Thread: Power supplies

They are big motors Bob.
I think you have got the best deal as the toroidals are expensive and heavy so the freight is reasonable as well.
I am far from an expert on the electricery so others chime in if something better is known.

Hi Bob

I will bring over some JMC 2m542 Drivers as well as a 48v PS give them a go first just keep an eye on heat you may need to stick a fan across them whist you test.

Check your front door mate I will drop them off on the way to work you will need to find the manual online.

Sean

Bob,

Firstly, those power supplies are good, i have one powering my system. I'd have to say it was great as at the time i didn't have the time to search and find all the bits and pieces at the prices i think are reasonable and by the time i had a quick look, i wasn't far off the mark even with postage. Plus i had someone to blame on my big system if the power supply failed. I'd have to say the communication wasn't the best and i did have an issue getting wrong daughter boards but in the end it all worked out and i did get the right stuff so the seller isn't too bad and maybe the service is better. Remember too, try getting something over-rated for your use, running the PSU at close to max will wear it out faster than something running at half throttle.

Next, and more importantly, Larger motors DOES NOT mean faster speeds. To get more speed on stepper motors, it is dependent on your power supply and motors inductance in mH. This lower the inductance the quicker it will move onto the next step in the sequence. The better matched your PS and caps the better the whole circuit will work.

In your machine setup the 286 motors are definitely underpowered on that machine size for ballscrews, however i'm not sure 1200oz/in is the best. A 640oz/in should get you out of trouble and save money but its your choice and 1200oz/in will work no worries. You can always go large and run a 1:2 pulley so you get twice the speed but then you reduce your accuracy (so many trade offs) Just remeber you'll need to change the mounts to suit nema 34 too. lol. As for the power supply, your other option is to run each motor off a smaller seperate supply, for some reason it gets frowned apon in the hobbyist world yet when you start looking at some large commercial machines, you find it becomes common practice. A mate of mine will be running 3 of 1200oz/in for a 1m x 1m mill for al., steel etc and each has its own supply. Just more options for you.

Anyway, just my $0.02.
Daniel
P.S Some good reading below:
Geckodrive Technical Support Library
Stepper motor - Wikipedia, the free encyclopedia

Thanks for your replies Rod and Daniel

Sean came over today because he saw what I had written and he hated the though that I might spend money on something that I didn't need when I could have been spending that same money on something that he needed me to buy.

Whatever, I think that he has just about convinced me that the problem lies with power supply I was suing. It is only putting out 36volts at about 6 amps and it just doesn't seem to have thegrunt that is required to get the motors moving at any sort of a reasonable speed.

To this end, he has told me that he will drop off his Gecko G540 and to try that with his 48volt PSU. I am ready to be convinced that this is the way that I need to go as it is considerably cheaper and more flexible doing this.

We actually took all the motors out of circuit except for the y axis motors and tested his theory. It appears to be proven in the affirmative.

Bob