rec.autos.simulators

by **millar..** » Thu, 14 Oct 1999 04:00:00

Hi. I'm hoping some of you technical minded guys can provide some
additional input on this subject. In a PC steering wheel a true
precision potentiometer will likely give better and more precise
signal input and resolution, but I have heard (just someone's casual
opinion) that a pc game port is not sensitive enough (or "precision"
enough, as it was put to me) to take advantage of high precision
input. I believe that the Thomas' wheel uses a Spectrol bushing mount
conductive plastic pot with Linearity of 2%. Would a ball bearing
conductive plastic pot with Linearity of less than 0.5 (or better)
yield even better results? or is there a limitation imposed by the
sensitivity of a game port? Has anyone experimented with using very
high (industrial/military grade) precision potientiometers in their
wheel?

by **keit** » Thu, 14 Oct 1999 04:00:00

>Hi. I'm hoping some of you technical minded guys can provide some
>additional input on this subject. In a PC steering wheel a true
>precision potentiometer will likely give better and more precise
>signal input and resolution, but I have heard (just someone's casual
>opinion) that a pc game port is not sensitive enough (or "precision"
>enough, as it was put to me) to take advantage of high precision
>input. I believe that the Thomas' wheel uses a Spectrol bushing mount
>conductive plastic pot with Linearity of 2%. Would a ball bearing
>conductive plastic pot with Linearity of less than 0.5 (or better)
>yield even better results? or is there a limitation imposed by the
>sensitivity of a game port? Has anyone experimented with using very
>high (industrial/military grade) precision potientiometers in their
>wheel?

I would say the nicest solution is an optical encoder and USB interface, but I
don't know of any wheels that have both. The gameport seems to be more of a
problem than the pot. My LWFF is very smooth after 9 months of use, has been
since new, and the steering pot is still working great through the USB
interface.

If you want to improve the feel of your analog wheel, better to focus on the
gameport than the pot in my experience - unless your pot is worn out. Some sound
card gameports work well, other don't, and the custom game cards are another
option.

Keith.

by **Doug Schneide** » Thu, 14 Oct 1999 04:00:00

I replaced the steering pot in my T2 with a high-grade conductive plastic
pot, and noticed no difference at all. I believe that the standard
gameport is indeed not sensitive enough to benefit from a more precise
pot. Unless you use a PDPI gamecard or something similar, it's probably
not worth the hassle. When you consider how a standard gameport goes
about determining where the controller is positioned at a given instant in
time, there are too many other variables involved for the quality
(linearity, anyways) of the pot to be a *** factor. For a much
better explanation than I could ever give, take a look at:

http://www.racesimcentral.net/

There is a very good explanation of how the gameport works and its
inherent limitations.

The biggest improvements I have seen in controller precision and response
have come with increases to processor and bus speed. Using a C300
overclocked to 450 with a 100MHz bus is pretty much perfect, response and
accuracy are no longer issues, now it's come down to my limitations as a
driver. All this makes sense, since the faster your machine is, the more
often it can monitor the gameport, hence greater response times and
resolution. Hope this didn't bore you shitless.

Zog

> Hi. I'm hoping some of you technical minded guys can provide some
> additional input on this subject. In a PC steering wheel a true
> precision potentiometer will likely give better and more precise
> signal input and resolution, but I have heard (just someone's casual
> opinion) that a pc game port is not sensitive enough (or "precision"
> enough, as it was put to me) to take advantage of high precision
> input. I believe that the Thomas' wheel uses a Spectrol bushing mount
> conductive plastic pot with Linearity of 2%. Would a ball bearing
> conductive plastic pot with Linearity of less than 0.5 (or better)
> yield even better results? or is there a limitation imposed by the
> sensitivity of a game port? Has anyone experimented with using very
> high (industrial/military grade) precision potientiometers in their
> wheel?

by **Peter Prochazk** » Thu, 14 Oct 1999 04:00:00

I also own a LWFF and I've hardwired my old Thrustmaster pedals onto it. The
LWFF (and maybe other FF wheels) seems to filter the signal coming from the
pots and eliminates all the noise coming from them. (I think, also short
peaks due to a little bit worn pot are filtered out). AFAIK, the PDPI does
the same.
I don't know, if a 'precision' pot really beats a new cheapo one regarding
generated noise and linearity, but for sure it will last longer.

