RRF 3 Z home not triggering.
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@joehsmash said in RRF 3 Z home not triggering.:
@JoergS5 right now the NC switch is in an inverted state, the entire weight of the gantry is resting on the lead nut, and the switch clamp is clamped to the leadnut and snugged up to the bottom of the gantry. so that when the nozzle hits the bed, it raises the gantry approx 1mm which causes either of the switches to trigger.
Ok I understand. That's a good idea and is very precise!
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Subtle switch trip https://imgur.com/a/RrO48ah
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I am not sure, but while watching the video, I think I see some subtle rotations of the endstop while it activates. The rotation means Z movement because the endstop is connected to the trapezoid spindel. Maybe this is the reason for your differing values.
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@joehsmash i dont mean to be a smart a$$ im not,
ive just had this machine apart and back together so many times now that im sure i can build it in my sleep.
i would just like to be able to get back to the auto level like i had before and get back to printing.
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@JoergS5 i could snug up the lead nut inside the gantry arm for sure. i have some .001 shim here.
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@joehsmash The video is counting down from 0.25 to 0, at position 0:12 the endstop rotates a bit. This changes the measured value. Because the endstop is assembled on the trapezoid spindle and the rotation itself changes the Z position.
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@JoergS5 to which i will do in the AM, as i will have to dissasemble the whole gantry and top half of the printer to get them out.
thanks for your help thus far... some times i wish there was just a chat button haha
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You don't need to disassamble. I think the endstop rotation could be the reason, so hindering it from rotating is a quick test.
Good night! For me, it's morning.
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@joehsmash said in RRF 3 Z home not triggering.:
some times i wish there was just a chat button haha
There is chat!
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I will have to take a closer look at this, but I don't think you can do exactly what you want to do using both switches for a single probe type, at least not currently. I'll see if I can find that out for certain.
However, adding an actual probe to the nozzle is by far the best solution. Then you can still use the endstops to level the gantry if you wish, but even so, using the probe makes more sense. The tilt needed to cause the switches to trigger makes for a very compliant system.
The fact that moving 50mm up and back down results in changed position means there is some mechanical slop in there somewhere that must be addressed regardless.
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@Phaedrux hmm im just not sure where the slop could be. Its only a lead nut and a gantry that is in the system.
And there is a little slop on the x axis where the lead nut goes into the x gantry but to account for over 1mm on 50mm seems like too much.
I have a bltouch that will be here tomorrow.
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I don't suppose you have video demonstration of how the leveling works in stock configuration?
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@Phaedrux its not my video but this is exactly what it does
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Basically the x and z are on the same tower just like any other printer. Only the y bed moves front to back. And not ghe zx gantry tower.
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That sure is a lot of flex.
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@Phaedrux its not flex, its a really solid frame.
It triggers either side switch and moves approx 1 mm, but only when the nozzle touches the bed. Other than that, all of the weight is on the lead screw. So theres no where for it to go
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It's hard to believe that has any accuracy at all.
Curious design.
The BL Touch should solve most if not all of your problems.
Frederick
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I'd like to understand how it's used in the stock setup because it should be possible to duplicate the behaviour. Do both switches trigger when it's pressing the bed like that? or is it only one or either?
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@Phaedrux in a homing scenario only the left one will trigger, but in a stock set up the switches are physically wired in parallel so it doesn't matter if one or both trigger one is basically like triggering both.
If you want more information feel free to chat me and i can explain every thing about it or just ask here.
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Ok I see. Well you could use it as a switch type probe much the same as the under-bed piezo sensors, albeit less sensitive. If one of the two switches always depresses when the nozzle goes down you can just use that switch in the M558 command. The problem I foresee is that the trigger height (which you'll need to measure just like a normal probe by the way) will vary between different areas of the bed because I think the amount of compliance will change. It would be interesting to see the heightmap at any rate.
You could even still use the switches for independent leveling of the gantry by configuring them as endstops before using them as endstops.
