Reprap Forum - Robots!

Remote controlled riding mower (4 replies)

tonynsx — Mon, 20 Feb 2023 12:27:06 -0500

This is my very first remote controlled project. I converted my Craftsman riding mower remote controlled.

Dual extruder in inverted directions (no replies)

acastles91 — Tue, 17 Aug 2021 15:58:58 -0400

Hello forum,
I put a SKR 1.4 board on a remote controlled tank to be able to control it with g-code files, and I defined both chains (what moves it forward and backward and also left and right) as extruders, since they don't have a bed size and I need unlimited movement. That seems to work fine, but I need the ability to chage direction, and when I move the tank by defining the movement as a toolhead, I can't define a negative coeficient for one of the extruders if I want to move it backwards, and I also can't define if they are inverted or not "on the go", but only in the precompiled firmware. Is there a way to give negative coeficients for multiple extruders or to invert the motors on the g-code file itself? I am using Marlin 2.0. Any hints are welcome!

Robot 3 d printer (3 replies)

ivan krcma — Sat, 21 Nov 2020 01:51:46 -0500

Hello everyone,

I hope I didn’t miss the question group. I have been doing 3D printing for several years and I am addicted to it :).
I would like to make my own 3D printer based on the principle of a robotic arm. I have a lot of steeper engines at home, arduino boards, mega 2560 ... Do you have any idea how to start since I don't understand too much about electronics and programming?

Thanks for the help.

Ivan

Mesh Morphing Robot Competition (1 reply)

Polygen — Tue, 14 Apr 2020 08:28:29 -0400

Light is not a practical medium to display information three dimensionally, since it's extremely hard to make it bend, start and/or stop in mid air, which are necessary for constructing true three dimensional shapes and not simple 2D rasterizations. This is when I came up with the idea of making a closed mesh of robotic polygons. That is, a mesh of edges that can expand and contract, as well as vertices that can control their angle in both the horizontal and vertical axis. Whilst this results in a very neat display, I soon realized it's potential as a general purpose robot.

Theoretically, this could fit in your pocket and grow to the size and shape of a human, and then proceed to do physical labor for you. This bridges the gap between display and robot, it might bring robotics to the general consumer and it has the potential to replace purpose built robotics. But if it does none of those things, it will at the very least look cool.

I've been working on designs for closed meshes of robotic nurbs and have settled on a final design. It uses continuum robots attached to tensioning/locking cap, which is then connected to modified hobsons joints that replace the smooth rods with expanding sliders, which then connect to a multiplexed driver, turning two or more motors into infinite rotational outputs. These are technically nurbs and not polygons, which have a lot of benefits over polygons in the real world. 2D rasterization of nurbs is hard but real life implementation is easier than polygons, since a continuum has less physical variables to control than a polygon.

I understand this might be hard to understand right now, but I'm planning on slowly updating this topic over time with more information and updates. I am about to receive my prusa and mmu, and that will hopefully help me make my first functional mesh.

I am making this topic not to brag about how cool i am, but to hopefully encourage you to pursue the field of mesh morphing robotics. I believe it is the future of both display technology and robotics, but again at the very least it looks cool. I hope some of you can design functional meshes that make mine look stupid. To make this interesting, I am willing to give away a brand new prusa to the first person who makes an open hand close into a fist, morph into a face, then smile in under a minute with a minimum of 48 edges. You're welcome to use any design that results in a mesh morphing robot.

Here's some assorted media to help you understand:

Existing Examples: [www.youtube.com]
[www.youtube.com]
[www.youtube.com]
My Videos: [www.youtube.com]
[www.youtube.com]
[www.youtube.com]

Closed loop stepper motors for robotic arm (4 replies)

kuan — Sat, 03 Apr 2021 10:11:59 -0400

Hello! I am planning to build a robotic arm (5 or 6 dof) with stepper motors (probably NEMA 17) which I want to be closed loop.
The budget is up to 30$ per closed loop stepper motor (motor + driver + encoder). In addition I will need a motherboard to control them. What option are there?

