how do you get the window to stop?

[RT]

usmc_butler
Yes, that is my build.  Thanks for your comments.
Check out my videos on youtube:

http://www.youtube.com/my_videos?feature=mhee

Especially view my recent "Replica Lambo walkaround".
I also have "how to" videos of many constructions.
Thanks again...

RT

[usmc_butler]

This is a very informative thread, RT great job on responses very detailed .


RT is that your Diablo in the pictures? Very nice, clean and detailed work


Dustin

[RT]

By placing the mechanical stops some place on the drive unit instead of the window or window frame, the load stresses will go directly to the drive unit and prevent stresses to the more breakable parts.  You don't need to put them where I did.  Look at your unit and find a convenient, strong location.
That also goes for the location of the switches except they will not have load stresses.
I have used www.mcmaster.com for almost everything, including limit switches.  Recently I needed switches immediately and found the local electrical supply store (the one that sells wiring supplies to electricians and lighting fixtures, etc.) had boxes of them on the shelf AND they were cheaper.  So look locally and you could see what you have before you buy and you could save some cash.
You are looking for snap action switches. You need SPDT (Single Pole Double Throw).  That has three terminals to connect the wires.  One is the common, one is normally closed, and one is normally open.  There will be designations molded into the switch housing.
The switches in the picture are Mcmaster number 7783K-13.
I have also used Subminiature number 7658K-16.  These are a lot smaller but require creative mounting and you will solder the wires on.
So there you are.  Get power window switches and wire them up!

RT

[notnilc20]

Thanks RT,

Those pics are very helpful (especially the way you mounted the  bolt for the mechanical stoppage).

RT, where did you get your switches for the windows?  Can you point me in the right direction?  I'm not too bright when it comes to electric work and all these switches are making my head hurt.  Please help me.  Thanks a mil.

[RT]

Yes, the limit switch connects that wire (to the motor) to ground so the motor can only be run in the other direction. DC motors reverse by changing the direction of the electric flow.  As soon as the window moves away from tripping the limit switch the switch re-connects to the power window switch.  It happens seamlessly.
Power window switches can provide the proper current flow from the switch.  If you don't want the full current passing through the window switch you can make the switch trip relays, one for each direction.  In that case, the motor wire connects to the relay common the NO goes to a 12 vdc supply and the NC goes to ground.  The window switch will pass power to the relay tripper with the other tripper wire going to ground.  The tripped relay sends power to the motor and un-tripped connects the motor to ground.
Check out these pictures.  They are just one way to go.
http://www.flickr.com/photos/49982981@N00/347113482/#in/photostream
http://www.flickr.com/photos/49982981@N00/347119987/#in/photostream/
http://www.flickr.com/photos/49982981@N00/347119990/#in/photostream/

RT

[notnilc20]

Thanks guys.... Is the reason that it switches to a ground is so you can then have power to move the window the opposite way?? 

I was planning on doing this but I guess I need a switch that will switch to another source once it's tripped instead of the one I have where it just switches off.  Where do you get your switches from?  Would like to find some that are spring loaded internally so they are only switched while the pressure is on them and then they switch back as soon as you remove pressure from the switch arm so that way I can avoid having to mount springs somewhere in this already cramped space.  Thanks.

Also, can you tell me some good ways for mechanical stopping?  Will doing mechanical stopping only be hard on the motor?  Is this the way the factory window motors are done?   

One more thing.  Some pics of your application would do wonders for me.  (Mounting, how did you get the switch to trip? etc etc )  I know, it's a lot of questions, but I appreciate it.  Thank you!!

[RT]

Thanks for posting that diagram, Jim.  You beat me to it!  LOL
I use that limit switch system for every motor drive.  I even had a door lock/unlock motor burn up because they can't take too much power while at the end of travel.  The wiring is too simple to not use.  Figuring the where and how of mounting the switches is the hardest (?) part but worth the effort.  Just make sure they are secure and won't move so the window (or other device) will always stop where you expect.

RT

BTW, I also use mechanical stops too, just in case.

[jdinner]

There are two ways.
1) study the mechanism to see what moves and weld on a tab somewhere so a long bolt will act as a stopper. The bolt can be adjusted in length to fine tune the stop point.
2) install micro-switches that cut off the circuit when it gets to a certain point.
Image stolen from RT.

[notnilc20]

Hi there,

For those that have built their doors with working power windows.  How do you get it to stop at the top when the window is closed and at the bottom when opening, so the window doesn't go all the way down? 

since the window is too big for the door you can only "roll" it down part way (about halfway).  How can you stop the motor at this precise point so you don't accidentally roll down too far?  Also, the same when going up.

Thanks