help building an ant

team tiny terror · Post by **team tiny terror** » Wed Mar 19, 2008 1:06 pm

hi i need some links for products

i need a battery for one of these http://cgi.ebay.co.uk/ws/eBayISAPI.dll? ... =p3907.m29 and everything i will need to charge the battery

cheers

Tim

leo-rcc · Post by **leo-rcc** » Wed Mar 19, 2008 8:33 pm

That is a regular brushed motor speed controller, you can power that with any battery between 6 and 12 volts. So 2 or 3 cell lipos would do it, and a small lipo charger. What kind of motor do you want to use with it?

team tiny terror · Post by **team tiny terror** » Thu Mar 20, 2008 12:24 pm

can you give me a link for a light battery and all i will need to charge it
and these are the motors i have but if there are better ones siuted to the specs of my speed controller can you give me the links for them

cheers

tim

http://cgi.ebay.co.uk/Motor-5-X-130-Bru ... dZViewItem

Post by **BeligerAnt** » Thu Mar 20, 2008 5:38 pm

Those motors really are cheap and nasty!

Do you want them for drive or for a weapon?
They probably don't have much power for a weapon, and if you want to use them for drive they are a bit big and heavy and you need to add a gearbox to them.

Your speed controller will handle much bigger motors, so these motors would not be a problem for it.

7.4V 300mAh lithium-polymer battery (22g):
http://www.gobrushless.co.uk/2s-lipo-300mah.htm

A suitable charger from the same supplier:
http://www.gobrushless.co.uk/imax-b5.htm

There are many other chargers available, it's worth shopping around and searching this forum for other recommendations.

team tiny terror · Post by **team tiny terror** » Thu Mar 20, 2008 8:32 pm

it sais you need an power source input where can i get one for this charger also my speed controller has a cut off at 4.5v so will i need a 11.1v battery i want this robot to be a speed freak so if there are better motors for us let me know and i would be using these motors for the drive

cheers

tim

Post by **BeligerAnt** » Thu Mar 20, 2008 10:05 pm

Most people are using these motors:
http://www.precisionmicrodrives.com/pro ... ucts_id=94

They only weigh 9g each and include a very strong metal gearbox. The 3V motors will run happily on a 7.4V LiPo battery pack.

Those motors give plenty of speed, especially with 50mm+ diameter wheels. Remember the bigger the wheels, the faster the robot!

The fact that your speed controller cuts out at 4.5V is ideal for a 7.4V LiPo pack, as you shouldn't discharge the batteries below 2.5V per cell (5V for a 7.4V pack). The speed controller will do a pretty good job of protecting your batteries for you.

For that charger you can use any 12V plug-in power adaptor. If you are only charging 300mAh packs you may have a suitable one lying around at home. If not you can buy them from Maplin etc.

If you haven't yet bought the speed controller, check that it provides forward and reverse. I know it sounds obvious, but speed controllers designed for aircraft don't need reverse so they don't do it. Obviously you will need a speed controller for each motor.

HTH

Critters · Post by **Critters** » Fri Mar 28, 2008 5:29 pm

team tiny terror wrote:can you give me a link for a light battery and all i will need to charge it
and these are the motors i have but if there are better ones siuted to the specs of my speed controller can you give me the links for them

cheers

tim

http://cgi.ebay.co.uk/Motor-5-X-130-Bru ... dZViewItem

To tell you the truth i think that ESC is too many amps to the motor. You might blow it

And for the battery you can basicly get any receiver pack that will fit in your bot and is not to heavy.

What receiver are you planing to use?

Post by **BeligerAnt** » Fri Mar 28, 2008 5:41 pm

Critters wrote:To tell you the truth i think that ESC is too many amps to the motor. You might blow it

Critters
You are mis-understanding the rating of ESCs. A 15A ESC can provide UP TO 15A to a motor. The actual current will depend on the battery voltage and the motor winding resistance (I=V/R = Ohm's Law). When the motor is spinning the current actually reduces due to the back EMF of the motor.

You WILL blow up a motor if you seriously over-volt it. You will blow up the ESC if you connect to a high battery voltage and a high-power motor.