What parts are needed?

[ccd2004]

First off I'd like to let you all know that I am a total newwwwwb, please forgive my lack of wisdom.

My project/robot is this.  I'd like to make a camera dolly motorized at variable speeds.  The dolly would be on some type of dolly track, weighing no more than 50lbs. and need to move slower than faster (no more than 5mph).
I'm thinking of having a cable attached to the dolly and at the other end, a take up spool connected to the motor and power supply, slowing reeling the dolly in.

My question is this, what type of dc motor, power supply and speed control can I use?  Is it that simple?  I start getting confused when I see the different ratings (amps, watts, volts etc.) on the PWM, Motor etc. and I don't want to fry anything.

I'm hoping I can power it using a 12 volt marine batter w/ 85amp Hours.

If any of you have any ideas I'd be grateful.

Thanks.

-cd

[gaurav.p]

is ur robot a RC robot or controlled through computer or is it autonomous one?

Regards,
Gaurav Parida

[ccd2004]

I don't really know how it would be controlled.

I'd like to be able to just turn a knob (potentiometer) and set the speed of it that way.  So I guess it'd be manual.

I just don't know what parts I need to hook up the motor so it can speed up and or down.

[gaurav.p]

i recomend u to make a pc controlled bot where u can use motor controllers to control the robot and in case of camera u can use the wireless digital cameras which may cost u around 50 $ in ebay .here is the link for camera-http://www.raidentech.com/miwispyca.html

this video may help u-[youtube]http://www.youtube.com/watch?v=X4stWDy-bPA[/youtube]
Regards,
Gaurav Parida

[AdvsNoob]

If you our completely new i suggest doing the 50$ robot!

Its pretty cool and teaches you how to get the hold on building robots!

you can also add a camera like you wanted on there!

SORRY FOR ALL THE "!!!!!"

[paulstreats]

The dolly would be on some type of dolly track, weighing no more than 50lbs. and need to move slower than faster (no more than 5mph).

I'd like to be able to just turn a knob (potentiometer) and set the speed of it that way.  So I guess it'd be manual.

so are you just wanting a scalextric with a camera on it?

[ccd2004]

Hi Paulstreats,

Forgive my ignorance but I don't know what a scalextric is.

My "robot" if you can even call it a "robot" would consist of a box, containing an electric motor w/ speed control and a wheel that can spool out or take up cable.

I have the dolly track (basically train tracks) and the dolly base w/ wheels (skate board type wheels) that fit on the track and it moves quite smoothly when pushed/pulled.  I'm trying to configure the dolly to move at various speeds (the slower the better).
I just don't know what type of Motor to get that would have enough torque to pull the dolly at a constant speed and I don't know what speed control (PWM) to match with it.

I hope this makes sense.

[madchimp]

any reason you want to use a winch type setup rather than just conventional drive?

[ccd2004]

Hi madchip,
I'm thinking of going the winch route b/c it's probably the easiest and most cost effective route for my wallet and bulding skill.

[Soeren]

Hi,

My project/robot is this.  I'd like to make a camera dolly motorized at variable speeds.  The dolly would be on some type of dolly track, weighing no more than 50lbs. and need to move slower than faster (no more than 5mph).

That's where people got you wrong, you didn't tell them what a dolly is.

If you do it with a wire, you have the advantage of less mechanical noise travelling to the mike(s) on the cam, but... You would have to deal with the wire on and on. I guess your mixer/producer will be able to filter out any kind of repetitive noise (if any should get on your lines) and personally I'd go with a dolly mounted motor and battery, controlled by the camera guy, but hey, lots of pros and cons either way, so it's a matter of personal taste.

I assume you allready use the tracks with a human powered "motor" now?
This person could tell you something about how hard it is to push, but if it's a real macho dolly (pun very much intended), or even a crane, perhaps it's a two+ person mover.

Talk to those that pushes it now and return with their answers (and perhaps if you know the weight of it), then you might get a more specific answer to sizing the motor power-vise.

Gee, the days when I was in TV broadcasting myself

[ccd2004]

Hi soren,

Thanks for the input.

Yes the dolly is man powered by 1 person and the weight of the dolly including the camera weigh 45lbs.
Any ideas?
Thanks.

[madchimp]

why not go with the motor and controller out of a used electric wheel chair? You would have the motors and control circuitry.

[ccd2004]

Hey Madchimp,
I would use the power chair but I think it could be cheaper if I found a used motor and then wired up the pwm and power supply.  I just don't know how big of motor and what kind of pwm.