drgary wrote:I'm not wild about the curved chute either. I would love to see an approach that causes less grind retention. And if you're going to use a chute, I wouldn't have it curve, which makes it hard to clean without removal via the retainer screws.

Hi Gary, we're all in agreement here, that a different chute design is a good idea to prevent grounds retention.

Today, I came back from a week in China meeting our suppliers, including the grinder factory owner (photo below). There will be a "making of" video in the future, for each of the products we sell, so you can see how each product we make is manufactured, and meet the people working with us to make them.



There's no problem for them with changing the chute. It's up to us to design (and 3D print to test), and my plan is to
a) make the chute straight for less grounds retention
b) remove the need for screws (make it clip on)

We're also going to change the grinder mould so that it snugly holds the scale in place.

And finally, I also found out that we have the option of paying more for imported-from-Europe burrs (left) vs Chinese-made burrs (right). Different quality materials (the European burrs last longer).

I've obtained CAD files from the grinder manufacturer, so we can modify the spout to our spec, to fix the grounds retention problem I've observed with the current design. Here is the grinder we're talking about: Decent Espresso Grinder Prototype

Here is what the current spout looks like:





and here is a CAD file, for those so inclined: http://magnatune.com/p/spout_prt0014.igs and http://magnatune.com/p/018%20grinder.igs

I photoshopped what I was thinking would be a better design, with a straight angle, and making the spout removable without taking the screws out.





We also have the option of making the grinder a bit taller,



which will let us make a steeper angle for that spout, which should help with retention. It will also give more clearance for spouted portafilters, that don't really fit with the current design.

I'm sharing this with you guys, to get feedback & ideas on mods to this grinder.

I'm looking to sell this in the $250 to $300 range. This is meant to be an inexpensive home grinder, with a built in Brewista scale. There is also a plastic hopper than you can put on the brewista, to do weighed doses for pour-over coffee.

Here is a photo of the grinder we started with (before we modded it with a Brewista, and our portafilter stand)

I agree, which is why I have a 3D printer here. We'll redesign the spout, print it, see how well it works, then revise.

In theory, the Brachistochrone Curve should be the best solution to this spout shape problem: https://en.wikipedia.org/wiki/Brachistochrone_curve
Unfortunately, the mathematics assumes low to no friction, and it might be that ground coffee gets stuck at the bottom of the curve and never gets out. We'll have to test.

If we want to stop splatter/spraying then perhaps that curve isn't the ideal solution in practice - it may be helpful to slow down particles of higher velocity vs those of lower velocity such that they fall into the basket neatly?

Just as a thought experiment, take a Brachistochrone curve, and mirror it for the top of the spout. The roof, being a mirror, should optimally slow down coffee grind particles shooting out of the spout. Looks weird, I know.

That's pretty interesting - I think there's many who would be interested in your results if you're happy to share them!

Just FYI, we've redesigned the spout using two Brachistichrone curves, as well as removable. I thought it would look weirder than it does.

Will be 3D printing this shortly and will let you know if this idea works.

-john

Epic fail! Coffee grinds are sticky and don't behave like toy race cars. Who knew?

We printed the brachistochrone spout in semi-transparent plastic, so we could see if there was any grounds retention. Just a wee bit...!

I like the idea of an affordable home grinder but find this implementation and design somewhat old school. The trend based on consumer demand is going in the direction of very low grind retention encompassing straight through grinding.
HB member Jason a.k.a C6MFG has come up with a design posted April 2016. Baratza Sette also follows the the flow through design albeit with a crown gear design for starters.
Maybe C6MFG would consider licensing his design for mass production.

Grinder project back from hiatus...

It's both aestheticly pleasing and functional all in one small footprint package.