Laser Tech

Electronic Throwing Gauge

Many potters use a throwing gauge to define height and rim widths of the piece being thrown on the wheel. Initially I used a simple stick but found it just got in the way. Michael Wendt showed me a laser pointer system he used as an electronic throwing gauge. Being a machinist, Wendt's system was complex and accurate but difficult to make. Youtube showed several alternative ideas using laser pointers as a throwing gauge but still pricey to make a simple throwing gauge. Searching Amazon.com, I found laser diodes were not expensive and devised a way to mount them over my wheel.

Ideas and Hacks

1. The lasers have replaced my wood throwing gauge.

2. Level your wheel before making the laser system.

3. The 3 volt red lasers are from Amazon and come in a package of 10. The amount of light coming from the laser was reduced and focused by covering with a piece of blue painters tape then poking a hole with a large sewing needle.

4. The power supply for the lasers is a 3 volt transformer plugged into a power strip that turns on the equipment in the studio. You can also use 2 AA batteries battery holder and a switch to turn off and on.

5. The lasers can be mounted to anything but the idea is to have one perpendicular to the wheel and one at an angle to the wheel. Originally I used a Harbor Freight 24 inch combination square with protractor, but recent versions are made with plastic wood and a swivel for the angle mounted on 1 inch aluminum angle stock (see photos below). I also made a portable unit for when I need to center a pot away from the wheel. It uses a camera mount clamp with a swivel head to allow laser adjustment. The portable unit is powered with 2 AA batteries.

6. Attach the mount to the wall in front of the wheel or use a tripod about 30 inches above the wheel. Use a level to insure it is parallel to the wheel and the laser at the end of the rule shines on the center of the wheel. Check to see if the perpendicular laser is really perpendicular to the wheel with a square or block of wood with square edges. Make fine adjustments to align the perpendicular laser. Wood shims may be used to adjust the perpendicular laser at the point where it is attached to the wall. If using a tripod to hold the laser just adjust the tripod more. Check laser alignment so the both dots are always within a 1/4 of each other or form a single point.

7. Make a wood spacer block the height of the kiln stilts used in your kiln and use them to setup the lasers for throwing. I use 3 blocks (4, 5 & 6 inch blocks). All laser adjustments are done prior to attaching the bat to give a little head space in the kiln.

8. An added bonus comes when the beams show the the amount of wobble when throwing on the wheel and if corrective action is necessary. I use the beam shining on my hand as a lift guide when pulling a pot wall.

9. Lasers also make lids a snap because the rim laser used for throwing the jar is used for throwing the rim of the lid.