Ultimaker 3 Extended behaves strangely when it finishes the print

[FLESKET2000 3]

My Ultimaker 3 Extended behaves strangely when I print tall prints (about 290mm and up to its maximum height measurement.) Has anyone else experienced the same thing? Watch the video I shot and you'll see what I mean.

 

 

[MariMakes 203]

Hey @FLESKET2000,

 

Welcome to the Ultimaker Community 🎉

I recognize this report! A change was made in the firmware because on the first version of the Ultimaker firmware the nozzle would leave these marks on the printjob. A change was made in both Cura and in the firmware to prevent this, but the change in Cura was never properly reverted.

 

I believe a part of the behavior can be resolved by changing the End Gcode in the machine settings in Cura.

This is an example of how you can change the gcode

G91 ;Relative movement
G0 F2400 Z3 E-{retraction_amount}
G90 ;Disable relative movement

If you know you are printing a lot of these printjobs you can also consider reducing the Z3 to something lower like Z1. 

 

A setting that might help here aswell is Lift Head.

It will move the head away from the model if it takes only short while to print.
Which usually happeneds in one of the last layers. 

 

That's an amazing printjob!
I hope this helps. 

[FLESKET2000 3]

Thank you so much for the quick response.
I'll try to change the g-code at some point. Working on a bigger print right now, but after that...

[FLESKET2000 3]

Hello again.
I tried using the G-code you suggested and printed a test print. But the issue continues to cause errors.
I don't know if it's my fault or what could be causing this. See attached video.

I am also attaching a picture of what my settings look like.

https://vimeo.com/789695717

[ElLoco3D 0]

I have the same problem! It is a Gcode problem. Every time it finishes printing it asks the printer to lower X amount of mm, this causes it to hit the floor of the printer if the prints are more than 290mm high. It then goes up X amount of millimeters, which causes the nozzle to stick in the plastic, leaving a mark that ruins the print.
Please I need this fixed.

Thank you very much.

[Torgeir 262]

Hi @FLESKET2000,

 

You need to put a number in for E- {retraction amount} as: E -4.5

 

Torgeir

[FLESKET2000 3]

Thanks for that tip!

I don't know anything about G-code so I guess I'll have to learn a bit.

But I will do another test today and try your G-code suggestion. Looking forward to the results and letting you know how it went.

[FLESKET2000 3]

Now I have tested again following MariMake's and Torgeir's advice. And it works! But I still think the printer behaves strangely and goes up and down when it has finished printing. Why can't it just go up and to the side? But anyhow. Many thanks for the help! I have also realized that it might be time to learn some basic G-code knowledge.
Thanks again!

 

( In the "End G-code" I wrote : 

G91 ;Relative movement

G0 F2400 Z3 E-4.5

G90 ;Disable relative movement)

 

 

[ElLoco3D 0]

@FLESKET2000

If you look closely the printer makes the same movement. If you send to print the same piece of the first video you will get the same result. It is a code that has the ultimaker that is already programmed.
It is a problem that has not been solved yet. My prints use the whole printing area and I always have the same problem. Changing the cura end gcode is not the solution. Since the start and end gcode is programmed in the machine.

 

Edited January 17, 2023 by ElLoco3D

[Torgeir 262]

Does this happen only when printing close to the max height?

 

This is some strange, to me it seems that the print is not finished and at next move down (to print a layer more) the Z down switch is hitted/activated.

This will move up the bed to the start position (thats is located in to high pos).

I'll think the Z end stop switch is a little to high adjusted and this will be an issue when printing object close to max height. 

 

Thanks

Torgeir

 

[FLESKET2000 3]

Now I have tried to test print again.
I did two tests. In both, I printed a very thin (0.8mm) "stick." Just because I don't want to wait for a more extensive print.

I am mainly interested in how the printer behaves; in particular the table and how it moves up and down.

At the print, which is 295 mm high, the table behaves strangely and goes down-up-down-up-down. and rattles when the print is finished!
This does not happen when I print an object that is only 100mm.
I see a clear difference when I print a print that is 395mm high when I compare with one that is 100 mm high, and here the printer behaves normally.

 

(I also checked the switch that regulates the height level when the table reaches its lowest position. I simply took a pair of pliers and cut off the screw under the table about 2-3 mm (the screw that goes down and pushes to the sensor) Now the table goes a little lower, but I Don't know if that helped?

 

I also measured the front edge of the table when it is at its lowest and the top edge of the aluminum table down to the bottom of the printer is about 25.4mm.

 

Would be interesting if there is someone who has a similar printer (Ultimaker 3 Extended.)
Who can measure their printer!?)