As you understand, at this budget I am looking for Chinese products and not the more expensive options like (original) Mechaduino, ustepper etc.
From what I have found so far (if there any mistakes please correct me):

MKS Servo42B (cpu: STM32 F103 C8T6, driver: A4954 , encoder: A1333LLETR-T) + MKS Gen 1.4 (~ $20 + $18)
BIGTREETECH S42B (cpu: STM32 F030 C8T6, driver: 2xA4950T, encoder: TLE5012B ) + SKR V1.4 (~ $24 + $21)

(I couldn't find any info on the steppers motors they use, torque etc., besides that they are nema17).

There is also the clone of Mechaduino 0.2 (with AS5047D encoder), but the board alone costs $24 and with a cheap nema17 I probably could make it below $35. But still it is a more expensive option and I am not sure if it is worth it.

Instead of using their motherboards I could (and would prefer to) use Arduino Mega 2560 + RAMPS 1.4/1.5/1.6 + Servo42B or S42B (is it even possible)?

Another option is to build it from scratch myself, e.g. Arduino Mega 2560 + RAMPS 1.4/1.5/1.6 + stepper motors + drivers (e.g. A4988, DRV8825) + encoders (e.g. AS5047P, AS5047D, AS5048A, TLE5012B ) + microcontrollers (e.g. STM32), but this is much more difficult to do for a beginner like me.

Any suggestions are welcome.

Sixi Robot Arm (no replies)

i-make-robots — Fri, 28 Jun 2019 14:20:00 -0400

Hello all!

We're making great progress on our latest robot arm and I think you'll be interested.
Here's a recent shot of it in action: [www.instagram.com]

- Almost entirely 3D printed
- 6 degrees of freedom, like a modern industrial arm
- can carry 2kg
- reach 80cm
- speed 50 degree/s
- accuracy goal +/-0.5mm
- open hardware & open source

I've written up the details on the Sixi page.
In the meantime here's an older page for Sixi 2 on Hackaday.io

My hope is that it can be used to help people everywhere, starting with 3D printing fans like you.

I believe the time is right to do for robot arms what Prusa did for 3D printers. My goal is to get the arm good enough that it can assemble its sisters. That will be the last time I will build a robot by hand.

Robotis Bioloid biped part files? (no replies)

dlc60 — Tue, 05 Mar 2019 17:12:51 -0500

I'll see if I can gen up some traffic on this list...
I have found a few Robotis Bioloid biped parts and part files on Thingiverse, but not all of them. Does anyone know if such things can still be found?
If not, I suppose that I can just craft up some of my own for a unique look anyway... But if anyone has any pointers, it would save some time doing all of the measuring to get the right hole spacing and part sizes.

Have fun,
DLC

Soft robot project (no replies)

kdtop — Sat, 30 Dec 2017 08:15:15 -0500

Hey all,

I have been working on a soft robot project with parts made with my 3D printer. I have done a write-up about this here: [docs.google.com]

Feedback is always appreciated!

Thanks

Kevin T

Kuka Robotic Arm 3D Printer (3 replies)

NoSkillzEngineer — Tue, 28 Mar 2017 10:19:30 -0400

[youtu.be]

This is Freeform Fabrication for the future. Once Strong AI is integrated into this, this will undoubtedly be a big part of the future....for that reason, it must be open source.

I have access to some pretty high precision servos from Faulhaber Motors, who sponsor our Hackerspace/Makerspace.

Servo motors and hall effect sensors (encoder) are fairly new to me, however, with the amount of them I have access to...It would be foolish not to learn them.

I also have access to $200+ of industrial High Precision Machining equipment. Who wants to help make this thing real?

How to use Marlin to control robot based on a stepper motors?? (no replies)

pavelsplavel — Thu, 05 Jan 2017 11:37:17 -0500

Hello! I would like to control my robot using Marlin firmware.
I m going to sent Gcode via rs232 protocol.
The software i use is a Visual Programming.

The problem is control motors independently

When i sent gcode to Arduino, it wait while motors finish their Positions.

My goal is sent different Gcode at any time.
For Example:
G1 X100
G1 Y30 Z50
etc.
While one motor make a movement, others motors could start at any time.

So what i need to change in Marlin firmware to solve that problem??

