CNC3040Z Motor and Spindle Selection.

[vksingh]

Hi Forum Members,

I am new to this forum and cnc world.

I have bought 3040Z CNC frame from china.
12586
12587

I would like to install my own stepper motors, Spindle and controller.
Objective of machine will be to mill some soft alloys and wood acrylic etc. Priority will be aluminum copper etc.
Please suggest the right motors and spindle.

Thanks

[Lee Roberts]

Hi,

Motors: Nema23 3Nm (http://www.ebay.co.uk/sch/i.html?_trksid=p2050601.m570.l1313.TR0.TRC0.H0.XNe ma23+3Nm&_nkw=Nema23+3Nm&_sacat=0&_from=R40)
Spindle: 2.2Kw Water Cooled
(http://www.ebay.co.uk/sch/i.html?_trksid=p2050601.m570.l1313.TR0.TRC0.H0.X2. 2Kw+Water+Cooled&_nkw=2.2Kw+Water+Cooled&_sacat=0&_from=R40)
Happy Shopping :).

.Me

[vksingh]

Hi,
Lee Roberts

The Stepper motors are 1.5 kg each and the spindle is 5.5kg.
Will the machine be rigid enough for these. And for the spindle which vfd will be good. Someone has suggested me sinamics V20 (http://www.automation.siemens.com/mcms/mc-drives/en/low-voltage-inverter/sinamics-v20/pages/sinamics-v20.aspx) inverter.

The parts I would like to purchase locally.

Spindle (http://www.tinycontrols.com/TS-23-High-Speed-Spindle-Motors.html)
Stepper Motor (http://www.tinycontrols.com/T57H111-4004-NEMA-23-Stepper-Motor.html)
Stepper Driver (http://www.tinycontrols.com/tstep-087-Stepper-motor-driver.html)
Breakout Board (http://www.tinycontrols.com/Enhanched-parallel-Port-break-out-Board-PP-BOB2-v1.html)

Are the above items ok for this machine.

Thanks

[vksingh]

Hi Lee,
What should be the rating for power supply for stepper motors.

[JAZZCNC]

Wouldn't fit 2.2Kw to this machine has the Z axis is too weak to handle the weight and the machine can't handle the extra capacity the spindle allows Ie 12mm cutters. 1.5Kw spindle are better matched.

For the motor/drives and PSU then you can use 2Nm motors and 50V drives running motors around 44Vdc. BUT if you want spare capacity for future upgrades etc then use 3Nm motors on 70-80~Vdc drives running at 65Vdc. Slightly over the top for these machines but better being over spec'd than under.

[vksingh]

Hi Jazz,
I am newbie to cnc and stepper world. I have gone through various forums for power supply rating for stepper motors, but could not understand.
I am using a 18V-80V and 1.2A-7.0A rated stepper driver. and the
Stepper specs are


Ph. Current


:


4.0 A


Ph. Res. (Ohm)


:


0.85


Ph. Inductance


:


3.8 mH


Holding Torque


:


32 Kg-cm


Detent Torque


:


1 kg-cm


Rotor Inertia


:


680 g-cm2


Lead Wires


:


4



rated voltage is 3.4V

I need 3Nos of stepper motor for my cnc. Now my question is what should be the rating of power supply if I am using single power power supply for all the three motors.
Can this power supply be used for the stepper drivers
800W-70V-11-4A-CNC-Switching-Power-Supply (http://www.aliexpress.com/item/800W-70V-11-4A-CNC-Switching-Power-Supply-Cooling-Fan-for-LED-CNC-Engraving-Machine-SM547/1126181657.html)

Thanks

[Clive S]

It is generally accepted that linear p/s are better ie http://www.zappautomation.co.uk/electrical-products/power-supplies-43/ps806-5-linear-power-supply-5.html I take it you already have the drivers. ..Clive

[JAZZCNC]

Like Clive says Unregulated linear supplies are considered best for CNC use but that power supply would work thou you would have to run it 70V or the lowest it can be adjusted to.

Rule of thumb for working out voltage is 20 x rated motor voltage. So 3.4 x 20 = 68Vdc. This is just general guide and in practice you can go higher depending on the motors/drives etc. Any where between 65-70vdc is about right for those motors.

[vksingh]

Jazz,
the other p[ower supply that i can get locally is 59V 12A. is it ok for all the 3 motors.

[JAZZCNC]

Jazz,
the other p[ower supply that i can get locally is 59V 12A. is it ok for all the 3 motors.

Yes it would work ok. You'll get slightly lower performance but still will be very good compared to if run at say 36V which is often done.!

[vksingh]

Jazz,
Spindle I am getting is 1.5kw air cooled locally and the vfd is sinamics v20 inverter from siemens. will they be ok

[JAZZCNC]

Jazz,
Spindle I am getting is 1.5kw air cooled locally and the vfd is sinamics v20 inverter from siemens. will they be ok

Cheap Air cooled spindles often have low duty cycles. This means they can't be run for extended periods so you will need to check the duty cycle of the spindle. I've seen some spindles have duty cycles less than 1hr which means they need to be shut down and allowed to cool which for CNC is not good enough.

Water cooled spindles don't really have a Duty cycle and can be run for days without stopping.!!

Don't know the VFD but Siemens is good quality so provided it's rated correctly then you shouldn't have a problem.

[vksingh]

Hi every one it has been a week now. I have assembled the frame.
126451264612647

I am running Mach3 Version R3.043.066

Every thing is running fine, but there is a problem. when a program is running or the machine is idle, motors rotates randomly. The motion is for fraction of a second. This can happen any time even when the machine is not running any g-code. I am unable to identify the problem. Please kindly help.

[JAZZCNC]

This will be electrical noise. Use shielded cable on all motors and signal cables and ground the shielding at one end only and take all grounds to a single point. Don't run single cables along side high power cables like Spindle power cable.

Don't fasten signal and power cables together using cable ties.