A few recommendations for the next update of cure control:
Turn off automatic backups, they’re adding unnecessary wear to the microSD card
Full profile support for stepped time / temp sequence / ramp rate control. This oven has a lot of industrial uses beyond just doing powder coating, why not add a few software features that will open up your customer base and make it a lot more versatile
Audible indications (and the ability to turn them on or off). There should be an option to provide some sort of audible indication for events like preheating complete, timer finished, and oven turn-off after inactivity to alert the user. The monitor in the pro electronics kit has built-in speakers, so both PC/Laptop and pro electronics kits should be able to do it. That way you can go about doing other things and not have to keep looking over at the oven to know when one of these events occurs.
Add another. Show the individual thermocouple readings so people can tell which one is acting up when you get a message that the temperature difference between the two is far apart.
Go to the top right of CureControl and tap on the page icon. You can monitor each thermocouple and even track them on the scroll setting, as for the temp differential alarm. There really isn’t an issue except that the alarm threshold is too tight in CureControl during warm-up. They will address that in the future, I am sure.
Thanks for that. Here is another reason I think it might be helpful to have the individual thermocouple measurements exposed on the main screen. The machine is just showing the average temp, but it would be good to see the delta to know when things are evenly up to temp. On mine, I see a 25 degree temperature spread between the two with the curculator fan running. That could be something else going on, as I know one of these thermocouples is behaving inconsistently, but unless you see that info up front, you wouldn’t know something is up because you’d just see the average. I think it would be a useful thing to see.
Out of curiosity, what is the temperature deviation you’re seeing between the two measurements on yours?
It looks like one is at 419° and the other at 389°.
I would get a meter on continuity and check if the thermocouple is going to ground via the metal shield cable to the oven chassis. I installed 600° shrink tube over the entire cable. The fiberglass cover in my picture keeps the spring from touching the chassis. I will check mine in the morning and report back. If one is grounding out, it will read low. The high temp shrink tube is available from McMaster Carr.
Another way to check is a sore subject, but if you temporarily disconnect the chassis ground and see if the thermocouple starts reading closer, that will tell you if it is a ground loop issue.
With mine, they sleeved them in fiberglass for about the first 4 feet off of the thermocouple. That said, it looks like what I thought were high temp plastic insulators aren’t doing so great, so I need to figure out a better solution there. That blackened ring around the thermocouple on the mount used to be a whitish color insulating washer. At a minimum, its now carbonized and could be the culprit.
The ceramic insulators are the fix. I installed thread rivets inserts in the oven and screwed in 1/4 - 20 x 1-inch SS set screws. 1/4 -20 x .375 button head bolts. They will screw in the insulators. Problem solved as long as the cables aren’t touching. Do you have them mounted at 20” and 29”?
With a setpoint of 410 degrees, thermocouple #1 @ 29 inches is at 429.80 degrees. Thermocouple #2 @ 20 inches at 394.25 degrees. My machine has a 35-degree difference between the two levels of the oven. This is without the fan being turned on. Hope this helps you. Just a note, I do occasionally get an alarm during warm-up due to a high temperature differential.
Thanks. I’m not surprised at that level of differential without running a circulator fan, but I am a little surprised that its as large. As it is on mine after temps have stabilized and with the fan running. I would have expected the air to stay mixed and for the temperature throughout the oven to be more even. At a glance, it seems like the circulating fan isn’t really making a huge difference, at least on low.
While outgassing my oven over the weekend, I noticed another fan issue. On mine, the fan motor thermal safety trips out after about 15 minutes at 400 degrees. It does this with or without the cover plate around it. I made sure the allow ample space around it when I removed the insulation to install it. If you happen to do a preheat and run with the fan on, I’d be interested to know what temperature differential you see and if you have any issue with the fan after the oven has been at temperature for a while. I think the should have used a blower motor with a longer shaft so they could have gotten the motor itself outside the insulation jacket where it would stay cooler.
Talking with the engineers over at Langmuir on Monday, I asked about the expected temperature differential between thermocouples with the over preheated and circulator fan running and they said they were only seeing like 3 degrees of delta. Just thought I’d pass that along.
Something worth noting is that both of those options require Langmiur to maintain some sort of infrastructure to provide that service in a way that that most users would be able to take advantage of it. For a budget oven, that’s probably not practical in the long run.
I respectfully disagree. It is WiFi capable and is an Orange Pi I believe. It could easily be setup to utilize my email or twilio account for notifications without any Langmuir infrastructure. If they did want to support all their control software with a mobile app then yes they would need to write some kind of app with supporting infrastructure but that would be cool too because then they could push messages, notifications, update notifications, etc via the app. As a user we could get critical info through an app, but I drift into dreamland. Back to reality, the ability to use postfix or msmtp with a Pi device is not hard, and email to SMS is simple with most major carriers.
Note that I said for most users… Sure, you can set up your own SMTP relay, do IMAP, point it at gmail, set up twilio, integrate it with Homeassistant with MQTT, etc. All technically possible but most are well outside the knowledge base of the typical user. Most folks aren’t doing all that. In order to make a user-friendly option available for most folks, Langmuir would have to set something up on the backend so the user would only have to check a box and put in their email address or phone number.
There are a lot of tech enthusiasts here, no question. We’re an exception, not the typical target market.