EEZYbotARM mk2 (2 replies)

gHiZmO — Mon, 23 Dec 2019 18:22:01 -0500

I made available the source CAD files of my EEZYbotARM mk2

thing files [www.thingiverse.com]
printing and first test [youtu.be]

you can find source CAD models on my Onshape account : https://goo.gl/ACnRhT
You can copy or export files

Carlo Franciscone

3D printed Robot Arm (no replies)

nic6911 — Thu, 22 Sep 2016 06:47:54 -0400

Hi!

I wan't to share my Robot Arm design with you guys. It's 3D printed and all parts (STL) and an assembly manual can be found on our github. It's the third iteration of my initial design, and it comes out quite nice now. I also spent quite some time on the assembly manual, to make it easy for people to assemble.

ustepper-robot-arm.jpg

To read more about the arm and for links to github, a video and more see:
[www.thingiverse.com]

The design is released under a CC NC-BY-SA license.

Best regards,
Mogens

“The Start of the Project. Part 1.1. How I Assembled a Wheeled Telepresence Robot.” Endurance’s Technologies (no replies)

Anonymous User — Thu, 28 Jul 2016 01:51:58 -0400

By 2015 most members of our future team managed to earn enough money to risk their time in long-term perspective (with 1 year time bucket). We decided to organize a startup. Do buying and selling? Nooo! Start a technological project. To develop robots and 1-10Wt solid lasers, in particular.
I have always liked the idea of being present at the right time in an interesting faraway place. All of us like online broadcasting. Thanks to the telepresence robot, I can remotely change the direction of my look, the place of my telepresence.
That’s why when we started the Endurence Robots in 2015 I set to development of the wheeled telepresence robot. The wheeled platform will allow it to move indoors and outdoors, and the telepresence system – to watch the occurring events. Our final aim is to create full virtual reality with a robot controlled by a person with the help of Oculus rift!

For a start I googled a lot to study similar solutions: PadBot (China), BotEyes (Russia), Double Robotics (USA), Webot (Russia), OrigiBot (USA), Oculus (Canada), Anybot (USA), RBOT Synergy (Russia) and drew a table of the robots’ comparative data. They differed in functions: some could take things with manipulators (a beer can from a frig), some could overcome high obstacles, autonomously take charge, etc. As you would expect, the prices ranged from $1000 до $10000. As I realized later, inexpensive devices (below $5000) were robotized platforms controlled by an operator, not autonomous robots with the ability to take decisions in various situations: recognize and skirt obstacle; travel a route from A to B; recognize spoken commands.

Our Endurence Robots team decided to enter the market of economy platforms at the price of $2000 and bellow. On the basis of the robots’ comparative data, I selected the features, with which we wanted to invest our device first and foremost. They are: operation time (8 hours and more, full working day), obstacle crossing (3,5 cm high, sill height), reliable transmission of control commands via Internet, high quality video and audio connection.
Somebody of the team suggested that we should make the robot body out of a dress form and install a tablet on its breast. We even bought a used dress form imitating a female torso for $2 (a new one costs ~$100), but due to the modesty of our financial means, the idea died.

http://i11.pixs.ru/storage/3/7/2/1png_3661367_22740372.png

Market research showed that people looked for not just a wheeled tablet but for a robotized smart platform, capable of speech and image recognition (open source, Open CV), capable of correctly answering the questions (Artificial Intelligence), of moving to the object to fetch it and carry it to another place. A wheeled platform is just a necessary addition to our solution. Strategically, a wheeled platform is the main form factor. As a notebook -> a tablet. A new form is a new product.

http://i11.pixs.ru/storage/3/8/8/2png_9801946_22740388.png

The first stage task is to develop a wheeled platform: inexpensive (below $200 for low-volume production), efficient (with a trouble-proof running, modularity, reliable software/hardware), easy to maintain, user-friendly (just mount the phone, upload the app, and activate the system), easy to upgrade and improve, operator manageable (an operator controls electro motors and servos via the Internet).
Essential requirements for the construction performance are as follows:
— Suitability for industrial production.
— Reliability in daily use (1 year, at least)
— Components interchangeability and complementarity (there’s enough room to fix one more speaker or a second camera).
— Attach hardware flexibility.
— Travel directness.
— Noise and vibration less than 10 DCB.
— Lightness and portability.
— For areas with even surfaces (laminate, tiles, wood, concrete, linoleum) and sills not more than 1 cm high.
— Design appeal, ergonomics, user-friendly, and portability

