First Robot

[Random]

Hi Everyone,
I am building a robot and using 2x of thesehttp://www.servoshop.co.uk/index.php...S04&area=Servo servos or mabye one of these[uhttp://www.active-robots.com/products/motorsandwheels/torxis.shtmlrl][/url]. It will be a feather wieght and I have a prototype that is basically a half cylinder 34cm wide x 30cm long.I will be using the ARGOS £10 12v motors. Should I go for higher? What do you think?
Ben

[Random]

Re: First Robot

Oh forgot to add that the servos are for a lifting arm.

[psycho_fling]

Re: First Robot

i presume you mean your using servos for the lifter control not to power the lifter?

yeh those drills will be fine

[daliad100]

Re: First Robot

You won't be able won't get a good lifter from the cheaper servos as a good rule of thumb is about twice as much torque than is required to hold the other robot stationary. To have enough force left you would need a very short lifting arm meaning that you can't lift things very high and probably cant self right with it.

The other £240 servos will definitely have enough torque but I don't think you will want to have to buy another one after having it broken. I would suggest using really cheap servo board to make a giant servo with some relays like Mart (aka Rallikas) did for his RC car http://www.fightingrobots.co.uk/foru...p?f=240&t=3382.

[Random]

Re: First Robot

How much torque is required to hold the other robot stationary?
I'm confused

[Random]

Re: First Robot

Shall I get some pics? there should be some posted tonight.

[rallikas]

Re: First Robot

My servo system is a lot cheaper and faster than that 200£ servo!

[daliad100]

Re: First Robot

Torque is a measure of turning force given by multiplying force by perpendicular distance hence a longer lifting arm means more torque is required.

A featherweight weighs 13.6kg so on a 15cm arm needs approximately 2kgm of torque to hold all of the mass of the other robot in the air, you don't necessarily need that much torque as you are unlikely to be carrying all of the weight of the other robot.

[Random]

Re: First Robot

What is kgm? Sorry I can't understand!

[Bodge Job]

Re: First Robot

a kgm is a kg meter so if a motor has 2kgm it means it can lift a 2kg weight on a one meter rod

[Random]

Re: First Robot

Hi
After watching rallikas's video, I have some doubt if I can actually make that, as I am not very skilled in that sort of thing. Any other option

[psycho_fling]

Re: First Robot

if you want to make a lifter you can make it using some threaded rod a motor, bearings and some arms to lifter another robot with

[daliad100]

Re: First Robot

If you don't need it to have feedback like an ordinary servo so it keeps turning until you centre the stick, then you can replace the potentiometer with a pair of resistors or just apply power to the circuit and tweak it until the motor stops and glue it.

[rallikas]

Re: First Robot

Actually that system is quite simple. Maybe i have to do a build video? :P

[Random]

Re: First Robot

Yes, That would be most helpful. I, am not very good at stuff DIY. By the way, What was that thing atached to the motor?