newbie from bristol soon to be up and running

**uppy121** · 31-03-2013

list of items left to get

400w psu 36v power supply
cnc micro switch
end cap 75x75mm
plus
sbr 20 x 900 supported rail kit

**Ricardoco** · 31-03-2013

Originally Posted by uppy121

list of items left to get

400w psu 36v power supply
cnc micro switch
end cap 75x75mm
plus
sbr 20 x 900 supported rail kit

Hi there, it looks like you are going to get the supported rail then. It is best, but i managed for a while with unsupported, by the way i think you may be hitting the +Post New Thread button Rather than the +Reply To Thread button, Im sure one of the mods will put them all as one when they notice it.

Rick

**Jonathan** · 31-03-2013

Presumably you've got the stepper drivers already, since they're not on your list, but which ones did you get? It looks like you have the common 3Nm motors. They work best with a lot more than 36V - ideally 70V. The reason is the inductance of the motor limits how fast the current can rise, so at high speeds the current can't reach the rated value, hence the motors don't output as much torque. However, by increasing the voltage you increase the rate at which the current rises, so that gets higher torque at higher speeds. If the drivers you've got will accept 50V, then you might as well get a 50V PSU instead of 36V. It will make a big difference.

Originally Posted by Ricardoco

by the way i think you may be hitting the +Post New Thread button Rather than the +Reply To Thread button, Im sure one of the mods will put them all as one when they notice it.

Already did it once...

**uppy121** · 31-03-2013

5 axis breakout board
4 x drivers m542
400 w power supply
and yes 4 x 3 nm stepper motors

**GEOFFREY** · 31-03-2013

Machine building in living room, second machine being planned before the first is finished. It seems to me you are a natural for this site. Well done. G.

**Swarfing** · 31-03-2013

Sure is

I must remember to shift that milling table out of the Utility room before the kids trip over it .....lol!

**martin54** · 01-04-2013

Welcome to the forum, if you still need to buy a power supply for those drivers then as Jonathan has said you would be better off with a higher voltage, think those will run up to 50v unless your buying a second power supply because the one you have won't be enough for all the motors.

Have a read through some of the build logs before you start buying new parts for the next build, it will give you a good idea of what will suit your needs best for the new machine.

Best of luck with it.