822 and 831 Rotary switch issues
– Revised 02/05/02Issue # 1
:The 822 and 831 modules are designed to conform to the MOTM size format standard.
However, the MOTM standard was never designed with rotary switches in mind. It is no
secret that Paul hates rotary switches. So, don’t go looking for rotary switches on any
official MOTM stuff. I am sure he could do something fancy with a rotary encoder and
uP. However, being the stooge that I am, I used rotary switches.
So, the standard specified rotary switches for the 822 and 831 encroach slightly into
the standard ½ inch clearance at the top of the MOTM panel. They leave only 3/8 inch
clearance. Otherwise, they are prefect. Here is a photo of a 822 module constructed
with the larger diameter standard rotary switches. These larger switches work perfect
for rack rail mounting. However, for wood case / flat rail mounting schemes, you will
want to use the smaller diameter switch.
A smaller diameter switch is available for wood case construction where clearance
at the top is critical. These switches are considerable more expensive and have a
different "feel" to them compared to the standard switch. Here is a photo showing
a 822 module constructed with the smaller diameter switch. You can download the
PDF data sheet for these Electroswitch the C5/C6 series switches here.
Issue # 2:
For the 822 only, the "step" rotary switch uses all 12 positions. So, it would be nice
if the switch supported continuous rotation. Both the standard and smaller diameter
switches listed above are available as either adjustable stop (appropriate for octave
switches) or continuous rotation (appropriate for step switches). You need two of
each for your 822. The 831 uses three of the adjustable stop switches.
The small-diameter, continuous rotation switch is not available in catalogs. I buy them
in batches directly from Electroswitch. You can buy them from me directly for $9 each.
All of the other switch catalog numbers are listed in the parts list.
