Machsupport Forum

General CNC Chat => Show"N"Tell ( Your Machines) => Topic started by: welderjosh on April 07, 2015, 09:48:40 PM

Title: Need help designing plasma table
Post by: welderjosh on April 07, 2015, 09:48:40 PM
I have purchased some steppers (Voltage: 4.2 V, Current: 3.5A ,Holding Torque: 440 N.cm, and gecko g540's. I plan on buying a smooth stepper too. What size power supply should I use? Will I need more than one to power 4 motors? Thank you.
Title: Re: Need help designing plasma table
Post by: welderjosh on November 04, 2015, 08:52:26 PM
427 views, and not one comment.. thanks for the help.
Title: Re: Need help designing plasma table
Post by: Overloaded on November 04, 2015, 09:03:01 PM
Hey Josh, this one slipped by me.
I rarely miss one ..... but you got me. :)

Here is gads of info for ya from the "Pro's", I hope it helps.

http://www.geckodrive.com/support/step-motor-basics.html

Kind regards,
Russ
 :)
Title: Re: Need help designing plasma table
Post by: robertspark on November 05, 2015, 02:29:31 AM
If you are buying the smooth stepper... Buy the Ethernet version as it does backlash compensation and torch height. Control and can use m10/ m11 codes to quickly toggle one output on and off.

I'll be back later to unload a load more info... Need to go pay the bills with the day job

Rob
Title: Re: Need help designing plasma table
Post by: robertspark on November 05, 2015, 04:48:24 PM
The specs for the G540 kind of are dictating your limiting power supply voltage for you as they are rated at 50v DC....

The current rating of your steppers is 3.5A, and its unlikley that they will draw 3.5A x 4 = 14A x 50V = 700 W

So you're looking for a lower supply rated at less than 700W and less than 50V DC allowing a margin for the back EMF from the drives.

http://www.cnccookbook.com/MTLatheCNCDrivers.htm
Probably looking at a 44V 600W one of these http://www.antekinc.com/600w/
http://www.pmdx.com/PMDX-137

My personal advice would be to not use a switched mode power supply but look for a toroidial transformer type power supply or build your own (in which case you will be looking for a transformer rated at less than 700W and 35V AC.   The reason being is they tend to deal with the back emf better and absorb the current flow they are also quieter when you're running your steppers.
There is a bit of info here for you to read up on.



If you're looking for ideas for the rest of the plasma, have a look at this link, it may give you an idea about doing an easy to expand system.
http://www.instructables.com/id/CNC-Plasma-Table/

Unfortunately everyone tends to buy the steppers, drives and BOB before they build their machine... and really they should consider doing it the other way around...

Hope some of this helps.

Rob

Title: Re: Need help designing plasma table
Post by: welderjosh on November 16, 2015, 08:31:32 PM
Thank you guy for the help. This helped me a lot.