Obel EB doesn't grind fine enough - help & suggestions

Equipment doesn't work? Troubleshooting? If you're handy, members can help.
HorseCalledGolgotha
Posts: 15
Joined: 3 years ago

#1: Post by HorseCalledGolgotha »

Hello,
this is my first post here, so I'll start from a quick introduction.

I live in France, I'm relatively new to home espresso, I've started with a Delonghi Dedica and a Lelit Fred (now sold) and quickly moved to a Cafelat Robot and a C40.
I enjoy mainly medium/dark roast and I'm still exploring the interesting coffee scene in France (some very good roasters here, at least for my taste).
In my journey I recently decided to buy a grinder with flat burrs, until now I used only conical (Lelit-C40 both small conical).
I found a nice offer for a second hand 2017 Obel EB Drogheria in what looked like good conditions. The grinder is basically the same thing as La Pavoni ZIP, some Bezzeras, Bregant and another ton of rebranded grinders.
It carries 63.5mm burrs.
I did some clean up, initially I wasn't able to remove the burrs carrier but finally I won my battle against the nut and I was able to do a proper clean up.
I also changed the burrs (little bit dull).
Now, my issue is that since day one (even before removing the burrs carrier or opening the case) the grinder doesn't grind fine enough to have a proper espresso with the Robot (and I suspect any espresso machine really).
I write in a french board dedicated to espresso and I received some helps (check burrs alignment, grind rice) but this grinder is not commonly used and I'm looking for some help from users having some experience with it (I've seen different topics here about this grinder).
I'm not an adept of DIY, but I bought this grinder used mainly to learn and try to service one.

TL;DR
My grinder doesn't grind fine enough. I've changed the burrs, tried alignment, cleaned everything but no luck. My robot squirts at first position before burrs touching. What could I check? Any help appreciated.
Also, if you have suggestions on how to reduce (crazy) retention...

Thanks in advance

HorseCalledGolgotha (original poster)
Posts: 15
Joined: 3 years ago

#2: Post by HorseCalledGolgotha (original poster) »

I added Teflon tape to the thread of the upper burrs carrier.
Huge improvement.

MemPast
Posts: 200
Joined: 7 years ago

#3: Post by MemPast »

Are you single dosing?
If yes, try to use half bound of coffee in the hopper.

HorseCalledGolgotha (original poster)
Posts: 15
Joined: 3 years ago

#4: Post by HorseCalledGolgotha (original poster) »

Hello,
Yes, single dosing.
I suspected something wasn't right due to lack of pressure from the hopper (I removed it) and burr carrier wobbles a lot.

Coffcarl
Posts: 260
Joined: 6 years ago

#5: Post by Coffcarl »

I have had two of these grinders. I have always been able to choke my espresso machine, except once in a whike with older, drier beans.

The main issue that I have had with these grinders is that the precision is not great, high tolerances as you found with the burr carrier, and the burr design seems to be less effective than other burrs.

I eventually went with a Eureka Zenith 65e, and am much happier with it. That being said, I did recently drag my obel out to use with an Oscar 1 that I bouggt for my sone, and I was able to pull a good shot.
You said you aligned the burrs, so not sure I would suspect this, but did you make sure there was no debris under the burrs?

Also, on one of the grinders I aligned by sanding the burr carrier. I don't think shims worked for me.

HorseCalledGolgotha (original poster)
Posts: 15
Joined: 3 years ago

#6: Post by HorseCalledGolgotha (original poster) »

I agree, precision doesn't seems the strength of this grinder.
I must say that maybe I messed up everything while trying to disassemble the mastodon.
Do you use the hopper? The massive 1.5kg (3.3 lbs I think) hopper, or did you find a smaller one that fits?

Edit: forgot to answer your question, yes, I removed the coffee cake under the burrs. I've also added a seal in the hole between the lower burrs and the burrs carrier. Retention now is much better. When I removed the burrs carrier I was surprised by the amount of coffee found in the hole where the shaft is and the carrier.

MemPast
Posts: 200
Joined: 7 years ago

#7: Post by MemPast »

I used to single dose with mine, and that actually worked for me. I do not think you can find smaller hopper. You can chop it if that that is not a problem for you.

On a side note, I used rancilio kryo burrs and it was better than stock burrs. Also, I did a stepless mod similar to this mod:
Stepless mod for Macap MC4

Good luck

HorseCalledGolgotha (original poster)
Posts: 15
Joined: 3 years ago

#8: Post by HorseCalledGolgotha (original poster) »

Thanks, that mod is quite interesting.
I'll have a look to those burrs.
I've contacted Obel and they suggested to avoid different burrs even within the same size but I'm not satisfied by the OEM so... worth a try

Coffcarl
Posts: 260
Joined: 6 years ago

#9: Post by Coffcarl »

As far as the hopper is concerned, I just removed it and single dosed.

HorseCalledGolgotha (original poster)
Posts: 15
Joined: 3 years ago

#10: Post by HorseCalledGolgotha (original poster) »

MemPast wrote:Also, I did a stepless mod similar to this mod:
Stepless mod for Macap MC4

Good luck
Hi MemPast, do you remember the size of the spring?
I bought some 3D printer springs but size is not the good one.

Thanks in advance

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