Running 24V 150W Gold Motors on 12V

[Guest]

Running 24V 150W Gold Motors on 12V

ah ok i understand now.

so will the h bridges cope with that or will it fry them, i thought they were only rated to around 30 Amps

[ewe2]

Running 24V 150W Gold Motors on 12V

Just a point on lower power motors. I am more interested in manouverability than pushing power. If you have an effective weapon like Vortexs spinner or a good flipper, the pushing ability is less important.

Do you plan to have a weapon?

Ian

[geoff]

Running 24V 150W Gold Motors on 12V

Ian,
I know a couple of girls who would take issue with you about the importance of pushing power!

But seriously Andrew, Ian makes a very valid point regarding the required balance between drive power and manoeuvrability. Also Jim is right when he says its easier to deal with higher voltages than higher currents My personal preference would be to use the 24v gold motor @24v with a reduction of 6:1 and a 100mm dia. wheel.
This would give you a speed of around 12mph with a reasonable amount of torque. As for speed controllers, with this set up you could get away with a pair of Electonize 30A units and a mixer you can get details of these from http://www.technobots.co.uk/http://www.technobots.co.uk/
It may be helpful to you to try to get to one of the many live events held around the country. Make yourself known to the roboteers and Im sure they would be more than happy to show you their machines, you will see most types of drive systems, everything from the Zeobot motors through gold motors right up to 750w Astroflight cobalt magnet drive units. You would probably also be offered more advice that you would know what to do with.
Check out the live events section of this forum and also http://www.roamingrobots.co.ukhttp://www.roamingrobots.co.uk
I hope this is of some help.
Good luck with your robot.

Geoff.

[grant_ploughbot]

Running 24V 150W Gold Motors on 12V

Hey Andrew, why not use standard drill motors for the moment? they are very cheap and easy to use and you get batteries that you can test it on with the drill. Also for the price you would save on buying gold motors and seperate batteries, you could afford four motors!
If you need ANY help with building or designing then Rc Wars/Robo-Challenge will be able to give you help and advise. We build many robots (6kg to 12kg) and have a fleet of just over 15 at the moment and so we would be able to build any components for you if you do not have the facilities. Where abouts do you live? we have facilities for testing your robot aswell if needs be, and supply electronics if you are uncertain of where to get things.

Grant

[big_nipper]

Running 24V 150W Gold Motors on 12V

Andrew, we have got 2 of those 5Amp (without heatsinks) H-Bridge controllers and have fitted them to 2 of our featherweights. They dont have failsafes, but I dont see why as its only a simple change to the software, I did concider re-programming them but found an easier way, but as it stands you would need failsafes, a PCM type Tx & Rx would do but they are more expensive than the standard ones.

As for the Heatsink, my brother came up with the Idea of using a standard PCs CPU heatsink and cutting it in half and bolting them threw the MOSFETS, these heatsinks are very cheep and on one of them he added a small fan too.

We altered them to work with a 0V-2.5V-5V signal to control the motor speed as they were slightly jumpy with the RC servo signal and the steering reverses going backwards, but so far we are happy with them and will test them out in combat at Sheffield.

One is running on 33.6V with 30V drill motors and the other is running on 19.2V with 12V drill motors, both have a 30Amp fuse on the batteries and has not blown them as of yet.

Current rating is a little difficult to figure out, If you have a 200W motor and your Gear ratio and traction can only deliver 100W before the wheels start spinning then it wont use any more then the rest is wastefull. But if it needs 300W of power to start the wheels spinning then your motor will try and deliver 300W and start to overheat, in time it would burn out if overstressed for too long. So its better to have an overrated motor and not use the power to be on the safe side but at the expense of wasted weight.

The lower the voltage you use the higher current needed for the same power output, also high voltage motors are more effeicnt and as they use less current they also generate less heat.

[Guest]

Running 24V 150W Gold Motors on 12V

Well ive already got too much advice than i know what to do with !!!

One reason i havnt considered using drill motors yet is i dont know where to get cheap drills and i dont know how easy they are to get out of the drill.

I live in the north east of scotland (no robot clubs or any live events that i know of round here)

Geoff, would it not actually be cheaper to use a H-Bridge than a pair of electronizes and a mixer ? Feel free to prove me completely wrong though Does a H-bridge also do the work of the mixer ?

At the moment im swinging towards using 24V Gold Motors since ive got all this advice. I can only realisticly afford 2 of them though, ive been told i could sort out with pulleys etc for each motor to drive 2 wheels, how practical is this, how expensive would that be and how complicated

[aliboy]

Running 24V 150W Gold Motors on 12V

Where exactly in Scotland Andrew ?

[team_ireland]

Running 24V 150W Gold Motors on 12V

Put simply Andrew 4 drills would be less cheeper, easier and less current hungry (possibly wrong there!). Getting the drills out is not too hard at all.

And they can be easily moded using doms mod kits!

Regards

Ian

[taurus]

Running 24V 150W Gold Motors on 12V

homebase are doing their own make 14.8v drills for £15.

[Guest]

Running 24V 150W Gold Motors on 12V

I live near Aberdeen in scotland.

How powerful are the drill motors, whats the Wattage for those 14.8V drills ?

[aliboy]

Running 24V 150W Gold Motors on 12V

Hey andrew i live in Montrose not so far away... im a bit sad that there is few robot events for us Scots

[typhoon_driver]

Running 24V 150W Gold Motors on 12V

fantastic, is that 4 feathers that we now have in scotland?

We should get together somewhere and have a wee battle up north when we are finished building

[aliboy]

Running 24V 150W Gold Motors on 12V

lol cool cant wait to see little hornet slicing everything . My robot Byte may be delayed a while as i have some exams to do and some serious cramming to do but will get as much done before then .

[Guest]

Running 24V 150W Gold Motors on 12V

hey cool, my grandparents live in montrose.

[aliboy]

Running 24V 150W Gold Motors on 12V

small world...