Help needed to get my 7i76E + 7i85S + 7i73 on my mill going.

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01 Aug 2017 14:33 #96837 by andypugh
This sounds like fun...

You have a system that is like a combination of my lathe and my mill. My mill has a manual 8-speed gearbox and my mill has an electrically-controlled 2-speed gearbox.

During milling operations the spindle speed tends to remain constant (unlike with a lathe in CSS mode).
Also, you should be able to change your motor speed with the spindle running? (I do not do this with my lathe).

On the mill the system uses the ratio of the motor speed to the spindle speed to detect the engaged gear:
forum.linuxcnc.org/47-hal-examples/27071...tection?limitstart=0

My lathe uses a custom HAL component to choose the spindle speed depending on speed command range.
(I don't think I have that on the forum)

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01 Aug 2017 14:50 #96838 by tecno
Yes it is ;)

One way to get me going is to setp hm2_7i76e.0.7i76.0.0.output-15 TRUE until I get all things solved with the gearbox position readout.

I never change Hi/Lo on the fly. In my earlier Kflop we did read S command and switch Hi/Lo before starting spindle.

So how to do with these numbers?
setp hm2_7i76e.0.7i76.0.0.spinout-scalemax 2500 is the new max in Hi rpm on motor and Shifter Out Geears set to A
What if it will not go to 2500 do I just add untill I am satisfied? Does these added numbers do anything unwanted for future sync motion?

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01 Aug 2017 15:09 #96839 by andypugh

So how to do with these numbers?
setp hm2_7i76e.0.7i76.0.0.spinout-scalemax 2500 is the new max in Hi rpm on motor and Shifter Out Geears set to A
What if it will not go to 2500 do I just add untill I am satisfied? Does these added numbers do anything unwanted for future sync motion?


What you need to do in this case is to consider the spinout number to be a _motor_ speed request and to calculate the motor speed required on the basis of the engaged gear. In fact, as you have a 2-speed motor you might even want to consider it to be a VFD frequency request.

The problem with my gear-detection system is that it can only work with the spindle turning. So automatic motor speed changes would need to happen with the spindle turning too.

However it is probably a _very_ bad idea to switch motor speeds with the VFD powered up. They don't like that.

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01 Aug 2017 16:31 #96842 by andypugh
Advice on the internet is to wire a constant-torque 2-speed motor as high-speed only and let the VFD handle all speed changes.

Your motor appears to be a constant-power motor, so it probably is worth keeping the 2-speed operation.

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01 Aug 2017 16:51 - 01 Aug 2017 16:52 #96843 by tecno
I am all ears on this subject, what I have learned it is called Dahlander type 2-speed motor.

So I assume what you are saying is constant-torque can withstand a wide rpm range as the cooling is good to do so.

My constant-power need to be handled as built to keep cooling etc under control.
Where did you find data saying this is constant-power type?

This is howe the motor is placed inside the Y axis boom

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Last edit: 01 Aug 2017 16:52 by tecno.

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01 Aug 2017 17:06 #96846 by tecno
Here my truth table for the gearbox.

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01 Aug 2017 18:43 #96852 by andypugh
If you have sensors then it's all rather easier and motor-speed selection can be made before the spindle starts.

This HAL component that I wrote some years ago should be a good start.

It doesn't handle the 2-speed motor case, but that should be a fairly simple modification.
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01 Aug 2017 18:53 #96854 by tecno
No sensors yet other than good candidates somewhere on a shelf ;) Need to build the mechanics first, may very well be 3D printed in ABS. But that is for later on.

Now that I have spindle more or less sorted out I need to get my axis motor parameters tuned in.

forum.linuxcnc.org/39-pncconf/33069-help...going?start=40#96623

File Attachment:

File Name: combimill_...8-01.hal
File Size:17 KB

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File Name: combimill_...8-01.ini
File Size:5 KB
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01 Aug 2017 20:36 #96860 by rodw
If you are going to use sensors per your truth table, you could use a MUX8 component and a select8 component. I have used this for 6 axis selection on my pendant. (but I only use 3 xes at this stage. Don't forget the loadrt and addf statements
#Axis Select (0=off, 1=x, 2=z, 3=y, na, 5=6, 6=4, 7=5) 
setp mux8.0.in0 0
setp mux8.0.in1 1
setp mux8.0.in2 2
setp mux8.0.in3 3
setp mux8.0.in4 4
setp mux8.0.in5 5
setp mux8.0.in6 6
setp mux8.0.in7 7
net mux8-sel0 <= hm2_7i76e.0.7i76.0.0.input-23
net mux8-sel1 <= hm2_7i76e.0.7i76.0.0.input-24
net mux8-sel2 <= hm2_7i76e.0.7i76.0.0.input-25
net mux8-sel0 => mux8.0.sel0
net mux8-sel1 => mux8.0.sel1
net mux8-sel2 => mux8.0.sel2

net mux-float conv-float-s32.1.in <= mux8.0.out

net mux-s32   <= conv-float-s32.1.out
net mux-s32   => select8.0.sel
net axis-select-x <= select8.0.out1
net axis-select-y <= select8.0.out3
net axis-select-z <= select8.0.out2
net axis-select-4 <= select8.0.out6
net axis-select-5 <= select8.0.out7
net axis-select-6 <= select8.0.out5

net axis-select-x => axis.x.jog-enable
net axis-select-y => axis.y.jog-enable
net axis-select-z => axis.z.jog-enable

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01 Aug 2017 20:48 #96861 by tecno
Hi Rod,
looks interesting will take a closer look when it is time to implement this.

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