JohnFox

Just seen an image of your print, it's in your profile as 'uploads'. Some of it is due to under extrusion, the skirt around the print is really thin and wobbly, it should be a clearly defined band. What is the temperature? The bits of filament from circle to circle is stringing, caused when the nozzle moves across the print in a non-print move. Have you got 'Enable retraction' on? In Cura, Layer view, the blue lines show the travel and retractions. Part of the problem may be the 0.5mm walls when the nozzle size is 0.4mm. It may be trying to print a wider layer than it should.

Ear plugs? Divorce? Is some of the sound being transmitted via the table to the floor or wall? Just wondered if mounting the whole printer onto foam would help. Ok order completed, I'll print your fan shroud too when I'm going to assemble the rear fan. Curious about the improvements tbh. Still my wife hears only the "beep beeps" of the retraction when we are in bed. The printer is located 2 rooms further... And I got a front-door and top cover on my UM2 but still she hears it... So no night prints for me for now until the beep-beeps are solved.

What you REALLY need is a Peltier heating/cooling system!!! Heating and cooling in one package. The parts will positively fly off the plate.

On my UM2, the noisiest part by far is the rear fan. Not tried changing it but I have printed a new, more efficient fan mount but it didn't alter the sound volume. Next noisiest are the other two fans.

Run your fingers over the rods and see if you can feel anything at all, they should be perfectly smooth. However, I strongly suspect the bearings, not the rods. The bearings should slide up and down the rods without any hold up at all. Maybe the balls have got out of alignment, moving up and down with a bit of a twist should set them OK again. Are the rods completely free of oil? I think this is quite important, I had a similar problem and it was caused by oil on the rods. Wipe the rods with some Kleenex and run the bearings up and down until they are free.

If it's brand new then I would send it back right away. On the UM2 the build plate moves with a bit more force then the movie clip implies but it still moves. Something is seriously wrong - rather annoying for a new machine.

I bought some 0.4mm drill bits to remove any blockages in the nozzle hole. If you heat up the nozzle to above 100C or so, then push the drill bit into the hole, you can push any junk upwards. An atomic clean then will get the bits out of the way. The great care not to break the drill bit, they are VERY small. Since switching to PLA it is now very rare that I get a blockage. I have also fitted a wiper to the filament, just before it goes into the feeder. A small square of micro fibre cloth removes an amazing amount of bits and fluff from the filament, all of which would get into the nozzle.

Oh, THAT's why it's called 3D printing! Oops! My excuse is that it's Christmas Day ...or 8x if you think threedimensional...

Don't forget that scaling up has quite an effect on the time taken to run a print. 2x the size = 4x the time You would be looking at multi-day prints. Not a trivial exercise.

Had printing stopped when you took the photograph? It just looks as though it had only printed a single layer for the top. What were the layer settings and top and bottom thickness?

Changing the coupler will make a HUGE difference. They do wear, so I would always keep one as a spare, ( nozzle as well).

Nothing wrong with the model. The Cura images look fine.

So you are the one who buys up all their stock and I have to wait.

Faberdashery 'Arctic white' is excellent - assuming it is in stock. It is in stock at the moment by the way.

Thank you folks - got it! Copied the file as text, saved as a .txt file, renamed to .step, opened in FreeCad, exported as .stl. Opened in Cura exported as .gcode. Easy - not! ;-) For some reason I couldn't download as a zip or do a 'save target as'. Anyway I got there in the end.

Found the files and downloaded FreeCAD, thanks. How do I download the STEP file, when I try to download it, it appears as an .html file. I can view it as a RAW file which looks like text. Not sure what to try. thanks

If it is the thread at fault, moving it up and down should gradually smooth out the imperfection. Is there anything visible at all? Repeated cleaning the pillars will remove any excess grease and help the ball bearings roll as they should.

Sounds like quite a common problem. Wipe the two Z pillars to remove any grease or oil. Try powering the build plate up and down a few times and listen for any hold up. Wipe the pillars again, it's best to have them completely oil free.

Hello, Has anyone got STL files for the plastic bearing holders on the UM2? On my machine, the top one has cracked and I am not sure I can repair it. thanks

I think you need to be quite a lot thicker to be fully waterproof. Double thickness is marginal.

Probably not the filament at fault then. Just wondering if you have a problem with the sensor, hence the question about when you changed the coupler, ( and disturbed the sensor cable ). If the sensor is giving false readings, then the controller will try and adjust the temperature to what it thinks is 210C, making it over and under extrude. Going to be hard to prove because the sensor reading will probably show 210C even though its not.

I think you must use the Robert feeder. I tried the Flexible filament and the standard feeder simply quashed it flat. You can adjust the tension on the Robert feeder and on my UM2 it now feeds perfectly.

That's probably due to friction on the feeder/bowden tube somewhere. Looks like highly variable extrusion, sometimes under then over. Regarding spools of filament, normally the ends of spools are worse because the diameter of the spiral is much smaller and it is harder to push the tightly curved filament down the tube. I have switched to coils because of that. Could it be temperature variations in the nozzle - anyone? Did this problem occur before or after you replaced the coupler?

It's a bit of a sod to get at the bolts holding the bearings, one needs fingers the size of a mouse. Not convinced it is due to the bearings though, that fault seems to be under-extrusion on the odd few layers, not over the whole model. However, I would wipe the Z axis pillars to remove any oil just in case. Have you any strands of old filament along the length of the Bowden tube? Just wondering if it is friction along the tube. Do you get any 'tocking' sounds from the feeder drive?

Try changing from the metallic filament to something fully opaque. That looks like the stock filament supplied with the UM, works perfectly but I think it shows more print lines than say an opaque white.