Elektra Microcasa a Leva portafilter exploded again

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jcolvin

#1: Post by jcolvin »

Love my micro casa a leva, it makes amazing coffee and looks fantastic. But have issues with the portafilter loosening off as I pull a shot and then it explodes coffee grounds everywhere under pressure. On a couple occasions I have caught it starting to rotate as the pressure comes on and grabbed it in time. But twice it has exploded everywhere. I see someone else has had the same problem so perhaps it is an issue with the design. I *think* it's probably either grounds building up in the housing or the gasket being slightly oversized, meaning you can't lock the portafilter fully. Anyone else had this problem?

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truemagellen

#2: Post by truemagellen »

I have an MCAL as well and a LSM lever group with very high pressure that has blown off way more than the mcal.

In most cases the pf gasket is getting hard or worn down and dirty.

Other potential reasons:
Pf lugs and or group is wearing down so pf gasket is too loose, in this case you can shim the gasket with a wax paper ring. This is very common in commercial groups.

Aftermarket pfs with different tolerances not matching your group.

Not locking in the PF hard enough. One of my strietman large baskets were too deep for the mcal PF and so there was a minute gap between the basket lip and the Portafilter lip. So when I locked in the basket was bending slightly...it was not properly locked in this situation.

Good luck. If you think about the factors needed to properly lock a PF:, gaskets, pf tolerances, group tolerances, water, coffee residue, and temp changes...it is a micracle it isn't blowing off regularly for most people

baldheadracing
Team HB

#3: Post by baldheadracing »

Yes, but in my case it was due to a combination of group wear (37 years of use) and an aftermarket portafilter - I have no issues with the stock portafilter.

If you look at the locking lugs when you mount the portafilter (with basket in place), but before you rotate the portafilter to lock it in, you will notice that you can wiggle around the portafilter and thus get more-or-less purchase between the portafilter lugs and the grouphead mount - depending on how you wiggle. Wiggle the portafilter the "wrong way," and you'll see very little purchase on one of the lugs when the portafilter is locked in. Locking in this position will lead to blowouts. However, if you centre the portafilter in the group, then the purchase will be even and symmetrical between the two lugs. With a little practice, one can develop a technique for mounting the portafilter such that the portafilter's lugs always have good purchase to the group. On my machine that means that I pull the portafilter towards me before locking it in, but I suspect every machine and portafilter would be different.

Note I am assuming that the group gasket o-ring is being regularly removed and cleaned - and the channel that the o-ring is in is also being cleaned at the same time. If you don't use a puck screen, then this removal and cleaning is beneficial about every 50 or so shots, and certainly right after an explosion episode. (The o-ring must be removed for proper cleaning.)
-"Good quality brings happiness as you use it" - Nobuho Miya, Kamasada

MCal2003

#4: Post by MCal2003 »

Assuming stock portafilter holder and baskets? The IMS baskets recently purchased have a broader, maybe taller border. Seating the holder into the head using those baskets requires a bit more attention than the stock. I can see how they may possibly blow off. Haven't looked, but guessing the tabs might be just marginally fully engaged.

20 years of use. Daily for the past 8 until recently acquiring a Flair 58. Prior to that ~3-4 days/week use. Stock portafilter holder with cut out to make naked and a "custom" (I think Richard Penney was the maker) massive brass unit. I replace the gasket when it requires more than a snug rotation. Never have had a basket blow out. Once in a while during a brain dead moments I've removed the filter holder a bit too soon and have experienced a "sneeze".
LMWDP #151

boren

#5: Post by boren »

Most reliable workaround - hold the portafilter handle with one hand while using your other hand to operate the lever (at least until extraction is about to finish). The only downside is that you can't steam milk in parallel to pulling the shot, but that's actually a good thing.

Elektra Microcasa a Leva: How the portafilter popping off turned out to be a blessing in disguise

kjarsheim

#6: Post by kjarsheim »

+1 with boren, this has become my "normal" practise

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truemagellen

#7: Post by truemagellen »

boren wrote:Most reliable workaround - hold the portafilter handle with one hand while using your other hand to operate the lever (at least until extraction is about to finish). The only downside is that you can't steam milk in parallel to pulling the shot, but that's actually a good thing.

Elektra Microcasa a Leva: How the portafilter popping off turned out to be a blessing in disguise
This is called PF sneeze PTSD. I still hold pf when I'm using a limited edition espresso cup :mrgreen:

baldheadracing
Team HB

#8: Post by baldheadracing »

boren wrote:Most reliable workaround - hold the portafilter handle with one hand while using your other hand to operate the lever (at least until extraction is about to finish). The only downside is that you can't steam milk in parallel to pulling the shot, but that's actually a good thing.
Once I figured out why my blowouts were happening, I haven't had a blowout since (nervously touching wood).

Then again, I always steam milk while the shot is extracting :) (except with direct lever/SBDU machines).
-"Good quality brings happiness as you use it" - Nobuho Miya, Kamasada