OSMC - Open Source Motor Controller 400a/50v

[danielDK]

Hi Guys

Have any of you ever built the OSMC? was it all it is cranked up to be?


For those who havent heard of it, its a 12-50v, 160a continous, 400+ amp peak, H-bridge controller which is used in a lot of the "battlebots".

In diy form it is around 60$ - and "retail" 230$..

the documentation is quite good as far as i can see:
http://www.robotpower.com/downloads/OSM ... _V4_25.pdf
http://www.robotpower.com/downloads/osm ... -clean.pdf
http://www.robotpower.com/downloads/osm ... 222001.zip
even gerber files with silkscreen:
http://www.robotpower.com/downloads/osm ... erbers.zip



So did anybody from the x-sim community build this?

Cheers
Daniel

[danielDK]

Yeah - i'm sourcing parts right now, it looks like the most expensive components like the FETs are quite reasonble when bying them in lots of 50 from China.

Yeah - i plan on running a pair of HP 253232-001 48v 3kw power supplies.. with the xyd-14a neodynium motors to drive large ballscrews -

Im basically building the forcedynamics type simulators, so i need the continous power keep the machine aloft without overheating.




/Daniel

[telfel]

Hi

Will watch with interest, been looking to drive 24 volt, 27 amp, 590 watt, 3200 rpm motors with a 25:1 / 120 rpm worm drive gearbox.

The problem seems to be staring / reversing current both the osmc and Speedy's H Bridge are both only the power section and lack any
current monitoring, over temperature control.

I've already destroyed a China DBK H bridge supposed to do 68 amps

At present i'm trying a Vex Black Jaguar 24 volt 40 amp cont, 90 amp surge, running it with a wheel chair motor @ 12 volt to test, will push the load up slowly to see how it performs, like the JRK's it has position control via pot or encoder and is priced @ $60.00
the cons are its serial to Can Bus so would require Sir to write a plugin and again shipping is pricey.

The VBJ may not be suitable for me as I'm now looking to build a 6 dof based on the work of Thanos, and Ian from BFF.

I've also considered the Motion Dynamics speed controler, but it would require modding, and the shipping from Aus is a no go.

regards Terry

[danielDK]

Hi Terry

I'm currently tinkering with induction rings and feedback to the pwm driver seems trivial... i dunno if it is at all needed tho..

As per the documentation - they did 400+ amps for 30 seconds with no ill effects other than hot fets... this is an good indication that it will do the 79 amp per fet the to220 package can deliver... each fet is silica rated at 170amps so i'm hoping 600+ amp spikes less than 2 seconds, shouldn't be a problem...


/Daniel

[motiondave]

Hello Telfel, you mention the work on a 6 DOF of Tronic and Ian of BFF, are they in partnership in business?

[telfel]

Motiondave,

Not to my knowledge, Ian has written 6 dof software for flight sims, so I am planing on using it with Tronics AMC.

I also believe Tronic is re configuring Robin's software to use with X-sim and be compatible with Ian's layout.



The reason I'm now considering a 6 dof, is that I see it as mechanically easier to build for a home build. I've also bought 11 big wormgear 24 volt DC motors,
as job lot, the only problem at the moment is finding a decent affordable H bridge to drive them.

regards Terry

[tronicgr]

No one attempt a brushless setup yet , that i publically know off.

Looking at the cost of the brushless drivers I think its more cost effective to head to VFD inverters and AC motors...

brushless dc motor controllers.jpg (156.59 KiB) Viewed 3318 times

But I know a person that is attempting to use Moog linear servo motors with my 6DOF electronics which are essentially brushless.

[tronicgr]

The size of the 6DOF platforms is the correct one as well the size of the AC motors (1HP each). The idea behind it is not to have only the driver/pilot on it but also controls and full cockpit, screens and why not the motion computer mounted on it as well. And why not 2 persons on it? I had really hard time trying to balance my joyrider back in 2007 for just the passenger a few controls and a tiny LCD screen using those windows wiper motors...

Threre are brushless drivers now with price as low as $20 but they are just speed controllers. They are not reversible! They do control speed but not position.

[x1610]

For brushless motors and drivers look on ebay with Leadshine
400watt max but cheap

[danielDK]

Hi Guys,


Just wanted to let you know my initial tests with the OSMC has been absolutely fantastic!

I build 3 of them for 200$ by ordering the boards from itead studio, the hexfets(irf1405) from ebay and the rest from digikey.

I have been testing one board with only 4 of 16 fets installed, and i'm able to burn heavy wires and large motors while the fets are still cold to the touch!


There are 3x my-1020 - 48v/1000w motors on the way along with 3x 3kw 48v powersupplies. The motor stall wattage will be around 18000watts so i need some sort of current limiting as not to overload the 3000w powersupply...

I'll post a video of the setup as soon as i get it all running!

Cheers
/Daniel