[stingray_65]

Greetings all,

My name is Ray, I'm from Toledo, Ohio and I'm starting the controller phase of my CNC router build.

As far as the machine goes it's a 3 axis fixed X gantry design.
26 inches on the X, 39 inches on the Y, I can go up to 12 inches in the Z.
Its an aluminum profile build, like 80-20, but metric. mostly 45x90 heavy wall Bosh-Rexroth, with a smattering of other manufacturers too.

I'm a machinery repairman by trade, early on I was a journeyman machinist, and in between those trades I did a 7 year stint as a machine fabricator.

I've built most of the machine from reclaimed profile.
The X and Y screws are 1605 Asian rolled ball screws and anti backlash nuts.

As for the controller part, I'm pretty much sold on using a G540.

Picking motors is being a bit difficult for me. I see a lot of 425 oz motors advertised as being 3 amps, and compatible with the G540's 3.5 amp per axis rating, but they will often claim a 9uH winding.
When I run the number according to the G540 manual,the motor would require: the square root of 9uh*32= 98V , well above what the G540 is rated at.
It seems that most 280 oz motors fit the bill pretty well, sqrt 3.5uh*32=59v

Am I on the right track here?
how much am I loosing by running at 48v?
At only 280 oz running at 80% power (48v) what kind of performance can I expect?

Oh!, and that 48V PSU,
The manual says a simple PSU is best, I could build one, but I see a lot of switching power supplys being used.
If I did build one, by time I bought the transformer and other sundries, I'm close to the same price as a switching PSU.

There is soooooo much information out there its hard to sort through it all, I have a difficult time even sorting through it all here on this forum.

Any constructive help is appreciated, I would hate to waste time and money going down the wrong path, or expecting more from a system that just won't deliver it.

Ray

[ger21]

These are 2.2mH.
http://www.automationtechnologiesinc...flat-282-oz-in

If you had 1610 screws, I'd say that the 380oz motors would be a better choice, but the 280's should spin faster, which you need with 5mm pitch screws.

The 425oz motors would be a terrible choice with a G540.

[LeeWay]

I will suggest that you look at the matched sets with cables, motors, G540 and power supply that CNC Router Parts sells.
3-Axis DIY NEMA 23 Electronics Kit | CNCRouterParts

You may save a little grief with it and support is first class. It also gives you peace of mind knowing that it is all selected to work well together.

[stingray_65]

Thanks for the recommendation Gerry.
Those motors look like a good match for the G540.
Also the price is definitely in my budget range