Needle height calibration

[akhilkollamvilakom]

Hi,

could anyone please tell me more about "needle height " calibration. I have placed a normal PCB under the Needle and pressed "next"", the needle comes down but it is way above from the PCB surface.But in "LIteplacer" basic setup page ,it has been said that "jog the needle up until needle barely touches the PCB" [url] http://www.liteplacer.com/basic%20setup/[/url .How could I jog it up when it is not even touching the PCB.


During "Needle height" calibration , does the needle comes all the way down till it triggers the "Z max" switch? or should I jog it down till it triggers the switch?


I tried the "Hello world" job and the needle is not coming all the way down to pick up component. It just comes down to a certain distance then go back up and move to the location to place it, same thing happens there too.It's no touching either component or PCB.

[JuKu]

> During "Needle height" calibration , does the needle comes all the way down till it triggers the "Z max" switch?

Yes. If it doesn't, there is a problem with that or some other switch. Please double check your wiring and perhaps, check with an oscilloscope that there is no excessive noise on the switch lines.

[akhilkollamvilakom]

Nop it doesn't.
As I said it is way above from the PCB surface to trigger "Zmax".And the Z axis is not moving down 10mm when I press Alt+F12. It only moves around 5 mm.

[JuKu]

And the Z axis is not moving down 10mm when I press Alt+F12. It only moves around 5 mm.

Your z axis is not set right. If you are using the kit motor, setting default values should already have set the movement parameters right (1.8deg./step, 8mm/revolution). If you are using some other motor, set the values so, that the z axis travel is as expected. Still, the z max limit switch should not trigger mid travel, there may be other issues than z parameters as well.

[akhilkollamvilakom]

In "needle height calibration" can I control the downward motion of the needle ,means how much it should go down or is it preset.
My needle goes around 80mm (as per the software) and stops.

[fake.jackieboy@gmail.com]

Hi

I am also having a problem with the Z-height calibration. I am unsure if it's me doing something wrong or if there is an issue with the liteplacer software, or a setting not set correctly.

Here is what I am doing and what I am getting.

1) Open the software and connect to tinyG board.
2) Click the start nozzle height calibration start button. ( I have tried to home the Z axis before doing this gives the same result)
3) The Z-axis starts moving until Z-Max switch is triggered.
The software automatically set Z position set to 80.00 even tough it only traveled +-40mm. I have tried to trigger the switch way above the PCB by hand and always defaults to 80mm no matter how far it has traveled.
4) I press next as instructed.
5) I jog the machine, trying to get it just touching the PCB. The problem is the switch disengages and triggers a travel error. I am then forced to reset the TinyG board and can't continue the calibration.
I am also able to only travel about 2.7mm before the switch releases (I believe this is a good value) however the process is then interrupted as indicated above.

On one run I was able to set it by triggering it in the air and then moving to the 40mm position and it accepted that, so I am working with that at the moment. But I would like to know how to do it as in the manual to get a more accurate result.

I there a way to manually set the nozzle height, backoff and placement height?

Any help with possible solutions or an indication of where I went wrong (which is a strong possibility) would be greatly appreciated.

Kind regards

[JuKu]

I have asked TinyG folks about this, but haven't yet received an answer. Point 3 sounds like a bug (max. Z travel is set to 80mm), but I don't know what might trigger this.

[fake.jackieboy@gmail.com]

Hi

To date have not been able to resolve this issue. Did you by any chance receive a reply about this problem?

Kind regards

[mikehibbett]

I am having exactly the same issue as fake.jackieboy.

Head comes down, nozzle compresses, Z max triggers, head rises slighly. Joggin Z up results in Z max opening, unsurprisngly, before head comes off the PCB. Tripping the TinyG Error.

Is there a resolution to this, as I assume I cannot continue?

Cheers,

Mike

[JuKu]

I am having exactly the same issue as fake.jackieboy.

Head comes down, nozzle compresses, Z max triggers, head rises slighly. Joggin Z up results in Z max opening, unsurprisngly, before head comes off the PCB. Tripping the TinyG Error.

Is there a resolution to this, as I assume I cannot continue?

Cheers,

Mike

When you manually push the tube up from the nozzle tip, these should happen, in this order: The tube goes up, triggering the switch. Then, the bottom collar goes up against the lower bearing. Only after this, would the spring in the nozzle adapter start to compress. When you let go, the tube should drop fully down under its own weight, at all rotational positions. If not you need to tune the bearings mount so that the tube moves freely in the bearings.

Assuming hte above is ok, when the head comes down under software, this should happen: Head goes down, nozzle tip touches something, tube goes up (nozzle spring doesn't compress), switch triggers. Head goes up a little, releasing the switch.