I have posted this before and repeat it here:
But ARE the other choices less expensive? Let's look at the ACTUAL total price of some other drivers, if they try to match G540 capabilities:
G540
$249 G540 with built-in sophisticated BOB, VFD, Logic PSU, Charge pump, high-speed morphing, mid band resonance dampning, Idle current limiting, Gecko effectively lifetime warranty. (Because if it is at all repairable, Gecko will fix it for free--Even if you broke it--and even long after the one year official warranty expires)
$008 Two 48V relays
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$257
http://geckodrive.com/product.aspx?c=3&i=14469
G203V
$533 G203V (4) The only REAL equal to G540 safety and performance, but at a much higher price. These drives are actually SUPERIOR to G540, because they can handle 7A and 80V, but at 3.5A and 50V the G540 and G203V would both provide the same performance. Gecko de facto lifetime warranty.
$109 C11G BOB with optoisolation,VFD, 2 relays.
$030 CNC4pc A20 PSU for BOB
$020 Motor connectors.
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$692
http://geckodrive.com/product.aspx?c=3&i=14460
G251
$196 G251 (4) Has many of G540 features, but missing some "unkillable safety options. Gecko de facto lifetime warranty.
$129 Equivalent sophisticated BOB.
$030 CNC4pc A20 PSU for BOB
$020 Connectors
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$375
http://geckodrive.com/product.aspx?c=3&i=14471
KELING 4030
$220 Keling 4030 drivers (4) Max Amps=3. Effective Voltage max=36. NO high speed morphing. NO mid-band resonance dampning. Keling drivers have a one year warranty, and enjoy a good reputation for reliability.
$129 Sophisticated BOB
$030 CNC4pc A20 PSU for BOB
$020 Motor connectors
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$399
http://kelinginc.net/KLDriver.html
EL CHEAPO option:
$220 Keling 4030 drivers (4)
$028 Simple breakout board with no optoisolation protection for your computer. NO safety charge pump to prevent dangerous surprise machine movement.
$037 CNC4pc C6 VFD card.
$018 C15 Relay card
$030 CNC4pc A20 PSU for BOB
$020 Motor connectors
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$353 With this option, compared to G540, you will have sacrificed some performance and safety--But saved NO money.
LESS POWERFUL DRIVE OPTIONS:
PROBOTIX:
$144 Four Bipolar Sidestep drivers
No full step morphing, no mid range resonance dampning, no Idle current limiting or recirculation. Amps= 2.5 max. Voltage= effectively 24V Max. Probotix drivers come with only a 90 day warranty. If the damage is deemed "your fault," there IS no warranty.
$129 Sophisticated BOB with charge pump, optoisolation, output relays, VFD.
$030 Logic PSU
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$303
http://probotix.com/
A word about Probotix motors.
These are ill-suited for 2.5A and 24V. They detune as follows:
The 3A 260 detunes to 216 oz on 2.5A. It's a 60V motor, so will run slower at 24V.
The 4.2A 280 detunes to only 166oz on 2.5A. It is a 48V motor, so will run faster than the other two on 24V, but still fairly slow.
The 4.2A 400 (Green monster indeed!) detunes to only 238 oz on 2.5A. It is a 62V motor, so will run slowest of the three.
XYLOTEX:
$185 Four axis drive board.
No full step morphing, no mid range resonance dampning, no Idle current limiting or recirculation. Amps= 2.5 max. Voltage= effectively 24V Max. Xylotex drivers come with only a 90 day warranty. If the damage is deemed "your fault," there IS no warranty. They have been known to easily lose their magic smoke. The Xylotex board IS a BOB, albeit a simple one without optoisolation. You CAN add a charge pump, VFD card and relay card though.
$027 C4 charge pump card
$038 C6 VFD card.
$018 C15 relay card
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$268
http://xylotex.com/
This board is available in a turn-key configuration that includes electronics box and motor cables, so it is a very popular choice for newbies. Unfortunately many will have wasted their money and have to spend MORE to replace it.
A word about Xylotex motors:
The 2.8A 61V 269 oz is essentially similar to the Keling 270. It will detune to only 241 oz at 2.5A, so is fairly low power and speed--although it WILL run faster than the 425.
The 2.5A 91V 425 is a poor choice for this drive. It WILL provide the rated 425 oz of HOLDING torque, but is seriously undervolted at 24V, so won't run very fast.
The following drive-card is a very low-cost option and you have to build it yourself.
HOBBY CNC PRO 4 AXIS:
$99 with 4 drives. Max Amps=3. Max Voltage= 36. This is a UNIPOLAR drive, so is only capable of producing about 2/3 of a stepper motor's torque. No full step morphing, no mid range resonance dampning. It IS a basic BOB, and has its own logic PSU, but it is very limited and has no outputs for relays or VFD. It has no charge pump and no provision to add one. You can add limit/home switches and that's all. In order to get even a FRACTION of the G540 capability, you would have to add the following:
$020 A25 2nd parallel port card
$028 C-10 BOB
$018 C15 Relay card
$038 C6 VFD
$030 Logic PSU
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$205
http://www.hobbycnc.com/
Lowest cost of this bunch, but fairly low performance and you STILL have to build it yourself. If you do it properly though, It WILL function and it enjoys a good reputation. I couldn't find any warranty information, but there IS a 20% restocking fee for a return.
A word about Hobby CNC motors. They are 8 wire motors but must be wired as 6 wire motors for unipolar operation.
The 46V, 2.1A, 185 will only provide 130 oz as unipolar.
The 47V, 3A, 285 will only provide 205 oz as unipolar.
The 57V, 3A, 425 will only provide 305 oz as unipolar.
MARDUS-KREUTZ:
Now if you have the skills, and want to REALLY build your own from scratch, THIS is one heck of a drive:
http://mardus-kreutz.blogspot.com/20...o-stepper.html
I choose the G540 for its AWESOME performance, safety, reliability, warranty and installation ease. The 3.5A, 50V, G540 can efficiently run up to a (S)X3 mill, (and surely also a G0704) when paired with Keling 381s, (and a Keling 906 for heavy heads like X3 or G0704) and almost ANY router. Professional quality and performance at hobby prices--What's not to like?
IMO, if the BEST equipment costs less or only a little more--Why not use the best?
CR.