|Monthly Tech-Tip |
3D printing is bringing the ability to easily and inexpensively make molds for jiggering smaller ceramic pieces. This jiggering attachment is for a Shimpo potter's wheel, it is made from 1/2 inch flat steel and is very solid. I have used it for many years, it works well and can be adapted to other potters' wheels (this is a Shimpo RK2). The drawings are in Fusion 360 format in 3D, with all measurements. It is parametric (so you can change measurements and the drawing will adjust accordingly). That means you should be able to submit the file or drawing to any fabricator and have one made.
We have mechanical drawings for this (and the cup heads). This is very sturdy and useful. The arm is relatively short compared to industrial jigger wheels and is thus useful for only small shapes. There is an advantage: The template contacts vertical walls at a more perpendicular angle. But the disadvantage is that the trailing edge of the template hits the outside edge of the lip on taller shapes. The pointed bolts hold the arm securely and their tightness enables varying the friction of movement. They have enough length to also position the arm horizontally. We 3D print templates and block masters for making working molds that drop into the cuphead.
The cup-head was lathed from a block of aluminum and it attaches to the shaft the same as a regular wheel-head. Plaster molds simply drop in and sit on their shoulder. The shoulder is the only point-of-contact, this prevents chattering while the mold spins when under pressure. I am using these molds for a casting-jiggering process (or just casting). For example, I can cast a mug in the mold, then pour out the slip, wait a few minutes and then, as the wheel spins, finish the rim and inside sure using a 3D-printed template/rib. I do not actually use the jigger arm, it is easier just to hold the template in hand. I can finish the rims on any round pieces made in these molds.
The arm is heavy, made from 1/2 inch plate steel. The counterweight at the end have 1 in plate weights. The swivel mounts are machined to fit the custom cone-ended bolts.
Made from 1/2" x 3" flat steel, this frame is heavy and very strong and solid. The two larger 3.5" long bolts are custom-made from 5/8in-11 threaded rod, they have a 45-degree cone tip and locking nuts. The small vertical stopper-bolt is made from 3/8" rod. It is 2" long with 1" dia washer welded on top and a locking nut. The small bolt setting determines the bottom point of arm travel. The pivot sockets on the jigger arm are 1" long and made from 1" steel rod, each has the 45-degree recess machined into it. The arm can be moved left or right and its tension set by adjusting the two larger bolts. The weighted collar on the back of the arm employs two pieces of 1" thick flat steel, it is heavy (important for convenience-of-operation). The triangular notch enables the arm to be lifted higher. The weight colar needs some sort of set screw to hold it in place. A number of corners need to be rounded or rubber-padded for safety reasons. If you would like this 3D file in Fusion 360 and STEP formats, it is available in the Files manager in your Insight-live.com account.
This is machined out of aluminum. We also have drawings of a 3D-printable shell-mold for making molds that drop into this. And methodology for printing the outside contour of pieces to be jiggered.
Showing dimensions to fit a Shimpo RK2 wheel, its shaft is 0.983 in diameter. The molds fit down inside as shown, only contacting the cuphead at the shoulder. This is machined from aluminum. We do not sell this of course, but you could take this drawing to a machine shop and have them make you one (the numbers are readable when this is zoomed to full size).
The head is lathed from aluminum. It fits on a potter's wheel (adjust the inside diameter to fit the shaft). The plaster mold drops into it this cuphead and stays in place by friction. The only point of contact between the mold and aluminum should be at the top inside corner of the cuphead.
Turn this upside down and center it over a precision plaster or 3D printed form of the outside shape of a mug. This creates a mold that drops down in our Shimpo cuphead. This opens slightly along one side for easy release from the plaster after set. It is held together by paper clamps during use. The upper flange can be glued down to a smooth surface with a clay slurry. If you would like this 3D file in Fusion 360 format, it is available in the Files manager in your Insight-live.com account.
2019 Jiggering-Casting Project
Jiggering is a process of forming pottery that employs a spinning plaster mold and a tapered template to press soft clay or porcelain against it.
|By Tony Hansen|
Follow me on