Linear verses log potentiometer. Why linear?

I am having trouble finding the exact pot I want. I am looking for a 10k 22mm+ body with a long solid shaft. However I did find one as a log potentiometer. So what is the difference and why can't I use it?

The red line is a linear pot. The blue line is an audio taper (log) pot. IMO it seems to be obviously why you can't use log pots. But: The green line is what you get with a 100K audio taper pot with a 12K from the center wiper to the top pin (clockwise pin)

Source

Nice graph thank.
I ended up buying a log pot. to see physically what happens. and it works. sort of.
If one uses a linear pot and finds the center where the motor won't move either way, then switches the outer wires of said put the motor stays still. However with the log it will not. In fact the position on the pot that stop the motors rotation is not center at all but only like 20% into the pots. rotation. so i could controll the Motors direction and even have it stopped but only use the first 40% of the pots total useable area.
Could the code not be writen to use the center ove the log pot?

For instance (and i know nothing of coding so bear wih my lamanoligy) If the code is written that on a pot a values for 0-5v , one end to the other, the center stop spot for the motor is 2.5v. ,could it be change to say 3.5v which ( am guessing) is the center of a log pot?

the aim of using a potentiometer is to know the position of the lever

if you use a linear pot, you have a direct relationship between pot value and lever angulation
pot value = K x lever angulation

if you use a log potentiometer, you still have a quite simple relationship
pot value = log ( lever angulation )



but this will induce a very bad behaviour on precision.
At one end (left), the lever will have to move more to change the output: loss of precision
At the other end (right), a little move from the lever will induce high change of pot values: noise increasing and peaks of value

In conclusion, indeed a sim can run with log potentiometers but it will induce a really bad behaviour.

Great to Hear from you again RacingMat. I was worried about starting anouther sim build not knowing if my old support group were still active.
I initaly asked about log pots because I was getting some strange reactions from my linear.

This video explains



I Had 10k pot in place And switched them to 25k hoping that would solve the issuse. I also replaced the motors and used insilated wires yet still its happening . Has anyone seen this before and how can it be solved?

My other issue is this maxed out problem as i show in this video.

I hope there is a easy solution.
Also I have been absent for a good part of two years. Whats new and exiting here?