Cormorant Squeaking and Grinding

Discuss roast levels and profiles for espresso, equipment for roasting coffee.
ShotClock
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#1: Post by ShotClock »

My Cormorant is making some squeaking and grinding noises - I assume that the spindle bearings are dry or otherwise malfunctioning. Has anyone serviced them? Any particular grease recommended?

Milligan

#2: Post by Milligan »

Is it during warm up or even after it is up to temp? I sometimes get a few squeaks as it is warming up. I assumed it was due to different parts warming up at different rates.

ShotClock (original poster)
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#3: Post by ShotClock (original poster) »

Yesterday it was throughout a roast session of ~90 minutes. There's a persistent squeak that makes me think of bearings, and a grinding sound that is a bit more concerning.

Trjelenc

#4: Post by Trjelenc »

Does it happen at cold temp? Does it ever go away during a roast? If it does, is it at a certain temperature?

My Huky does this at times and in its case I'm 90% sure it has to do with a thermal expansion mismatch between the drum and the outer metal, causing the drum to start rubbing on the body. I find it happens the worst when I really have the gas cranked until yellow and tends to go away when I make my lowest gas setting a bit before first crack.

It really is a horrid noise.

Milligan

#5: Post by Milligan »

Ouch, sounds like a misalignment or, like you said, dry bearings. Have you run the drum and then opened the bean door? Look at the lip of the drum as it rotates. Does it wobble? I'd email Johan and see what he says about it. I don't see grease zerks on mine so I assume the bearings are sealed or need to be hand repacked every so often. I'd use a food safe grease like super grease, one with an H1 rating, or one that Johan suggests.

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LBIespresso
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#6: Post by LBIespresso »

It might help if you post a video.

I'm pretty sure a bean fragment got caught between the outside wall of the drum and the inside of the roaster body once for a couple of roasts and the sound was excruciating. Fortunately it worked its way out on its own once the machine cooled.
LMWDP #580

ShotClock (original poster)
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#7: Post by ShotClock (original poster) »

Thanks, will try to get a video over the next few days. Have sent a message to Johan too, will update with any useful info from him.

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mkane
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#8: Post by mkane »

Milligan wrote:Ouch, sounds like a misalignment or, like you said, dry bearings. Have you run the drum and then opened the bean door? Look at the lip of the drum as it rotates. Does it wobble? I'd email Johan and see what he says about it. I don't see grease zerks on mine so I assume the bearings are sealed or need to be hand repacked every so often. I'd use a food safe grease like super grease, one with an H1 rating, or one that Johan suggests.
The bearings need to be serviced way before they squeak.

ShotClock (original poster)
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#9: Post by ShotClock (original poster) »

Johan recommended a bit of mineral oil on the interface of the spindle and bearing on each side of the drum, and the motor. Running the roaster cold, seems to have quieted things down. Will report back if this was a good fix when I get chance to roast.

Milligan

#10: Post by Milligan »

Curious to see what you found? My roaster came damaged due to a shipping issue and I've been working with Johan (excellent person) to resolve the issue. I had a bit of squeak recently after being fully warmed up so I decided to check the bearings for damage due to the other damage in shipping. The front bearing is very easy to get to. I took it out and it was tight and dry. I've only had 30 or so roasts so far so I was surprised to find it needed oil/grease again. It is a metal shielded bearing but not fully sealed. As far as I can tell it is exposed to the roast chamber so grime and chaff could eventually work its way in. I gave it some lubrication and it feels much better now. I took the shell off of the roast chamber to see if I could get at the rear bearing. It looks like I'd have to do a full disassembly to get at it. I removed the bearing cover and gave it some oil as well.

I can see a hole that the roast chamber sit on that blocks airflow from going around the drum and instead through the drum. It fits very close to the drum exterior and any wobble/expansion would likely rub there. So perhaps the "grinding" noise is against that piece.

I was thinking about trying to find some bearings that are more easily serviced with a traditional grease zerk. Or perhaps the front could be open bearings/removeable seal where they could be repacked with grease instead of oil. Minor things, this isn't a commercial roaster so this isn't a knock at all against the Cormorant.

I know they make grease needles that may make greasing through the shielding a bit easier.