Does anyone know of any practical reason why one should use potentiometers with metal shafts versus plastic? Are they more prone to breaking? Bending?
The reason I ask is: I like the “feel” of Bourns potentiometers, however; the only ones that seem to be reasonably priced have plastic shafts. Even the approx. $3 that mouser wants per potentiometer is a bit steep for me, but, $3 is closer to my price range than the 5+ dollars the others are going for…
Thanks,
Robin
Nohohooooormallyyyy (***) metal shaft pots have higher power ratings and are used for that stuff (e.g. in row with relais, direct control of motors and other higher power (>0,5W) stuff). So in MB´s there´s aaabsolutely no need for metal shafts.
Greetz
I am actually using plastic shaft pots from Bournes that I found for next to nothing (.75 a piece!). There are potential issues if you are really tough on equipment, but if not then there’s no big difference. The forces applied to the shaft are primarily rotational, and so a composite shaft is just fine - particularly in the larger sizes. But I tested my pot choice through 1 straight hour of back and forth twisting - no degredation noted, and that is on a 1/8" shaft!
EDIT: No Masturbation jokes please. 
Alright, the good news: at a local computer/electronics store I found a stash of bourns pots that are pretty much everything I need… 10k, 5/8" diameter base, great <ahem> rotational action on the shaft, they’re even of the conductive plastic type. I was able to buy a box of 26 for $40! (eat it, mouser)
The trade off: the shaft is metal, but it’s 1/8th inch in diameter… were aluminum knobs just never made for 1/8th inch shafts??? Oh well, thanks for the swift replies guys.
Robin
the shaft is metal, but it’s 1/8th inch in diameter… were aluminum knobs just never made for 1/8th inch shafts???
Check my post in Parts Archive titled “God I love Knobs”!, where you will find a company that makes very nice aluminim knobs for 1/8" shafts.