[aliazhar97]

I am in a process to build my SX2 with CNCFusion kit....
can any1 help me with the info on setting MACH3 steppers?....revolution per rotation settings and stuff?....i am planning to use G540 with 385oz on X/Y and 425oz on Z...
Also, can any1 help on installing the home switches?

Please help if you can....

[eartaker]

When you get the kit installed and you are ready for the steppes per.... Take the steps per rev of the motor DIVIDED by your step increment on your driver boards such as 1/2, 1/8, 1/16, this now gives you how many steps the computer must put out to rotate the motor 360 deg. now that you have that you need to multiply that by the screw pitch.

Here is an example for a 200 step per rev motor, on 1/2 stepping with a screw pitch of 10TPI. (200/.5)6 =2400 this means it will take 2400 steps to move your machine 1 inch if you have those parameters. BUT THIS IS NOT ACCURATE!!!

In mach 3 there is an axis calibration tool that once you get that rough estimate you will use a dial indicator to measure how far the bed moves when you tell it in mach to move a specified distance. It then asks how far it actually moved and adjusts your steps for you.

Here is a video Hoss made that shows what I mean

[nomedia="http://www.youtube.com/watch?v=XkO5tc-jSxw"]YouTube - Improved Mach 3 Axis Calibration[/nomedia]

[hoss2006]

With the G540 and 5TPI screws (Cncfusion ballscrews) you'll need to set the Steps per to 10,000.
Multiply the motor steps/rev (200) by the microstepping denominator (10) then by the screw TPI (5)
the G540 is at 1/10th microstepping except during rapids (1/2)
200x10x5=10,000 steps/per
A quick way to setup Mach3 is to download the G540.XML to your Mach folder then load the G540 at startup.
G540
All the inputs etc, are set though you'll need to change the Motor Steps Per to 10,000,
the default is 20,000 for 10 TPI screws.
Increase the velocity to what your mill can handle.
You'd also be better off using 381 oz/in motors with the G540.
Hoss

[aliazhar97]

Thank you guys....excellent info...exactly what i was looking for...

one question i have on the stepper, why 381oz?....on all 3 axis?

i have selected 385oz on X/Y and 425oz on Z....with 36v 10A buying ready from Camtronics....is there any drawbacks on using these steppers on SX2 ?

i have heard that this the max you can go on X2 and anything more than that is not recommended...

one more question: i am planning to setup a coolant system, and would like to know how you guys did it....i have a 8 feet table, where i have space for the X2...would like to make a enclosure for it....any help on making the table coolant proof (Water proof)?

[hoss2006]

Thank you guys....excellent info...exactly what i was looking for...

one question i have on the stepper, why 381oz?....on all 3 axis?

i have selected 385oz on X/Y and 425oz on Z....with 36v 10A buying ready from Camtronics....is there any drawbacks on using these steppers on SX2 ?

i have heard that this the max you can go on X2 and anything more than that is not recommended...

one more question: i am planning to setup a coolant system, and would like to know how you guys did it....i have a 8 feet table, where i have space for the X2...would like to make a enclosure for it....any help on making the table coolant proof (Water proof)?

The keling 381 oz/in motors are a near perfect match for the g540,
Page Title
don't know where you got 385 and 425.
You want a motor to take advantage of the g540's 3.5 Amps and
an inductance around 2.8 to get the best performance from the g540s 50 Volts.
You can see some kelings motors in comparison at the bottom of this page.
G0704 Electronics
My flood coolant setup is here.
Projects 8
Hoss

[aliazhar97]

The keling 381 oz/in motors are a near perfect match for the g540,
Page Title
don't know where you got 385 and 425.
You want a motor to take advantage of the g540's 3.5 Amps and
an inductance around 2.8 to get the best performance from the g540s 50 Volts.
You can see some kelings motors in comparison at the bottom of this page.
G0704 Electronics
My flood coolant setup is here.
Projects 8
Hoss

Thank you Hoss....This is an excellent info for me since this is the first time i am converting to CNC...
I am going to use the above mentioned setup....
what resistor value needed for these steppers?

[hoss2006]

This is from the G540 manual.

The resistor is calculated by taking the current in amps and multiplying by 1000. If your motor is rated at 2.8A per phase you will have to use a 2.8K 5% 1/4W resistor. If your motor is rated at 3.5A or above you can safely not use a current set resistor; however, your G540 will not go into current standby mode which will result in increased motor heating.

A 3.48K resistor should be used with the 3.5 Amp 381 oz/in motors.
Circuit Specialists Inc. - 3.48K Ohm 1/4 Watt 1% Metal Film Resistor (RC3480)
Hoss

[aliazhar97]

Thank you Hoss...

