Question for developers. Why isn’t there an option in #Slic3r or other programs like it, to re-home the x and y axis after each layer? Or every X layers? Wouldn’t that save a lot of prints that would otherwise be ruined? At the cost of some extra print time, to be sure, but still… reliability is more important than speed right? Or is there a way to do this and I’m just missing it? #rehome #fail #loststeps
That seems like trying to wallpaper over a hardware problem with a software patch. You should probably try to figure out why your printer is losing steps and fix that issue before something burns out and you lose all the steps.
Joe, my printer doesn’t normally loose steps. However, from time to time, “things happen”.
Jeff / Joe, here are some examples: Cat runs over the printer at full speed and knocks the x axis out of position. Binding filament roll pulls the y axis out of position. Re-homing XY could very well save a print that would otherwise have to be tossed.
Or… if it sensed that it was out of position when homing, it could stop the printer rather than waste a gob more filament. I suppose that would have to be done in firmware though. Just rehoming should be possible in g-code though, right?
Home stops are not that repeatable, typically, except the Z.
Printer settings > custom gcode > layer change gcode
Put “G28 X0 Y0” in there to do what you’re trying to do, but I recommend against it for the reasons others have mentioned.
Ha! Genius! Thanks Rich!
yeah main reson is that homing is not going to be exact, I’d expect you’d notice it fairly significantly in your zlayer allignment. @Jasper_Janssen even z is not that repeatable, try printing at a very low first layerheight and you’ll see what I mean.
I printed this to experiment with re-homing the X and Y axis after each layer. The concern was that variation in the homing switches would introduce more error than it was worth to prevent an accidental loss of position due to e.g. a sticking filament pulling the print head, or someone bumping the table during printing. As far as I can tell, the re-homing introduced no error on my Printrbot Jr, and since the part was positioned close to home, and is a pretty small part, it cost very little extra time.
For narrow, tall prints, I recommend adding:
G28 X0 Y0 ;rehome X and Y only.
to the layer gcode. It will keep the print from being destroyed when “Murphy” comes knocking.
https://lh6.googleusercontent.com/bF3g-7GK0NOIBLvXzvoCixCsIyJZXpiPDvbSbDObAlI=w806-h851-no
Well, I have found one problem with re-homing X and Y every layer: The extruder tends to drool a bit and then when it returns to start printing the next layer, that blob gets “wiped” off onto the side of the part being printed. You get these little “rain drops” down the side of your part. They seem to crack off pretty easily, but I’ve not been able to get rid of them, even with increased retraction. Maybe I just need to retract more…
Yeah, you might need extra retraction in your layer change code, but you still have to deal with the fact that the plastic sitting in the hot barrel is expanding while you do your homing. If you’re not already, you should do a high-speed travel to get close to the endstops before homing, so that there’s less time waiting for the slower homing move.
Doh! Why don’t I think of these things on my own? Of course, I can add g-code to rapid to near home and retract more, then after the home, I can run the extruder back to where it was.
Or I can add g-code that retracts and just goes some where at a slower speed, then comes back to slow things down a bit.
I still think these options should be built into slic3r to help out with certain objects in PLA. If you are printing something tall and thin, it should just know that you need to move the head off the part for a while between layers.