Device to rotate flashlight? Like PTZ

[alexus]

Hey all!
I want to build some sort of PTZ device that I can use to rotate reflector in the car headlights (assuming reflector is reasonably small, like flash light size) I probably need no more then 90 degree pan & tilt maybe even less then that. I could use brackets and mount them on servos like in case of PTZ camera but that not going to hold position firmly when i drive so i thought to use spiral type of sprocket... there is only one problem, i have no idea where to get parts and how to mount them ... well i'm not good with mechanics at all ... so maybe some one can help me out? Thank you!

[nickc]

http://www.trossenrobotics.com/c/robot-turrets.aspx

here's some pan-tilt turrets. 

[alexus]

i have thousem but is power is not suplied it will loose position and if i dont have high torque then it shales a bit i need some sprokets to have fixation of the position

[nickc]

I didn't understand some of the words in that sentence but I think you mean you want something that can hold position without power.  Worm drive motors can't be back-driven so they would work. Or motors with brakes on the shaft that require power to release the brake would work.
Rotating just the reflector in a car head light would be tricky as you would have to keep the position of the bulb relative to the reflector constant or you would lose (not loose) focus.  This implies that the center of rotation for the reflector would have to in front of the reflector.  Mounting the reflector in gimbals and using small linear actuators to move it might work.
An easier solution would be to use a self contained light like an after-market fog light or off road light mounted on a pedestal and manipulate the whole thing.

[alexus]

where can i get those motors?

I thought to put reflector on flat object with  center under the lamp and use same "arm" as i use in RC plain to control torque. this weill give me rotation  (pan) but for tilt its harder....

brackets on tossen also take lots of space that I don't have

[nickc]

IF you took that whole mechanism and then mounted it inside another ring for tilt you would have a gimbal mount.

[alexus]

http://en.wikipedia.org/wiki/Gimbal
is that what you are talking about?

I guess that some what, what i need.... but it still leaves me with question of locking the reflector in place and especially for tilting

[nickc]

I don't know of another system that can give you rotation about orthogonal axes about a common center. I would suggest looking at some books on classic mechanical systems. Used low level engineering textbooks would be a cheap way to go.
Not sure why you have to lock rotation. Just keep the servos powered or store the location at power down.

[alexus]

is there online tutorials?
i think the spiral type of sprocket will not rotate by itself. it is used in car power mirrors system which is essentially pan and tilt table ... i just dont know where i cam get sprockets and how to much them together

[walkercreations]

It may seem over simplified but I would think you could make a pan and tilt head like you are talking about out of an aluminum U bracket and two servos. One for the tilt and the other for pan. There are numerous ways of controlling it depending on your needs. Depending on size you could make something small using Lego gears.

[alexus]

u brackets are the same thing as shown in the lin in previous post
http://www.trossenrobotics.com/c/robot-turrets.aspx



this one even better then U bracket but still leaves me w/ the problem of not holding well when there is no power, +  construction is some what flimzu so on bumpy road light beam will jump like crazy

http://www.sector5labs.com/Product.aspx/smt-pt

[walkercreations]

Yes, those are U brackets. A high quality servo will hold its position until moved otherwise but as I mentioned before, you could probably find some type of gears if that is what you really wanted to go with.

[Soeren]

Hi,

this one even better then U bracket but still leaves me w/ the problem of not holding well when there is no power, +  construction is some what flimzu so on bumpy road light beam will jump like crazy

You actually want to install this in your cars head lamps?
It will be highly illegal, will ruin the lamps completely and give you much less light to move around.

Insanity aside... If you really want to move your light around, a much better solution would be to move the lamp (bulb) around within the housing. This would take only small movements, directly up, down, left and right, to cast the beam at different angles.

However you do it, make sure it's sealed against moisture, or the mirror finish of the parabolic reflector will be ruined in a short time.

[alexus]

my carhas too many illegal devices already

I'm actually leaning toward projector lamp rather then reflector one so moving lamp inside does not change the palay that much... I can try to do that on high though, but then small shaking of the lamp will do even more distortion of the beam...

by the way im using led light source so i dont care about heat and i have less problems with focopoint

[nickc]

If you are moving your headlights, you only need a few degrees of movement.  My car automatically levels the lights and moves with corners and it's only a few degrees of movement either way.  The worm drive motors I suggested are the type used in side view mirrors.  Stripping them off a car in a junk yard would be the easiest and cheapest way to get them. 
Just be sure to let everyone know where and when you are testing so we can be sure to stay off the road that night.

[alexus]

I need junk yard now