Z axis tool change hight in webcontrol

I’m a bit of a forum Hunter. I have seen asks for z axis limit switches and standard hight control. There are problems stated behind these ideas.

For the limit switches, if wired to z motor power to stop movement there would be no way move the z away from the switch other than by hand.

For the z hight standard, the z has no noway to know where it is until it is zeroed so a tool change hight say at 45mm would be different depending on the length of bit and where the z was when zeroed.

My uneducated question.

Could webcontrol/firmware be updated to allow the z axis to have a stored position of limits outside of zeroed position for the bit that calculates the range of movement after each zero and prevents the z from moving past that point.

To set the stored position nights one would move the z axis without bit to just before it bottoms out saves position and raises it to just before it tops out and saves position. This would be implemented in calibration.

Z zero - the zeroing after bit installed
Z limit value - the real values of the router bottomed and topped out on the z axis without bit.


Z stored low limit value = 0 mm
Z stored high limit value = 65 mm

Z zero after bit installed would be 0 but stored limit position would be for example 25mm. In the background the limit value will prevent the plunge from going lower than -25 from the bits zeroed value, 0. The high z limited after zero would be calculated at +40 (above zeroed z value) this is because the bit is causing the router to sit 25 mm up from it’s bottom limit.

This limit value can only set at calibration and calculates the limits during bit install and z zeroing. In the background the z always knows where it is via the z limit value even after bits are changed.

This eliminates the need for limit switches. And could provide a button in webcontrol to raise to the top limit position for tool changes.

That is called soft limit and it was added a while back but isn’t in an official release.

See here for the GitHub discussion

It looks like it worked?!

That is one of the features rolled in, but not released. I tested it and it works, but we have not had a major release of webcontrol with it. The tricky thing with webcontrol releases is that it gets bundled with a newer version of the firmware too for newer boards. My efforts on this are really messy and not well segregated into nice organized single feature commits, so having a second person check that functionality is very difficult without a huge allotment of time… So no new release yet.

How many times did I spell height wrong in this post…

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