TECHNICAL FEATURES OF THE CONSTRUCTION
— Max. speed up to 3 km/h.
— The height of the upper screen edge is ~1.5 m (preferably, with the height range of 1.2 m -1.8 m).
And a million questions poured.
What is the max. allowed weight at the height of 180 cm? A tablet + a cradle + two servos? Will a three-wheeled construction be stable with the chosen batteries at the sides if one or two wheels come across an obstacle 3,5 cm high? What is the optimum size of the wheels? What kind of wheels, of what material?

http://pixs.ru/uploaded/3png_7803379_22740397.png/22740397_2702026/

What kind of wheels: omni, smooth tread, ribbed cord tires?

http://i11.pixs.ru/storage/4/0/4/4png_5528391_22740404.png

How many wheels: three or four? How to fix them to the shaft?

http://i11.pixs.ru/storage/4/1/3/5png_7403695_22740413.png

To the gear reducer shaft or motor shaft?

http://i11.pixs.ru/storage/4/2/6/6png_8945696_22740426.png

What kind of motor to choose? Commutator, commutatorless, stepper? What kind of material to choose to make a frame?
Eventually, I made my first prototype of the materials available in any hardware store: three wheels (2 drive wheels and a swivel wheel), a frame made of thin aluminum n-shape, self-threaded screws, screw bolts, and two steppers.

http://i11.pixs.ru/storage/4/3/8/7png_3436076_22740438.png

http://i11.pixs.ru/storage/4/4/8/8png_6368831_22740448.png

Important, that this prototype was of good service to our circuit designer Andrey for thorough electronics testing.

In this article I described the beginning of our long path. The products and photos are amateurish. But in the next parts I’ll show a more professional approach.

This is the mechanics and electronics scheme we used.

http://i11.pixs.ru/storage/4/5/7/9png_2296313_22740457.png

Opensource Firmware for ABB IRB460-like Robot Arms (2 replies)

jonahl — Fri, 11 Nov 2016 18:29:37 -0500

I just completed a firmware for ABB IRB460-like robots arm, hope it can contribute to the robot arm open source community.
[github.com]

The firmware mainly serve for education / hobby purpose and hope you all enjoy it.

Compatible example in the market/open source world include:
• MeArm [www.thingiverse.com]
• EEZYbotArm [www.thingiverse.com]
• EEZYbotArm MK2 [www.thingiverse.com]

The firmware includes a complete infrastructure for calibration and G-Code control, which provide a easy way to interact with the arm.

An working example:
[www.youtube.com]

Re: First-ever 3-D printed robots made of both Solids and Liquids (-1 replies)

VDX — Wed, 31 Dec 1969 19:00:00 -0500

... read this post from 2007 ;)

[forums.reprap.org]

Arduino Robot? (2 replies)

sarf2k4 — Tue, 15 Dec 2015 21:34:20 -0500

Hi, I recently had a problem with my Arduino Robot here [www.arduino.cc] for the robotics competition last week. I'm unable to make the robot to switch between 2 modes. The main problems was that the Robot didn't really follow the lines whenever I put in the maze/wall navigation codes. Here is my code [github.com]

All the issues were there and this Arduino Robot were given to us to be used during the competition

If anyone owns the same thing hopefully can test my code out and help me troubleshoot. Although the competition has already ended but I really do want to know what produces this problem.

For this, you will need 3 ultrasonic sensors; front, left, right

Stepper/servo robot ramps 1.4 mega 2560 (4 replies)

egghead419 — Sun, 31 Jan 2016 03:20:13 -0500

Hey all,

I have printed and built the Robot released by Zortrax. It works fine 3 axis using nema 17 steppers .

[youtu.be]

I want to add some servo control for my end of arm tool i have connected the servos to the D11, D6,D5,D4 and added the jumper from VCC to 5V.

I have been trying to use the bed leveling threads as a guide.

