Polar bed homing.

CNCModeller

Hi all.
My polar build is almost ready for the electronics!

Id like to be able to home the rotating bed to allow me to orient to print on a laser cut first layer, and also use the restart on power failure feature. As such I will need a bed rotation home switch.

When the polar printer configuration was created what hardware was envisaged for the bed rotation home switch?

I was thinking about a hall effect sensor but didn't know if it being triggered every rotation would be an issue?

Also does bed mapping with a bltouch work on a polar printer? If so what is the maximum bed deviation it can allow for? My bed is 600mm dia sheet aluminium and it has enough warp to be an issue. I will probably mount a sheet of glass on it after initial testing, but would like to dilo initial tests with pla on kapton tape.

Any thoughts would be much appreciated.

Many thanks
Barry M

bondus

It will work fine to home the polar bed, triggering while printing doesn't do anything.

You could use an optical fork-style endstop mounted on the frame with a flag on the bed. They are cheap and work very well (unless you are in direct sunlight).

You might have to edit homeall.g and make a homebed.g to move the bed to home.

Add something like:
G1 S1 Y-360 F1000 ; Rotate counterclockwise, up to 360 degrees.
G1 S2 Y2 F1000 ; go back a bit
G1 S1 Y-4 F120 ; approach slowly

dc42

@cncmodeller said in Polar bed homing.:

When the polar printer configuration was created what hardware was envisaged for the bed rotation home switch?

I was thinking about a hall effect sensor but didn't know if it being triggered every rotation would be an issue?

As @bondus said.

Also does bed mapping with a bltouch work on a polar printer? If so what is the maximum bed deviation it can allow for? My bed is 600mm dia sheet aluminium and it has enough warp to be an issue. I will probably mount a sheet of glass on it after initial testing, but would like to dilo initial tests with pla on kapton tape.

Yes, bed compensation should work.

CNCModeller

Thanks for the info. Hopefully I will be putting it all together this weekend.
Many thanks
Barry M