Firmware 1.19RC1 released - please help us with testing!
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Further to my previous response 2 posts up, I have now discovered a problem with specification #2 with the bug fix applied. If I select a tool and then select another tool without moving it first, there is unwanted movement because the commands in the tfree file assume a starting position that does not correspond to where the the head is. The unwanted movement is benign because it gets undone, but ugly.
So I'm reluctantly forced to treat different axes differently. I'll revert to specification #1 for all axes, except that after a tool change the requested user Z coordinate shall be restored to what it was before the tool change. I hope this will keep everyone happy. It should work provided that after issuing a tool change command, the slicer always specifies both X and Y coordinates (but not necessarily Z) in the next movement command.
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A G1 Z without X coord should not change the X coordinate, But just leave X where it is, right?
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But a G1 command with no Z coordinate does need to change the Z height, in the case that you have just done a tool change and the new tool has a different Z offset from the old one.
There is no single specification that, applied uniformly to all axes, results in the desired behaviour in all cases.
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Tbh, this (#4) is what I would have preferred. #2 was confusing if you were using the Web interface to test movement. I guess if there was a good reason for going with #2 to get more compatibility with slicers you could have changed how the gui move worked and made it issue absolute moves.
Also in RC3 I some side effects (don’t know if it’s part of the know bug you are talking about).
If I move T0 to x 250, switch to T1 x-1 moves to 249 deselects T1 (both tools in standby now) and the activate T1 again it will move to min x (all the way next to T0).
If I activate T0 and move it to x 250. Deacitvate T0 (T0 moves to parking pos). Both tools are now on standby. U-1 will not move T1 but It moves T0 to 250.When I do x+0.1 a few times I could not make T0 go to 255.0.
x+0.1 254.8 x+0.1 254.8 x+0.1 254.9 x+0.1 254.9 x+0.1 255.1 x+0.1 255.2 x+0.1 255.3 x+0.1 255.3 x+0.1 255.4 x+0.1 255.6 ```I would guess this is a rounding issue in the presentation and the real position is something like 254.95 and next 255.05? The .05 for T 0 might somehow been picked up from T1 “G10 U0.15”. Anyways, these issues might not be a problem if you revert back to beta11 behavior for X and Y. Btw, maybe a G1 R2 command could be added that one could put in a tool change script to get the behaviour of #2 if it has any practical use…? (or the reverse if you decide to go with #2) -
I've just released RC4. Please try it.
I did consider whether instead of restoring the initial user-requested Z coordinate after the tool change is complete I should actually have the Z axis move; but I thought of some problems with doing that, so I didn't.
G1 R2 is already implemented. However, it needs to be tested on an IDEX machine. The complication is that after changing from T0 to T1 or vice versa, where does the U axis end up? If we switched T0->T1 then we want the new U position to be the mapped X coordinate, not the old U position. If we switched T1->T0 then we want the new U position not to be restored at all but to be left nas it was after execution of the tool change files. I suspect it isn't accounting for this. And then are the other 4 cases of switching between no tool (T-1) and T0 or T1, in either direction.
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You could make variables to use in Gcode. This way it could be the responsibility of the free.g to:
- Store current position to user-named variables.
- move the head to park position
and post.g
- move the head back to user-stored position
This would be much more flexible and support different configurations and be the responsibility of the user to support the functions he needs.
I think if you make the following variables available, we would come a long way:
TnX TnY TnZ En where n is the extruder or head number.
For starters the user variables could be just an array of 30 floats that are indexed like data[n] and the user can keep track. - that should be relativly easy to implement and very flexible.
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True, but explaining how to use them to novices would be complicated. I prefer to get as close to an "it just works" solution as possible for the majority of users.
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Just to give you some quick feedback on RC4, my initial move x/y/u tests worked!
I'll recompile it with my modification to get it to work with cura and do a test print and report back when its done. -
Thanks for the feedback. I think I've cracked this one at last - provided that the user (can't remember who) who reported tool Z offsets not working is happy with it.
