Sabertooth alternative

All things antweight

Moderators: BeligerAnt, petec, administrator

Sportball
Posts: 46
Joined: Mon Sep 23, 2013 7:29 pm

Sabertooth alternative

Post by Sportball »

Good Afternoon,

Does anyone know of a cheaper alternative to the Sabertooth 2 x 5a ESC? I am looking to control 2 x 300 RPM brushed gear motors for drive.

I have found the below.
http://dx.com/p/brushed-electronic-spee ... een-218621
...so I guess I could use 2 off these.

I have now spent so long looking for a cheaper alternative I could have earned the money to buy the real thing but at $59.99 it seems like a lot of money for something so small.

Any help is appreciated.
User avatar
Rhys
Posts: 738
Joined: Tue Oct 29, 2002 12:00 am
Location: Caerphilly, South Wales

Re: Sabertooth alternative

Post by Rhys »

See my post in your other thread. Baby O is probably the best cheap speedo I've used, only £17. Alternatively the botbitz ones look pretty good, but you're going to have to pay for postage from down under
Image
EpicentrE
Posts: 831
Joined: Mon Jun 09, 2003 12:00 am
Location: Coventry
Contact:

Re: Sabertooth alternative

Post by EpicentrE »

I think it's worth mentioning that both Andy and I have had some weird issues with Baby Os. I know many people have used them without issue - as have I on occasion - but Andy and I had a few particularly bad ones where the driver IC just popped, seemingly without reason (this is what put Void out of AWS40 - it popped two Baby Os in 24 hours).

I also havn't seen anyone mention Peter Waller's boards yet - information about them can be found here.
Scott Fyfe-Jamieson, Captain of Epic Robotics. Champion of AWS38/41/42.
http://www.epicrobotics.co.uk
User avatar
peterwaller
Posts: 3213
Joined: Fri Feb 15, 2002 12:00 am
Location: Aylesbury Bucks
Contact:

Re: Sabertooth alternative

Post by peterwaller »

Because of the high cost of approvals I can't offer them for general sale.
Also because hand making the boards is very time consuming I only make them for people I know to try and keep the numbers down.
User avatar
Rhys
Posts: 738
Joined: Tue Oct 29, 2002 12:00 am
Location: Caerphilly, South Wales

Re: Sabertooth alternative

Post by Rhys »

I can't say I've had any problems with mine. I've got 5 of them so far, and the only issue was caused by me shorting the motor terminals. You and Andy both run them on 3 cells though, don't you? Do you think that might have anything to do with it? They are supposed to be rated to 13.5v though, so maybe not...
Image
User avatar
peterwaller
Posts: 3213
Joined: Fri Feb 15, 2002 12:00 am
Location: Aylesbury Bucks
Contact:

Re: Sabertooth alternative

Post by peterwaller »

Three cells could well be the problem.
If you are using them with HP motors they have a stall current of 1.6 A at 6 V.
This goes up to 2.24 A at 8.4 V (2 cells) and 3.36 A at 12.6 V (3 cells).
The TB6612 driver chip is only rated at 1.2 A continuous.
I found on my controllers doubling up the TB6612 giving a continuous current of 2.4 A and only rateing the HP's for two cells was the answer.
User avatar
BeligerAnt
Posts: 1872
Joined: Wed May 15, 2002 12:00 am
Location: Brighton
Contact:

Re: Sabertooth alternative

Post by BeligerAnt »

The Baby O uses the same TB6612 drive chip that Peter uses. The problem is that they don't like any more than 2 cells. I killed one quite quickly running on just 9-10V. Fortunately I was able to replace the driver chip.
Gary, Team BeligerAnt
Sportball
Posts: 46
Joined: Mon Sep 23, 2013 7:29 pm

Re: Sabertooth alternative

Post by Sportball »

Thanks for the info, I will order a baby O and have a look. I am happy to do some basic soldering as long as I know what to do.

That's the final component then; now I just need to figure out how to wire it all up, programme the transmitter and build the chassis....easy :oops:
User avatar
Rhys
Posts: 738
Joined: Tue Oct 29, 2002 12:00 am
Location: Caerphilly, South Wales

Re: Sabertooth alternative

Post by Rhys »

Don't forget though, you will need to buy an AVR programmer too. The official pololu ones are about £14, but you can get knock-off versions from hobby king for under $4. I've only used the official ones, but lots of people on the Australian antweight forums have used the hobbyking ones just fine. But once you have the programmer you can quickly and easily programme as many boards as you like.

The soldering is very simple and there's lots of guides online for how to get the board programmed. I'm pretty useless at soldering and programming, but I've never failed to get the baby o working.
Image
marto
Posts: 25
Joined: Thu Sep 15, 2011 1:05 pm

Re: Sabertooth alternative

Post by marto »

Post Reply