August 19, 2025
Description
Yes, this is a real, (moderately) functional milk frother. Can also be used for mixing small batches of paint. If you create an alternate attachment, it could also be used as a small rotary tool.
A few caveats before we get into this:
NOTE: Spring wire also goes by “piano wire” or “music wire”
Most of the pieces can be printed in PLA at 0.2mm layer height and 15% infill. The exceptions are:
I printed the “door”, “front” and “back” pieces in black, the “top” and “bottom” pieces in silver, and the “button” piece in red.
Put a 90° bend in the 1.6mm wire 100mm from one end, and place it in the wire guide as shown (the 100mm section is pointing upward in this image).
Using pliers to shape the wire, wrap the other end around the cylinder until you've made slightly more than one circuit. Take care to keep the 90° bend centered. Cut off any excess and reshape as needed.
Take one length of the 0.8mm wire and wrap as much of it as you can around a 4mm rod. I used a variable speed drill for this. If you want to try this, be careful. Go slow at first, and watch out for backlash when you let go. I got whacked pretty hard on the knuckles when I did this.
Cut off the loose ends and stretch the coil until it's about 60mm long in its relaxed state.
Slip the coil onto the ring of the whisk, until it covers the entire ring. Bend the ends of the coil so that they're not exposed (you don't want sharp ends scraping your cup).
Take the remaining piece of 0.8mm wire and bend two each of a spiral cone and an M (or W) shape. These will be your battery contacts.
For the M wire guide, insert either M2 bolts or pieces of filament in the 5 holes.
NOTE: The guides aren't going to be strong enough the hold up to having wire bent around them. They're just guides for the general shape. Use pliers to do the actual bending.
If you've gotten this far without hurting yourself, congratulations. You're doing better than I did.
Cut 4 lengths of hookup wire, strip the ends, and solder to the battery contacts. This is a bit trickier than it sounds. Stainless steel really doesn't like to be soldered. I ended up roughing up the ends, wrapping the hookup wire around that, crimping the end with pliers, and soldering at the highest temperature I could manage.
I'm sure someone will mention a technique that works better (e.g. acid core solder) but this worked fairly well for me.
Push the battery contacts into the slots of either end of the battery compartment (the midsection of the “front" piece). It's a tight fit, so you may need to use a bit of force. Slip the free ends of the wires through the holes behind the slots.
Strip the free ends of the wires and solder to the motor and tactile switch. The wires to the tactile switch just need to be soldered to 2 diagonal pins. For the motor, wire the positive (M shaped) battery contact to the motor terminal nearest the bottom of the image. The negative (spiral) contact should be wired to the other motor terminal. Cram a couple AA batteries into the battery compartment and press the switch. The motors should spin.
Squeeze the tactile switch into the notch as shown. The top surface of the actuator should be flush with the surrounding plastic. If it's not, you'll need to push it in (toward the batteries) a bit. Stuff any excess wire into the gap between the switch and the batteries.
Push the motor into the “bottom” piece, and slide the piece into the groove in the left end of the “front” piece. Tuck any excess wire into the space behind the motor.
Insert the “button” piece into the “top” piece, and slide them into the groove on the other end. If it hits the switch actuator, the switch isn't pushed in far enough. You may need to mess with it a bit. Try pushing the button to verify the motor spins.
Snap the “back” piece onto the “front” piece. You might have to push around some wires before it fits properly.
Snap the “door” piece into place. It may be a bit stiff the first few time opening and closing it.
Push the coupler piece onto the motor shaft (use the end with the larger opening). Push the whisk into the end of the coupler. Depending on the tolerances of your print, these might be a very tight fit or a loose fit. In either case, once you're happy with the build, it probably wouldn't hurt to secure the coupler with a drop or two of glue.
It's pretty much just, push the button. However, if the whisk wobbles a lot, you may need to stabilize it when you start it up. To do this, hold the shaft near the end when starting up the frother. Once it's up to speed, it should remain stable.
DISCLAIMER: Use at your own risk. Not responsible for damage, accident or injury.
Feel free to remix this model as you see fit. It might be interesting to repurpose it as a small rotary tool, for example.
Let me know if you have any issues following the directions. I'll do what I can to clarify.
Also, since the front surface is printed face-down, it's relatively easy to personalize this with a name or graphic.
License:
Creative Commons — Attribution
Steve DeGroof
