Centroid Community CNC Support Forum

Hi,

I have a question about limit switches.
Would it be better mechanical or inductive?
In case of inductive, next question is how circuit would be.
They would be NC and can be powered with 24VDC; would they work same as mechanicals, towards ACORN input IN2?

Thank you.

Yes they will work, and work well provided you get good ones and install them correctly. Yes, NPN 24vdc is required. Acorn doesn't care what sinks it's input signals.

Hi Marty,
I am thinking about limit/home switches circuit using inductive NC sensors.
I have attached a pdf with some ideas and also questions/remarks.
Thanks for supporting!
Lorenzo

Lorenzo, you don't post make and model proximity sensor you want to use.
Watch this video for good info on Proximity Sensors. At about 1:20 they discuss putting them in series. (Automationdirect.com is a good source for sensors, encoders and MANY other items for CNC control)
A good NPN NC Proximity Sensor should be no problem to sink Acorn input
Yes, you can wire a proximity sensor one per input for each axis and use soft limits
The only reason Home All is suggested and one input is to conserve inputs as Acorn ONLY has 8 inputs.

Marty

Very good information. Thanks Marty.

Hi Lorenzo

My F1210HS is fitted with Euchner N01K550-m home switches which is standard OEM fitment by Wabeco on both your model and mine. These are mechanical, IP67 rated (essential if you use coolant) and accurate to 30 microns (~ 0.0008"). Link as follows:

https://www.euchner.de/en-us/a/084904/

FWIW, my machine was supplied by Wabeco as "CNC ready" with Sanyo Denki 103H8221-6241 stepper motors and Euchner switches fitted complete with pulley and belts etc with each axis terminating in a single CY cable with DB9 connector. The stepper motors are 2.74 Nm (approx 390 oz.in) and are perfectly adequate for driving my leadscrews so your ball screws would not present a problem. I realise these parts are not cheap when buying separately and your budget may be different but this is purely meant a guide as to what Wabeco fit themselves.

Personally I would have thought that accuracy and repeatability with home switches is paramount and for that reason prefer mechanical switches although doubtless Metrol or even Euchner may produce prox sensors that could fit the bill.

Hope this helps

Nigelo wrote: ↑Sat May 09, 2020 2:12 pm Hi Lorenzo

My F1210HS is fitted with Euchner N01K550-m home switches which is standard OEM fitment by Wabeco on both your model and mine. These are mechanical, IP67 rated (essential if you use coolant) and accurate to 30 microns (~ 0.0008"). Link as follows:

https://www.euchner.de/en-us/a/084904/

FWIW, my machine was supplied by Wabeco as "CNC ready" with Sanyo Denki 103H8221-6241 stepper motors and Euchner switches fitted complete with pulley and belts etc with each axis terminating in a single CY cable with DB9 connector. The stepper motors are 2.74 Nm (approx 390 oz.in) and are perfectly adequate for driving my leadscrews so your ball screws would not present a problem. I realise these parts are not cheap when buying separately and your budget may be different but this is purely meant a guide as to what Wabeco fit themselves.

Personally I would have thought that accuracy and repeatability with home switches is paramount and for that reason prefer mechanical switches although doubtless Metrol or even Euchner may produce prox sensors that could fit the bill.

Hope this helps

Hi Nigelo,

Thanks for your comments.
My approach has been to get the machine with ball screws to have accurate positioning, and totally manual to make 100% design of the movement.
Motors will be closed loop steppers. Many many lots of thingking to decide between servos and steppers... I have been studying DMM DYN2 and have a quotation of 400W servos, Z with brake. Finally I have decided to use closed loop steppers motors:
- from StepperOnLine, T series; I believe all T series material is Leadshine. Some German integrator such as Steureung use also StepperOnLine (from my "pictorial" investigation )
- X and Y axis is 4 Nm; Z axis is 12 Nm. I bellieve it is more than enough to hold the horses.
- Driver is similar to Leadshine ES-D808. I think it is exactly same product.
Regarding limit switches, I will choose the model "IE5349 - IEBC003BBSKG/AS" from german brand IFM. This model is NPN NC and can be connected with 2 wires according to the circuit diagram; will bench test it of course.
I have designed all mechanical fitting of motors to the milling machine, and I am now in interation 3... let's see if it is last one.
I am machining manually with F1210HS and finishing is quite good.
Also suffiently acurate; I am drilling all holes positioning spindle manually with the dials (do not have DRO), and accuracy is even below tenth of a millimeter. No backlash at all. Machine is small but I think that with 2kW VFD spindle and good tools it can work pretty well.

Happy with the results so far.

Will post some photos one of these days.

Hi Marty,

I am having a look to integration of my machine spindle VFD with Acorn. If needed I will mail Wabeco for some clarification.
I have checked Centroid's drawing for standard Acorn connection; will not use the optional contactor (because I am putting a contactor already in the main board, and VFD will be powered from it).
I am attaching a scheme joining Wabeco's scheme and Acorn's scheme.
If you can have a look and let me know unclear things or errors would be great.

