Linear Actuator vs Motor/Servo

bl3nd3r · 06-26-2006, 01:13 AM

I am wondering what would be a better idea for tilting a screen in a custom enclosure. If you check out this diagram it shows either a motor with a gear or a small linear actuator. (The pink thing is the screen)

From experience which would be more expensive? What would be the most reliable and have the best operation? Also what is the main difference between a servo and a regular motor?

Wiredwrx · 06-26-2006, 12:34 PM

Quote: Originally Posted by kmstech

I am wondering what would be a better idea for tilting a screen in a custom enclosure. If you check out this diagram it shows either a motor with a gear or a small linear actuator. (The pink thing is the screen)

From experience which would be more expensive? What would be the most reliable and have the best operation? Also what is the main difference between a servo and a regular motor?

Actuators are very expensive.

Servos and Steppers and DC motors are cheap in comparison. Steppers and Servos need some sort of control.

You should do some searching on this board, since this has been covered several times.

There is currently a double din enclosure being discussed.

Michael

slantman · 06-26-2006, 05:50 PM

you might find what your looking for here http://www.mpja.com/ they are very cheap

turbocad6 · 06-26-2006, 06:04 PM

dude, before you even figure out how to move what it is you want to move, you have to actually build it & build sliders, tracks..... you should be able to build it complete, then figure out the best way to add motorization..... whether you use a motor/gear or actuator doesn't matter at this point......

you've got enough ahead of you to figure all the rest out & get it working before thinking about adding motorization....

psyrex · 06-26-2006, 06:07 PM

Quote: Originally Posted by slantman

you might find what your looking for here http://www.mpja.com/ they are very cheap

I looked into the MPJA one when I was researching my motorized setup. It's very very slow. I don't have the calculations anymore, but I remember it was something like 5 seconds to fully deploy with the fastest servo controller I can find. Doesn't sound like much, but after running a few simulations, it was just too damn slow for me. I'd rather it deploy in 2 seconds or less.

edit: oh, by deploy i mean extend/retract 4.5 inches.

bl3nd3r · 06-26-2006, 08:39 PM

I am working on the CAD drawings right now for the actual enclosure and to build my first prototype.

Right now I have a couple phidget usb servo controllers on order and am wondering if they will be able to control motors if i decide against using servos.

Also what is the actual size of a double din frame? I have seen a few different measurements but most are saying 7in x 4in. However if you look here you will see that it says the dimensions are 7-1/8in x 4in.

0-0-7 · 06-26-2006, 09:09 PM

you might be able to use the CD drive mechanism from old drive. Its 5V dc so no stepper driver is required.

kiltjim · 06-27-2006, 01:01 PM

With a CD drive mechanicsm though, you are going to be limited by the original travel distance of the drive. They only have something like a 3" of travel. Unless you add your own mechanism.

They do sell linear servos though. They use them in planes, or sailboats I think. I know they exist, I have no idea how much they cost.

Maximus · 06-28-2006, 06:14 AM

My original plan, using flat wing servos and a USB servo controller.

bl3nd3r · 06-28-2006, 11:50 AM

Maximus I like your idea. I am building part of the box today and I get my USB servo controllers tommorow so I should be ready to test out different things over the next week or so. I will definitely keep you posted. Thanks for the drawing though

bl3nd3r · 06-28-2006, 07:27 PM

Maximus, did you get a chance to actually test out that idea? Also do the wing servos go under any other name? It seems like I can only find one company who sells them and was wondering if you knew of any really cheap versions.

The design seems to be a good idea as it is low profile and takes up little room (which will help when trying to fit everything else in.) I have built a cardboard template and am trying out a few drives including a cd-rom powered one (using the motor and gear).