UM2 Olsson block touches fan shroud

[stephenbrooks2 0]

I've had some strange problems when reassembling my UM2 with the "Olsson block" for interchangeable nozzles.

 

I find the brass block always ends up too low and touches the aluminium fan shroud.  This block is pressed downwards by a spring.

 

There's also not much transverse room between the nozzle itself and the shroud hole.  The interchangeable nozzle seems to stick out further than the standard one but maybe that's because it's interchangeable.

 

Anyway, when the brass block or nozzle touches the fan shroud I get heater errors.  I tried sandwiching the white teflon ring above the fan shroud and around the nozzle, but the heat and pressure made it melt.

 

I don't really understand what's going on with the spring because it pushes all the brass components (Olsson block, heater, nozzle) down onto the fan shroud at the bottom.  Further up, there's a steel ring around the coupler that looks like it could rest on an aluminium horizontal piece to relieve this strain, but it doesn't, there's a 2mm gap.

 

Edit: on this diagram

https://ultimakernasupport.zendesk.com/hc/en-us/articles/115004172206-Printhead-Diagram-Ultimaker-2-

...the "isolator nut" is flush with the metal plate below it.  But for me, there's always a gap and the spring is pushing the brass components below onto the fan shroud instead.

Edited May 17, 2020 by stephenbrooks2

[stephenbrooks2 0]

This is a better diagram

https://ultimakernasupport.zendesk.com/hc/en-us/articles/115004154583-Printhead-Diagram-Ultimaker-2-

...the "isolator" is suppose to touch the "holder bottom" in the 2nd picture, but for me it doesn't.

[IRobertI 521]

Post a picture of what your setup looks like instead, that would make it a lot easier to figure out what's going on.

[stephenbrooks2 0]

Here's a photo, but it doesn't show you much other than that "isolator"/"isolator nut" isn't touching the metal plate below.  The brass components are all hidden in the fan shroud.

[stephenbrooks2 0]

If I take the shroud off, the spring pushes the nozzle down, so now the isolator touches the metal below - this also makes it a pain to get the shroud back on as I'm fighting the spring.

 

These pictures show the Olsson block and nozzle.

 

There are areas where it looks like it hasn't screwed on enough but the thread didn't seem to go any further.

 

Edited May 17, 2020 by stephenbrooks2

[IRobertI 521]

Your block simply isn't screwed in far enough into your hot end isolator (the thing with the holes). If it doesn't want to go any further it's because you have dirt in your threads most likely. Try heating the block up and tightening again. The isolator should be able to screw in all the way until it touches the block.

[stephenbrooks2 0]

That's fixed my vertical alignment problem!  Thanks.

 

I had another go at moving the thread in and out and found it was just very sticky where it had got dirty.  After a few times it moved a bit more freely.  (I'm not sure how I'd do this with it heated up because presumably that would mean still being attached to the heater element.)

 

Anyway now I've reassembled it, the isolator is resting where it should be.  I had to recalibrate the build plate height of course!  First few layers of a test print appear to be OK...

[IRobertI 521]

It can be turned by inserting something like a small allen wrench or screw driver into the holes and then turning. To give yourself some more space to work you can remove the front left screw from the print head so that you can turn further before having to reposition. Not necessary now of course, but good to know for the future 🙂