catfish

Hello all. I'll start by telling what I want to do. I want to have a 10" monitor slide out of the dash then flip up. I have searched for several different methods for motion and I think that a gear and rack setup will be the best route for me to go. I'm not sure from this point on...lol.

I assume that I will need at least two motors depending on torque and things of that nature. I have found a "stamp" that will control two motors but, I have no clue what a stamp is, how it works, and how to make it do what I want it to do. As far as activating this setup, the possabilities are endless. I'm pretty sure that once I have a good understanding of how to control the motors I will be able to figure out how to activate it, switch wize.

If it helps i have a general knowleadge of relays.

The screen will have to travel between 6-8 inches out then, at the very least, rotate 90 degrees up. It would be really nice for the screen open to 90 then have adjustable angles up and down from there. That should help with veiwing and glare. (I think stepper motor for this but once again unsure)

PS. Sorry for the misspelled words :roll: and don't worry, I will not be watching the screen while driving. The screen is strickly for shows and for entertainment while waiting for the judges to come around.

Thank you in advance for all help!!

kinjalgp

Steeper motors will best suite your purpose because you can very very accurately control its shaft position and they are also high-torque motors. Look for stepper motor control schematics on google. For STAMP try: www.parallaxinc.com

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catfish

Do stepper motors just turn the specified degree then stop or do they make a constant motion for a specified number of revolutions? Is a "stamp" what I need to conrol the motors? I really just don't know where to start. Please give some direction, something along the lines of " Hey dummy, this is what you need!" :P Thanx

kinjalgp

In brief, Stepper motors rotate in discrete steps normally of 1.8 degree (smaller are also available). To turn it to 90 degrees you have to make 90/1.8 = 50 excitation sequences of the stepper coils. Each circular excitation sequence of the coild will turn its shaft to 1.8 degree.
For driving this motor you can use any type of microcontroller but since you are a newbie, I think Basic Stamp would be easiest for you to learn. There are 100's of free tools and tutorials available on net. Just try google once for "Basic Stamp Stepper Schematic" and "stepper motor tutorial"
See this:
http://stage.itp.nyu.edu/~tigoe/pcom...stepperBX.html
http://www.seattlerobotics.org/encod.../steppers.html

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catfish

Kinjalgp thank you!! Excelent explination of steper motor. Also, kudos on the links! One more question... . In order to make the motor turn several degrees I would have to energize the coils several times, will this movement of the motor be "smooth" or will it be very jerky? Is this something that is specific to the motors or the controls? Thanks for all help. [/img]

kinjalgp

The movement of shaft is fairy smooth. It is even used in scanners for moving the scanning sensor bar which requires very precise and smooth movement.
There specificcations you require when you go to buy stepper motors are:
1) Starting Torque (imp. for lifitng the load)
2) Holding Torque (Shaft Torque when motor is not running. It will hold your load in position even without locking gears)
3) Step Angle (ex. 1.8 degree)
4) Operating Voltage (Doesn't matter much)

For Controller
1) It should be able to handle current and voltage that motor requires.

I think for your application, a 2 kg/m torque stepper motor will be ok with ULN2003 darlington transistor driver as shown in the web pages given above. You can use high-torque if weight of your load is higher.

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catfish

Kinjalgp, what can I say? You tha man! Thanks for the info. This will give me a really good start on the project. Also, mucho thanx for the tips on what to look for in motor and controler. I'll let you know how it turns out.

fish