[fulengineering]

Hello Everyone,

Im new in the cnc world, i have never used a CNC machine, but im quite familiar with manual machines.
I have a SX3 milling machine and i want to convert it to CNC
I have read a lot about programing (intend to really get a grasp of g code once i have a cnc to practice with) and how to convert a manual mill to cnc.
The problem is that most of those articles i read assume the reader knows some things. Thats why i wanted to ask you guys if you could help me understand what i need to build my cnc
So far i know where to get the mechanical elements such as ball screws and such (CNC FUSION.COM) and as far as the electronic and software im not so sure;
Correct me if im wrong
I need:
the stepper motors (nema 23 for XY and 34 for Z)
the drives for steppers (what type of drives? what is half step, full step, microstep on the drives description?)
interface card
PC

and for software: mach 3

Thanks in Advance

[alan_3301]

I think the first step is figuring out what your budget is, and how much performance do you want?

you could search threads here on similar conversions and see what they used, and maybe they explained why somewhere.
You can search here and on google for cnc conversion newbie, etc... I'm sure there are a few guides out there that explain a lot of the different systems.
As far as the whole subject of cnc conversions, I don't think you will get all the info you need in this thread, you will have to spend a lot of time reading.

[fulengineering]

Hello, thanks for the replay. I intend to use the machine to make parts for a small profit, so I need good performance. I need it to be able to cut aluminum as well as stainless steel. I'm willing to invest 2000 dolars and maybe I can Strech a little more...
I have seen some kits, but I just Dont know enough to determine which one is the right one for me...

I like to buy the electronics from gecko, since I understand they have good drives aND steppers... but what drives do I need? They seem to have several kinds of drives for the same motors, I don't know what drives are best for me...

[LeeWay]

I thinkk you will want power with a mill.
I use Gecko 203V's on my home made mill. I use all Nema 34 motors though.
I don't think you would want a G540. It won't play well with a Nema 34 motor on your Z.
You could go a little cheaper on your drives if you are pretty confident in your electronics reading and wiring skills.
The G201X drives might work fine.
Look for a 72 VDC power supply with maybe 12 AMP rating.
Antec is probably the best brand on Ebay.

Hopefully others that have actually coverted an X3 will chime in. My first conversion was an X2 that never really got completed. Instead it got redesigned into my Home made mill and wound up only using the spindle and head casting from the X2.
Good luck with it.

[louieatienza]

Check out the MetalWorking section, go to Benchtop mills, and there's a subforum for SX3 machines...

[fulengineering]

I been researcing and trying to understand what I need for my machine. I'm a little confused still.. I want the machine to have X-Y-Z-A axis and a automatic tool changer. As far as electronics go, all I need is:
A 5 axis breakout board
The 5 motors
and the drivers
Also the home switch and nothin else right?

What do you think of these electronics (for X-Y-Z axis) for less than 600..

【German Free SHIP】3Axis Nema34 Stepper Motor 1600oz Indual Shaft Driver CNC Kit | eBay


could buy 2 separate smaller motors and drivers for the A axis and tool changer axis and hook them up to the breakout board from above?
Thanks in advance

[109jb]

Those are way to big for an SX3 and the motors have a very high inductance of 22 mH. In order to work optimally they would need a very high voltage power supply.

For an SX3, NEMA 23 steppers would work on all axes. You could go with a NEMA34 on the Z axis, but not absolutely necessary.

For steppers you want to read the following: http://www.geckodrive.com/support/st...or-basics.html

Here is a very good motor that would do all 3 axes NEMA23 570oz/in 5A 3/8? Dual Shaft Stepper Motor (KL23H2100-50-4B) | Automation Technology Inc

Here is a decent driver KL-6050 Bipolar Stepper Motor Driver,Max. 60VDC,5A | Automation Technology Inc
A better driver: KL-5056D Digital Bipolar Stepper Motor Driver-32 bit DSP Based | Automation Technology Inc

Here is a NEMA 34 motor for the z if you decide to go that way : NEMA34 Stepper Motor ? 906 oz in 6.1A Single Shaft (KL34H295-43-8A) | Automation Technology Inc

For the NEMA34 above you would need a different driver. http://www.automationtechnologiesinc...-driver-kl8060
or this one is digital (better): http://www.automationtechnologiesinc...nk-is-included

All of these motors will operate from a single 48V power supply. A switching power supply is fine, but a torodial is better (more expensive) but not necessary. You would need one about 12 amps or so and a single power supply would run all 3 motors.