Defined 4 servos in the configuration.h

as far as the code construction of entered m280 p_ S___

this is vexing me I've tried variations but only get immediate movement while the bot moves around but i cascaded a stepper move to a servo move

G21
G91
G1 Z-13 F409
M280 P0 S10
M280 P1 S10
M280 P2 S10
G1 Z13 F409
M280 P0 S45
M280 P1 S45
M280 P2 S45
G1 Z-13 F409
M280 P0 S90
M280 P1 S90
M280 P2 S90
M107
M104 S0

but movement doesn't happen as i envision can someone please help?

my robotic casket (no replies)

tommyjee — Wed, 08 Jul 2015 21:42:16 -0400

I have been advancing thi for years.
[tommyjeeze-robotalk.blogspot.com]

Robot vs. Samurai video, check it out! ::o (1 reply)

AndrewBCN — Thu, 11 Feb 2016 20:42:48 -0500

[www.youtube.com]

Mecanum Wheels? Marlin + Ramps?? (1 reply)

Ohmarinus — Sun, 15 Feb 2015 12:52:46 -0500

Hi guys, I want to make a robot for a graduation project. I am thinking to either make the mecanum wheels myself, or buy them somewhere.

I've seen pretty decent priced ones, I don't believe in ultracheap, I need something that works for my project and is balanced between quality and price. In other words: I don't need mecanum wheels that they use on industrial machines, but still, I need a good set that can survive especially in outside environments like uneven streets, etcetera.

Besides that, I have to find out what kind of firmware and electronics I have to use to make the robot run. I want the robot to 'perform' movements how you see them on your 3D-printer. Is there a possibility that I rig the machine in such a way, that it translates the X-Y movements to X-Y coordinates by using the mecanum wheels as output?

I have been thinking of making my own kind of machine, that instead of using mecanum wheels, uses wheels with small rollers that are angled in a 90º angle from the direction of the main wheel they are on but am worried that when I let the robot 'perform' movement, it might lose track of it's X-Y coordinates easily. With mecanum wheels the control you have over the movement is more fixed and repeatable. I other words: if you let the robot trace the line of a circle, it should end up where it began to make a perfect round circle.

Hoping that anyone here has some experience with this, I am completely ready to get into this project!

Has anyone here worked with Articulated Robots? (3 replies)

picthings — Wed, 02 Mar 2016 08:53:04 -0500

I am trying to find a sub-group of roboticists here who are new to robotics, maybe we can throw ideas around or discuss projects and other cool stuff. I have started working with Articulated Robots I am facing problems with the harmonic drives. a random arm just collapses out of no where. any suggestions how to fix this?

Robot humanoide opensource (9 replies)

78moebius — Fri, 31 Oct 2014 07:41:39 -0400

interesante
poppy

My First Robot (2 replies)

Anonymous User — Thu, 11 Feb 2016 20:50:28 -0500

Bluetooth Remote Control and for Android Smart Phone.
It features with the function of obstacle avoidance, infrared remote control and Bluetooth remote control system.

Steps to build it

C51_robot.jpg

InTech Open Access Robot Books (3 replies)

A2 — Fri, 17 Feb 2023 10:11:03 -0500

Books on robotics:
[www.intechopen.com]

Delta 3D printers are parallel manipulators:

Parallel Manipulators, New Developments
[www.intechopen.com]

Parallel Manipulators, towards New Applications
[www.intechopen.com]

About InTech

InTech is a pioneer and world's largest multidisciplinary open access publisher of books covering the fields of Science, Technology and Medicine. Since 2004, InTech has collaborated with more than 85877 authors and published 2336 books and 6 journals with the aim of providing free online access to high-quality research and helping leading academics to make their work visible and accessible to diverse new audiences around the world.

Our mission is to give all researchers equal opportunity to share ideas, develop their career and for their work to have impact around the world.

Possibility of an anthropomorphic robot handyman (2 replies)

Nikita K — Sat, 22 Nov 2014 06:27:49 -0500

6vXXgag.jpg

Basically, the idea is to create a robot can effectively use tools designed for humans.

