PM-30mvl stepper/driver selection question

Hi all,
I have a few questions on my stepper/driver/power supply for a cnc conversion of a PM-30mvl mill i will be doing shortly. I'm still waiting to pick up the mill since it was back-ordered but it should be here shortly. I have decided to go with the centroid acorn, nema 34 640oz on the x/y, and a nema 34 906 on the z. Also, i am planning on purchasing the ballscrews and mounts for Arizonavideo when he has his kit ready. Now for the questions, would KL8060 stepper drivers be correct for KL34H280-45-4A and KL34H295-43-8B steppers along with a KL-7212 toroidal power supply? I've done alot of research with how to properly size the power supply to the drivers and motors, and using gecko's max voltage=? of motors inductance x 32 i believe i have the right setup. According to that equation the max voltage for KL34H280-45-4A would be ~48v and the KL34H295-43-8B would be ~83v. So do i need separate power supplies? Just trying to wrap my head around this stuff (definitely enjoying it!). Thanks for your patience in help. Jason

If you want to go 50V or 60v then the KL34H280-45-4A should be fine. The Z will be a bit slower but still OK.

The 900 oz does not come in a lower inductance or higher current but you can get the 640 oz with a higher inductance of 6.8mH if you want to run a higher voltage.

I have found that Gecko voltage formula is a bit underrated. The 5.1A 640 ox is fine at 60V and the some what low inductance 900 oz will work fine at 60V.

You can save a little money by using the 60V drives all the way around.

If I go the 60v route for both size motors would the KL-6050 driver be correct, I see it only has a 5 amp rating? Also, I see from what your saying that the KL34H280-45-8A would be a better match at 60v with its lower inductance. I just don’t want the Z to be too slow in comparison to the X/Y, and if so I don’t mind buying the larger driver/ separate power supply for that axis if I really need too.

Jason, I'm running my setup on servos. I stopped in to see a few local stepper conversions and am convinced that servos are superior in every way. Given excellent compatibility with the acorn, you may want to consider the clearpath units. It's really an all-in-one solution that just works. Conversely, a mess of chinese drivers and servos seem infinitely more noisy and clunky. I know the steppers do work, but I guess it's the difference between driving a Lada and an Audi.

I agree but they are somewhat outside my intended budget. What machine are your clearpaths mounted on?

I think that this is a bit of a relationship for CNC's work direction.
If it is engraving, I think stepper motor is the best choice, after all, this is the default configuration in many industries.
If it is cutting, I think the servo motor is the most suitable, because the efficiency is more concerned with ATC cnc router

I'm running the panasonic series on the PM25. I'm running some clearpath servos on a completely different piece of automation, but have found they are excellent for the price.

From what I've seen steppers suffer from missed steps, a lot of flakiness from poor quality drivers, lower and inconsistent speed/torque and a lot of vibration. There are some that use feedback (hybrid) to fault on missed steps, but the smoothness factor just isn't the same. I was surprised to see how much of a difference it made cutting an arc. The challenge of course is when people go down the stepper path it is a lot of jumping around upgrading this part and that part until the final project costs the same or more than if they had used servos from the start. I worked in the automotive industry for many years so this is a very familiar story. If you start with the cheapest option, you often spend a lot more in money and frustration. Buy it cheap and buy it twice.

For the smaller machines steppers are a great choice and loosing steps almost never happens. A $39 stepper and a $59 driver can last for years and never give you any problems.

As you get to larger steppers and drivers its only about $80 more per axes to go to the Clear Path servos. Few would say steppers are better than the CP but your really don't need them.

Most cutting is done on our mills around 10 to 30 IPM and that is the ideal speed for direct drive steppers. The one big thing is steppers make much more noise.

I changed from DC Gecko driven servos on my IH mill on the Y and Z and the steppers have been perfect and I never loose steps unless I clog a tool and stall the spindle. Most the time it will snap the tool off but sometimes I get lucky and stall a stepper as I go for the stop switch.

Good cutters and chip removal is more important than if you have steppers or servos.

Thanks for all the help and advice, it’s greatly appreciated.