TRIFECTA - Fancy 1Zpresso Grinder Motorization K-Series / ZP6

Update 10/30/2024: *Now with RPM Control!* 

Instead of using the sketchy (but free) electronics down below, you can use this rectifier and voltage controller combo unit I found on AliExpress: https://de.aliexpress.com/item/1005006215241132.html

I just drilled three holes into the motor cover to mount the speed controller, there is enough space behind the motor. The models will be updated soon to natively support ESC mounting.

Also, I've certified compatability with the ZP6, the only part that needs reprinting is the fines knocker. Now both the ZP6 and K-Ultra are officially supported.

General info

Last year I found an old brew and grind filter coffee machine in the trash at work, still working but in pretty rough condition, so I decided to salvage the inner components and keep em for later projects.

Now, I really like the 1zpresso K-Ultra, it's got quite the enjoyable flavor profile and is the most capable espresso grinder I had so far, but I do not like hand grinding in the espresso making workflow, especially for dialing in new beans, so I motorized it using the motor of the beforemetioned brew and grind machine. Couldn't resist to add some funny little features such as a spot for 58mm accesories (occupied by the tamper in these pictures) and a little drawer in the base to store my puck screens.

Turns out the brew and grind machine is just a white label product sold by many different importers, you should be able to get one of those for really cheap or for free on the second hand market or your local electronics recycler. You can recognize the type of machine by the water tank, fill indicator, side button, bean hopper, grind size dial, and general shape: https://imgur.com/a/bc2X0pg (the button array on the front differs from model to model, but all of them should have the same/a similar grinder motor).

Be aware, all of this has only been tested with an 1zpresso K-Ultra, it should fit all of the K-Series grinders though minor adjustments might be required. All of the original cad files are included if you need to do so.

BOM

- 1m metal tube outer diameter 22mm, inner diameter 20mm
- probably a roll of filament (do yourself a favor and dont use cheap stuff)
- old pc power supply (for switch and ac socket)
- one of those brew and grind machines
- small rubber band for the fines / static knocker
- 3 socket screw terminal: https://www.amazon.de/L%C3%BCsterklemme-16-25mm%C2%B2-380V-Reihe-Verbindungsklemme/dp/B07DHFJYS3
- brass self tapping wood screw set:
https://de.aliexpress.com/i/1005004448891502.html?gatewayAdapt=glo2deu
- heatset insert set: https://www.amazon.de/gp/product/B07QWKDHSN/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
- countersunk screw set: https://www.amazon.de/gp/product/B089F33G9P/ref=ppx_yo_dt_b_asin_title_o08_s00?ie=UTF8&th=1
- optional: mhw3 blind shaker:
https://de.aliexpress.com/item/1005004724543075.html

(please use original cad models to check what screw and insert sizes are required for now, i didn't write these down sorry lol, will add this information later)

Electronics

The motor I salvaged is a 230V DC motor with the product number: "KH44/33-F DC230V 100W CM4802 Class 155 2019 09 17 ZE" (as pictured here: https://imgur.com/a/t1SibYr).

BE AWARE, I am NOT an electrical engineer, and this is the point where I advise you to not trust some random person's wiring diagram on the internet without understanding it. Understanding & utilizing safe electrical practices is critical to your safety and safely completing this project as mains voltage is involved. I am not responsible for any damage to health or property you might inflict onto yourself, you are following these guidelines on your own risk.

I am using a Full Bridge Rectifier and a X2 safety capacitor connected to a switch and socket from an old PC power supply, as seen in the following wiring diagram. According to my measurements, this is all thats needed to safely provide the needed voltage to the motor. BUT, as mentioned before, I AM NOT AN ELECTRICAL ENGINEER, just a hobbyist learning new stuff. I could have very much missed something and you should probably do your own reading on the required safety measures.

The mains wires are routed through one of the tubes, I just wrapped the electronics in electrical tape and glued them in the upper compartment and fixed them with a dab of hot glue.

Important: Depending on the material you've decided using for the tubes you should connect these to earth so you've got ground fault protection in case something goes horribly wrong. 

Printing

- most parts can be printed without support, but it does somewhat depend on the capabilities of your printer. use them when you feel like you need them.
- "v2-gearbox-coupling" should be printed solid as it needs to withstand quite some force
- you need 3 of those: v1-tube-insert_heatset-insert

Assembly

1. Get all of the heaset inserts into the parts
2. Cut the tube to size (you can reference the length I've used in the cad file but the exact length doent really matter, the front one's gotta be a little shorter though)
3. Do all the wiring as seen in electronics
4. The hopper shoot needs to be super glued to the hopper mount
5. Mount the hopper first, center it to the thread in the gearbox, screw the motor coupling into the gearbox using the original screw (left handed thread)
6. Push hexagonal shaft of the grinder upwards into the motor coupling
7. Fix your grinder with clamps

Epilogue

If you decide to build one, make sure to test everything before assembly and keep a fire extinguisher around ;)  Feel free to improve on every part of the design as you wish!

Full credit to https://www.thingiverse.com/thing:1959745 @SpoonUnit for the hinge design used in the fines knocker!