last update: August 26, 2008

Roderick Wall made this mechanism from easy to get parts for the Opto encoder.

"Shaft encoder was made up with a ball bearing clamped between two Car mud-flap washers.

The centre of the two washers was drilled (15mm diameter) to allow space for the two nuts that clamps the shaft (a bolt) onto the inner part of the ball bearing. Three 4mm diameter holes (120 deg apart) are drilled in the washers for three 4mm screws that are used to clamp the bearing between the washers and for mounting the shaft encoder to the front panel.

The shaft is a inch bolt with the head cut off. You may need to file the thread on the inch bolt to allow the 6mm inside diameter of the bearing to fit onto the bolt thread. Or use any 6mm outside diameter bolt.

Two Car Mud-flap washers with two nuts are used to clamp the optical disk to the shaft.

Parts: 4 x Car mud-flap washers (31.5mm outside diameter with inch hole) 1 x inch bolt (select one that has a shaft 6mm diameter) or any bolt with an outside diameter of 6mm. 4 x Nuts to fit above bolt 3 x 4mm 35mm long metal thread screws 6 x 4mm Nuts for above screws 1 x 6mm inside diameter, 19mm outside diameter, 6mm wide ball bearing 1 x Tuning knob (6mm shaft) (Rockby Electronics - Australia) Lead to balance the tuning knob (fishing sinker), an unbalanced knob will always turn.

All the above parts except for the ball bearing, tuning knob can be purchased from BUNNINGS WAREHOUSE (in Australia). "

pdf Version


Jan 8th 2008. Hi Glenn, Thought you may like a photo of my Pic'a'Star with the boards mounted onto an aluminum panel for system testing. I thought that the aluminum panel would make a good ground plane for system testing. To the left of the Pic'n'Mix display board is a bracket on which is mounted the +12V plug-pack power socket, stereo RS232 connector (to connect to the PC) and the RS232 command/DSP switch. The Pic'n'Mix, butler board, DDS carrier board and encoder board have all been tested and are working. Timer board has also been tested and is working. I'm waiting for the DSP chip to arrive (since before Christmas) to test the DSP board, Codec board, DSP Mother Board and Audio board. Thanks again Glenn for your help and for the PC Boards,

Roderick Wall.













created from builders page on 25th Aug 2008