« Last post by greenace92 on March 17, 2015, 10:25:57 PM »
My aim is to build a crawling robot ( four legs ) that operates on WiFi (initially) and then following its own "exploration protocol"
Anyway, I'm wondering if this is a waste both on power consumption and weight to use an entire computer like a Raspberry Pi.
My aim is to control it via mouse, directional pad and additional keys for other functions.
It would carry a camera (or two for stereoscopic), IR sensors, gps, accelerometers, gyros, and additional components.
Also, I'm new to this, I'd like to know what direction I should take, reading materials regarding Microcontrollers
The goal is to build small exploration drones, that operate autonomously and connect to a local transmitter / receiver which is then linked to a master transmitter/receiver whether a geosynchronous satellite or a large long distance antenna array.
I realize it's ludicrous, out of my reach
I'd appreciate any information
Just for an estimate, a simple four legged robot, maybe 8 to 12 servos, battery, computer, etc... what kind of a price tag am I looking at, bare minimum? I'm not talking a ready to buy kit, I'm looking to build from scratch. I would probably opt for laser cut wood for the body of the robot for prototyping.
« Last post by Admin on March 17, 2015, 09:07:25 PM »
This 3D printer literally takes minutes where others take hours. And it's continuous, meaning no flaws from layering.
Check out the two videos:https://www.youtube.com/watch?v=VTJq9Z5g4Jkhttps://www.youtube.com/watch?v=74BjdHDJeE0
« Last post by lexxtoronto on March 17, 2015, 06:21:52 PM »
Thank you! Im a bit sceptical about Parallax because both PBASIC and SPIN are specific to Parallax; I mean I dont want to invest in languages that dont land me a job, or will they? I was looking for languages that would also be good for me in the long run in terms of employment.
I mean if I had lots of time I would def try Parallax, but time is very precious to me.
What do you think of MRDS? Is it of any use in terms of getting a job?
« Last post by RainMan on March 17, 2015, 05:14:22 PM »
Awesome job on the terminator!
Great security guard too!
Thanks . Im used to it now but it scared me a few times when I walked into my living room lol .
As I mentioned it was thrown together rather hastily as I have home renos to finish first . I have the Endo skeleten arm and it should be on the left arm and damaged to be screen correct , but I was debating to do an undamaged Endo on the right side instead and motorized . Tough call . Just received the chest plate and waiting for the knee . It kinda sucks as I have to destroy the jacket , sleeve missing and bullet holes etc .
This is a 1/6th scale but it shows you what he should look like when done . I think motorizing the the left battle damaged arm would be ok ?
Was going to make it go on a timer with the stamp but random would be better yet
« Last post by mklrobo on March 17, 2015, 03:30:03 PM »
I would offer an opinion.
In your dual
quest for learning a programming language and
learning in robotics, it may be a good idea to hedge your bets
In other words, invest in a well supported robot product
also gives a wide learning platform
in a mainstream language.
By this direction, I would look at Parallax products, specifically
the basic stamp, (pbasic and simple
) to the Propeller.(more complex,
uses combos of C++, java, python, concentrated in a crucible language
). Their products are well supported, by techs and forum,
and have accessories to accommodate your robotic growth.
Remember, a journey of a thousand miles begins with one step.
« Last post by mklrobo on March 17, 2015, 09:48:02 AM »
Awesome job on the terminator!
Great security guard too!
« Last post by Schlayer on March 17, 2015, 07:41:57 AM »
There are probably a lot of geared motors with large amounts of torque at the expense of speed that can run at lower than 12V. I found one motor with a massive gearbox mounted to it that takes just 5V DC. In hopes of using it for a display stand turntable, I was able to solder a switch to it and then splice on a regular old AC/DC converter wall socket from an unused cell phone charger directly to the switch and motor contact. It works like a charm and has so much torque I cannot physically stop it from turning with my bare hands, which is pretty good for something that takes less than half an amp of current! It only turns at like 10 RPM, but for my purposes that was fine. What kind of speed requirements do you have for your project?
« Last post by RainMan on March 16, 2015, 09:00:16 PM »
Thanks for the reply . I have linear actuators at home and thought about it , but just not seeing the mechanics that well . I would have to get a piece machined for the actautor to push on by a pivot point . So I think I'll look at other options .
Thought about the wiper motor but again no feed back
I'm really liking that motor in my last post , although I wish it was geared lower like 10 rpm but I think it will run down to 3 by adjusting the voltage .
Just have to study encoders now
« Last post by bdeuell on March 16, 2015, 08:46:28 PM »
many types of motors can maintain a position but the system must be designed accordingly. RC style servos are typically brushed dc motors with a gear reduction, potentiometer position feedback, and a built in feedback control circuit. the feedback loop in a servo enables the motor to actively maintain a position. there are methods of electronic braking but that may not provide sufficient holding force in your case. additionally you can get motors with a break that is controlled like a solenoid.
if you go the feedback control method you may want to read up on PID. you could use an encoder, there are absolute and relative styles. an absolute encoder can identify the current position not just change in position. the best feedback sensor for your case might be a simple potentiometer (easier to read also).
all that said I recommend looking at linear actuators. i think the mechanics will be easier because you wont have to deal with a high torque joint. also depending on the mechanics (if it is a leadscrew) it may be inherently not backdrivable. And of course it would look more like the actuating cylinders seen in the terminator movies.
A worm gear motor would also be a decent choice as they are typically not backdrivable. a good source for these is car window and wiper motors (i have picked up a few for free before, robotics stores/sites also sell them). they pack a lot of power but are relatively heavy.
« Last post by bdeuell on March 16, 2015, 08:22:41 PM »
I am aware of some brands that produce high quality motors such as Maxon and Portescap but i'm not sure if they get into the bigger sizes you are looking for. I would focus on finding a motor that best fits your requirements then if you still have several options look at how well they are built or the manufacturer but i think that first part will narrow your options much quicker.