Z Zero macro ?

[SW0rden]

I was looking at this set of macros because my set/usage is similar to the DT/DTMax and I was wondering what 'PZ, PX, PY' is? I see and understand the parameters, but this is a new SB command to me and when testing the Z zero macro, it just raises up to the backoff final + plate thickness and quits. It appears that the 'P' command is ignored. Is this something that has been implemented in a newer fabmo image/release and isn't enabled in mine? Currently running 1.7.0 and 1.5.2.

[ryansturmer]

This is something that is only available in the 1.6.0 release candidate. You can switch to the RC by changing your packages url to http://fabmo.github.io/manifest/packages-rc.json if you want to try it out.

[SW0rden]

I've been trying to place a pause for a few seconds in the z zero macro (time to get hands on the plate) and any attempts cause the routine to fail. The manner in which if fails is that after the pause period, the tool will touch off, but apply extra pressure (excessive over travel in motion) and then retract. It seems to do the double touch all in one shot without retracting for the second touch.

The issue of over travel in relation to probe speed has always been an issue in g-code probing (of which I assume your new P command is equivalent to). If the feed rate is set to high, the over travel is greater and the accuracy of the location is way off. The slower the feed rate, the less over travel (and resulting pressure on the tip of the tool touching the plate), the closer the accuracy. I'm running the same settings as the Desktop/Max and with the default feed rate setting in the macro, there still is a noticeable amount of over travel.

I used to have a z zero macro that used the jerk settings to make it stop quicker when touching the plate, but that has stopped working in the latest rc versions. The latest one here, I can't get it to be accurate at all. Plate thickness changes to try an tweak it, make no difference. It also seems that when set with $ instead of & for the plate thickness variable, the $ one makes no difference. Not sure what's up here, but maybe some of this will shed some light. Never-the-less, pressure on the tip of the tool when touching the plate at .5 feed is too much and could chip/break a delicate tool.