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Hmm.. something is going wrong after I pause and stop a job. I do a few extrudes on both tools (maybe up to 10mm) to prime the tools. When I do "print another" it moves to where it should start and do a huge retract! Is there some code that tries restores the e0 and e1?
M190 S63 M104 S210 M104 T1 S210 M109 S210 M109 T1 S210 ; G28 ;Home G1 Z15.0 F6000 ;Move the platform down 15mm M83 T1 G1 E2 T0 G1 E2 M82 ;LAYER_COUNT:420 ;LAYER:0 M107 M104 T1 S180 G0 F6000 X221.18 Y236.445 Z0.3 ;TYPE:SKIRT G1 F1800 X220.667 Y236.983 E0.01398 G1 X220.193 Y237.581 E0.02834Edit: retract was on T0
Edit 2: I get retract on T1 too -
Ok, Ill put that in the start g-code… Are you planing to go back to old behaviour (where it worked without G92 E0) for this (pre RC) or keep it this way?
Edit: Plenty of G92 E0 just to be sure it works
G1 Z15.0 F6000 ;Move the platform down 15mm M83 T1 G92 E0 G1 E2 G92 E0 T0 G92 E0 G1 E2 G92 E0 M82 -
Absolute extrusion in 3D printers must rank as one of the worst ideas ever. Whoever thought it was a good idea was a moron. It causes problems with supporting pause/resume, resume after power fail, mixing extruders, and filament change support. Please nag the Cura developers to add support for generating relative extruder coordinates.
You and the Cura developers between you have fallen into one of the traps of using absolute extrusion. The first extrusion command generated by Cura (G1 F1800 X220.667 Y236.983 E0.01398) does not have a G92 E0 command before it to define the datum for that extrusion command. You should insert a G92 E0 command in your start gcode after the M82 command.
EDIT: your post crossed with mine.
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You should insert a G92 E0 command in your start gcode after the M82 command.
Will that reset it for both tools?
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No, only for the current tool. RRF maintains separate cumulative extrusion amounts for each tool. AFAIK nobody has ever defined whether this is what 3D printers are supposed to do, or whether a single value should be maintained. Yet another problem caused by using absolute extruder coordinates. Relative extruder coordinates make things so much simpler.
Your question and my response would not have been needed had your slicer generated code that used relative extruder coordinates. Please nag the Cura developers to add support for relative extruder coordinates.
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Ok, it seems RC4 works for me too. I have not done a full test with pausing etc, but for just normal printing it seems to work.
And the "tool Z offsets not working" bug was reported by me, so you can strike that off your list.
Thank you
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Ok, it seems RC4 works for me too. I have not done a full test with pausing etc, but for just normal printing it seems to work.
And the "tool Z offsets not working" bug was reported by me, so you can strike that off your list.
Thank you
Thanks for the feedback! Got there in the end.
Unless I receive any more problem reports, I intend to release RC4 as the 1.19 release. It's now very similar to 1.19beta11 apart from the tool change Z offset fix and refactored homing code to support SCARA.
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Yep, looks like basic printing works now, have not tested to change offsets. I'm out of time now…
I'll let the cura developers know of your hatred of absolute extrusion at first opportunity I get!
The following start code should prime and reset both tools..?
G1 Z15.0 F6000 ;Move the platform down 15mm T1 M83 G1 E2 M82 G92 E0 T0 M83 G1 E2 M82 G92 E0 -
Yes, that looks good.
Your question and my response would not have been needed had your slicer generated code that used relative extruder coordinates. Please nag the Cura developers to add support for relative extruder coordinates.
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I have made some contributions to Cura and one of the recent changes is that it now really does differentiate between Marlin and RepRap flavour gcodes. Until recently it had RepRap(Marlin) flavour that has to conform to various Marlinisms and so wasn't really that well matched to RepRap. It now has separate Marlin and RepRap flavours and so there's no obvious reason why the RepRap flavour gcode could not support relative extrusion. I shall investigate and will keep you posted.
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Thanks, that would be great!
Another good feature would be to write T0 to the Gcode file before any temperature-setting commands, if no T commands would otherwise be written.
