Hi All,

When trying to home the X-axis on a Huxley duo it doesn't stop when the IR sensor is over the white tab, it keeps going and crashes into the z-axis. I've checked the readings from the sensor using G31 at close proximity and far away using a piece of paper and they are as you would expect (over 900 for close proximity and below 50 for far away). I've updated the firmware to the most recent and checked that the SD card is being read upon starting up the printer (I believe this is required in order to turn on the sensor). The readings I get when the IR probe is over the tab are 300 if I use a white piece of paper on the tab and around 400 if I use foil as someone in an ormerod discussion suggested.

Any ideas?

Cheers,

Ed

Edited 1 time(s). Last edit at 08/17/2015 01:09PM by EJC91.

Some suggestions:

1. Check that the proximity sensor board is vertical.

2. Check that the leads of the black IR sensor head on the proximity sensor board have not become bent. The sensor should face the horizontal white tab square on.

3. When the sensor is over the white tab, how large is the gap between them? If it is too large to get a high enough reading from the sensor, you could glue a piece of white card on it, so as to raise the height of the reflecting surface.

I don't know the Huxley, but I am wondering whether it is possible to mis-assemble it in a manner that causes the proximity sensor to be too high above the homing tab.

Edited 1 time(s). Last edit at 08/17/2015 01:30PM by dc42.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

The board is vertical, the sensor is square to the tab and none of the pins look bent.

The proximity sensor reads between 300 and 400 when over the homing tab (300 with white card and 400 with tin foil) but it still crashes into the z-axis. I'm no expert but it sounds like a problem with the software although all the firmware is fully up to date.

I don't believe it is something to do with the assembly since for the first week it was running the axis homing worked fine without any problems.

I'll be tempted just to buy a mechanical end stop for the x-axis at this rate.

Edited 2 time(s). Last edit at 09/03/2015 10:33AM by EJC91.

Quote
EJC91
The proximity sensor reads between 300 and 400 when over the homing tab (300 with white card and 400 with tin foil) but it still crashes into the z-axis. I'm no expert but it sounds like a problem with the software although all the firmware is fully up to date.

The proximity sensor is generally reliable so there is no need to use a mechanical endstop switch. However, the default G31 P value in config.sys is 400 AFAIR, so a reading between 300 and 400 will be too low to trigger it. If it was working for the first week, it could mean that it was marginal and you happened to get readings above 400 then. So I still think you should check the gap between the sensor and the white tape, and if it is more than about 1mm then use a piece of white card to reduce it.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Had to use several pieces of white card in the end but is working perfectly now!

Thanks for the help dc!