90 degree hall sensor pot 2.8:1 gearing for Gseat. Backlash vs direct

Hey chaps

I've been designing some Hall sensor pots and im thinking about doing an internal gearing for more steps. My levers dont really move more than 30 degrees or so and my range is from 512 to about 700 and i want to start at 50-70

Also since i'm a complete idiot. If i have a range from 512 to 800 before it flattens out and i probably have another 100 steps before it reverses. So if i do 800 - 512 = 288. 288 x 2.8 806 . Teeth 45 / 16 = 2.825 which is close enough at 810. Then id have a little to go on since my actual use is about 512 to 700-750. Correct? I also need about 50, (at least in its current direct state) well probably more since it moves less per step now steps for negative throw. Perhaps a lower ratio is better?

My concern is if the extra steps will just be nullified with the slight backlash of the gearing (and using wiper motors) given that the hall sensor is very accurate. Thoughts?

Here's my current design. It's with bearings. Its just from my direct design so its not finished but you get the general idea. It will be a closed system.

Hmm, I think that you are better of using a timing belt with pulleys instead og gears. I think it is quite difficult to get the gears lined up perfectly without binding. Gears always have slop.

I ended up doing a redesign of the mechanical setup and got a range from 350-800 now. Happy with that

have you tried a 45 degree pot - might be a lot easier

Its been suggested in another post yes but since i got all i need here i'd like to keep the costs down. Would be 300€ or so with admin fees tax and shipping for the pots i need and i can make the 7x 90 degree for about 20-40€ or so. Most of that cost are the (actually i got for 20 pots should i ever need em or for other projects, 30€ incl shipping there) bearing's. I got no idea how to actually make a 45 degree, i may need a specific sensor which i haven't been able to find and no information on the way to do 45 so if anyone has any ideas there id love to hear it.

They cost approx £15 farnell sell them

I'm not able to by from them here in Norway as its only for companies so I have to use Mouser. The 45 oddly cost over 30 there but the 50s was along the price you mention. Minimum order of 70 though as not in stock and the 60 they don't have enough of. At the moment it's not that interesting anyways

@Trigen
Assuming that you have the desired input range of 0 - 5v you can adjust the range of the pot by adjusting the reference voltage to the pot.
A case in point would be say you want only half range of a 270° pot (135°), if you provide 10v as the reference the first 135° will give 0 - 5v output.
An adjustable power supply would be ideal as you can adjust to suit the range you want, even a 12v supply with a pot to adjust the reference voltage but watch out the pot may get pretty hot.
A 5v zenner diode would protect a microprocessor's input from over voltage.
Make sure you use a linear pot.

@OZHEAT Interesting. I'll give that try, Thanks!

Would you mind explaining how that works with the 5v Zener diode? How does that work if i supply as you say if supply from 12v supply 10v trough a pot. Wont that limit the voltage range from 4.8 to 5.2? I've tried reading up on it but i have to admit i'm not very theoretical. On a side note the hall sensor signal outputs 0.2 to 4.8 if i recall correct

Another question. Im assuming could use just one to power say 7 hall sensors without any issue?

@Trigen
I have to apologise to you as I not sure how I missed that you are using a hall sensor instead of an analog potometer. You cannot change the output of the sensor by changing the input voltage.
You can however change the output by using an op-amp, just as you can use mechanical gearing. The op-amp would be used as electrical gearing(gain) but without any backlash(you will still have backlash from the gearbox and as result you will have lost motion) as the hall sensor is directly connected to your lever.
You would lose resolution as any voltage from the hall sensor would be multiplied eg.. an 1.1v hall output to an op-amp gain of 2 would result in 2.2v and a 1.2v hall output would give 2.4v etc... Depending on the hall sensor's resolution(smallest voltage step) will result multiplied as well.

The 5v zenner diode in my previous post was to limit the output so that it would not exceed the micro controllers 5v i/o threshold if by chance you applied >5v to the pin by clamping any voltage above 5v. to only 5v