Motorising A Hario Coffee Grinder

Link to STL files:
www.hangbar3d.com/other-projects
My wife got me a Hario Skerton Plus, but I ended up not using it because it takes me quite a while to grind coffee.
So I decided to motorise it with the help of my friend Barak.
Barak's website:
www.hangbar3d.com
Credit:
Sound Effect from Pixabay
Sound Effect by Alex_Kizenkov from Pixabay
Sound Effect by UNIVERSFIELD from Pixabay
Sound Effects Wiki

[@Nightmare-Engineer]

The entire process.... such a GRIND!

[@matanpazi3777]

Touché

[@OdedArlevski]

Love it!
I need one too!

[@matanpazi3777]

STL files:
www.hangbar3d.com/other-projects
Cost details:
Must have parts:
DC motor - 16 USD
Planetary Gearbox - 13.6 USD
AC to DC 24V 10A power supply - ~27 USD
3D printing of housing + Miscellaneous - ~ 15 USD
Shipping - 20 USD
Total - 91.6 USD
Engineering curiosity / nice to have:
PCB - 40 USD
3D printed metal parts - 23 USD
Total - 63 USD
If we only used the "Must have", it would've cost us ~92 USD.
A comparable off the shelf product, which costs €109,95 (~116 USD) is the "Electro Solo" by Hario:
www.hario-europe.com/products/electro-solo-portable-electric-grinder
Shipping ~ 25 USD.
Still not the best financial decision :)

[@someguy9520]

Call me stupid, but i would wager that seeting the gear box ratio in such a way that the grinder makes 1rpm could help with cup quality. Lots of tests suggest that lower rpm makes less fines and more clarity. Thats especially good for filter/pourover and modern espresso
There is a very expensive commandante c40 motor kit for like almost 300bucks. But the low rpm really made excellent shots

[@matanpazi3777]

No need for name calling :).
I chose the speed to be as fast as possible without hurting the ground coffee's quality based on the following video:
th-cam.com/video/DKQ6veaTmv8/w-d-xo.htmlsi=nWw2kBimcjNmLaOc
It took me around 3 minutes to manually grind a Tbsp of coffee at ~120[RPM] (2 revolutions per second), so 1[RPM] would be insanely slow.

[@someguy9520]

@matanpazi3777 Oh, in that case, it makes sense. Lance hedricks video suggested that the 1rpm mode a very clean cup compared to the 300rpm or so
3 minutes seems like a lot. How many grams is that? The 1zpresso JE-plus, for example, does 14g espress fine in like 45sec
For me, personally waiting 4-5min is okay for the occasional "special" coffee with that extra care. After all, i wait a bit for the espresso machkne and portafilter to warm up. Might as well let the grinder do its best

[@simontremblay6204]

Is there anyway your friend would share the stl files? I'm trying to do the same to my Hario. Thanks!

[@matanpazi3777]

I'll ask him about it, will update you when I have the answer.

[@matanpazi3777]

Added link in the description.

[@dimitrikatsaros9212]

So, what was the total cost (not including the value of your and Barak's time, but including the Hario, the prototype prints, etc.)? Could you have bought a decent powered grinder for the same amount or are you still ahead?

[@matanpazi3777]

Good question. I'll pin a comment with the cost details + comparison to a comparable off the shelf product.

[@dimitrikatsaros9212]

@@matanpazi3777 Thank you! As for supplying it with power for daily use, couldn't you use an AC adapter to get the voltage you need?

[@matanpazi3777]

@@dimitrikatsaros9212 Of course.
But I need a 24V 10A AC to DC power supply which is quite expensive.
I'll try to get one someday, not exactly urgent :)