Let's Make Robots!

power

08M motordriver and power supply board

 

After a few weeks of waiting, my PCBs have arrived. I just soldered the components on the first one and it works like a charm. I had to drill out the holes for the resistors a bit and then solder the resistors on both sides of the board to get a good connection, but hey: this was also my first shot at having a PCB made and it works. Next time I'll be more careful checking out the dimensions in diptrace.

how to calculate motor strength?

Is there a common formula for finding required motor strength?

If I know the total bot weight and wheel diameter, could I find out what kind of motor I need. I know that gearing will come into play, but I dont know anything about these physics thingys so I choose to phrase the question as vaguely as possible.. 

Like, what kind of specs would a motor for a scooter (with me on top of it), doing 35km/Hrs require

or,  an offroader weighting 10K, doing 3km/Hrs with 10cm big wheels in rough terrain?

Coil Gun Rifle

I have been making soem good progress on the Coil Gun Rifle:

CoilGunRifle.jpgCoilGunRifle_2.jpg

 

Larger images in attachments.

 

RC power for my picaxe

I'm using RC ESC's to drive the motors in my current robot project. These speed controllers has a built in power regulator (called a BEC) that is meant to power your RC receiver. I've measured and the voltage produced is a steady 5.03 Volts.

Can any of you think of a reason why I couldn't or shouldn't use this as power source for my Picaxe 28x1 ? 

 

Can't seem to insert hyperlinks with Opera browser on my old iMac, so here are a link if you wanna read more about RC ESCs or BECs

http://en.wikipedia.org/wiki/Electronic_speed_controller

Battery Question

Hi all,

I am very new to building robots and don't have much knowledge of electronics, apart from the basics many years ago at school.

However, I got an arduino at the weekend and have started doing experiments with it. I've just managed to take apart a cheap RC toy car and get the arduino to make it go backwards and forwards via a L293D motor driver and a very basic program. There are two motors in the car - the other one is a DC one attached to rack and pinion steering - I've not connected this to the other side of the L239D though yet.

The Pulse - 2009w33

LMR on the Brain
Sensing the living LMR community since 2008w43.

Ten thousand

This week LMR is hitting the 10000th node. A node is a page as our content management system calls them. Look in the URL bar if you have never noticed these numbers before. Ten Thousand must be some sort of anniversary.

A bit of advice on choosing the right battery

Hello

I've been running around past few days trying to figure out a suitable power source for my yet to build robot. It will be powered by two 12V gearmotors (about 1amp stall), on a simple diffrential drive. I am looking for a balance between power consumption and efficiency. My rough estimate is that the robot will weigh under 1kg (2.2lbs) after construction. 

Would this motor be able to lift 150 lbs?

Would this motor lift me?  150 lbs or so?

 

http://www.superdroidrobots.com/shop/item.asp?itemid=722

 

Its for my walking chair, it will be chained to a shaft and the shaft will have about 150 lbs (NOT static load) or so of force to deal with.

 

Thanks :)

The KA378R05 is a low-dropout voltage regulator from Fairchild Semiconductors. From the page, "Dropout voltage of KA378R05 is below 0.5V in full rated current(3A)". … Read more

USB power?

Is it possible to use this USB breakout board as a 5 volt power supply for your microcontroller projects? If so, then do you have to use a voltage regulator?

giving away power adaptors

I've recently bought a small wireless camera on ebay, and the seller sent along two american power adaptors. I live in Norway and can't use them. So, if any of you americans want one 12 volt and one 8 volt adaptor (the kind you plug into your wall outlet) just holler, OK? I get free postage at work, so it's totally free if anybody wants them.

My only condition is: You have to use them. I can't be bothered bringing them to work and sending them away just so they can end up in a drawer on the other side of the atlantic ocean

Price: $15 USD
I have yet to order one, but these things are amazing! They take a input voltage of any value between 6.3V-30VDC and it outputs a steady 5VDC at up to 1A of power! Read more

Providing more power

Ok, so i have my Arduino, 3 x servos and an ultrasonic range finder.  Running all these at once from the 5v that the arduino provides is not supplying enough current (i think). I can run at maximum any two of these components from the 5v.

So i guess my solution is that i need to supply the servo's with their own separate power source.

If i hook up some AA batteries to the + wires of the servos connect the gnd to the gnd and the PWM wire to the arduino, will this work? How have other people dealt with this problem?