[samsagaz]

Hi,i will order from China 5 stepper motors with the following specs
Nema23 - 435 Oz/In - 4.2A - 3.8mH

32*sqrt(3.8) = 62v

So i was thinking about use betweeen 60 and 65v PSU. think that will build my own PSU coz dont see anything bigger than 50v at good prices.

Btw, will be OK use 80v drivers like DM860A and D2HB882MB?

Someone recommend me other model/brand?

i have an gecko g540 but cant use it with that high inductance.

will use other motors with my gecko

[louieatienza]

I believe the G540 can handle up to 50mH. It's the current rating that will hurt your performance with the G540. The Leadshine drives look really good and have a set for a build.

[samsagaz]

I believe the G540 can handle up to 50mH. It's the current rating that will hurt your performance with the G540. The Leadshine drives look really good and have a set for a build.

I see, but if its an 3.8mH motor will need like 62v to get max performance and G540 dont support that high volt :/

Checking Leadshine now.

[louieatienza]

I see, but if its an 3.8mH motor will need like 62v to get max performance and G540 dont support that high volt :/

Checking Leadshine now.

Yes I understand that... My point is, depending on the application, you may not need or want max performance. It does come at the price of heat. I used 425in-oz with the G540 and 48v psu and drive 8-start (1tpi) leadscrews with plenty of power and speed, rapiding at over 700ipm. I'm sure I could raise those rapids with a higher PSU, but that and the drives would end up costing me, without much more useable performance. Might be different for r&p with a larger gear ratio or ballscrew, but for my setup it's just fine.

Leadshine's digital drives use DSPs instead of the CPLD used in the GeckoDrive products, which allow more options (for example microstep up to 100k steps/rev), with some units user-programmable. The prices are pretty competitive too.

[samsagaz]

Thanks dude. i really dont know how much power i will need, im just trying to purchase the most powerful units as i can, i spend like 1500USD in ballscrews and rails, im making 2 big machines, one is 1000x1000 Router Table, and other is 2000x1000x1000 Foam Cutter.

I think that dont will need too much power for that, but first i need to purchase some stepper/drivers and check if are ok for my project, i dont found any "formula" to know how much power i will need for my machines.

Waiting the answer from Leadshine.

[louieatienza]

Thanks dude. i really dont know how much power i will need, im just trying to purchase the most powerful units as i can, i spend like 1500USD in ballscrews and rails, im making 2 big machines, one is 1000x1000 Router Table, and other is 2000x1000x1000 Foam Cutter.

I think that dont will need too much power for that, but first i need to purchase some stepper/drivers and check if are ok for my project, i dont found any "formula" to know how much power i will need for my machines.

Waiting the answer from Leadshine.

Mariss at GeckoDrive has very informative information on how to figure this on the GeckoDrive website. It's not exact but should get you close. Their drives are excellent too as well as the service so I'd check them out as well.

[samsagaz]

Well, purchased the leadshine drivers! digital and analog ones (to test the diferences)

I need to build the PSU now, i was doing this calculations....

i need to run 3 x steppers with this specs 3.8mH 4.2A

so 4.2a*3steppers = 12,6A => close to 9A (efficience).

to calculate the volts im doing 32*sqrt(3.8) = 62V

so i was thinking about purchase an 220/45V 9A transformer, after rectification i will get a little low than 63V coz the loose of the diodes.

What do you think? will work that PSU?

What about if use 48V transformer instead 45V ones? motors will get more speed but will be very very hot, right?

[dmalicky]

The 32*sqrt(mH) formula gives the maximum V for the motors, not necessarily the ideal V.
http://www.geckodrive.com/gecko/imag...cs%20Guide.pdf
As Louie said, it's fine and often best to run them below the max V.