HobbyCNC vs Gecko 540

[LogansMind]

Okay, so I've been reading up on both of these, Gecko is the clear 'winner', but I don't know why. What are you really paying for in the Gecko that's so much better than other drivers? Like most others, I'm on a tight budget and the HobbyCNC kit looks tempting for my first CNC. I don't expect I'll be using it all that frequently, just for little projects and things, so I don't care about IPM much.

Also, another noob question, on the Gecko website under the 540 page, what's the left hand column in the prices list (the side that ranges from 1-1 to 10000-20000)?

[dertsap]

the hobby cnc board is limited to running unipolar motors only , the geckos are bipolar and will run either unipolar or bipolar motors , gecko is a much higher quality of a driver but many here have had great success with the hobbycnc board and the price of it can't really be beat , i think you'd do well with that board

[LogansMind]

Sounds good to me! Thank you!

[dertsap]

one thing to keep in mind is you will be limited to lower amp motors but if your not planning on building a massive machine then you will be fine , take a look in the forums for the joe cnc builds , many of them use that board including Joe , so you should be able to get some great info in regard to motor size and what you should be able to expect performance wise

[LogansMind]

Yeah, mines fairly similar to Joe's. One last question: What oz-in would be the best fit for a 2' x 4' machine for cutting wood, and maybe thin metal?

[dertsap]

ive seen a lot of guys use 280 oz motors with that driver , i believe thats what a lot of the guys have used on the joe cnc build

[LogansMind]

Oh, I was thinking of just getting the kit, save myself some trouble:
130oz-in,
205oz-in,
or
305oz-in

What's the difference anyway? I know smaller ones are faster (and cheaper), but what's better about having a greater oz-in?

Edit: Got the 305's I was linked to this transformer however its 24v AC the hobbycnc asks for DC. Is this alright?

[rowbare]

Originally Posted by LogansMind Also, another noob question, on the Gecko website under the 540 page, what's the left hand column in the prices list (the side that ranges from 1-1 to 10000-20000)?

Those are quantities, if you want to buy 10,0000 of them, you can get them really cheap :-)

As for your transformer, you will need to full wave rectify the output and add some filter capacitors. Once that is done you will end up with about 34VDC.

bob

[BobF]

The hobbyCNC kits are unipolar as mentioned. Get the 305 oz/in motors. The rating is in unipolar drive since that is what the kit drivers are capable of. In bipolar drive these same motors are capable of 425 oz/in. In fact many Joes builders of the 2006 have moved up to the 4x4 and used the same motors. A lot of them are now using a Gecko 540 (a few have used 200 series) and the same motors now perform at 425 with the Gecko.
The long and short is: If you buy the hobbyCNC kit for now with 305 motors, you can upgrade the drive later and have 425 oz/in from the same motors. Just replace the hcnc driver with a Gecko. You can probably use the power supply you made for the hcnc, since the amp rating has not changed.

[steve323]

Originally Posted by LogansMind Oh, I was thinking of just getting the kit, save myself some trouble: 130oz-in, 205oz-in, or 305oz-in What's the difference anyway? I know smaller ones are faster (and cheaper), but what's better about having a greater oz-in? Edit: Got the 305's I was linked to this transformer however its 24v AC the hobbycnc asks for DC. Is this alright?

Good choice on the motors for a 2x4 machine. Just about the largest size you can use with the HobbyCNC 3A limit.

The transformer is rated at 24V AC, but might put out 26-27V due to variations in load and input voltage. This could produce around 36V after the bridge rectifier. The max limit for HobbyCNC is 40V, so this is close enough. The 10A limit is good for 4 steppers running at 3A each with idle current reduction turned on. It is a good transformer. Many people are using it.

Hopefully you bought the complete kit from HobbyCNC. It comes with everything you need to build the power supply except for the transformer and a case. The price is good also.

Steve

[Crevice Reamer]

Originally Posted by BobF You can probably use the power supply you made for the hcnc, since the amp rating has not changed.

The Amperage WILL change from 3A Unipolar to 4.2A Bipolar [Series]^PARALLEL. The G540 can only output 3.5A, so the HCC 425 oz motor will be detuned to a 354 oz motor with it. Otherwise it's a fairly good match--except that for best performance with G540 it will need 50V instead of 36V.

CR.

[steve323]

One more thing: If you didn't buy the complete kit, you could save yourself some trouble and buy a pre-built switching supply at

http://www.mpja.com/prodinfo.asp?number=17429+PS

for about the same price as the transformer alone. The voltage is a bit low, but the price is really good, $25 for a 12.5A 24VDC supply. Many people at the HobbyCNC message board are using it with good results.

Steve