I am going to request this configuration to Camtronics....

After contacting Keling, and keep waiting for a reply from them, i have found that Keling is the most hopeless in replying to customers questions....i will get old waiting for their reply....i wonder how they mentioned this on their website:
We welcome your OEM projects and are glad to work
closely with you to create custom production techniques.
they should also mention that it will take years !

anyway, once i have all electronics, i will post how it all goes and will ask if i need more help from you experts!

[Dougal]

I think your steppers are overkill.
Even a 280 oz-in stepper can provide about 250kg of push, more than enough for a machine this size.

I have yet to stall my 280 oz-in motors while cutting, I reach the machines limits of rigidity (especially cutting & drilling steel) before the motors have any problems.

[hoss2006]

I think your steppers are overkill.
Even a 280 oz-in stepper can provide about 250kg of push, more than enough for a machine this size.

I have yet to stall my 280 oz-in motors while cutting, I reach the machines limits of rigidity (especially cutting & drilling steel) before the motors have any problems.

They may be a tad overkill for a basic machine but he is building an SX2, a larger table and saddle, i.e. more mass to move around.
Add a 4th axis, lathe attachment, bigger vise, etc. and the mass increases.
I went beyond the limits of my 270's so I know what they are capable of,
better to spend $10 for a motor that's a perfect match and not have to worry about it.
Hoss

[Dougal]

When you say "beyond the limits of your 270's" what do you mean?

Di you stall them cutting or do you mean you had to detune the acceleration to get them to run smoothly?

[hoss2006]

Thank you Hoss...

I am going to request this configuration to Camtronics....

After contacting Keling, and keep waiting for a reply from them, i have found that Keling is the most hopeless in replying to customers questions....i will get old waiting for their reply....i wonder how they mentioned this on their website:
We welcome your OEM projects and are glad to work
closely with you to create custom production techniques.
they should also mention that it will take years !

anyway, once i have all electronics, i will post how it all goes and will ask if i need more help from you experts!

Surprising, Keling usually has great support, you won't find many complaints about him.
Hoss

[hoss2006]

When you say "beyond the limits of your 270's" what do you mean?

Di you stall them cutting or do you mean you had to detune the acceleration to get them to run smoothly?

Stalled.
Hoss

[Dougal]

Stalled.
Hoss

What size cutters were you pushing?
I have no problem breaking smaller cutters (up to 8mm) with my 280 oz-in steppers. With larger cutters (12mm) it's machine rigidity that limits my cut depth and the force I can apply.

[rewster]

A 3.48K resistor should be used with the 3.5 Amp 381 oz/in motors.

I'm wiring up the shiny new G540/381 kit that came in the mail today. Just got back from the shack, they only had 3.3k ohm resistors. Will these be sufficient? I also have some 100 ohms laying around, should I pair a couple up to get closer to 3.48k? Thanks, and sorry again for the noob questions.

[hoss2006]

I'm wiring up the shiny new G540/381 kit that came in the mail today. Just got back from the shack, they only had 3.3k ohm resistors. Will these be sufficient? I also have some 100 ohms laying around, should I pair a couple up to get closer to 3.48k? Thanks, and sorry again for the noob questions.

A 3.3k ohm resistor will detune the motors to 359 oz/in.
If you add another 100 in series you'll get 370 oz/in.
Add 2 and you'll get all 381.
3.48k is used because that's a fairly commonly available size and it only drops the output 2 oz/in.
Hoss

[rewster]

Thanks Hoss, just making sure. It's been a while since I've had any electrical classes, and it shows

[hoss2006]

Thanks Hoss, just making sure. It's been a while since I've had any electrical classes, and it shows

Same here, been a couple decades since I've been in an electronics classroom.
This hobby finally puts it to use.
Hoss

[aliazhar97]

just received the CNCFusion kit.....
while checking before installing, i have noticed that on Y axis, when i rotate leadscrew by hand, the balls are coming out of it....one of the ball came totally out of the ballscrew and the other one i can see on the edge....
although i have put the one came out by rotating the leadscrew to other direction...but, it looks like it will come out again when i will go to the other direction.......
i have also noticed that the Y asix lead screw is a little crunchy sometime....

while the ball was out i have also measure the ball (just incase for future reference) and its 0.125"...

anyhelp?......why the balls are coming out when i unscrew the leadscrew?....

i have emailed Michael at CNCFusion, but, have not heard back from him yet....

[aliazhar97]

figured it out!....
reloaded all the balls from scratch and now know how to load it with a help of a youtube video.

lesson learned!