Portafilter Funnel?

Grinders are one of the keys to exceptional espresso. Discuss them here.

Postby walt_in_hawaii » May 16, 2018, 3:00 pm

There is a significant amount of wasted coffee under my grinder, and I've taken to doing the WDT over the wastebasket due to a little inevitable spillage while stirring with a straightened paperclip. I gave the cut-the-paper-cup-to-make-cheap-funnel thing a try, but although it kept most of the grounds pretty much in place, it required removal prior to tamping and always left a dent in the outer margin of grounds and worse, required removal prior to tamp because my tamp won't fit with it in place. So I did a quick search online and found a remarkable lack of funnels for portafilters... searching the *bay listings, I found something close to what I'd like but not quite, and it was $35!! Astonishing, for a simple metal ring. I don't wanna accuse someone of scalping, but then... ok, I sorta do want to say it :). that's scalping.

Still, there are a couple things I'd like to see addressed and no one's done it, so I've resigned myself to have to get off my lazy butt and add this to the list of things I have to do.

1st off: the lip inside these funnels has to be a very close fit to the basket, so it will almost certainly have to be a custom sized thing for each basket. I want the tamp to fit very closely inside the funnel, so I can tamp without removing the funnel. I only have representative samples for HQ14g and HQ21g (ridgeless), I don't have any VST or LM baskets so I'm not sure if they are very similar in diameter just below the lip.
2nd: Looking at the baskets, I suppose I could make a funnel with a simple straight top edge that sort of drops down to a small lip that goes inside the inner diameter of the basket a short ways... but what would really float my boat, I think, is a very good concave fit of the basket outer circumference to the bottom of the funnel by duplicating the curvature of the top edge of the portafilter so the funnel becomes self centering and hugs the basket tightly and will refuse to move when bumping into it during WDT. This means grinding a custom form tool to form the lip... easy to do, but I'm not sure if all baskets have the same shape. I suspect they are close enough that it won't make a difference, but I thought I'd throw this out there in case anyone knew the quick answer. I suspect I'll have to sacrifice one basket to cut it in half to get an accurate profile in order to grind the form tool.
3rd: Want to try singles at night after discovering that 'decaf' still has enough caffeine to keep me up at night :( and the singles baskets (thanks for the suggestions JohnB!) are very difficult to dose and tamp without a purpose built funnel and specially sized tamper, which no one seems to sell, so these are both at the top of my list. Tamper is easy. Funnel for singles, not so much.
4th: (yeah I know this is more than a couple) I'm not sure I want to use aluminum or stainless for these funnels. Heat is important in the portafilter and I don't want an aluminum funnel stealing the heat out of the basket while in place. It will be more than just a funnel, I think it'll be pretty substantial and solid so plenty of opportunity to steal heat capacity. So maybe delrin (a near cousin to nylon... if you've seen the 'bean funnel' that comes with a pharos, that's similar)? rather than aluminum or stainless... much more insulative and easy to machine.
5th: anybody else out there with the same problems? Could we make a small amount and just defray the materials cost between us? If in delrin this would be easy. But this would only be possible if other baskets share the same diameters and dimensions (which means universality in tooling, although I suppose I could adjust the dimensions for each item if participants send me their dimensions beforehand), which is why I'm posting this. I am also not sure what height the funnel should be, because some will want it under the grinder/doser, others will want to place it only before a WDT? so probably somewhere between an inch or 2 in height, I'd guess. Also the width of a funnel is open to discussion, should it be a wide flower or a very steep, tight cone or a compound/combination of both? This is only in the planning stages. Dan, sorry, should I have cleared such a discussion with you first? Apologies... there is no profit motive, I volunteer my time in this. But not with regard to materials cost, you'll either have to provide your own materials and cover shipping, or else we go in together and split costs evenly. Hell, I'm not even sure I'm in the right forum, but couldn't figure out if it should be somewhere else... but its close to the grinding process, so I stuck it here. But I need a gauge of how many would be interested, and also input into the design (width, height, portafilter lip sizes).


