# Rocket naked / bottomless portafilter



## MediumRoastSteam

Hi there,

I am the new proud owner of a Rocket Cellini Evoluzione V2, and am very happy with it so far.

However, there is something that is bugging me a bit.

The machine came with two porta filters (single and double spout). Separately, I have bought a Rocket naked portafilter.

What I find interesting is that, with the same filter basket, the portafilters supplied with the machine lock perfectly at 6 o'clock. However, the naked one, with the same filter basket, will lock at around 7 o clock and "feels" very stiff in the process.

Does anyone have any ideas what that will be the case?

Aren't all Rocket portafilters, regardless of the type, made to the same measurements?

Alberto.


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## jlarkin

It sounds similar to a post I just saw here: http://coffeeforums.co.uk/showthread.php?p=333595


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## hotmetal

Ha ha ha that is exactly what I found with my R58. My naked PF which came in a Rocket box locks in at 7. After getting my Vernier calipers out I replaced the group gasket with an 8.5mm Cafelat silicone one which was a couple of quid from Bella Barista. The bottomless now locks in at 6pm and the standard ones are now ever so slightly tighter and lock in at about 6:15 if that makes sense. I have no idea how it brings the naked back by "1 hour/30°" and only pushes the standard ones back 7°. It makes no sense to me but that is my experience and I'm pleased. It will of course have something to do with the softer compound, which seals at low torque but will 'give' if you twist further.

I thought maybe my naked had been machined wrong (as a one'off rogue one) but it seems common. I very nearly ordered another naked from BB to try, but when I realised my group gasket needed replacing I thought I'd try that first rather than order both at the same time.

Edit: I didn't click through the quoted post above and D'oh! That was my post from the other day. Oh well, double post.


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## MediumRoastSteam

Thanks @hotmetal. The more I read about this the more I realise this is a rather common thing.

The only thing I can think of is that the "normal" portafilters are designed for an 8.5mm Gasket, whereas the naked one is an standard e-61 and is designed for an 8.0mm gasket, thus locking slightly before.

And maybe the cafelat gaskets are softer so allowing for some flexibility?


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## hotmetal

You're welcome buddy and I think you've hit the nail on the head except the wrong way round. Rocket standard gasket is apparently 8mm so the PF in the box is milled with slightly thicker lugs.

However if you're right, that begs the question "What is 'Rocket' about this bottomless filter holder?". There is no logo on the PF, not even an R on the end of the handle. If the lugs are not machined to the same spec as the original (they're not), then putting a generic PF in a Rocket box and selling it as compatible is s bit cheeky.

Then again, they're not more expensive than generic E61 handles and they do fit okay apart from the angle so it's no biggie. But I got given mine for Christmas and she saw the look on my face when it went past 6 o'clock and she was all for sending it back, which put a very slight dampener on things, although I wasn't that bothered really. Nice to get it sorted though.


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## MediumRoastSteam

I wondered the same thing. No logo, nothing. Thanks for the replies.


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## hotmetal

No worries. Mine was dispatched the same day and came through the letterbox the following morning and including post it'll be less than a fiver so if it's bugging you then you'll have it sorted by Saturday if you want to!


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## AL1968

Slightly off topic but when you replace the gasket one side is flat the other is slightly rounded, so which way round should they go?


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## funinacup

Rounded/chamfered edge goes up


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## AL1968

There seems to be more questions than answers in this game!! Thanks for the reply, another note to jot down in the little coffee book.


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## hotmetal

Think of it like this: The rounded edge sits against the rounded/rolled lip of the shower screen; the flat part of the gasket sits flat against the PF


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## Rhys

hotmetal said:


> Think of it like this: The rounded edge sits against the rounded/rolled lip of the shower screen; the flat part of the gasket sits flat against the PF


Same with the La Pavoni. mine has a new shower screen gasket, and the pf sits nearly straight in front instead of to the side. I removed it to find it was upside down. My pf sits a little more to the side now.


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## MediumRoastSteam

I went on and ordered both the 8.0mm and the 8.5mm Cafelat gaskets from Bella Barista on Sunday and got them today. And that's the verdict: Not a great deal of difference, although I am keeping them.

The bottomless portafilter now locks at 6:30, whereas the original one locks at 5:30 or so. A 30 min difference so to speak. The interesting thing is that this is with the 8.0mm gasket, not with the 8.5mm as described by hotmetal. Anyway, minor detail, let's enjoy the coffee.

I'll start using the original portafilter as it seems to fit so much nicer / smoother than the bottomless one. However, I am keeping it handy with a blank disk, and will use now and again to ensure my technique hasn't gone astray.

Thanks for your help everyone!


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## hotmetal

Oh that's odd. Yeah it's a minor thing not to interfere with the serious business of coffee drinking, but sorry my experience wasn't quite replicated. Not sure why but I suppose if 0.5mm makes '1hr' difference then 0.25mm would have seen you right but that's obviously within the aggregate tolerances of group, gasket and PF lugs.


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## Zephyr

How soon you change gasket on R58 ? thx


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## MediumRoastSteam

I think you're right hotmetal. 0.1mm here, 0.1mm there difference in manufacturing measurements must make all the difference here. Minor detail though.


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