[simpits-tech] phidgits + Building Gauges

[Marv De Beque]

Servos are very fast.  At least in the gauges I make.  I would estimate I
can make a 360 rotation in about 1/4 second.

Additionally, there are optical encoders that have a 360 degree span and at
least a 1 degree resolution.  Adding additional encoders can expand that
resolution.  This would allow the use of DC motors to make very rapid
changes in rotation and to very precise positions.
-- 


> From: "Rod Dale" <rodd@castle.net.au>
> Reply-To: simpits-tech@simpits.org
> Date: Mon, 28 Oct 2002 14:56:11 -0800
> To: <simpits-tech@simpits.org>
> Subject: Re: [simpits-tech] phidgits + Building Gauges
> 
> No problem with the servos. These are used to drive needles that require less
> than 360 degrees travel. Most aircraft gauges like this , ie airspeed ind &
> RPM etc don't need to travel as fast as the altimeter. So servos work well in
> that situation.
> Rod
> ----- Original Message -----
> From: Joseph Daigle
> To: simpits-tech@simpits.org
> Sent: Sunday, October 27, 2002 11:14 AM
> Subject: Re: [simpits-tech] phidgits + Building Gauges
> 
> 
> I would guess the stepper motor would be slow to catch up, but how responsive
> were the servos?
> 
> Joseph Daigle
> 
> 
> <original>
> From: "Rod Dale" <rodd@castle.net.au>
> To: <simpits-tech@simpits.org>
> Subject: Re: [simpits-tech] phidgits + Building Gauges
> Date: Sun, 27 Oct 2002 21:16:37 -0800
> Reply-To: simpits-tech@simpits.org
> 
>> Yes, that's John Dunkley at http://www.senet.com.au/~dunkleyj/menu.htm
>> It's his setup that I tried. As I said it works well except for the speed of
>> the altimeter.
>> Rod
> 
> ----- Original Message -----
> From: Ben Jones <bjones@pipecomp.com.au>
> To: <simpits-tech@simpits.org>
> Sent: Saturday, October 26, 2002 6:34 PM
> Subject: RE: [simpits-tech] phidgits + Building Gauges
> 
> 
>> rod ,
>> there has been a aussie who is making a 747 sim or something in australia
> out of a ford car shell,
>> 
>> i cant think of the site at the moment i'll have to look for it, but they
> used a standard radio controlled servo running of a basic stamp board, with
> a PI hanging off the shaft to report a zero point , aparently it works well.
>> 
>> 
>> BEN   JONES
>> -----------------------------------------
>> bjones@pipecomp.com.au
>> ------------------------------------------------
>> 
>> 
>> -----Original Message-----
>> From: Rod Dale [mailto:rodd@castle.net.au]
>> Sent: Saturday, 26 October 2002 11:35 PM
>> To: simpits-tech@simpits.org
>> Subject: Re: [simpits-tech] phidgits + Building Gauges
>> 
>> 
>> There's a small electronic device called a Photo Interrupter (PI) that
> could
>> be used. This consists of an IR LED (Infra Red) on one side and a
>> photo-transistor on the other. These are used in printers to indicate
> where
>> the carriage is. All you need to do is put a small piece of plastic on the
>> shaft of the stepper motor and each time this plastic piece passes between
>> the two parts of the PI it cuts the IR to the transistor and signals the
>> controller (PC, Basic Stamp, Phidgit etc) that the motor has turned one
>> revolution. If you could set up a counting program then you keep track of
>> the revolutions and hence the start point and any number of other points
>> too.
>> I got hold of a heap of old printers and stripped them of these devices
> and
>> the stepper motors - ready for this sort of thing.
>> Can anyone add to this theory ?
>> Rod
>