[bodi]

This is my first CNC machine I'm building. I have no experience so could use a little help choosing boards and motors. I'm building a 3 x 4 work table with
light weight aluminium, the lead screw is 1/2" 10 threads per inch. I'm looking to get a good quality break-out board, stepper motor board, Etc. I'm retired and on a limited budget, so I want the most bang for my buck.

I've narrowed it down to three sellers.

The first is this one. From what I understand this is a very good controller. Any opinions??

Geckodiver G540 4 axis kit (One G540 + Four
NEMA 23 KL23H284-35-4B (1/4” Dual shaft with a flat) 387 oz-
in + one KL-600-48 48V/12.5A 115V /230Vpower supply):
$574.95

The second one is this one:

Stepper Driver and Electronics for CNC Routers

4 Axis Electronics Combo - $470.00
(4) 425 oz-in stepping motors
(4) Drivers (3.0Amp 24-40 Volts, 1-1/64 microstepping)
(1) 36v 8.8a Power Supply
(1) Breakout board

And the third is:

4-Axis CNC Stepper Motor Driver Kits

Kit Includes: $459.00
4x ProboStep VX Uni-Polar Stepper Motor Driver
4x HT23-400-8 400ozin Stepper Motor
PBX-2 Parallel Port Breakout Board
24Volt 8.5Amp Switching Power Supply
6ft. DB25 Male-to-Male Cable
4x 4" IDC Cable 10-pin

They all seem to be very good people to deal with. Hopefully there are people here that can help me make a decision. Thanks

[ger21]

The G540 is the best of the 3, imo.

If you haven't yet purchased the 1/2-10 acme, Dont! They will severely limit the performance of your machine
Go with a 2 start or 5 start screw instead. If you don't do it now, you'll end up doing it soon enough anyway. Better off spending once.

[Fastest1]

I agree with Ger regarding the G540, especially for a first timer. Much less set up understanding required. Use a 48v power supply though. The gecko is small, self contained, well designed and has excellent support. Not knocking the others but they will consume more space and time to get running. If it is not too late the screw suggestion is a valid one. OTOH speed of rapids is relative. They all seem too fast if you are crashing!

[ger21]

OTOH speed of rapids is relative. They all seem too fast if you are crashing!

With single start 1/2-10 acme, you'll be limited to 70-100ipm max.
I do the majority of my cutting at 150ipm or more.

[dfmiller]

+1 on the G540.
I like mine.
And if Gerry thinks is good it's hard to go wrong.
They have a reputation of just working. And I think they have a good warranty.
Dave

[DonFrambach]

Agree with the G540 suggestion. I use 1/2" x 10 single start ACME leadscrews on my small router. As others have advised, I think you'll much happier with multistart leadscrews on your larger router.

[ssutton]

IMHO go for the G540. Mine has been bulletproof so far in 100 degree heat. I am running a rack and pinion for my X and Y axis but I am using a 10 TPI acme rod for my Z. It works well for the Z but other than that I would not use it for X or Y.

Scott

[CarveOne]

I also recommend going with the G540, in addition to the multi-start ACME screws. The G540 and 1/2-10 5 start is easily giving me 600 ipm jog speeds. Mine is the CNC Routerparts kit with 380 in-ounce motors.

CarveOne

[bodi]

Thanks for your opinions. Do you have any thoughts good or bad about the other two I'm deciding on?? I was kinda leaning towards the second one, it was more in my budget. I like the tech support on the probotix one, the guy talked to me about it for over an hour. Len seems to be a super guy and he said he would help get me through the whole thing. He said he could sell me one with two green motors 400 oz. for x and y and two yellow motors 280 oz. for z and lathe for $409.95. tech support means alot to an old jarhead.

[TarHeelTom]

I'm not using the G540, as it's a little light for my application. Using the G203V instead.

Gecko has excellent tech support, usually given by the boss himself. He'll spend maybe 2 minutes with you on the phone and solve your problem.

Not to mention his warranty. If you put your Gecko out in the street and run over it with a bulldozer, then cut it into several pieces with a torch, he replace it for you free the first time.

So, plus one on the Geckos.

Tom

[DonFrambach]

I know we're all saying the same bottom line about the G540 but with regards to techinical support, your're likely not to need any because the connections are very straightforward. I bought my G540 as part of a kit from CNCRouterParts.com and was up and running literally in a few minutes!

Do you really need four motors for your first build? There will be considerable savings if you just buy three motors. I did that but also got the larger 12.5 amp power supply just in case I wanted to do more later. If you can live with three motors and the smaller power supply your cost will fall substantially! Here's a link to the CNCRouterParts.com 3 motor kit for $519 (with cables!): CNCRouterParts.

[DonFrambach]

Here's a nice thread for connecting the G540: http://www.cnczone.com/forums/diy-cn...ecko_g540.html

[bodi]

Which one of these 3 drives are going to give me the most in micro-stepping.

I found a great site with great info.

Homemade CNC Router The Builder's Guide (FREE!)

