Marlin response too early

*Moved from General*

The issue I am experiencing is that Octoprint sends Gcodes to RAMPS(Marlin) and RAMPS responses with ok, however, before it actually having moved its motor to the position.
So what actually happens is only few of the Gcode sent by Octoprint being actualized to the machine. Although I made an STL file with star shape, it makes some random shape or even completely ignores XY movement and only raise extruder head every 2 seconds which is insane. The estimated print time is 3hours according to CURA, but RAMPS, which experiences almost instantenous response from RAMPS, estimates its finish time to 10 minutes!

Here is the terminal log from Octoprint :

Send: N6725 G0 F600 X205.675 Y141.513*78
Recv: ok
Send: N6726 G1 F1200 X207.931 Y139.258 E124.31224*57
Recv: ok
Send: N6727 G0 F600 X208.769 Y139.833*77
Recv: ok
Send: N6728 G1 F1200 X207.089 Y141.513 E124.31378*50
Recv: ok
Send: N6729 G0 F600 X208.503 Y141.513*77
Recv: ok
Send: N6730 G1 F1200 X210.027 Y140.696 E124.31480*54
Recv: ok
Send: N6731 G1 X209.918 Y141.513 E124.31533*89

it would have been much more descriptive if I could configure octoprint to print out timestamps, but I can tell you that this much log happened in less than 2 seconds.

Our printer in fact isn't conventional - we are extruding chocolate out of cylinder, so we have some few irregularities on CURA settings. Since we are extruding molten chocolate out of cylinder, we set filament diameter to 42mm and layer thickness to 1mm (both causing warning message), although I don't really think this is the source of error.

Did anyone experience same problem as me when using octoprint + marlin? I would appreciate it if you could share your solution. I am also attaching my configuration.h

Thanks!

Edited 2 time(s). Last edit at 06/12/2015 10:59AM by totorovirus.

It is entirely normal for 3D printer firmware to acknowledge commands before they have been fully actioned. If it didn't, the machine wouldn't be able to do lookahead, which would result in very slow and low-quality prints. What should happen is that once the lookahead queue is full, the firmware only sends OK in response to a new command when it has room in the lookahead queue for it.

Do you see the same problem when you use e.g. Pronterface to print the file, instead of Octoprint?

---

Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Did you mix up filament diameter with nozzle diameter?
Filament dia is more important in relation to extruder-steps, but you seem to have a problem with x/y movement and it´s calculated based on nozzle dia.
-Olaf

Edited 1 time(s). Last edit at 06/12/2015 11:54AM by o_lampe.

Here is the nozzle and diameter setting in CURA.

Quote
dc42

Do you see the same problem when you use e.g. Pronterface to print the file, instead of Octoprint?

I'll try it with Pronterface though I don't really think the driver caused the problem.

42mm diameter filament? You're sure it's not 3.0?

Note they said this is extruding chocolate . . . this isn't your Mother's RepRap . . .

- Tim

But still, 42mm diameter = 1.68".

From Configuration.h
#define DEFAULT_AXIS_STEPS_PER_UNIT {100,100,1600,266.67} // default steps per unit for Ultimaker

So 1 extruder step gives pi*42*42/266.67 = 20.8 cubic mm of chocolate = 6.6mm of extruded chocolate

This seems like an order of magnitude (or two) out.

Quote
frankvdh
So 1 extruder step gives pi*42*42/266.67 = 20.8 cubic mm of chocolate = 6.6mm of extruded chocolate

It is a geared stepper for sure. Paste extrusion often use a leadscrew design.

Did you mix up radius and diameter?
"Pi/4 D²" would be right
-Olaf

Doh! You're right, Olaf.
Correctly,
1 extruder step gives pi*21*21/266.67 = 5.19 cubic mm of chocolate = 6.6mm of extruded chocolate

Which still seems an order of magnitude or two out.

Quote
frankvdh
Doh! You're right, Olaf.
Correctly,
1 extruder step gives pi*21*21/266.67 = 5.19 cubic mm of chocolate = 6.6mm of extruded chocolate

Which still seems an order of magnitude or two out.

Looks better!
But could you please draw a mental picture how a steppermotor would directly drive such a syringe/paste extruder?

There has to be an ( unknown for us ) gear-ratio between stepper and syringe, right?

@totorovirus Does the problem still exist?

I haven't even considered gears and so on. I believe that the mechanical side is irrelevant... the steps/mm in Configuration.h gives the relationship between the stepper motor steps and the feed rate into the hotend.

SOLVED

the software endstop caused the problem. whenever the movement was set to out of bounds, it completely ignored the movement.

maybe printing warning message rather than just sending recv: ok would be a better.

Thanks for your support

Edited 1 time(s). Last edit at 06/18/2015 03:40AM by totorovirus.

Good to hear, it is solved... where is my chocolate bunny?

@frank
Now I got it, you were talking about 6.6mm / step...I caculated, my extruder would produce a track of ~19mm per 1mm filament (1.75/ 0.4 nozzle ), so I thought 6.6mm is OK