Peter
Vienna, Austria

> >Hi. I'm hoping some of you technical minded guys can provide some
> >additional input on this subject. In a PC steering wheel a true
> >precision potentiometer will likely give better and more precise
> >signal input and resolution, but I have heard (just someone's casual
> >opinion) that a pc game port is not sensitive enough (or "precision"
> >enough, as it was put to me) to take advantage of high precision
> >input. I believe that the Thomas' wheel uses a Spectrol bushing mount
> >conductive plastic pot with Linearity of 2%. Would a ball bearing
> >conductive plastic pot with Linearity of less than 0.5 (or better)
> >yield even better results? or is there a limitation imposed by the
> >sensitivity of a game port? Has anyone experimented with using very
> >high (industrial/military grade) precision potientiometers in their
> >wheel?

> I would say the nicest solution is an optical encoder and USB interface,
but I
> don't know of any wheels that have both. The gameport seems to be more of
a
> problem than the pot. My LWFF is very smooth after 9 months of use, has
been
> since new, and the steering pot is still working great through the USB
> interface.

> If you want to improve the feel of your analog wheel, better to focus on
the
> gameport than the pot in my experience - unless your pot is worn out. Some
sound
> card gameports work well, other don't, and the custom game cards are
another
> option.

> Keith.

by **Peter Prochazk** » Thu, 14 Oct 1999 04:00:00

<snip>

Just out of interest: What is a 'true digital game port'? AFAIK, all
gameports have to digitize the analog signal coming from the pots. So why is
the MX300 'more digital' than others?

<snip>
Peter
Vienna, Austria

by **Thomas Enterprise** » Thu, 14 Oct 1999 04:00:00

>Hi. I'm hoping some of you technical minded guys can provide some
>additional input on this subject. In a PC steering wheel a true
>precision potentiometer will likely give better and more precise
>signal input and resolution, but I have heard (just someone's casual
>opinion) that a pc game port is not sensitive enough (or "precision"
>enough, as it was put to me) to take advantage of high precision
>input. I believe that the Thomas' wheel uses a Spectrol bushing mount
>conductive plastic pot with Linearity of 2%. Would a ball bearing
>conductive plastic pot with Linearity of less than 0.5 (or better)
>yield even better results? or is there a limitation imposed by the
>sensitivity of a game port? Has anyone experimented with using very
>high (industrial/military grade) precision potientiometers in their
>wheel?

We have used nearly every type pot available in all resistor types, several
resistance ranges etc and have seen very little to no difference in any of
them, other than longevity, there are people who will swear that this or
that type of pot will do this or that (usually because thats what they
happen to use) but dont buy into that.

We use 3 different types now with the best being the Spectrol, sealed,
conductive plastic type which are supposedly good for millions of cycles, so
far they have worked quite well but a PC gameport will probably always be
just that and not precision enough to make any apreciable difference.

Now we'll probably see about a dozen messages saying this is BS but we've
got well over 6 years experience and several thousand wheels in everyday use
to back my opinion.

Trev

by **Pickar** » Fri, 15 Oct 1999 04:00:00

you need a good gameport.

At the moment.. the best actually apears to be the MX300.. I've had
expereince of a few,

PDPI
SB LIVE
MX300
SB PRO

The MX300 is a true Digital game port and is fantastic.. gave me about
half a second a lap instantly!!!

But.. it isn't the steering that need the precision.. the most important
is the brake and then the accelerator.. they need th MOST precision
inputs possible..

The wheel is important.. but you will be steering with opposite lock..
steering in.. steering out.. so fast that it isn't as important to have a
huge resolution.

Just some thoughts

James Pickard

> Hi. I'm hoping some of you technical minded guys can provide some
> additional input on this subject. In a PC steering wheel a true
> precision potentiometer will likely give better and more precise
> signal input and resolution, but I have heard (just someone's casual
> opinion) that a pc game port is not sensitive enough (or "precision"
> enough, as it was put to me) to take advantage of high precision
> input. I believe that the Thomas' wheel uses a Spectrol bushing mount
> conductive plastic pot with Linearity of 2%. Would a ball bearing
> conductive plastic pot with Linearity of less than 0.5 (or better)
> yield even better results? or is there a limitation imposed by the
> sensitivity of a game port? Has anyone experimented with using very
> high (industrial/military grade) precision potientiometers in their
> wheel?

rec.autos.simulators

precision potentiometer use in steering wheels

precision potentiometer use in steering wheels

precision potentiometer use in steering wheels

precision potentiometer use in steering wheels

precision potentiometer use in steering wheels

precision potentiometer use in steering wheels

precision potentiometer use in steering wheels

precision potentiometer use in steering wheels