What should I say? I'm just confused by what's happening and don't know how to solve this. I am of course grateful for any tips and advice I can get (and those I have already received.)

 

(click on the links to see video of the tests.)

 

test print 295mm

test print 100mm

 

 

Edited January 18, 2023 by FLESKET2000

[Torgeir 262]

Hi @FLESKET2000,

 

Normally we ask for the firmware version you are using on the UM3E, then the version of Cura and the gcode of the model to see if the gcode is doing this.

 

Could this be something with the new Cura? -Or, are you using the old version Cura? Further, could this be a firmware/hardware failure -or is this caused by a "plugin" module?

There is plenty of combinations here.

 

However, when the head collided with the print, you could hear the there was missinig steps, also the Z axe made a synch when hitting the bottom Z end switch.

 

Have you ever printed this model before without any issue, or did this happened just the first time you printed this object?

 

If your printer still have this problem, the information about firmware/Cura version and the gcode is needed to go any further.

 

Thanks

Torgeir

 

 

 

 

 

[FLESKET2000 3]

Hello Torgeir.

 

I have the latest, updated versions of both cura and UM3E.

Cura 5.1.0

Cura G-code flavor Griffin.

UM3E Firmware 5.3.0

But this has happened before I updated to these firmwares. But it only seems to happen when I print at its full height, which I don't do very often but it happens a few times every year. I discovered the problem by chance when I was printing a part where I used the entire height of the printer and when I got to work (where the printer is) it was just finishing the print and then I saw what happened when the print head collided with the part it printed: this was in february 2022 and i don't know what firmware i had then.

You mention that it misses steps. What do you mean by this? Are the stepper motors causing problems? Or is it some kind of software bug?

 

Many thanks for the help and your commitment Torgeir

 

[Torgeir 262]

Hi @FLESKET2000,

 

Thanks.

Missed steps happen when the print head hit a sudden stop, then the stepper motor skip back and "try" again and again until the number of steps it should go is done. The firmware do not have any control of the position, so it will just go on printing further on the object offset in the  air. (This mean that the printer is out of synch and the printing must be aborted. If you do this, the printer will home all axis, assuming they all might be in outer extreme position. When you then restart for another print all axes are synchronized.) 

So when the printer hit something, this may often lead to missed steps and it makes a lot of noise.

The stepper motors torque is adjusted by the current feed to the motor.

 

Note: The setscrew for the Z axis need to be (filed) rounded off after the cutting, if not the repeated bed position may vary a little from time to time. This as the sharp cut may slide off the lip differently for time to time and cause some height differences. So if you use manual bed adjustment, this might cause some problem.

This screw can be adjusted from top by using a hex tool, but may also contain a lock nut to prevent the screw from turning and de adjusting over time.

 

I would turn on the printer and "home" the bed, make the bed to go to start position the position that make the highest object. Set the right core in down position and measure the height from the glass plate and straight up (90 deg.,) to nozzle 2.  This height should be at least 300 mm.

 

Hmm 295 mm is just 5 mm from the max height, so some fine tuning might help if this is close.

 

(This test will answer if the height is too low.)

 

Hope this help.

 

Good luck.

Torgeir

 

[FLESKET2000 3]

 

Now I have tried to print again!
I cut off (and filed the end smooth) another 2mm of the screw that goes towards the bottom of the Z position. When I measure from the glass panel up to nozzle 2, the measurement is 305 mm. I tried printing a 0.8mm/diameter cylinder, 300mm high and it seems to work fine now! I hear no more rattling from the stepper motor, which seemed to be losing steps. But I must first, to be sure, maybe print a "real", more complex print before I can be sure. But it might be sometime next week.
Thanks once again for all the help I got from especially @Torgeir
See the video of this morning's print test

 

 

[Torgeir 262]

Hi @FLESKET2000,

 

Great job and good feedback.

 

I'll think 305 mm is good and makes a good overlap for the Z clearance when printing at max height.

 

Thanks

 

Torgeir 

[FLESKET2000 3]

Finally!

Now everything seems to work as it should.

Did my more special-time-consuming-test-print which is 300 mm high, and everything went like clockwork.

(see video down the page)
To summarize:
 -Change the Gcode and possibly the Z height in Cura's machine settings (see picture)

 

 

-Cut off the screw on the underside of the table that pokes the switch. (and grind it smooth.)

Done!

 

Now all that remains is to print something "for real" But I don't have such a job at the moment. But I will come back and report when the time comes.

 

Thanks again for all the help!

 

 

 

Edited January 20, 2023 by FLESKET2000