[bpratl]

My lathe is presently set up on Mach3 turn, XP, LPT ports and single index pulse and I would like to try UCCNC software because I am not satisfied with the threading features of Mach3. Should I add a quadrature wheel to the spindle or some sort of spindle encoder? I'm planning to use a UC400ETH controller but I can't seem to find a good wiring diagram to help me setup the lathe. Any suggestion on the best indexing setup would be most appreciated. Bob

[OlfCNC]

I think there is no wiring diagram because all inputs on the UC400ETH are identical and any of them can be configured to any input functions in the UCCNC.
For threading you have to have an incremental encoder connected to the spindle and wired back to the UC400ETH inputs.
From the config page it looks the encoder must have A, B and Index channels. And I'm assuming the index has to make one pulse per spindle rev.
The encoder has to output 0/5V voltages if you connecting them directly to the UC400 input pins.

[bpratl]

olfCNC, thanks, I see the pinouts now after downloading and installing UCCNC and checking out the configuration files. I guess I will have to fabricate a 100 slot encoder wheel to add two more optical sensors as I presently have a only and single slot index pulse that I was using for Mach3. Bob

[samco]

You could try linuxcnc with a single index pulse... Just to see if it threads well enough for you.. (then you would not have to change anything - it will work with the printer port)

sam

[bpratl]

Sam, thanks, I have used Linuxcnc a few years back but I thought that it required A, B & Indexes, I will give that a try again.

[OlfCNC]

You don't just use an encoder. Why need to fabricate anything?
Something like the AMT102 is cheap enough IMO: AMT102-V CUI Inc. | Sensors, Transducers | DigiKey

[OlfCNC]

I think cutting threads with index pulse is not a very precise method. The OP probably has that as problem with Mach3. I mean what happens between 2 full turns? The system is blind with a sensor on just a single point.

[vmax549]

It must be an AB encoder. You can use your index if you wish or the encoder index. You can always import the mach3 XML into UCcnc but there cannot be that many set features on a lathe.

Encoder threading works very well in UCcnc and very easy to set up (;-). There may also be a Mach3 Plugin soon that allows encoder threading in Mach3 (;-)

(;-) TP

[samco]

I am not saying it is perfect - but it does work with linuxcnc. (single index threading). I just though instead of switching things over - he could give linuxcnc a try with his current setup...

sam

[OlfCNC]

In my opinion the issue he has with Mach is probably because of the single pulse index.
I don't have a CNC lathe yet, but if I will I will sure select an encoder feedback over a single pulse feedback any time.

[cyclestart]

You don't just use an encoder. Why need to fabricate anything?
Something like the AMT102 is cheap enough IMO: AMT102-V CUI Inc. | Sensors, Transducers | DigiKey

It still requires fabricating something ? Some way to mount and drive it, probably a belt running 1:1 off the spindle.
Unless there's an easier way I'm missing.

[OlfCNC]

It still requires fabricating something ? Some way to mount and drive it, probably a belt running 1:1 off the spindle.
Unless there's an easier way I'm missing.

I ment electronics

[vmax549]

We found out there ARE many Glitches and bugs in Mach3 turn threading code.

(;-) TP

[vmax549]

You could build a new disk with 50 holes and position 2 optics in proper timing to create an AB signal. Then add a single hole separate from the 50 holes pattern for teh index. But encoder are simple to install in most applications.

(;-) TP

[cyclestart]

I ment electronics

my mistake.
The AMT encoder could be a good idea as the number of pulses/rev can be changed.

[samco]

Right - I have played around with linuxcnc's single index threading and it seems pretty good. (again - just to try to see if it solves your issues without having to re-wire/add encoder stuff) Just a thought

We found out there ARE many Glitches and bugs in Mach3 turn threading code.

(;-) TP

[OlfCNC]

I don't think it is good for small lathes where spindle RPM can drop significantly on a single turn when the system is still blind about it.

[bpratl]

Thanks. You guys convinced me that quadrature indexing, with UCCNC, is the way to go for precise threading. I my case, it's better for me to fabricate a another multi slot index wheel for A & B pulses than add sprockets and belts to the spindle to drive an off the shelve encoder. Any other suggestions are most appreciated. Bob

[OlfCNC]

Thanks. You guys convinced me that quadrature indexing, with UCCNC, is the way to go for precise threading. I my case, it's better for me to fabricate a another multi slot index wheel for A & B pulses than add sprockets and belts to the spindle to drive an off the shelve encoder. Any other suggestions are most appreciated. Bob

Sounds like a good plan if it fits your spindle better than adding an encoder. It can be the case if there is tight space at the spindle.
I would use a cut (laser cut or CNC milled) disk with some fabricated hub on the disk and opto-gate sensors like a Heds module or something like that.
First I would select the sensor modules, check the datasheet to see what disk thickness fits in.
And finally I would design the holder for it possibly a bit alignable to get the 90° shifted A/B signals.

I would also edit a half turn cutout for the index on the same disk then all sensors could connect to the same disk next to eachother.

[vmax549]

You do NOT have to have a half disc slot for the index. The Controller is PLENTY fast enough to see the index hole. IF it can read the AB signal it can read the index signal. It is plenty fast enough to read an Encoder index mark.

(;-) TP