PF Switch - recommended uses?

[SteveNesta]

Along with all the motors and lights and IR units and controllers recently purchased, I also have a PF switch.

As some of you have read, my current (and first ever) MOC is a large tank with as many functions as I can think of.

I'm struggling to find a use for the Switch. Can anyone give examples of where they have built or seen the PF switch out to good use and where I might find a use in a tank and its various mechanisms?

Cheers. :-)

Edited May 10, 2013 by SteveNesta

[Zerobricks]

A pneumatic pump regulator

[Doc_Brown]

I'm using one in my latest Moc, where I have 2 motors on the same channel but I need one of those motors to run opposite direction to the other.

[fresko]

To switch PF-lights on. Normal lights (example headlights), flashing lights or traffic lights.

Greets,

Fresko

Edited May 10, 2013 by fresko

[SteveNesta]

So how would I install it into the MOC to be able to make use of it remotely? I understand how I can do things by moving the switch by hand, but I don't understand why and how I would get a motor or mechanism to move the switch.

1. Regulating a pneumatic pump.

- I think I understand why, but how would this work?

2. Opposite motor direction where multiple motors share the same power line.

I get this, but that is just a 'change once' and leave it alone function.

3. Flashing lights

I get this, but not sure how to implement it.

Would you be able to share the why's and how's?

Any other useful uses for this little device?

Thanks :-)

[Doc_Brown]

I will take a pic tmr, showing how I use the switch for 2 motors, but apart from that I don't know any more tricks.

I'm curious about flashing lights too.

Edit: I think if you use it to control a servo, the servo will only go one way. Not sure if that is that useful or not.

Edited May 10, 2013 by Doc_Brown

[Alasdair Ryan]

In my latest moc I am using it for a servo/switch device.

Edited May 10, 2013 by Alasdair Ryan

[fresko]

1. Regulating a pneumatic pump.

- I think I understand why, but how would this work?

Here you go:

and:

3. Flashing lights

I get this, but not sure how to implement it.

Hope you understand it...

Greets,

Fresko

[SteveNesta]

Fantastic help with the photos. It's beginning to make sense now. Slowly lol.

Thank you so much :-)

Edited to add I have one servo motor at present. So ideas for uses would be great :)

Edited May 10, 2013 by SteveNesta

[Doc_Brown]

Thanks too for flashing light photos! I wanna make that too.

[Splat]

Sariel has a 'Automated Trafficator System (2)' that he developed that uses three switches to create a set of flashing turning/indicator lights: http://sariel.pl/201...ators-system-2/

To explain the pneumatic pump regulator: the idea is that you have a motor that is spinning and moving a pneumatic pump which pressurizes a pneumatic system. Once enough pressure has built up, the pump will have a hard time putting any more air into the system, so you have a pneumatic cylinder that then switches off an electrical switch, which turns off the motor. Once the pressure in the pneumatic system drops, the cylinder will retract (thanks to a rubber band or spring), and this will turn the electric switch back on again, which will turn the motor on again, which activates the pneumatic pump and the system re-pressurizes again. The rubber band can be 'tuned' to turn the switch on/off at certain pressures. This allows you to have a replenishing air supply, but not burn out the motor trying to over-pressurize the system.

Edited May 11, 2013 by Splat

[Doc_Brown]

Here is a pic of what I made using the switch.

Then if you had a system to turn the switch from center to down, you would control the gearbox from high gear to low gear.

I'm using this at the moment in my Moc.

Hope that helps!

[750ACE]

Here is a pic of what I made using the switch.

Then if you had a system to turn the switch from center to down, you would control the gearbox from high gear to low gear.

I'm using this at the moment in my Moc.

Hope that helps!

I do not see how that is high or low gear. If one motor is idle and the other one is spinning the idle motor is actually causing strain on the spinning motor. When both are coupled and running the same rpm you are not in any sort of higher gear you are only adding torque.

[Doc_Brown]

I do not see how that is high or low gear. If one motor is idle and the other one is spinning the idle motor is actually causing strain on the spinning motor. When both are coupled and running the same rpm you are not in any sort of higher gear you are only adding torque.

Thanks for your comment. When one motor is idle the other spins around it in the diff causing a 2:1 reduction. Under high load the still motor will actually spin backwards, which actually saves gears crunching!

Not really the best for Off-roaders but for instant change in speed its works.

[Splat]

I do not see how that is high or low gear.

1. If both motors are spinning the same way, then their rotation cancels each other out, and the output (red 1x2 thin liftarm in the pic above) does not rotate (assuming both motors are spinning at the same speed).
   
2. If one motor is spinning and the other is turned off (with the switch in the centre position), then the differential casing will spin, but at half the the speed of the motor that is spinning. Then there is a slight increase in speed between the 28 teeth on the differential casing and the 20 tooth bevel gear.
   
3. If both motors are spinning, but in opposite directions (one spinning clockwise, and the other spinning anti-clockwise, which is possible via the use of the switch which can reverse polarity), then both motors will spin the differential casing, and the casing will spin at the average speed of both of the motors.
   

Having one motor connected to a switch allows you to control the speed of the output between stopped (not much good), low speed, or high speed.

When one motor is stopped (situation number 2 above), that means that you only have one motor providing torque to the system. So while the speed is halved, you aren't doubling the torque at the same time. Therefore it is a low speed gear, but not a high torque gear.

Whether or not one of the motors tries to back-drive the other motor really depends on the resistance that you have on the output of the differential (red 1x2 thin liftarm).

If you want more 'gears' using a similar setup, you can have one side with the motor connected directly to the differential, and the other motor geared up or down a bit (eg, 24:8). This can give you the following gears:

Differential side 1 @  300rpm, Differential side 2 @  100rpm, Output at  200rpm.
Differential side 1 @  300rpm, Differential side 2 @   0 rpm, Output at  150rpm.
Differential side 1 @  300rpm, Differential side 2 @ -100rpm, Output at  100rpm.
Differential side 1 @     0rpm, Differential side 2 @  100rpm, Output at   50rpm.
Differential side 1 @     0rpm, Differential side 2 @   0 rpm, Output at       0rpm.
Differential side 1 @     0rpm, Differential side 2 @ -100rpm, Output at  -50rpm.
Differential side 1 @ -300rpm, Differential side 2 @  100rpm, Output at -100rpm.
Differential side 1 @ -300rpm, Differential side 2 @   0 rpm, Output at -150rpm.
Differential side 1 @ -300rpm, Differential side 2 @ -100rpm, Output at -200rpm.