Let's Make Robots!

Servos not "smooth" during operation

Hie all. I am currently making a robot arm for my explorer robot :
http://letsmakerobots.com/robot/project/terrestial-explorer-v10

The problem is when i power up the arm, it violently moves to the  "upright" position and there is a lot of buzzing in the gripper and wrist servo when i'm not lifitng anything. the arm is able to lift a quite a bit and is very light. 

3D printer issues

Why do homing my z axis it will go up 2mm and then go do 6mm? I had to plug my z end stop in the max part on my ramps 1.4 to get it to work this far. Is there something i need to set in my marlin file?

Here is my Marlin file, sorry I don't remember how to bracket it as a code for easy viewing.

Wild Thumper T'Rex and ROS

Forum to discuss experiences @ryan

forum death?

Is it me or is the forum death. On some forum the last reply was years ago? :(

T'Rex Controller I2C status request from RaspberryPi master triggers Shutdown

I am currently working with the T'Rex controller via i2c with a RaspberryPi as the i2c master, and using the Python smbus module to send/receive data to/from the controller. What I have found is that when I send a motor command, everything works fine, but as soon as I do a status request from the controller it seems to raise an error which results in the controller executing the Shutdown command. Specifically, this block in the controller code seems to trip the Shutdown:

camera vs kinect

Hi, what do you thin is better? Ordinary camera* connected to arduino ( if that is not enough, Rasp Pi will be better? ) or kinect ?

I need that to recognize a object and sending video to the pc or mobile. 

*camera like pixy or something like that :)

How to calculate IK

Ive been working on a hexapod robot and trying to get it to walk and look good as its doing so. I have a sequencer program but its very limited on what can be done. Ive managed to get it to walk thanks to help from the peopke on this forum but it sucks and is slow.

Any way i would like to learn IK so i can make my bot walk right but i have no idea how to calculate the problem. Ive looked at many tutorials but they only focus on the what and not the how. I understand the what but not the how. And im no mathematician.

Please any help would be appreciated.

Trick switch not working.

I built a trick switch using  Make's basic Arduino Projects bookelt the other day, and I'm running into a problem.

Books, Lots of Books

Hi,

I'm unpacking boxes and replacing the stuff that I'll be keeping from the divorce. That leaves a lot of stuff to get rid of. I have a lot of robotics books that I'll be putting up on the Marketplace.

My question is that I have a ton (or maybe two) of science fiction/fantasy/mystery books. Do you think they would sell here, or should I put them up on EBay?

Many of these are old and aren't available as an ebook yet.

Book Recommendation: "The Peripheral" by William Gibson

I dl'd the eBook version of this to read while recovering from surgery last week and could barely put down the iPad.  It adds makers to the list of hackers that Gibson has been writing his tributes to for the last several years.  I was surprised by how much the idea of 3D printing could become a part of the fabric of a story and have it remain interesting.

Book Recommendation: "The Peripheral" by William Gibson

I dl'd the eBook version of this to read while recovering from surgery last week and could barely put down the iPad.  It adds makers to the list of hackers that Gibson has been writing his tributes to for the last several years.  I was surprised by how much the idea of 3D printing could become a part of the fabric of a story and have it remain interesting.

Of course there are robots as well, but they don't feature as heavily-or, depending on how you look at things (was

Wild Thumper 34:1 slow driving

 I am currently using a 6WD Wild Thumper chassis as an autonomous mapping robot (in progress). I am really struggeling with the PID controller as I often get a humming noise instead of motor turn at low PWM values.

Options For a Remote Control T'REX

Dagu's T'REX robot controller has several options for operating the board with a remote control device of some sort.

The program which comes with the T'REX can accept several different remote inputs. These include (but not limited to) Bluetooth and pulse length signals from a RC receiver.

Can't connect to Mini Driver board

I recently purchased a Standard Educational Tadpole. This little kit for beginners comes with a Dagu Arduino Mini Driver Board. Here is the link: https://sites.google.com/a/rocketbrandstudios.com/rocket-brand-studios/store/tadpoles/tadpole-educational Tutorial for it: https://sites.google.com/a/rocketbrands ... main-minid Anyway, I have the pins and everything in the correct place, but the board itself is giving me problems. I've installed the driver over and over again (at least 5 times) to no avail. It has a blinking blue light that comes on, and a red light.

Program freezing (or getting stuck?) when asked to calculate large numbers

Hi Guys! Ive done buckets of trouble shooting on this, and i THINK i have identified where the problem is, but i cannt work out how to correct it. In short i am programming my CNC router (converting GCode into CNC movements)

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Record PWM values over time, tweak graph, playback to robot possible?

Hi All,

I'm trying to find the best way for me to drive an RC car around, have either the transmitter or car send the PWM values its using back to a computer which will record it over time.  I then want to tweak the graph, and then play it back, and have the computer send the RC car the new "tweaked" PWM data and it will then drive around by itself.

Charging LiPo Batteries

Hi;

I have a Turnigy 2 Cell 7.4v 2200mAh battery and iMax B6AC Balance Charger.

I made it

Looks like the procedure was a success. BP has been hovering around 130/70 all day but no cortisol counts are back yet. The Foley is in a really bad place though. My roommate brought someone with smokers cough along so I'm not getting much sleep...

using Multimeter as current sensor - can it output to Arduino?

Hi All,

I'm in need of a current sensor, but don't want to wait 40 days to get it shipped from China, or want to pay over 10 times as much buying it locally.

I have an old cheapo multimeter lying around, and I just opened it to see if it had a current sensor IC in it.  It didn't, and now that i've put it back together, the conductive rubbery strips that press against the LCD are misaligned and the display shows me gibberish.