Also some doubts indicated with yellow background cells.

Something I do not figure out how to do, is to incorporate the VFD to the "drive OK chain" to IN5 indicated in Acorn drawing... maybe it is not strictly necessary as the stop/emergency circuit of main board will control power to VFD... I do not know.

Thank you.

LorenzoRR wrote: ↑Sat May 09, 2020 6:39 pm Hi Marty,

I am having a look to integration of my machine spindle VFD with Acorn. If needed I will mail Wabeco for some clarification.
I have checked Centroid's drawing for standard Acorn connection; will not use the optional contactor (because I am putting a contactor already in the main board, and VFD will be powered from it).
I am attaching a scheme joining Wabeco's scheme and Acorn's scheme.
If you can have a look and let me know unclear things or errors would be great.

Also some doubts indicated with yellow background cells.

Something I do not figure out how to do, is to incorporate the VFD to the "drive OK chain" to IN5 indicated in Acorn drawing... maybe it is not strictly necessary as the stop/emergency circuit of main board will control power to VFD... I do not know.

Thank you.

Do you have a manual for the WABECO that M1 Drive? We need pin functions. What is FQ?

It "appears" to me that the Forward and reverse use +24VDC inputs to activate them. But I don't know what FQ is, and it is in the mix.
Is the drive truly a VFD?

In general, you use an ESTOP contactor. It breaks the axis drive motor power and opens the COMMON of the spindle drive so that the spindle drive signal can be removed from FWD/REV input.

See the new Acorn SYSTEM drawings in the latest schematic package for further information. I encourage everyone to use those drawings and use the Estop contactor. Its safer. I don't believe in powering up and down a VFD to start and stop a motor. Most of the machines I have worked on do not operate that way. VFD's are powered up when the main power is on. The COM from the VFD goes through the Estop contactor.

Marty

martyscncgarage wrote: ↑Sat May 09, 2020 7:02 pm

LorenzoRR wrote: ↑Sat May 09, 2020 6:39 pm Hi Marty,

I am having a look to integration of my machine spindle VFD with Acorn. If needed I will mail Wabeco for some clarification.
I have checked Centroid's drawing for standard Acorn connection; will not use the optional contactor (because I am putting a contactor already in the main board, and VFD will be powered from it).
I am attaching a scheme joining Wabeco's scheme and Acorn's scheme.
If you can have a look and let me know unclear things or errors would be great.

Also some doubts indicated with yellow background cells.

Something I do not figure out how to do, is to incorporate the VFD to the "drive OK chain" to IN5 indicated in Acorn drawing... maybe it is not strictly necessary as the stop/emergency circuit of main board will control power to VFD... I do not know.

Thank you.

Do you have a manual for the WABECO that M1 Drive? We need pin functions. What is FQ?

It "appears" to me that the Forward and reverse use +24VDC inputs to activate them. But I don't know what FQ is, and it is in the mix.
Is the drive truly a VFD?

In general, you use an ESTOP contactor. It breaks the axis drive motor power and opens the COMMON of the spindle drive so that the spindle drive signal can be removed from FWD/REV input.

See the new Acorn SYSTEM drawings in the latest schematic package for further information. I encourage everyone to use those drawings and use the Estop contactor. Its safer. I don't believe in powering up and down a VFD to start and stop a motor. Most of the machines I have worked on do not operate that way. VFD's are powered up when the main power is on. The COM from the VFD goes through the Estop contactor.

Marty

Thanks Marty.

Will contact them to get pin functions.
Product is described as "frequency-controlled main drive motor". Will clarify with them.
Company CNC-Steureung controls Wabeco spindle motor with external controller (CS-MIO in this case).
They have an explanation in German language, but I do not understand it completely: https://www-cncsteuerung.gitbook.io/doc ... zahlregeln

It is maybe a good idea to take out the cover and take some pics and voltage measurements at different rpms.

Regarding main protection, approach is to follow JW's setup described in below video; I like it (remember, I'm mechanical eng and maybe easy to get impressed ).

Power is input through a main switch with 4 poles: two poles are for a main contactor; other two are for 24V PSU for contactor's 24VDC coil and cabinet fans.

It uses an ESTOP in cabinet closes circuit to energize the 24VDC coil of a four pole contactor (L1+L2+L3+1xNC); the NC is used to open IN8 input of Acorn. L1 and L2 are used to close two "circuits" of 220V; one of them is for spindle motor. Other one is for servos and Acorn PSU's. L3 is used to maintain energized the 24V coil when it is pressed a push button in the front panel, keeping contact ON. When circuit is opened with a ESTOP, coil's circuit is opened and all stops. Acorn receive this signal from pole 4 in contactor (that is NC by default).

I am attaching the first draft of cabinet's circuit. This is y'tube link for JW specific video: https://www.youtube.com/watch?v=zGqc5HcvdEw

I would expect to get feedback from Wabeco next week.

Thank you.

Lorenzo