Lastly, you will need a breakout board. http://www.automationtechnologiesinc...ional-breakout

Even though all of these links are to a single supplier, these products are available elsewhere including e-bay. In addition, in relation to the BOB, I have used a few Chinese BOB's I bought off of e-bay and had no problems with them.

As for the driver, a G540 would work well if using all NEMA 23 motors as listed above, but would not be sufficient for the NEMA34 because of higher amp draw. I personally don't like all-in-one units because a failure of a component means added trouble fixing it. In terms of the G540 probably not a problem as I believe it is modular and a single drive or the BOB section can be replaced easily. Some other all-in-ones aren't that way. Individual Gecko drives would also work well, and you could mix and match them to use a NEMA 34 on the Z.

[fulengineering]

My browser went crazy, Im not sure it's posting my reply

[fulengineering]

Thank you very much for the info and taking the time to search for the parts. I very much appreciate. Thank you
I like the supplier, has everything and a reasonable price.

You are right using nema 34 for all axis would not be cost effective.. (I always tend to oversize things.. haha)

About the breakout board, the Mach 3 one caught my eye, it's more expensive, but is it worth it? what do you think ?
6-Axis Motion Control Card USB2.0 Interface, CNC MACH3 USB Card XHC-MK6 | Automation Technology Inc

[H500]

I have a SX3 with 280 oz-in motors on all 3 axes. I set x and y to 100 IPM, which is as fast as I want. Z is set at 70ipm.

[fulengineering]

I have a SX3 with 280 oz-in motors on all 3 axes. I set x and y to 100 IPM, which is as fast as I want. Z is set at 70ipm.

Now I see how oversized the nema 34 would have been... Thanks.

[fulengineering]

Question (maybe a silly one) do I need a specific BOB for digital drives?

[109jb]

Thank you very much for the info and taking the time to search for the parts. I very much appreciate. Thank you
I like the supplier, has everything and a reasonable price.

You are right using nema 34 for all axis would not be cost effective.. (I always tend to oversize things.. haha)

About the breakout board, the Mach 3 one caught my eye, it's more expensive, but is it worth it? what do you think ?
6-Axis Motion Control Card USB2.0 Interface, CNC MACH3 USB Card XHC-MK6 | Automation Technology Inc

That motion card appears to be something like a smoothsteppe. Personally I would say it is not necessary for an SX3. Where those type boards are beneficial is when you have trouble losing steps or want to operate at a high step rate. The specs say that board can go to 200kHz. with motors set to 1/16 microstepping, and 5mm pitch ballscrews, 200 kHz would be 18,750 mm/min or 738 in/min. Way faster than you would ever need on a SX2.

Lets say you had a 25kHz step rate which is perfectly capable using the parallel port. That would be 2454 mm/min or 92 in/min using the same microstepping, but you could double that just by using 1/8 microstepping rather than 1/16.

I would suggest trying an inexpensive parallel port BOB first to see if it is sufficient for your needs before going to something like that.

- - - Updated - - -

Question (maybe a silly one) do I need a specific BOB for digital drives?

Same BOB for digital or non-digital.

[LazyMan]

I converted Grizzly "X3." Im using Gecko 203Vs with a PMDX BOB with some 400oz Steppers. The electronics are great and work very well, but I'm getting .003" lost motion with my CNC fusion conversion kit. If I were to do the conversion now, I would use a leadshine MX3660 drive/BOB to save money and simply things. It wasn't available at the time. However, if I could go back in time, I would never bother converting it at all...I would buy a Tormach 770.

