I take it this is just a recipient, it is not flexible in order to act as an air pump.

It is flexible and acts like a pump. I used NinjaFlex filament which is a flexible material.

Again, this is amazing. Feels like you should sell these for 25 a pop.

Thanks for the support. There are still a few design tweaks that need to be made before it get's to the "set it and forget it" printing stage. If there's enough interest... maybe.

On a side note. I took the black washer off today and am happy I did. Much less column jump while grinding and single dose speed is much more respectable. Took the upper burr carrier out and cleaned out the whole grind chamber and chute, reassembled, and did a quick retention test with the 3D printed bellow. 10g in and 9.5g out with pumping of the bellow while grinding. Still not sure the single dose work flow is for me but it may be usable for others. Will definitely use the bellow to purge the grind chamber between coffees though.

Another demo of the blow up

Ok, I emptied my hopper yesterday. Set the grinder to a very course mode. No difference though. I also don't get the effect such as the Atom in the Elektros video or what my experience was at the WOCvenue earlier this year.

The only things I can think of is that my Atom was originally a V1, which was retrofitted with the improved V2 declumper by the dealer under waranty and there is a slight difference in instalation and thus internal resistance. Or that I tend to use very lightly roasted beans which may differ from what is used to test the grinder with the Blow Up system elsewhere. So for me, apartfrom having a nice dark hopper, it's basicly a dud in terms of functionality...

I think I have just indentified why the blow up hopper does not work for me... I may have to go an check how the declumper is installed. The funnel is apperently copletely filled with ground coffee at its base. Even though the grinder works. I think I'm now also starting to understand why my grinder 'speeds up' after one or two cups of coffee and why there is a large amount of ground coffee in the grinder when I open it up for cleaning...



An earlier pic of ground coffee in the grinding chamber before cleaning...

I wonder how customs react to a shipment note with "Blow Up System" on it?

I have a v1 Atom with v2 chute also. The pictures posted by RikC are typical of what I see when I open up the burr chamber after just pulsing the grinder until empty. I typically don't see much of a flow variation on sequential shots.

Pic of grinder after running empty and then pulsing until no grinds come out of chute. Notice the exit port is full of grinds:




If I use my homemade bellow I get a relatively clean chamber. This time notice the clean exit chute. Note that this is not with single dosing. I ran ~20 shots through the grinder, pulsed until empty and then bellowed until no more grounds came out. Presumably, bellowing while single dosing would result in a cleaner grind chamber.

Hey Kran, thx for sharing your experience. I think I have to take a look at my declumper installation...