G540 or G203Vs?

[braidmd]

After nearly 18 months, I've finally resumed work on my DIY router. And I'm happy to say that it's nearing the point of hooking up the steppers & electronics. I had originally purchased a 4-axis/425 oz package from Xylotex for this build (FYI - I'm using 1/2-10 single start ACME screws, which I plan to upgrade to multi-starts on X & Y axis). Now I'm rethinking the setup due to all of the "advances" in technology - I want to switch over to Gecko drives. But I need some advice on the most cost-effective way to convert. Here's how I see it...

I could keep the steppers (425 oz/5.0 A bipolar parallel/ 2.1 mH inductance) & go with G203Vs (4 each: $600), a suitable breakout board (not sure which or how much), and larger power supply (KL-600-48 48V/12.5A $139.95). That's going to be at least $740, but would likely get the best performance out of the steppers.

The alternative would be to go with the G540 ($299), a better power supply (KL-600-48 48V/12.5A $139.95), and possibly four better-matched steppers (KL23H284-35-4B/387 oz-in @ $49 each), which comes out to be ~$640.

So... Which configuration is "best"? Will the G540 with matched steppers perform comparably to the G203Vs? Is there a less-expensive, "middle ground" configuration that I'm missing? Thoughts??? Help?!?

[TOTALLYRC]

Originally Posted by braidmd After nearly 18 months, I've finally resumed work on my DIY router. And I'm happy to say that it's nearing the point of hooking up the steppers & electronics. I had originally purchased a 4-axis/425 oz package from Xylotex for this build (FYI - I'm using 1/2-10 single start ACME screws, which I plan to upgrade to multi-starts on X & Y axis). Now I'm rethinking the setup due to all of the "advances" in technology - I want to switch over to Gecko drives. But I need some advice on the most cost-effective way to convert. Here's how I see it... I could keep the steppers (425 oz/5.0 A bipolar parallel/ 2.1 mH inductance) & go with G203Vs (4 each: $600), a suitable breakout board (not sure which or how much), and larger power supply (KL-600-48 48V/12.5A $139.95). That's going to be at least $740, but would likely get the best performance out of the steppers. The alternative would be to go with the G540 ($299), a better power supply (KL-600-48 48V/12.5A $139.95), and possibly four better-matched steppers (KL23H284-35-4B/387 oz-in @ $49 each), which comes out to be ~$640. So... Which configuration is "best"? Will the G540 with matched steppers perform comparably to the G203Vs? Is there a less-expensive, "middle ground" configuration that I'm missing? Thoughts??? Help?!?

The xylotex 425 oz motor is 8mh inductance, based on what there web site says, so the g203v with a 70+v power supply will give you the best performance.

I am using a keling 425oz motor with a g251, same as g540 drivres and it gives good power and speed on a 50v power supply. But I am using a 5tpi screw.

Mike

[braidmd]

Thanks Mike - Yep, I was reading the wrong column on the spec sheet regarding the inductance value... got "parallel" & "serial" reversed in my head, even though I had everything highlighted on the page in front of me. Yesterday was a long day...

Due to budgetary constraints, I'm leaning towards the G540 & upgrading in stages - G540 first, then other parts as funds permit. I have no doubt that the drive package alone will make a great improvement in speed & stability, based on other posts I've read here. But I don't wan't this thread to be perceived as a "convince myself to buy this or that" session that lacks a fruitful question...

Let me focus on the real issue... What are the performance advantages of the G203V over the G540, when both drive packages are matched with appropriate steppers & power supplies - "with all things equal"? Is it just a matter of power & speed???

[TOTALLYRC]

The g203v and g250/251/540 would have the same performance if run at 50v and 3.5 amps. The 203v will allow more amperage and more voltage so you run more powerful motors. If you thought that the xylotex would work, then you will be thrilled with the g540. g203V MIGHT BE OVERKILL if it is a smaller machine.

Mike

[braidmd]

Mike - Thanks again. That makes complete sense. I was curious if the stepper motor design & efficiency might play a role... and I'm sure it could to a degree.

My primary concern with my build, in "hindsight" - based on the experiences of others, is that the xylotex board will create serious resonance-issues, especially when you pair the 425 oz motors with 10 tpi/single-start screws. I suspect the xylotex package would perform better with a multi-start screw, as that would keep the rpms lower in the torque curve. But the G540 seems to nearly double cutting & rapid speeds just as a "bolt on" fix (all based on others' posts) - simply because Gecko's drives are smooth-pulsing (& morph the stepping on the fly?!?).

Man, I really wish the G540 would have been out 2 years ago... I feel like I bought a Beta VCR just before VHS hit the market...

[TOTALLYRC]

Originally Posted by braidmd Mike - Thanks again. That makes complete sense. I was curious if the stepper motor design & efficiency might play a role... and I'm sure it could to a degree. My primary concern with my build, in "hindsight" - based on the experiences of others, is that the xylotex board will create serious resonance-issues, especially when you pair the 425 oz motors with 10 tpi/single-start screws. I suspect the xylotex package would perform better with a multi-start screw, as that would keep the rpms lower in the torque curve. But the G540 seems to nearly double cutting & rapid speeds just as a "bolt on" fix (all based on others' posts) - simply because Gecko's drives are smooth-pulsing (& morph the stepping on the fly?!?). Man, I really wish the G540 would have been out 2 years ago... I feel like I bought a Beta VCR just before VHS hit the market...

Of course Beta was actually better.

I have the xylotex on a 20tpi scew on my Taig and the rapids are painfully slow.
If I knew then what I know now!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

The G540 on the existing power supply would give better perfomance since you will not get the resonance issues. Not to mention the morphing which allows the motors to carry their torque higher into the rpm band.

So if you are on a tight budget, just get the g540 to start and then the power supply, and then the motors if you really need to, but I think once you get the 425's on 50v they will be more than enough.

[LeeWay]

Actually I think you may be overlooking the 201's. They would save you nearly $200 over the 203V's.
I went from Xylotex to 201's initially and went with the 425's from Keling along with a 72 VDC supply. The difference in preformance floored me. It was almost unbeleivable.
From that point on, I only bought 203V's. I liked the extra comfort they provide with all the safety circuits.
Well worth the extra cost.
Something else I noticed between the 201's and 203V's is that my motors are warmer under 201 control.
I think the 203's have a current reduction circuit or something that kicks in when idle.
Not an issue, just a difference. To me they otherwise preform identically.

[braidmd]

Yes, Beta was better. Sony learned a hard lesson on that one. Ah, but I digress...

Lee - I had mulled over the G201 briefly, but seemed to gravitate towards the "Cadillac" series G203, perhaps because they are newer, more "bullet-proof" & can morph the stepping on the fly, if I recall correctly. Your point makes good sense.

I have to say that I really like the G504 best of all - simply due to the price, features and the all-in-one package, with the BOB is built in. What BOB would y'all recommend for the G200 series?

Oh, I finally updated my build thread with a few pics. Here's the link, should the details help with the selection of drivers...
http://www.cnczone.com/forums/showthread.php?t=43748

Thanks - Mike (yet another...)