5 votes

How has the Mars Exploration Rover (MER) has been working for 11 years if it was designed for 90 Sol?

There are 2 main reasons why the MER is still operating long after it's 90 Sol planned lifetime. The first is political, strategic, and can be summarized as 'Under promise, over deliver'. When a PI (...
hauptmech's user avatar
  • 4,435
4 votes

Name of the linkage (or carriage) in video

The video shows 2 linear actuators driving a universal joint through ball and socket joints.
Ben's user avatar
  • 5,855
3 votes
Accepted

Robot mechanism parts names

This is called a Stewart platform. You can use any linear actuator type, hydraulic, pneumatic or electric.
drerD's user avatar
  • 501
3 votes
Accepted

High power jumping mechanism in small robots

Looks like it uses a propane powered ram to launch itself into the air. The end of the piston is visible in the back of the vehicle. This webpage states that source of power is battery and propane ...
jsotola's user avatar
  • 548
3 votes
Accepted

What's the name of a robot manipulator construction with multiple thin arms joined together?

They are parallel manipulators. You may find chapters on parallel manipulators in robotics textbooks, for example, A Mathematical Introduction to Robotic Manipulation, useful. There are also a number ...
Petch Puttichai's user avatar
3 votes
Accepted

Different methods to determine DOF: Chebychev-Kutzbach-Grubler method vs. Screw method

I will try not to skip too many steps. Assuming a Global coordinate frame at the base and the arm is fully extended along the Y-axis of the base frame. Since SCARA has four joints, we will create ...
Dimis's user avatar
  • 103
3 votes
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What is meant by the phrase "movement positional jitter"?

We can think of "jitter" as a fairly quick, fairly small perturbation upon the intended controlled behavior. A semi-quantitative design guideline (like "within 5%") needs a ...
r-bryan's user avatar
  • 1,271
2 votes

Double/Triple inverted pendulum always on a cart?

There's no reason why you couldn't do it with a servo on the first pendulum, but the problem is very different. Instead of motion constrained on a line (cart), motion is constrained along an arc. The ...
Paul's user avatar
  • 1,278
2 votes
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Any books or web resources for robotics mechanical design?

You could look at three books. A Mathematical Introduction to Robotic Manipulation - S.Sastry, X.Li and R.Murray provides a theoretical foundation to the kinematics, dynamics and control aspects of ...
Tvaṣṭā's user avatar
2 votes

I need the scheme of iRobot Create 2

The schematic for the main board on the iRobot Create 2 is currently not available. It is advised to remove the plastic top cover before drilling into the electronics below. (This is good practice for ...
Steve's user avatar
  • 942
2 votes

Sliding system basic question

This is a great problem to hone mechanism design skills on. There is a set of dimensions for which this mechanism works fine. The condition for this is that the contact of each rod & hole, ...
hauptmech's user avatar
  • 4,435
2 votes
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I need help figuring out what motor is used in this design

This looks to me like a linear pneumatic actuator. Pneumatic cylinders can be very fast acting, depending on the air pressure on hand, but they can be hard to control at any position other than their ...
Mark Booth's user avatar
  • 4,253
2 votes

What is the front mechanism of this robot's track called?

They seem to be called 'flippers' in most of the literature. This review of the iRobot 310 SUGV on Army Technology notes that: The 310 SUGV has an overall length of 76.1cm and width (flippers on) ...
sempaiscuba's user avatar
  • 1,074
2 votes

Can somebody explain how these forward kinematics matrix equations were formulaed?

It looks (to me) like there's a typo in that answer. The approach is to recognize that you have to wind up at the same point, whether you get there via the left arm (d->e->blue dot) or the right arm (...
Chuck's user avatar
  • 16k
2 votes

How can I attach an arm to a double-flat drive stepper motor?

You can use a D or Double D shaped shaft collar/coupler. Or obtain a Double D shaped punch, depending on the design of the piece you are attaching to the shaft.
SteveO's user avatar
  • 4,386
2 votes

How to seal a threaded rod so I won't lose oil?