[109jb]

I converted Grizzly "X3." Im using Gecko 203Vs with a PMDX BOB with some 400oz Steppers. The electronics are great and work very well, but I'm getting .003" lost motion with my CNC fusion conversion kit. If I were to do the conversion now, I would use a leadshine MX3660 drive/BOB to save money and simply things. It wasn't available at the time. However, if I could go back in time, I would never bother converting it at all...I would buy a Tormach 770.

I find it funny when people talk about the money saved going to the MX3660 or the G540 over individual components. The MX3660 is simply a BOB and 3 drivers in a single package for $265. You can get a C10 BOB for $28 and individual digital drivers for $85 each. If you add that up it is only $18 more using the individual components.

The benefit of using individual components is that if a driver craps out you can get any kind of driver you want. With the MX3660, a crapped out driver means trying to find an exact replacement that fits. There is another user of an MX3660 on the forum that is dealing with this right now and he is having problems finding a replacement driver. With separate components you don't even need the same brand, type, or size driver. Just about any driver will work. The same things can be said for the G540, with the difference being that the manufacturer, Gecko, has a great reputation and I don't think it would be a problem getting a replacement from them.

If you are willing to go with non-digital drivers the cost is much cheaper. The BOB/driver package I use on my G0704 is rock solid and costs $161 total. $50 each for 3 drivers and $11 for an import BOB.

The PMDX (smoothstepper) is nice, but only works with Mach3. There are many other motion control programs out there. If you are sure you want Mach3 then it could be a good choice, but I don't think it is really necessary, particularly in the beginning.

[fulengineering]

I converted Grizzly "X3." Im using Gecko 203Vs with a PMDX BOB with some 400oz Steppers. The electronics are great and work very well, but I'm getting .003" lost motion with my CNC fusion conversion kit. If I were to do the conversion now, I would use a leadshine MX3660 drive/BOB to save money and simply things. It wasn't available at the time. However, if I could go back in time, I would never bother converting it at all...I would buy a Tormach 770.

What do you mean, you lose 0.003 in motion? can you please explain?

Tormach 770 is a nice piece of equipment , but it is way more expensive than converting... how much did you spend to convert?

[fulengineering]

That motion card appears to be something like a smoothsteppe. Personally I would say it is not necessary for an SX3. Where those type boards are beneficial is when you have trouble losing steps or want to operate at a high step rate. The specs say that board can go to 200kHz. with motors set to 1/16 microstepping, and 5mm pitch ballscrews, 200 kHz would be 18,750 mm/min or 738 in/min. Way faster than you would ever need on a SX2.

Lets say you had a 25kHz step rate which is perfectly capable using the parallel port. That would be 2454 mm/min or 92 in/min using the same microstepping, but you could double that just by using 1/8 microstepping rather than 1/16.

I would suggest trying an inexpensive parallel port BOB first to see if it is sufficient for your needs before going to something like that.

- - - Updated - - -



Same BOB for digital or non-digital.

thanks for explaining. I will use a more inexpensive BOB than. Thanks again

[hoss2006]

I'm a fan of individual components myself but other things make a package like the mx3660 attractive.
A built in spindle control, $50 value.
Much smaller footprint than needed for 3 drivers, BOB and spindle control.
Simpler wiring.
The failure referred to I would suspect be to user error in placement of the mx3660 on top of his power supply as it was damaged at the same time, chicken or the egg.
There are many electronics packages suggested here for the g0704 that will work equally as well on the SX3.
G0704 Electronics
Hoss

[109jb]

thanks for explaining. I will use a more inexpensive BOB than. Thanks again

I said start with an IN-expensive BOB. I don'tthink the expensive one is necessary for an SX3. The BOB I use was $11 and works fine. The C-10 BOB is popular and not too cost prohibitive at $28

[louieatienza]

I converted Grizzly "X3." Im using Gecko 203Vs with a PMDX BOB with some 400oz Steppers. The electronics are great and work very well, but I'm getting .003" lost motion with my CNC fusion conversion kit. If I were to do the conversion now, I would use a leadshine MX3660 drive/BOB to save money and simply things. It wasn't available at the time. However, if I could go back in time, I would never bother converting it at all...I would buy a Tormach 770.

Are you losing motion because of the Geckos, or the Chinese rolled ballscrews?