X-Axis opto switch working 'in reverse'

Hi,

I've reached a monumental moment today. Finsihed my build and now have a printer that does things (heats extruder, moves all axis) - Hooray!

However.............I've some odd X-axis opto switch behavour. When the x-flag breaks the infrared beam it doesn't stop the carriage moving further left. But it does stop me moving it back to safety (i.e. right). The Z and Y work fine (stops me moving further down/back but does allow me to move up/Forward to safety).

I wondered about swapped wires on the opto switch (there's one green, one brown and 2 black so that would be easy to do). But I assume the opto switch just registers if the beam is broken or not, so that wouldn't be the case??

Also positive movement (e.g. +10) moves my x-carriage to the left, which seems counterintuitive to me. Is that what it should do?

I'm using redsnapper with Gen6 electronics
Any thoughts???

Also, if the co-orinates are X,Y,Z all at zero where should the print head be? (e.g. Right hand side, Front (bed is all the way back), lowest(just of print bed)???????)

Thanks

Pete

No don't swap the wires on the opto, you will probably destroy it. The opto sees the tab, so it is working correctly. What seems to be wrong is your axis moving the wrong way. You can reverse it by turning the motor plug round or swapping the first two wires.

0,0,0 is in the middle of the bed with the nozzle nearly touching it.

Positive X values move the carriage to the right hand side of the bed. Positive Y values move the bed to the front of the machine so the nozzle is over the back of the bed.

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[www.hydraraptor.blogspot.com]

Brillant

Sorted! Looking good now - all axis move correctly and all find their home correctly

Cheers

Pete

I thought 0,0,0 was located on the front left corner of the bed.

Edited 1 time(s). Last edit at 04/23/2011 09:33AM by brnrd.

It is, some people change it in their start up code.

I leave my 0,0 in the lower left hand corner of the table where the home switches are and print objects centered at 100,100.
At the end of the print I move to 100, 200 so the extruder is in the middle of the x-carriage and the table is sticking as far out to the front as possible to make it easier to remove the printed objects.

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Bob Morrison
Wörth am Rhein, Germany
"Luke, use the source!"
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