I think I found what I am looking for.

Micro-stepping
The micro-stepping mode is the most complex of all the stepping modes. That is why some stepper drivers only offer full and half step modes. Micro-stepping is when the current applied to each winding is proportional to a mathematical function, providing a fraction of a full step. The most common divisions are 1/4th, 1/8th, 1/10th, etc. However, there are some drivers that provide up to 1/256th of a full step. Micro-stepping provides greater resolution and smoother motor operation. This is very advantageous as it reduces the need for mechanical gearing when trying to achieve high resolution. However, micro-stepping can affect the repeatability of the motor.

I'm not so much looking for speed as I am for accuracy.

Where can I find the info I am looking for on geiko site about this board. I can't find anything on their site telling me what it does.

[ger21]

I'm not so much looking for speed as I am for accuracy.

Everyone says that before they build a machine, and everyone wants more speed after it's running.
You'll have more than enough accuracy. The reality is that the quality and precision of the construction will affect accuracy more than anything else.
Also, depending on who you listen to, microstepping can or can not be counted on for accuracy. The reason is that the more microsteps you have, the less torque that is available from each microstep.
Personally, when considering the resolution of your system, I'd use 1/2 microstepping for your calculations to determine the resolution you have, even though you'll be using 1/8 or 1/10. It's a pretty safe bet that your motors will be accurate at 1/2 step locations, but they may lag slightly at 1/8 or 1/10.

Where can I find the info I am looking for on geiko site about this board. I can't find anything on their site telling me what it does.

All Gecko's are 1/10 microstepping. They also have some technical information that explains why there's little to no benefit to more microsteps than 10.

Everyone that's replied so far has told you that gecko's are the best way to go. The extra $100 they'll cost you is well worth it.

[ger21]

Let me add that generally, microstepping's biggest benefit is smoother running motors. The Geckos have a few other features that the others don't have.
One, is mid band resonance damping. Resonance can sometimes rob up to 50% of you motors performance. Gecko's anti resonance circuitry keeps resonance at bay.
The other is morphing to a full step drive at higher speeds. As I mentioned, microstepping reduces the available torque. Gecko drives use microstepping at low speeds for smoothness, and switch to full step at higher speeds for more torque.
This results in smoother running motors at lower rpm's, and more powerful motors at higher rpm's. The best of both worlds.

[bodi]

I guess now that everyone has decided that the geiko g540 is the way I should go, now I have to determine the size of my motors. Is this a good way to determine the torque on the lead screw.

The Torque Approximator (measuring lead screw torque)

Thanks

[dfmiller]

That method will determine the torque required to move the table.
You have to add in expected cutting forces and the amount of acceleration desired. If I recall and it was along time ago the desired acceleration may be the biggest limiting factor.

I would suggest thats not the best article on sizing motors.
I would have a look at this one.
http://www.cnczone.com/forums/diy-cn...otor_size.html
Dave

[JC50]

Once I got my system built and began connecting the electronics, I evidently let my power supply's hot wire touch something on my 540. (Dumb mistake on my part, I know. I shouldn't have had the PSU powered up, but that's another discussion for another time.) Anyway, I smelled something coming from the Gecko that I knew wasn't right. Turns out that I pretty much fried the 540. Called Gecko and was told to send it back. Got it back about 10 days later.........REPAIRED AT NO CHARGE!!!!!!!!!!!! Turns out they have a one time free repair just for dummies like me, and believe me, I will never forget it and will always recommend them.

To me, Gecko is one of the best companies I've dealt with in a long time.

[TarHeelTom]

Once I got my system built and began connecting the electronics, I evidently let my power supply's hot wire touch something on my 540. (Dumb mistake on my part, I know. I shouldn't have had the PSU powered up, but that's another discussion for another time.) Anyway, I smelled something coming from the Gecko that I knew wasn't right. Turns out that I pretty much fried the 540. Called Gecko and was told to send it back. Got it back about 10 days later.........REPAIRED AT NO CHARGE!!!!!!!!!!!! Turns out they have a one time free repair just for dummies like me, and believe me, I will never forget it and will always recommend them.

To me, Gecko is one of the best companies I've dealt with in a long time.

Actually, I found another company years ago, David Clark, who make high end headsets, etc. No one has ever been able to figure out their warranty. I've had some of their headsets for over 20 years. Once in a while, I break something. Call them and ask about replacement parts, sure, but we need an address to mail them to.

They've never ever sent me a bill.

I've had a Z axis not turning on the Bridgeport I'm rehabbing. After many hours of troubleshooting, found that the first connector after the Gecko had a dead short in it. After repairing the short, the Z axis works fine. The Gecko 203V is just about indestructable.

Tom

[bodi]

Every time you change material type from soft to hard, would you have to recalculate the motors, or change the tool.
Would I be able to attach a manual control device to the G540. I'm pretty good at sculpting and would like to have the computer save it when I'm done. Then let the computer make copies. Would I be able to attach a fifth axis later on? I would like to angle on the z.