A high-quality inexpensive studio/lab mixer is here

For many years we have searched for a credible alternative to our Lightnin lab mixer. We found this unit on Amazon but then bought it from FristadenLab in Nevada. These are made in China but packaged, documented, shipped and supported in Nevada. This cost about $300US (a programmable one costs a little more). The first impression is how heavy the unit is. The base is 1/4" solid steel. The rods are all solid stainless 5/8". The clamp is also solid metal. The shaft is 3/8" and is held in place by a good quality chuck which enables easy release. The propeller is about 2 1/2" in diameter and screws on, it would thus be easy to 3D print other propellers and mount them on a hex nut. The locking mechanism enables mounting at an angle (important when trying to achieve the highest speed without sucking air bubbles). It plugs in via a 24v DC adapter (it has a DC stepper motor so it responds gradually to speed changes selected on the dial). On this occasion, I mixed 3500g of plaster in this 2 IMP gallon bucket (2.5 US gallon) with no problem. It runs completely silent. A propeller mixer like this is a great start to DIY glazes.

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A must-have: Laboratory variable speed propeller mixer

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If you are at all serious about testing glazes and clay bodies, you need one of these. There are other methods, but nothing else comes close to this. It is the most valuable and frequently used tool in any ceramic bodies and glazes testing lab or classroom. This is the Lightnin brand, they are expensive but high quality. This is a 1/20 hp variable speed unit, it could be $4000 new! But you can get them used on ebay.com (the industrial mixers are most common, lab mixers are jealously guarded). This one uses a 7.9mm dia (5/16") shaft. We adapted a mount (to give it vertical adjustment) from small drill press.

Here’s my setup for pouring plaster in the kitchen

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Because of the ease of 3D printing case molds at home I can now pour plaster in them also. Of course, I am not in production; this is about creating prototype molds. This technique makes it possible to be precise in the amount of plaster used, so there is almost no waste. My tools are simply a good propeller mixer, and a scale and a 3-D printer (and a cooperative wife). Here is my procedure:
-Counterbalance a plastic container.
-Fill the mold with water and pour into the plastic container to get the weight in grams (and thus cc's).
-Plug that weight into https://plaster.glazy.org, set it to use centimenters and get the USG recommended weights for plastic and water.
-Put that amount of water in the flexible plastic container and tare it.
-Dump in the plaster needed (no need to sprinkle it, I have a good mixer).
-Set the timer for 4 minutes and let it soak.
-Put it under the mixer (at an angle as shown), set the speed to create a whirlpool just shy of pulling in any air (thus avoiding adding bubbles). Mix for 4 minutes and then pour it into the molds.
-Clean the mixer blade and shaft in a container of water (and throw that away outside). Let the plaster harden in the plastic container (it breaks away cleanly later).
-Let it set overnight and use a heat gun and pliers to carefully remove the PLA from the plaster.

Learn to draw and print a mixer propeller

Available on the Downloads page

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Lilly will take you step-by-step through the 3D design process of drawing a propeller. We tried many methods of doing this to finally arrive at a simple procedure that produces a flexible parametric design. Follow the full transcript as you watch. Use the same process to create one in this or other CAD software. Our design has only nine steps yet is flexible enough to accommodate a different number of blades, changes in the blade shape, angle, thickness and size and different heights and diameters for the hub and hole.

Depending on the degree to which this can be secured to the shaft, it can be quite durable on a lab mixer, even for high speed mixing. Test, adjust the design and reprint (using PLA filament) until it is working well and then have a metal one printed at a 3D printing service provider. Or from a harder plastic.

Videos

Links

URLs	https://fristadenlab.com/ Based in the USA, Fristaden Lab provides core equipment for labs and industry at reasonable prices, without a middle man. They claim a goal of providing lab and industrial equipment at a fair price while maintaining the high standards.
Glossary	Propeller Mixer In ceramic studios, labs and classrooms, a good propeller mixer is essential for mixing glaze and body slurries.

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