What is hot and has chains?
No, dangit. Let’s see, what is hot, has chains and can hurt you a lot?
Ah, fuck it! I’m talking about a reflow oven!!
The other day we were working as normal (“normality” in my job has some weird meanings, but let’s save that for another bed-time story, okay?). So, my boss had put in the oven a special, humongous (5300x350mm) prototype board, and everything was fine, until the oven weng BANG!
No, literally, the sound was deafening even over the compressor and pneumatic feeders. So, we all ran to the oven, BANG!, tried to figure what was wrong, did the board fell off the rails? BANG! was it stuck somewhere? BANG! none of those where positive, and we figured that the board altough stopped inside, BANG!, was already in the cooling zone, so, we removed it as carefully as we could, BANG!, and performed an emergency shutdon of the
core oven. BANG!
While my boss was shutting it down, I notticed that the lateral chains weren’t moving (whereas the central guide chain was). After some more banging (not the right one, sadly) everything was stopped, and I could do an inspection of the mechanism. Everything was oiled or greased, so I didn’t take any photos, sorry. Anyhow, the culprit was something blocking one of the lateral chains, wich in turn made a chain slip, and since the oven is mostly sheet metal, it acted as an acoustic chamber, multiplying the sound.
When I finally got rid of my boss and coworker, who where “trying to help” by being around or in the middle of what I needed to check (they don’t have much mechanical knowledge) I did my thing, and here’s what I found:
Aaaaand that’s it.
I suppose we should lube the chain a bit more, but my boss hasn’t found yet a cheap enough high temperature oil (He doesn’t want to pay 500€ per ounce of special grease either), still, that’s not my problem, I’ll just clean or repair what I can.