Tank Mod advice
 

Hi Everyone, amazing forum community and wealth of information you have here!

I am seeking a little bit of electronics help here.....

I have a nice little HL pershing tank, unfortunately the speed control on one side of the board is blown.

Basically, rather than replace the HL board, i wanted to get some autonomy going on in the tank, using something like a picaxe, Arduino, oopic or a similar type of microprocessor along with Ultrasound/infrared etc sensors ....

SO....im trying to figure out what kind of current the motors in the pershing draw up to stall? i dont think microprossesors could handle that king of load, and wouldnt want to be blowing expensive little things like those away! I am vaugely aware of H-bridges, and am also trying to figure out if i can use a dual h-bridge to power the motors, in turn being controlled by the microprocessor.


.....At the moment i have the black capped (stock) motors in there, and i also have a set of white cappped motors too. I would like to be able to use either, as i also have a walker bulldog with metal gearing and tracks which i would also like to convert....

Any advice would be much appreciated!

thanks,
chris

RE: Tank Mod advice
 

Welcome Chris,


First off I am a retard when it comes to electronics, with that being said, I believe Darkith would be the go to guy for that. Just wanted to welcome you on board, other then that I really don't have anything to add. But these guys on here are great and someone will come along and help ya. Cheers

Wade

RE: Tank Mod advice
 

This is all that I've found that might be able to help with your stall question:


http://www.microhydros.com/400_motor_complete_info.htm

http://homepage.ntlworld.com/edward.matthews/motors.htm


The manufacturer model numbers should be stamped/printed on the motor casing.

RE: Tank Mod advice
 

Hi Philipat! cheers for the links.....unfortunately though, i am holding a whitecap motor in my hand at the moment, and there is nothing stamped on the casing other than the word "Yuxin", which is on the plastic endcap. So basically i dont know if its a Mabuchi or Graupner......

From the other link, can i assume that these motors (roughly) draw between 0.5 (no load) and 3.5 Amps? it still doensnt tell us how many amps it will draw on stall, only its stall Torque!

I have been looking into the Sabertooth esc range, they look as though they might do the trick, but i need to find some definite values for what that HL motor draws under load.





Oh and thanks for the warm welcome rebellion!

cheers all
chris

RE: Tank Mod advice
 

The motors are Suntech 385s. The black capped motors turn about 16500rpms and the white ones 11,000rpms. Don't remember the stall amperage but they're both less then 10. The least expensive way to repair the tank is to simply buy 2 boards. One to replace the broken board and another for a spare. The black capped motors really should have a fan cooling the heatsink when using the TK-RX13 or the newer TK-RX14 board. The "search" feature is your friend.

RE: Tank Mod advice
 

Hi Swathdiver, thanks for your reply! i have looked through a lot of posts here, like your motor testing thread (using the friendly search function!) and all seem only to give amperage under no load, rather than its working current draw.

I know i could easily just order myself a new rx18,and fitting it would be much easier, but i would still like to make an autotank! My housemate is a coding guru (i think hes about 68% digital now!) and he is quite keen to let his skills loose on a picaxe microcontroller, so we have joined projects to try and create an automated drone tank.

But yeah "less than 10" fantastic...that at least gives me a rough idea of the size of current i am playing with here!


Blessings,
chris

RE: Tank Mod advice
 

Remember, the circuit breaker is your friend. :D Install a 5 amp breaker and then build your stuff to handle at least that.

RE: Tank Mod advice
 

Yeah definetly! the first problem lies in how to power those motors from a microcontroller, as most boards seem only to be able to handle half an amp max and work on 5v. I think they are all designed with much smaller motors in mind.

RE: Tank Mod advice
 

Hi,
i would like to build something similar, basically an autonomus / rc platform built around arduino.
Was considering using an Heng Long tank as chassis / motors / gears. Seems a decent enough platform for mildly rough terrain.
Plus, it would look cool! :D

My question is: do you really have to power your engines through the micro? why? that seems to me the work of the esc. From the arduino board you send the signal to drive the motors, not all the amps to power them.

See for instance this diagram:
http://www.irit.fr/~Nicolas.Lassabe/diagram.jpg
(he uses servos in his case)

taken from:
http://www.irit.fr/~Nicolas.Lassabe/robot.php

This, of course, if your really want to work on micro programming and have an autonomous robot rather than just repair your pershing.

Regards

RE: Tank Mod advice
 

Grumble,

No offense intended, little buddy, but from your questions, I fear you may be heading a mite out of your depth.

However, if you want to persist ( and I, most heartily, urge you to do so), try these sites (particularly the third one:

http://www.mcmanis.com/chuck/robotic...dge/index.html
http://robotroom.com/HBridge.html
http://www.foxflier.com/stuart/radio.htm

Then if you start to feel a little befuddled, try this one (i'll bet it will be the most help to you) :

Dave Lancaster's http://darkith.dyndns.org/~darkith/

Good luck.

RE: Tank Mod advice
 

I could well be splat!!! although i have a mechanical engineering background and an audiotechnology degree, im still a bit confused as to how the whole system architecture flows where microcontrollers are concerned.

Brilliant links, very informative!

cheers again all!

chris

RE: Tank Mod advice
 

and ddrake, i think your post just answered one of my previous confusions!

RE: Tank Mod advice
 

Grumble (Chris, You'll note that I like using nicknames),

System architecture is nowhere as important as more basic concepts at this point.

Basicly, you have a low current capable control (component 1) driving (component 2) a high current draw system (component 3):
component 1: the recv'r board in the tank, the PC in ddrake's picture, or your desired Artificial-Intelligence processor.
component 2: The DRIVER circuit ( an H-Bridge circuit for each motor.
component 3: the motors.

It gets infinitely more complicated from here.....
Your choice for component 1. The easiest solution is the supplied HL recvr board. possiblly more versitile, much more complicated, is a PIC processor interface to intrepret whatever type of input commands AND,,, the software to support it. And so on, and so on, and so on.....

RE: Tank Mod advice
 

I forgot that I'd made some charts a long while ago. Here's some of the info I have about amp stalls:

Bane Bots M1-RS385-72 stalls at 17 amps. Turns similar RPMs to black capped Suntechs.

Jamara 400 stalls at 20 amps.

Mabuchi RS380SH-4045 stalls at 21.6 amps.

Permax 400 stalls at 8 amps.

If you send me a PM with your e-mail address I can send you the excel file tonight.

RE: Tank Mod advice
 

Cracking info guys, thanks!

Splats last post has cleared up a small area of confusion for me (nice one, thanks!), PM sent to Swathdiver!

Cheers again all!

peace
chris

RE: Tank Mod advice
 

for what you want use a vex robotic radio system it will do all you want

RE: Tank Mod advice
 

Yep i have looked at the Vex kit....very interesting modular approach, same with the lego robotics system (NTX or something like that?). The goal in this wee project is to switch the tank from radio control to complete autonomous self control, so my other RCtanks can attack (or be attacked!) by it!

Now if i could find a way to interface either of those with the tanks motors, then that would be a start towards a solution. same thing goes for the microcontrollers as well....


Thanks all!!

chris