CNC Touchplate as Z stop?
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I'm sure people have done this before and there is a reason no one does it... but it seems like CNC touchplates get very good accuracy and repeatability for setting tool heights, so could a spring loaded touch plate mechanism be used as the Z axis end-stop?
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@lael generally, you set the z axis at maximum travel and then use a probe to set your workplace coordinates
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@lael said in CNC Touchplate as Z stop?:
I'm sure people have done this before and there is a reason no one does it... but it seems like CNC touchplates get very good accuracy and repeatability for setting tool heights, so could a spring loaded touch plate mechanism be used as the Z axis end-stop?
I do exactly that. My various hot ends fit using a kinematic mount which allows some movement in Z (against a spring) but none in X or Y. The hot end stop consists of a brass plate fixed to the carriage and a brass bolt fitted to the hot end. The brass bolt and plate form a switch as well as a mechanical stop. So the nozzle itself is the Z probe. As soon as the build plate lifts the nozzle off it's physical stop, that also breaks the switch which is the trigger that sets Z=0 homing position.
In practice, it is impossible to see any movement of the hot end and as you say, it's extremely accurate and repeatable with no hysteresis. The slightly difficult part is the kinematic hot end mount but the switch is as simple as they get.
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Maybe you will find this interesting
https://forum.duet3d.com/topic/18106/tool-length-sensor-tls-for-e-g-tool-changing?_=1606417499239Custom ANET A8
Custom Delta: D-PATCH (Delta Printer with Automatic Tool CHanging) https://forum.duet3d.com/topic/16082/d-patch?_=1596131234754All I do here is under this license: CC BY-NC-SA
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@deckingman This sounds great! Do you have photos / posts about this somewhere?
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@taconite That is very interesting. Have you made the design available somewhere - i'd be curious to see how much travel it has.
