Endstop hit issue

[alberto 0]

Hello,

after using my printer (Ultimaker Original with Hot end UpgradeV2) for around two years, I am no longer unable to correctly print.

In several prints, after printing a few layers correctly, the printer head starts to move erratically outside the correct path ruining every print. The behaviour always seem to occur after a few layers.

I attempted to print two newly designed STL with the same results.

I updated the slicer software (Cura and Netfabb) and the problem occurs with the Gcode of either application.

With the Cura update (14.01) I also updated the printer software (Arduino drivers).

With the Cura diagnostic (communication, temperature, endstops) no problem was detected.

By checking the printer display messages during a print, I noticed that when the printer starts to behave erratically It gives an endstop hit warning on X or Y. On a particular print, this always seem to happen at the same position after 3/4 layer.

Of course, the endstop switches are not actually activated as the print is not placed near the envelope borders.

I tried placing the object on two different positions on the print bed and the issue still occurs.

I checked the endstop connections to the controller and everything is ok.

 

[IRobertI 520]

Maybe there's some cross-talk going on between wires? A simple first test could be to disconnect the end stops that are not used for homing and see how that works. If it's still getting errors, moving wires around a bit might help.

 

[alberto 0]

The fact that the issue reproduces consistently make me doubt that the issue is a mechanical one.

However i will verify

 

[Dim3nsioneer 557]

What happens if you run the printer for a while (with the erratic behavior, maybe without filament), stop it and immediately restart it? Does it behave again or does it stay erratic?

 

[alberto 0]

What happens if you run the printer for a while (with the erratic behavior, maybe without filament), stop it and immediately restart it?

What do you mean with stopping /restarting it?

 

[Dim3nsioneer 557]

I mean execute a print job for at least 10 minutes. Then abort the print, home the printer and start the same print job again...

 

[alberto 0]

Yes, done. No effect

 

[gr5 2,189]

The first 2 layers are printed at slower speed (by default in Cura). So I'm thinking the higher velocities are shaking the machine harder and it's mechanical. It always happens at the same spot because there is probably a hard turn or long run where it gets up to speed or maybe several moves in a row hit a harmonic and the printer shakes more.

You only need 3 endstops. UM recognized this long ago and finally in the UM2 there are only 3. The versions of Marlin that come with Cura have "software endstops" already. So disconnect those 3 unused connectors right now and consider trying one more time printing.

To test my shaking theory you could hook up pronterface:

printrun/pronterface/prontrface download:

http://koti.kapsi.fi/~kliment/printrun/

 

Pronterface is very easy to use GUI to control your printer. You can use it to test your 6 limit switches (or the remaining 3). You can shake your machine or tap it or tap the switches to see if they are flakey.

Also consider printing with the machine on it's side and with a large fan cooling the bottom board (the UM can print upside down). After homing unplug one of the endstops to see if that's the faulty one. This way you can isolate it down to a single endstop.

 

[Dim3nsioneer 557]

Yes, done. No effect

 

So it's still behaving erratic after restart? In this case it might have something to do with a part heating up. Some thermo-mechanical issue. A loose contact maybe which gets (partially) disconnected if the surrounding sees thermal expansion.

If it's again behaving normal after restart, then it's most probably something velocity related as gr5 just wrote...

 

[alberto 0]

I tried disconnecting all end stop switches (I disconnect also the home switches after the print starts)

After a printing a few layers now the printer controller resets (like turning the power off/on).

I checked and cleaned from dust the controller fan but no effect

 

[Dim3nsioneer 557]

You're referring to the main electronics board on the bottom of the printer, not to the Ulticontroller, aren't you? For the case you have an Ulticontroller: do you print via USB or via SD card?

 

[alberto 0]

I refer to the main electronic board. Still, i always print via SD card

[peggyb 171]

does the printhead move easily along the rods by hand? Might be necessary to oil the rods..

 

[Dim3nsioneer 557]

I tried disconnecting all end stop switches (I disconnect also the home switches after the print starts)

After a printing a few layers now the printer controller resets (like turning the power off/on).

I checked and cleaned from dust the controller fan but no effect

Sounds like a loose contact somewhere in the main power region, maybe even the power supply itself...do you have any possibility to measure voltages on the main board?

 

[alberto 0]

The rods are well olied.

Yes I have a tester to measure voltage. the shutdown too is quote consistent

 

[Dim3nsioneer 557]

I don't see any other option than to take the scheme of the Ultimaker shield and to check the voltages starting from the power supply. Try to move the power cable and check if you can provoke a reset.

Is it possible you make a video of such a shutdown and post it here?

 

[gr5 2,189]

Be careful probing the bottom of the UM while it is printing - there are several parts that will overheat. The first part to overheat and self destruct is IC1 which converts the 19V to 12V. This is the part that you are supposed to lift up off the board into the air stream. It has 3 pins which should be at 19V, ground (0V) and 12V.

If you power up the board without a fan touch this part every few seconds and if it is too hot to touch, then you need to turn off power.

The other parts that can get too hot are the stepper drivers but they don't need as much cooling.

Where to get circuit diagram:

ULTIMAKER1

The circuit diagram, and board layout are here:

http://reprap.org/wiki/Ultimaker%27s_v1.5.7_PCB

There is a zip file at the top. It contains the "brd" file which is the layout. Also the "sch" file which is the schematic.

Both files can be opened by eagle software which is free:

http://www.cadsoftusa.com/download-eagle/

ULTIMAKER 2 SCHEMATIC

https://github.com/Ultimaker/Ultimaker2

 

 

[alberto 0]

Before probing my machine i would like to get feedback from support. I am astonished that they still didn't reply

[gr5 2,189]

It's a 2 year old machine. It's out of warranty. They are very busy. Eventually they should reply to you.

Also you will get better response from them *after* you "probe" your machine as you will have more information for them.