect, had I known what I know now, I could’ve made this viable. I remember that at the time I was reluctant to test it because I was scared of what would happen if it didn’t work. Would months of work be down the drain? Would I look like a fool? (Hint: it didn’t work very well at all)A more complete version of the electronics in the previous picture. An interesting example of an attempt at big TTL Quad-half H-bridge and some other shit I don’t remember.So what was supposed to be a gentle walk down memory lane is now a look at the iterations of a single project. This version is now closer to the one that works. As I write this I’m genuinely surprised how much I did in such a short period of time while doing other things at the same time. This one as you can tell is rotary with a sealing area kept lightly pressurized with a small air pump. This one is still intended to run in-line along a pipe or side of a tank. Here’s a look down the legislature grounds in September 2008. Is it different now? I don’t knowThis is from when I moved myself from the maintenance building over to the lab building. I don’t remember why or how, I just remember that I did.Another prototype! This one appears to be the one where it’s intended to merely hang on the top of a tank. For reference we’re in March of 2009 here.Here’s something from June of 2009 that’s kinda fun. I may have an older post about it but this is something that actually works. it’s meant to make a point cloud with 3 linear potentiometers and by using a button you can put the high-res ADC input into a file or whatever and create a point cloud from known values about the analog values. This was neat.Here we go, the final version of this project. It worked surprisingly well. That said I probably wouldn’t use Phenolic to make the frame but it does look nice. Odlly enough, I even like the smell of phenolic being cut. Here it is with the protective tube cut. Merely wave your hand over the top and it’ll start up. I had to angle the viewing window in order to allow the infrared sensor to detect objects. In retrospect I wouldn’t have done it this way. The window would be either scuffed or covered in paint and therefore useless. If I recall correctly I had another version of this with a large external perfboard version of what’s inside. This machine never made it past this stage, I was going to implement MODBUS on it and whatever else but didn’t get to that point. The recession had hit hard and that was that.
Well, there we go. Thanks for walking through 2007 to 2009 with me. I was expecting to be enthralled with my pictures of Edmonton but I guess work was, as always, more interesting to me.
Well, I’ve been here at Rejent on and off for the last 12 years. Now the company is moving to different digs and I figured I’d take some arguably unflattering pictures of the shop. Things are in disarray and thigs are a bit dirty as well.
A view across some the main path through the back
The Drilling area. Used to be the grinding area with CNC tool grinders but those are gone.
The sundeck. There doesn’t appear to be any lights here
A view of the EDM bay from the back.
Looking down on the EDM’s
The lunch room
The parking lot
The EDM bay again
The AW3
The AW6
A bad pano of the CNC area
Right now these things seem mundane but in 20 or 40 years there will be somebody, perhaps even myself who will enjoy looking at photos like these. Our new place will be in the old Precimax building and while it doesn’t have that much more room, it will be a fresh start and we can organize things with a pinch of pride.
We’ve had these things in waiting for quite some time. I’ve designed them to be lighter, more accurate, less snaggy and a bit sleeker. They take the standard heads that I’ve made for the last 4 years and still move linearly so that you can put whatever kind of styli you want on them. The older ones used to snag due to the fact that there were two bearing being forced to cock over in certain circumstances.
A view of the working end of the gage
As things heat up in the world and the economy either booms or busts, hopefully we’ll be able sell some!
Over the years I’ve had issues with large parts and finding easy ways to lay them out angularly, especially on the ram EDM. During this time I’ve kind of tinkered in my head with an idea whereby you have a level of sorts stuck to the part and you simply rotate it and have a direct reading of rotation applied to the part. I have tried those digital levels but accelerometers don’t have the precision required to get within a few thou over, say 6 inches.
The prototype device as it is right now
It’s obviously very rough and uses a cheap Chinese 2000ppr encoder but it’s good enough for .045 degree increments. I would trust this thing for some larger layout and alignment work. That said, I have a nice US digital encoder on the way with 10000cpr (40000 ticks all the way around) so a resolution of .009 degrees. Some issues I’m having is with the mass. If the mass is too small it won’t overcome the friction of the bearings completely and if the mass is too large it swings for a long time making it a hassle to allow it to settle. I’d like to find a solution whereby I can add friction without adding stiction. Frankly the whole thing needs a good concept redevelopment but I believe it’ll be a handy tool in niche situations.
Well, here we are, 2021 is here. Let’s show the shop as it stands in 2021. This is of course only the machining side but in another 10 years the pic will be of interest to people who like this kind of stuff. Also, been here for over 10 years now. wow.
Rejent Tool from the north-east sideRejent Tool from the north west side.
Well, for some time we’ve taken to building new Bore Gage for a customer. In an odd twist, I had very little to do with the mechanical design but was primarily focused on the electronics and software.
Basically what this device does is measure the bore of a hydraulic cylinder in a comparative way all the way down the bore. It uses a Mitutoyo encoder for the diametrical size and a US digital rotary encoder on the wheel to keep track of the distance down the bore. As the device measures, it keeps track of the position and the measurements therein and creates zones where an average, maximum, minimum and sample size is kept. It is then plotted out along the distance.
Anyways, I had some fun doing this project and I am looking forward to doing more.
Now that COVID-19 is in full swing around the world, I have a bit of extra time. I designed a new measuring head using the Renishaw RLC2IC magnetic encoder head from RLS.
This was borne from a need for one of these things but not wanting to spend $1200 CAD. Also, being able to use whatever connector you want is a nice touch.
A little overview of the head
In a package that’s 1.65″ x 2.5″ x .75″ you can plop this guy on the end of whatever and measure the insides of things (or dial them in). Also not shown is the strain relief for the ribbon cable or cable that would come out of the unit. The design isn’t fancy and I haven’t thought about attachment provisions yet but I should be making one of these this week.
The encoder itself is quite small and the output is standard quadrature so that makes it quite handy for all kinds of applications. Anyways, will update when I actually make this little guy.
Like many of my posts, I simply update for the sake of updating. That’s fine as far as I’m concerned. A lot has happened since my last update. Been to Japan, designed a bit of stuff and just have been simply living. Here are a few things I’ve been working on…
This is a gage I designed and is now going all over the place.This is a prototype master I am working on which will have motion control.
So, with that. I finally took the trip I’ve been wanting to go on for 20 years, to Japan. Now, I’m not a real weeaboo or anything but I’ve always been fascinated by the notion of such a large dense city such as Tokyo and so, with my girlfriend, we went to Tokyo for almost two weeks. It was absolutely amazing!
All in all, I’ve been enjoying my days, playing Rust and just plugging away.
The Amp Hour Radio Show