Sometimes knobs have a certain mechanism built in (like a detent) that gives them a bit of resistance by design - so that they are more difficult to twist to varying degrees. I'm looking for a word or technical phrase to describe this type of action. Something that means "difficult to twist" but not necessarily "sticky" because it is by design, not due to lack of lubricant or corrosion.
"Torsional resistance" or a "high torque" setting would probably fit. (http://www.dictionary.com/browse/torsional)
I think you could call it stiff:
1c : impeded in movement —used of a mechanism
Examples from the web refer to a vehicle's "stiff suspension", a piano's "stiff action", and so forth, indicating that it takes greater force or effort than normal to make the tires bounce or the keys to play a note.
The (very rare) noun torsibility actually means just about what you want. From Merriam-Webster:
resistance to torsion; also : tendency (as of a twisted rope) to untwist
Since "torsion" is twisting, this is essentially a word for "difficulty of twisting". It was originally used for describing materials rather than mechanisms (it's a measure for wire, like tensile strength), but I think it could be easily extended to other things that are twisted. So you could say
Due to the (high) torsibility of the mechanism, it was difficult to twist.
Except...it might possibly mean exactly the opposite of what you want. From Collins Dictionary (emphasis added):
- the ability to be twisted
- the degree of resistance to or the capacity of recovering from being twisted
And their "American" definition (on the same page):
ability to undergo, or resistance to[!], torsion
These definitions appear to me to be in direct conflict with themselves, and half in conflict with the M-W definition. If you're using the "ability to twist" meaning you would need to say
Due to the low torsibility of the mechanism, it was difficult to twist.
which is essentially the exact opposite of the first suggested sentence. Now, with that particular sentence, I think either formulation would be understood purely from context. But a harder case would be if you said something like
A detent is added to a mechanism to increase/decrease torsibility.
If your audience already knows what a detent does, either formulation would be understood. But if you want to define detent for an audience that isn't already familiar with it, this would probably be confusing.
Bottom line, the word is probably rare enough that your audience would just roll with the word however you use it, so long as you're consistent (but there's a very slim possibility that you will run into someone who has heard it before, in a way that's not consistent with however you choose to use it).
I'm not sure this helps you at all, but torsibility is so very close to suiting your needs (and also the most self-contradictory definition I've ever seen) that I had to post it.
High torsional stiffness combines the best of BenL and Hellion's answers. It is both technical and specific. Or, torsionally stiff (per AlanT's comment).
Pass me my wrench -- this bolt has a high torsional stiffness.
Also, you might consider tight as a less technical alternative. I think it could be a useful description if enough context is given.
- ...hard to move, undo, or open. "she twisted her handkerchief into a tight knot" Google def.
The concept I suspect you want to embrace is that the knob does not turn by itself or accidentally. The knob is re-positioned by intent, not serendipity.
So including difficult is ultimately misleading.
I think of it as positive knob setting or positioning.
This high end stereo amplifier has a volume control using positive knob setting for the ultimate in mechanical feedback and fine control.
A detent is a device used to mechanically resist or arrest the rotation of a wheel, axle, or spindle. Such a device can be anything ranging from a simple metal pin to a machine. The term is also used for the method involved.
Detents are for example used to simply arrest rotation in one direction or to intentionally divide a rotation into discrete increments. –Wiki
I'm talking about a stepped knob and a toggle knob (similar but only 2 positions)
Rotary switches typically employ detents to keep the control shaft properly aligned with the appropriate contact.
as well as a timer knob that resists being twisted back to 0 because of the timer
Any spring-powered wind-up toy employs one, in order to disallow unwinding of the spring.
Those are three different knobs with different purposes but all having a common property - resistance to twist by design.
To resist movement (or when creating incremental steps), methods are employed which include a spring-loaded ball bearing that locates in small incremental depressions, or a piece of spring steel that snaps into position on flat surfaces or shallow notches milled into the shaft or wheel.
And here's a fourth.
To arrest movement, the method commonly employs a small gravity or spring-actuated lever paired with a notched wheel. The lever is mounted on a pivot point in proximity to the wheel.
Apparently notchy is a word.
(of a manual gear-changing mechanism) difficult to use because the lever has to be moved accurately (as if into a narrow notch)
‘the gear-change action is rather notchy’
Fixed [fikst] /adjective
- fastened, attached, or placed so as to be firm and not readily movable; firmly implanted; stationary; rigid.