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Postby SonVolt » May 16, 2018, 3:09 pm

Orphan Espresso has a variety of funnels and rings that work perfectly for me. Never have spare coffee grounds anywhere other than in my portafilter.


Postby Nunas » May 16, 2018, 3:12 pm

I found something close to what I'd like but not quite, and it was $35!! Astonishing, for a simple metal ring. I don't wanna accuse someone of scalping, but then... ok, I sorta do want to say it :). that's scalping.

I paid the big bucks for one of those nice stainless funnels and love it. But, I've seen posts where people simply cut the bottom off one of those single serving, round, tapered yogurt containers and voila! Cut it just far enough up so it sits snugly in the top of the basket.

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Postby Jake_G » May 16, 2018, 3:33 pm

I'm working on it!
This is a prototype with bayonet receivers to lock into the PF. It's a work in progress and not yet ready but I'll post it to thingverse or the like when it's ready. The funnel profile is a cycloid, much like the decent funnel. I'm still working on the geometry to make sure it's ergonomic for WDT and tamping through with no retention. The photo is a quick print so the layers are much more prominent than the final high quality print will have.


- Jake


Postby 3cordcreations » May 16, 2018, 7:17 pm

Denis with Kafatek makes a nice one, see photos. His has a small lip that will sit inside the basket, not a big deal. Very well made.
You can not tamp through it though.

Decent Espresso has one that I have not seen in person but it does not have an inside lip. Look more at how DE did theirs and I think theirs is coated alum.


Prescott CR

Postby Prescott CR » May 16, 2018, 7:48 pm

Just a warning- I tried out a clip on funnel from an ebay seller that was affordable.

It worked well, but it was metal so the way it clamped onto the PF actually scratched the PF after a few uses as it's a soft metal.

A plastic clamp would probably not cause this issue, so I'm guessing Jake's would be a better solution.

The one I bought was like this one -

https://www.ebay.com/itm/Espresso-Coffe ... SwlY1ZLoyo


Postby Kran » May 16, 2018, 7:50 pm

I also use the ones from Orphan Espresso. I prefer the stainless steel to the aluminum since the extra heft keeps the funnel in place. I think cannonfodder makes some custom wood ones that could be spec'd to provide the pass through tamping, without removing the funnel, that you're interested in.



Postby walt_in_hawaii » May 16, 2018, 8:24 pm

Thanks. Good looking funnel, but none of them seem to have a form fitting bottom that will catch the rim of the basket nicely and keep it immobile... I do want a lip in it, but it has to be tight fitting to the side so that a tamp can still fit and not be blocked out. All that I've seen have no concavity to catch the rim of the basket; they all have a simple ledge, or else the backside of the funnel's flare to register on the basket lip and keep it there. Of course, that may be enough, I've never used one so don't know how effective they are. I'll go and check to see if I have any delrin lying around that is big enough to use to make a test funnel. I know I have lots of small diameter (1") pieces, but I'll probably need something at least 3" diameter to make a nice funnel.


Postby OK31 » May 16, 2018, 8:49 pm

Tidaka makes exactly what you're talking about. Sits on top no lip inside but doesn't fall off, tamper fits through. You can order different height. I got the 30mm, picture was on another thread Help Adjusting Flavor The only issue I have is some of the fines get between the lip and the funnel when doing wdt but it's contained.


Postby walt_in_hawaii » May 17, 2018, 5:00 pm

Thanks Oleg... nice funnel you got.
I found a scrap around 6" long on *bay last night and ordered it... it should be enough to make 2, possibly 3 funnels if I don't make any mistakes. I know I need at least 2... one for normal and one for the singles basket (much narrower) and tamp. Boy delrin in this size (a little bigger than 3" diameter round stock) is pricey! but it works out to about $10 per funnel, I guess, in materials cost. I'll post the results here when they're done up.

***if anyone else out there needs a funnel built, now is the time to speak up.... order your delrin NOW and measure up/plan out your funnel or give me dimensions!