The idea isn't new. Many organisations such as NASA and DARPA are working on their own variats. There are also many anthropomorphic robots of any size and price range available commercially, though most of them are either completely inadequate at handling any sort of tool, or extremely expensive,

The purpose of this thread is to discuss the feasibility and practicality of creating such a robot.

Why use tools?

There are many advantages to having a robot that can use tools.

Hand tools get the job done and are cheap, but require a steady hand and for you to spend your own energy laboring all day.
Having a robot use hand tools effectively gives you the power and precision of a large CNC machine.
You do not have to pay for a specialized machine, and you do not have to design a separate robot (or separate end effector) for each task.
A robot can bravely march into any environment and work with dangerous equipment and materials. You do not have to worry about getting your arm chopped off or molten metal spilling over your pants. If you absolutely have to work with something dangerous, let a robot do that instead.

Why anthropomorphic?

If you want a robot that interacts with a human-centric environment, it would have to somewhat resemble a human. The upright frame of a humanoid is the most advanced frame that can walk through a doorway, halls, ladders, and messy crowded workshops. The two legs allow for greatest mobility, although technologically difficult and can, for the most part, be replaced by wheels. The human hand, on the other hand, is not easily replaceable.

8clp0zi.png

Take a look at some of the tools that a robot would have to deal with. There are many manipulators that are quite good at picking up a specific kind of objects, and some that do reasonably well with a wide variety of objects (such as the ground-coffee ball vacuum manipulator) but the only manipulator that can adequately manipulate the whole spectrum of tools developed for the human hand, is the human hand.

Ideal case

The final shape of the project, as I see it, would be a very anthropomorphic robot. Here are some requirements:

Matches or exceeds human abilities on the range of motion, speed, and strength.
Able to move with great agility and precision.
Employs advanced passive-dynamic bipedal walking, i.e. able to walk or run quickly and efficiently on any terrain.
Able to use any tool designed for humans as it was intended to be used.
Can be commanded by voice to perform most manual tasks (ones that do not require much decision making).
Can be programmed by voice (i.e. told how to perform new tasks), shown, or guided through the process.
Can recognize some classes of objects
Can navigate through unknown environment

First stage: dexterous hand

The first step in making such a robot, as I see it, is simply making a human-like hand and attaching it to a simple manipulator arm. It should be possible to create a single hand with simple servos and 3d-printed plastic mechanical parts. Keep in mind though, a hand has many requirements to satisfy before it can be considered useful.

Let's look at a human hand. Look at your hand right now. It should have five fingers, plus or minus. Each finger has 4 degrees of freedom (up/down, left/right, and two more pairs of up/down for the two joints in the finger). Like any manipulator, each finger has a range of motion or envelope (the volume of space encompassing all position that the tip can possibly reach). Four fingers have similar position and envelope. The thumb however is attached opposite of the other fingers, and has a wider envelope. Most of this peculiar arrangement can be explained theoretically, although some things are still a mystery to me.

Trivia: 8 fingers (other than thumbs) are together strong enough to lift the whole weight of a human. In other words, each finger can alone lift about 15 kg. It's hard to say how this translates to torque though, but I'll give 4.4 Nm (Newton-meters) as a ball-park for joint torque involved.

Theoretical study of theoretical fingers

I'll try to explain why the hand has fingers, and how does having a certain number of fingers relate to being able to grasp various shapes.

First of all, look at a traditional claw. Two fingers, two degrees of freedom each.

vmk3XUQ.png

The white circles represent tips of the manipulator, i.e. points that can collide with an object to apply a force to it. The gray dashed line marks the envelope, all the points reachable by each of the tips. This is to get you familiar with the notation used here. As you can see, the base of the hand is also considered a tip here.

Now the principal function of a finger, as I see it, is to apply force to an object, at a particular offset, and in a particular direction. This force does not allow an object to move past the tip in some direction, and makes it difficult to slide tangent to that point.

