This is just the thoughts I needed to put it right in my head.
A centerless pott is what I wanted.
I need about 40 degress each way so your ideas are right on.
I will check my sources for the pot.
Thanks, if anyone else has additional info I am open to it.
My current controller works fine for me but the others using the boat would like a more "conventional" setup. Right now you can throw it into gear, for or rev, at full speed! Exciting but not fun while docking. My left handed wife is still trying to get a hold of tiller steering. I know, it has nothing to do with her being left handed, but it's a cute excuse. She thinks a tiller is all backwards and would like a steering wheel like a "regular" boat.
--- In electricboats@yahoogroups.com, James Massey <jcmassey@...> wrote:
>
> At 05:10 AM 18/06/2011, you wrote:
> >I am looking for a pot and not having much luck so I thought I'd ask
> >here. My controller uses a 5K pot, Max speed is at 5K ohms, I think
> >this is the reverse of normal setups. I would like to have a center
> >"off" pot to make a forward reverse throttle lever. I can use cams
> >and micro switches for the for/rev solenoids.
> >But I cannot come up with a simple easy setup for the pot.
> >Any suggestions?
>
> G'day ...um Matt?
>
> I had to convert a joystick-operated forklift to a Curtis controller,
> that had the same 0 to 5k 0 to full speed requirement. What I did was
> as follows:
>
> The original joystick included a pair of gears to 'speed up' the pot
> motion, so it actually turned the pot about half of the normal
> 240-degree rotation each way, so I had to use a 10K pot. The type I
> used was a ceramic-substrate (cermet) with no mechanical stop
> [similar to
> http://au.element14.com/vishay-spectrol/357b0103mab251s22/potentiometer-1w-10k/dp/1144764
> . Ebay worldwide gets 8000+ hits for "potentiometer", asking for
> '"stopless potentiometer" gets zero hits, so may need to go to an
> electronic supply house such as mouser, Newark, etc. to get what you need].
>
> I marked the original 'end' (open circuit) zone relative to the
> shaft, then prised out the back, and cut the track at a point
> opposite the end dead zone (just roughed at it with a 'dremel'
> grinder until I could measure the disconnect between the halves, then
> gave it a little more for good measure). Epoxy glue put the pot back together.
>
> I turned the pot to its' original end zone (would not want to be
> running back and forwards across the ground out part) and mounted it
> into the joystick. Connecting the two ends together makes the wiper
> contact one or other end, then as it continues to turn away, the
> resistance increases up to just under 5k before it hit the ground out
> part (curtis controllers hit 100% at about 4.8k usually, so not a problem).
>
> If you only need a small amount of rotation, the pot value could be
> in the order of 100k-ohms, giving about 17 degrees each side of
> center, with no need to break it open and cut the track, since the
> remaining path to the 'other' end is insignificant. A 50k 'pot' would
> give around 35 degrees each side of center, although probably need to
> be a little more than that due to the parallel path around the
> 'unused' side of the pot.
>
> Although these types of potentiometers are not cheap (in the
> industrial world they are considered relatively low cost, similar
> ones can easily run over $100 just for a pot), they are well made, of
> corrosion-resistant materials and come with a manufacturers' spec of
> 5 million rotations.
>
> And if you are wanting to put the pot straight into the end of your
> operating lever, a 50k-ohm one turning 35 to 40 degrees each side of
> center means no modifications to the 'pot', microswitches or
> forward/reverse and fulfills the requested "simple easy setup for the pot".
>
> Hope this helps
>
> Regards
>
> [Technik] James
>
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