Smash
I made another attempt to place an order and I got stuck on the Pots again.
You have 2 different kinds of pots of different sizes. What’s the difference?
The only difference worth noting is the diameter of the shaft. On the pots with the round shaft (19b) they measure 1/4 inch diameter, and require a knob with a round 1/4 inch hole for the shaft.
For the D-shaft pots (19a), the shaft diameter is 6mm. A knob made to fit one won’t fit the other.
All of the other measurements of the pots besides the shaft size don’t really matter.
Spline shaft knobs won’t fit either pot I sell correctly.
I’m forced to make an uninformed decision with the pots and I don’t know the difference.
Just find some knobs you like, and if they have a 1/4" round hole with a set screw use 19b, if they are 6mm with a D-shaped hole or round hole with a set screw, use 19a. Don’t be forced into anything, the info is out there if ya dig or ask… 
The difference is that one is 6mm, the other 3/8", simple as that. 
Actually that should read “the other 1/4 inch, simple as that”…3/8" is the shaft lenght, they are 1/4" diameter… :)
The constant jumping between Imperial and Metric measurements makes me a bit spin-dizzy on sizes too! ;D
Previously Smash only stocked encoders in 6mm format and pots in 1/4" format - all fine and dandy if you were buying them separately but if you were mixing encoders and pots on the same box there was a problem with knobs - 6mm knobs will not fit on a 1/4" shaft (1/4" is slightly bigger), so Smash very kindly has started to stock 6mm pots with the same D fitting as the encoders he stocks after I told him about the problem (I believe that others have had the same issue now that people are starting to make bigger/more complicated boxes with various mjxes of pots and encoders) I was having with knobs. Most of the knobs out there seem to be in metric format and to mix 1/4" and 6mm on the same box would mean having a different type of knob for each - not neccessarily very good for aesthetics.
That is my story…and I’m sticking to it… Eufex has it right, in the past people were using either pots or encoders on thier boxen, now people are starting to use both on the same box.
To avoid confusion I changed the 3/8" size to 1/4" in the quote above, edits in blue…
I’m still on the hunt for cheaper quality pots, but it seems a majority of the cheaper pots are spline shaft, so if I add any spline shaft pots to the store I will have matching knobs also.
I’ll never trade quality for price though, so don’t worry if I throw the “cheap” word around a bit.
Best!
Smash
