Step motor resetting

[Claude]

Before winter i tries to fix one of my mixing temperature step motor support (passenger side), the plastic support is broken and the step motor operate freely but it can't open and close the air mixing flap that way.

I found out very helping solutions / hints on the forum historic messages to repair the support, but i wonder if there is a resetting procedure for the step motor.

In other words, having operate freely up to now will the set motor find out is natural open and close positions itself after reinstallation in a new sturdy support or will i have to force it in some particular start up position ?

[pingu]

There should be no need to reset the stepper motor - stepper motors can't sense their position.

As for how the stepper motor finds it position, there might be a sensor such as a microswitch. But it's more likely that the stepper motor finds it position by being (deliberately) driven an end stop. For example, if there are 100 steps between the two extremes of the stepper motor's travel, moving the stepper motor 100 steps in one direction is guaranteed to hit an end stop, no matter what position it started in. Once the motor has hit the end stop, the controller knows where the stepper motor is.

[taseal]

whats a step motor?

[Rus]

whats a step motor?

Here's an explanation: http://en.wikipedia.org/wiki/Stepper_motor

[Claude]

There should be no need to reset the stepper motor - stepper motors can't sense their position.

As for how the stepper motor finds it position, there might be a sensor such as a microswitch. But it's more likely that the stepper motor finds it position by being (deliberately) driven an end stop. For example, if there are 100 steps between the two extremes of the stepper motor's travel, moving the stepper motor 100 steps in one direction is guaranteed to hit an end stop, no matter what position it started in. Once the motor has hit the end stop, the controller knows where the stepper motor is.

Thanks for reply. In this particular case ( stepper motor #3 on the following pictures : http://bmwe32.masscom.net/johan/ihka/ihka.html ) there is no micro switch that monitor or detect the position of the step motor so as you say it seems to run until it encounters a certain mecanical resistance (ex: until the flap that it control is completely close or open). Perhaps this step motor support's or fixture's had some sort of STOP build in it before it broke (i partially did rebuild it without making such a STOP... because did'nt know where to do it if it must have one).

The torque of those stepper motor is rather high, enough in fact to break it's support over time.

So i am still in doubt, the motor now have a sturdy fixture but is it OK to count on the flap that it control to limit the extreme positions the motor could reachs ? Installed without a STOP build in the motor fixture, could the motor break some part of the flap for exemple ?

[pingu]

I guess something could break - maybe someone else can help, although if the flap didn't break last time, I don't see why it should this time.

[BimmerMeUp]

...
I found out very helping solutions / hints on the forum historic messages to repair the support, but i wonder if there is a resetting procedure for the step motor.
I have a broken support as well and was looking for repairs others have done. Could you tell me where you found it or what keywords you used. Thanks

[Claude]

I have a broken support as well and was looking for repairs others have done. Could you tell me where you found it or what keywords you used. Thanks

Here are the two main links that help me the most
http://bmwe32.masscom.net/johan/ihka/ihka.html
http://www.bimmerboard.com/forums/posts/200205/
the first one is not an exact representation of my car system (i have an E34-535 and it show an E32) but is very close and it help to locate the different stepper motor. The second one ginve you some hint as how to remake your step motor support. Bye

[Claude]

Before winter i tries to fix one of my mixing temperature step motor support (passenger side), the plastic support is broken and the step motor operate freely but it can't open and close the air mixing flap that way.

I found out very helping solutions / hints on the forum historic messages to repair the support, but i wonder if there is a resetting procedure for the step motor.

In other words, having operate freely up to now will the set motor find out is natural open and close positions itself after reinstallation in a new sturdy support or will i have to force it in some particular start up position ?

Fresh air stepper motor.... That's in fact another question of mine, having open both side of the consol (under dash section) driver and passenger side i did give a look to all the step motor of the ventilation system and check each one (it's support state, if it open and close related flap properly, what control activate what step motor).

On my car i have 5 of those step motors, i've been able to check each one but the "fresh air" one, it's support is fine but i can't see what control or conditions activate this one. Does some boddy knows the answer ? How could i check if that one operate properly ?

[Claude]

Before winter i tries to fix one of my mixing temperature step motor support (passenger side), the plastic support is broken and the step motor operate freely but it can't open and close the air mixing flap that way.

I found out very helping solutions / hints on the forum historic messages to repair the support, but i wonder if there is a resetting procedure for the step motor.

In other words, having operate freely up to now will the set motor find out is natural open and close positions itself after reinstallation in a new sturdy support or will i have to force it in some particular start up position ?

An update on this one: I finally found out that when the "air Recirculation" button is press it activate at the same time both the "air recirculation" step motor (it opens a flap under the dash) and the "Fresh air" step motor (it probably close the fresh air flap - i did saw the motor operate but can't see the flap that it control inside the HVAC box).

I still have a question about the "fresh air" step motor or flap, beside the "air recirculation" condition where the fresh air flap is probably completly close (we don't want any outside air to get inside of the car) does the fresh air flap have only one other position (completely open) or could it take different positions ? If it could take different positions (let fresh air come inside the car in different quantity / volume) what exactly tell the electronic control that drive the fresh air step motor how much it must open the flap ?