Miscalculation?

[zarthcode]

I just blew a wad of cash ordering my mill (LMS HiTorque) and CNC Fusion conversion kit.

I have yet to decide on what to do about electronics, as it seems that every time I decide, I find a better option (or discover a problem with the decision I made). So it's time to ask for some advice, since I'm a total newbie to machining (I'm an electrical/software engineer by day).

Prior to this, I was simply debating using a G540 w/4 channels, or purchasing some low/mid Keling stepper drivers and a breakout board. On the other hand, I'd love to get my hands on the KFLOP (but the KANALOG seems to be out of stock, not to mention pricey. And I kinda want to use EMC2 instead of Mach3) For now, I don't mind using a breakout board - as long as I have enough inputs to implement things such as Auto-zero/probing, limits/homing, etc.

I'm only planning on working with aluminum and delrin, and I have plenty of patience. This machine will *Very* soon have a 4th axis, and possibly even a 5th axis/trunnion table - so I'd like to make sure I can upgrade/expand my electronics. I want this machine to have as many features as I can pack into it.


But the real problem may be the motors I ordered from ebay, a set of 3 425oz-in motors ebay. But I've since realized two issues:

* An 8mm shaft for the front side of the motor (which I specified for the heli-cal coulplers from CNC fusion!)
* The Phase inductance is 6.8mH, and the motor is rated at 3A per phase.



Initially, I thought all stepper motors just required as much voltage as you could give them to get the torque you want, and simply limit the current to keep from burning them up...

To make a long story short, once I figured out that motor wants to run at 83V, it has made (economical) driver selection difficult. I already ordered a 24V power supply, will this work at all? What would the effects be? I haven't seen many drivers that approach 80V, even the best drivers seem to top out at 50V.

Should I just ditch the motors, (and ask cnc fusion for standard couplers), and choose better steppers? Ideally, I'd like to spend under $700, but if I have to save an extra couple weeks, so be it.) Or am I worried about nothing?

I'm close to just picking up (at least) some KD-4042D drivers, and steppers with much lower phase inductance as to work (well) at or below 48V.

(As an aside But, if I decide not to get the G540, what could I use to gain that nice VFD/Spindle control?)

[judleroy]

The motors will work with the g540 and 24v supply. You would be better off if you get a 48v supply. There not the best match for the drive but the motors holding torque is rated at 0 rpm at a certain amp rating not volt rating. The more volts you put into the motor the faster it will spin and the torque should also holdup better upto a higher rpm.
Judleroy

[ger21]

Gecko 201's or 203's can handle 80V. But it would be cheaper to just sell the motors and power supply on Ebay and buy a G540 kit from Keling with 380oz motors and 48V.

And the KANALOG is in stock right now?

[zarthcode]

Thanks, I suppose I'll live with the 24V supply for now, and will replace it with a 48V (or larger). I looked at keling's 425oz kit, their motors are very similar to the ones I ordered - that makes me feel much better.

Just noticed that the KANALOGs are back in stock...which makes me pretty happy - but they are still so difficult to justify! (I might just have to abandon the idea of using EMC2, I *really* like that controller!)

I'm done waffling about this: I'm going for the whole hog:

* KMotion + KAnalog (8 Axis, so when I build an ATC and axis #4/5, just add drivers! Plus, the option to add closed loop-feedback makes me feel warm & fuzzy) Smoothstepper is also an option, but I'd rather avoid needing parallel port accessories. Yeah, it's $500, but I see it like the PS3..."it only does EVERYTHING!"

* Mach3 (Probably not required to start with, but I may end up using it anyway)

* Homann sells a 3-pack of G251s (50V, 3.5A) for $179 (Need to investigate if I will require an active cooling solution, I'll be running them at 3A) Later on, I can upgrade these to keling digitals, and move the G251s to the ATC/4th/5th steppers.

* Upgrade/Add to 48V PSU later, if I truly require more speed.

I can't wait :-D