Have you considered putting the motor inside the same oil-filled box as the part that needs to move? Many electric motors -- such as the coolant motor in practically all household refrigerators -- ...
David Cary's user avatar
  • 4,545
2 votes

Design a robot that can apply hot glue to paper

The problem I see is that after a while of holding the trigger, you have to let go of the trigger and then squeeze again. This is because the trigger has advanced the stick of glue as far as the ...
sa_leinad's user avatar
  • 207
2 votes

Controlling Actuated Robot Hand in Underactuated Manner

I don’t think underactuated is the proper term. You are trying to control multiple actuators with a single DOF. That is redundancy resolution. I have used the Simplex Method to compute stable ...
SteveO's user avatar
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2 votes
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How does this end effector work?

The actuator has two raceways cut into it. One is a screw thread, and engages with a rotary screw nut that is turned by a motor. Turning the nut moves the actuator linearly. The other is a spline ...
jsotola's user avatar
  • 548
2 votes
Accepted

Wall-E Legs mechanism

This is an appropriate question over at movies SE, but even here its probably interesting. Wall-Es character is definitely an interesting one, very dynamic, anthropomorphic, and modelled quite ...
DrMrstheMonarch's user avatar
2 votes
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Why do we say a robotic arm have 2 dof even though the two joints rotates along the same axis?

The degrees of freedom of a serial manipulator equals its number of joints. A more general definition can be found on Wikipedia. It is about being able to describe the state (configuration) of the ...
50k4's user avatar
  • 6,662
2 votes

How to choose a servo motor for solar tracking mechanism?

Most solar tracking rigs only move along one axis because the efficiency savings from moving along 2 doesn't make up for the energy losses of having 2 motors. If you're just doing this for fun, then ...
Jacob Waller's user avatar
2 votes

How to choose a servo motor for solar tracking mechanism?

Servo 1. Referring to your diagram, first consider the tilting part at the top. Imagine a line connecting its bearings. It will tilt (rotate) about that axis. The weight (force due to gravity) of the ...
r-bryan's user avatar
  • 1,271
2 votes

What thread to use for a load-bearing telescoping lift

Look into fishing line. It rests quite comfortably on spools, can be quite strong, is applied where weight is a concern, and is readily available (although I don't know anything about its stretch). A ...
r-bryan's user avatar
  • 1,271
2 votes

What thread to use for a load-bearing telescoping lift

I've used Spectra® braided fishing line for a cable driven robot hand. (I believe there are many similar products by other brands). I think it would probably work for your application too. Steer ...
Ben's user avatar
  • 5,855
1 vote

How should I create a Pangolin (Armadillo) structure?

I would work backwards, looking at the design when it is closed. From that, you'll see how much larger each piece needs to be than the one below. Each piece is probably connected to the one below it ...
jekso's user avatar
  • 31
1 vote

How do I calculate the direction robot is facing, pose from velocity and yaw rate?

Close. A simple solution is to first track the heading over time using the yaw rate sensors. If you're getting measurements every $\delta t$ seconds ... $$ H(t+1) = H(t) + Yaw(t)*dt $$ The, you ...
Josh Vander Hook's user avatar
1 vote

Rotating two things on the same axis

It's called a sleeve bearing if you intend for the shafts to rotate relative to each other or a bushing if you intend for the shafts to move axially relative to each other. They generally look pretty ...
Chuck's user avatar
  • 16k
1 vote
Accepted

How to transfer motion between these two parts?

I believe what you are looking for is a 4 bar linkage. When opposite links are equal in length, they stay parallel.
Ben's user avatar
  • 5,855
1 vote

Connecting two servo motors to drive one shaft

One bigger servo is better. You can just hook them both to the same shaft. If you give them the same command, they will fight each other a bit and waste some energy but should work. To improve ...
hauptmech's user avatar
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