1y7IaDI.png

The number of points (fingers) that touch the object determine just how restricted it's motion is. One point is enough to keep an object from falling due to gravity, but does not restrict it's motion much. Two points restrict motion along a line, and with enough force, can pinch an object to prevent motion alltogether (for small loads), however they do not provide much resistance to rotation. Three points can restrict an object in a plane, and usually provide a good grip for most objects (except for long ones, such as sticks or hammers. Since the only thing preventing rotation is friction, if the outside force acting on an object gets even a little bit of lever distance it can cause rotation). Four points (corresponding to three fingers and the base of the hand) can form a tetrahedron and completely restrict both motion and rotation of the object, and are thus preferrable - any possible rotation of the object would end up pushing against at least one of the tips, so the force preventing motion is compression rather than friction-based. Five points (four fingers and a base) are no different from four points, but one finger is free to do something else, such as push a button on the object, without compromising the stability of the grip.

Therefore, if we want a hand to pick up a power drill and use it, it will need at least four fingers.

I will also shortly go over some more subtle things you can do with fingers.

wyTvNKP.png

Firstly, rolling. With one finger stationary (or replaced by flat plane), another finger can push the object while maintaining a rolling contact (and thus still restricting it's motion). This way three points of contact can control the orientation of the object without ever letting go of it. It's a useful technique that can drastically reduce the amount of overall hand/arm motion needed for a particular manipulation.

cFdhlje.png

Secondly, crawling (at least that's what I call it). If there are enough points of contact to make sure the object doesn't do anything crazy for at least a short time, the rest of the fingers can be freely repositioned to anywhere on the object in order to get a better grip. This is similar to a spider (or a hexapod robot) crawling/walking by moving one leg at a time, while standing on the rest.

Summary of hand requirements

At least four fingers, arranged radially to grasp round and cylindrical objects.
Each finger should be able to position it's tip with 3 DOF.
Each finger should be as long as an average human finger and have a similar range of motion.
Each finger should needs up to 4.4 N*m of torque. Alternatively, it should be able to lift 15 kg or one-sixth of the robot's total weight, whichever is larger.
Lifting 5 kg with one finger should be more than sufficient for most applications though.
The peculiar positioning of the thumb is not necessary in general case. It's only used for some really weird manipulations such as using a touch-screen phone with one finger.
Each finger should be able to go through it's full range of motion on any axis three times per second.
Fingers should be covered with rubber or similar high-friction material.
Fingers should have some degree of force sensitivity. It is necessary to measure somehow the force applied to an object.

Current status

41PSAex.jpg

I am currently designing the hand part of the robot, electronics needed and forces involved and such. Once my 3d printer is working correctly, I should be able to print a prototype hand... sometime between now and never.

Let me hear your comments and suggestions!

Smart Surgical Robots (no replies)

zoya33522 — Mon, 28 Oct 2013 03:33:02 -0400

National Robotics Initiative has announced tht it has granted permission to create surgerical robots that will help surgeons/doctors in operation.

machine for painting (1 reply)

andrew — Thu, 22 May 2014 21:57:36 -0400

Hello everyone!

I would like to ask if any of you know answer for my question. : ) I was searching for automatic machine for painting 3D stuff. And i have no luck :D So i would like to ask if this kind of machine exists?
What is the best way to paint 3D >>car<< i printed?

best regards

Andrew

inMoov prints ? (7 replies)

Mickman — Sat, 03 May 2014 23:09:52 -0400

Just wondering if anyone from the RepRap community has tried printing the
InMoov humanoid robot ?

inmoov_robot_arm_3d_print220.JPG

DSC05988.JPG

DSC05991.JPG

PLA mechanical pieces for robotics. (1 reply)

Xanderjanz — Tue, 04 Jun 2013 01:43:10 -0400

Hey RepRap

I'm very interested in 3D printed robotics. Ive watched a lot of videos on various 3D printed robotics projects people have done. However, most of them have metal pieces for the high strength components like rails and bearings. I don't have a printer, but could someone with experience enlighten me to to how PLA parts work on a robot?

Could you print an all PLA gearbox for a motor?

Tanks for the help, you guys rock!

Best robotics platforms? (3 replies)

xclusive585 — Mon, 18 Feb 2013 02:04:32 -0500

For simulation and/or firmware/programming purposes what are some of the better softwares out there?
I've just learned of the player-stage combo being very popular.

Any other robotics platforms worth looking into, open-source free or otherwise?