Are you asking how much physical load the plastic base can carry before it breaks or how much load the stock motors can pull?
Both questions will depend on the use. You can spread the load over a wider area and it will be able to withstand greater force. It's basic physics. A larger surface area will spread the load where as a smaller surface area will concentrate the load. Think about a nail and a nut, hit a nail with a hammer in to a piece of wood and because the CSA where it meets the wood is smaller the force is concentrated there and it will go in to the wood. Try it with a nut with a larger CSA where it joins the wood, it will take much greater force for it to go in. Or, stand on a fragile roof, you will fall through, lie on it spreading your weight and you may not.
If on the other hand you are asking about the motors, again this will depend on the voltage used. The voltage used will vary the torque which will effect how large a load it can move.
Why do you need to know? What are you planning to do?
I have a plan to make a robotic trash can and so I was trying to find a platform I can use to move it around. the omnibot base looks around the right size for the trash can im looking at. some trash will be heavy so im trying to find out the max weight the omnibot motors can carry at regular voltage.
In which case, I would first offer a few suggestions;
The RAD base is both cheaper and easier to work with. Removing the body from the base gives a nice rover platform for very little money and the motors are very strong in them. An Omni 5042 is still pretty expensive with prices going up and availability coming down, RADs on the other hand are plentiful and cheap.
Whichever way you go you will want something smaller and better than a SLA battery, a LiPo or NiMh pack will fit nicely in either base without raising it up too high.
Both bases should be capable of transporting a small to medium sized waste bin but it depends on what waste goes in the bin. Paper, food wrappers etc. wouldn't get too heavy. Old batteries, food waste etc can get heavy.
If you are doing a trash car robot, I'll suggest saving the Omnibot for something else, since they are rare and expensive. A trash can robotic base, is really straightforward. It depend more on the motor that you will be using, and the torque that it provide. A set of wheelchair motors, set of windshield wiper motors, or a set of 12v motors, to be more specific a set of 12v brushed DC motors. ( Click me )
Torque (T) is defined as a turning or twisting "force" and is calculated using the following relation: T = F * L
The force (F) acts at a length (L) from a pivot point. In a vertical plane, the force acting on an object (causing it to fall) is the acceleration due to gravity (g = 9.81m/s2) multiplied by its mass: F = M * G
The force above is also considered the object's weight (W). W = M * g
The torque required to hold a mass at a given distance from a pivot is therefore: T = (m*g)
The weight of the object (the "load") being held , multiplied by the distance between its center of mass and the pivot gives the torque required at the pivot. The tool takes into consideration that the links may have a significant weight (W1, W2..) and assumes its center of mass is located at roughly the center of its length. The torques caused by these different masses must be added.
But it's moving a mass not holding a mass. And once moving the torque required to continue moving it is only determined by what is opposing it - a body in motion will remain in motion... :D
You could just attach the motors/wheels directly to the bottom of the bin, fit a false bottom inside which covers the battery and EZ-B and voila. Would be cheap, easy and require only a couple of motors, a couple of casters and something to make a false bottom out of. Reinforce the actual bottom with wood or metal to improve it's stability.
Or I could mount high torque servos under it and do the false bottom thing you just suggested rich. Although with the high torque I want some speed.
Does anyone know a brand of continuous rotation servo that has high torque and is pretty fast? Not crazy fast but faster than the continuous rotation servo in the shop.
Anyone? really? No one knows?
I doubt anyone has attempted to find out.
Are you asking how much physical load the plastic base can carry before it breaks or how much load the stock motors can pull?
Both questions will depend on the use. You can spread the load over a wider area and it will be able to withstand greater force. It's basic physics. A larger surface area will spread the load where as a smaller surface area will concentrate the load. Think about a nail and a nut, hit a nail with a hammer in to a piece of wood and because the CSA where it meets the wood is smaller the force is concentrated there and it will go in to the wood. Try it with a nut with a larger CSA where it joins the wood, it will take much greater force for it to go in. Or, stand on a fragile roof, you will fall through, lie on it spreading your weight and you may not.
If on the other hand you are asking about the motors, again this will depend on the voltage used. The voltage used will vary the torque which will effect how large a load it can move.
Why do you need to know? What are you planning to do?
I have a plan to make a robotic trash can and so I was trying to find a platform I can use to move it around. the omnibot base looks around the right size for the trash can im looking at. some trash will be heavy so im trying to find out the max weight the omnibot motors can carry at regular voltage.
In which case, I would first offer a few suggestions;
The RAD base is both cheaper and easier to work with. Removing the body from the base gives a nice rover platform for very little money and the motors are very strong in them. An Omni 5042 is still pretty expensive with prices going up and availability coming down, RADs on the other hand are plentiful and cheap.
Whichever way you go you will want something smaller and better than a SLA battery, a LiPo or NiMh pack will fit nicely in either base without raising it up too high.
Both bases should be capable of transporting a small to medium sized waste bin but it depends on what waste goes in the bin. Paper, food wrappers etc. wouldn't get too heavy. Old batteries, food waste etc can get heavy.
If you are doing a trash car robot, I'll suggest saving the Omnibot for something else, since they are rare and expensive. A trash can robotic base, is really straightforward. It depend more on the motor that you will be using, and the torque that it provide. A set of wheelchair motors, set of windshield wiper motors, or a set of 12v motors, to be more specific a set of 12v brushed DC motors. ( Click me )
Torque (T) is defined as a turning or twisting "force" and is calculated using the following relation: T = F * L
The force (F) acts at a length (L) from a pivot point. In a vertical plane, the force acting on an object (causing it to fall) is the acceleration due to gravity (g = 9.81m/s2) multiplied by its mass: F = M * G
The force above is also considered the object's weight (W). W = M * g
The torque required to hold a mass at a given distance from a pivot is therefore: T = (m*g)
The weight of the object (the "load") being held , multiplied by the distance between its center of mass and the pivot gives the torque required at the pivot. The tool takes into consideration that the links may have a significant weight (W1, W2..) and assumes its center of mass is located at roughly the center of its length. The torques caused by these different masses must be added.
If need more help , simply ask :D
But it's moving a mass not holding a mass. And once moving the torque required to continue moving it is only determined by what is opposing it - a body in motion will remain in motion... :D
You could just attach the motors/wheels directly to the bottom of the bin, fit a false bottom inside which covers the battery and EZ-B and voila. Would be cheap, easy and require only a couple of motors, a couple of casters and something to make a false bottom out of. Reinforce the actual bottom with wood or metal to improve it's stability.
Or I could mount high torque servos under it and do the false bottom thing you just suggested rich. Although with the high torque I want some speed. Does anyone know a brand of continuous rotation servo that has high torque and is pretty fast? Not crazy fast but faster than the continuous rotation servo in the shop.
12v brushed DC motors should do the trick, powerful enough to carry wait, high on torque, price are reasonables.
I agree, use motors and a H-Bridge over servos. Servos don't have the speed and probably would cost more.
ok. thanks. ill look into it.