eldrick

Here was my testing last year: http://umforum.ultimaker.com/index.php?/topic/5447-um2-does-not-meet-its-build-volume-specs/ Some of the issues about the clips have been fixed in newer versions of Cura, but the basic issue remains, that it does not meet its specs. At least not without loose definitions and some after-sale tweaking.

Jonny's got it it right. If the second nozzle were functional, you would still not be able to print at the extreme right using the left nozzle, because of the spacing between the two nozzles. Bottom line is that the UM2 cannot meet its build-volume specs, as I pointed out here in another thread a year ago.

Print at 100C, instead of 110C.

The other UM2 issue is that the build area width is less than specified due to the missing second extruder. The spec describes a build area that ranges from the left edge where the left (standard) extruder mount reaches, and the right edge defined by where the missing second (right) extruder could have reached. Unfortunately, that cuts about 20mm from the specified usable build area width.

If you have the original CAD files, you can put a small chamfer on the bottom edges, to compensate for the flange that the bed creates.

.5mm and .6mm would be good choices: they each add a significant amount of flow vs. the stock .4mm. Smaller than .4 gets pretty fussy, IMHO, and I'm not sure that the accuracy of an Ultimaker warrants the loss of print speed.

That's exactly how I'd do it, and how I'd expect the menu that now appears on Pause to work - less error-prone.

Yes - I'd change it so Pause and Abort are a click away from the main screen, as they were pre-15.10. This was not a well-thought-out change by Ultimaker, IMHO.

I hit that abort bug, too. BTW, when you select Pause from menu 1, it immediately retracts to the corner, before giving you any choice of abort or not - no chance to change your mind if you click Pause by accident.

Use a brass "suede brush" from any shoe repair shop.

So what changed in the 15.01 "a" version?

I don't know - how would one check?

Mine is not a rod lubrication issue. It is loud enough that it is hard to believe that it doesn't affect print quality, but I can't see any effects.

I have a similar issue. Same results - it does not affect print quality. Sounds like maybe a bad bearing?

Just use a 1/8" drill bit to open it up.

As of 1/26/15, no UM2 dual-head: http://umforum.ultimaker.com/index.php?/topic/9344-company-update/

The spec assumes that you have a (never going to happen) dual-extruder UM2. Here in reality, the machine cannot print all the way to the right, because the single nozzle is in the left hole of the two in the supporting plate.

SOLD

Assumption on your part?

One step missing from IRobertI's description is that to use a flame to burn out the crud, you first have to Remove the nozzle from the machine... But first, try the "atomic" or "cold-pull" method a few times.

Agreed re. the larger flat for larger nozzle, but a more precise method would be to mount the nozzle in the printer, put some very fine sandpaper on the bed and move the head around a bit, to ensure that it stays level to the bed.

Colorfabb, the US distributor, offers only .75kg spools, and this - it is not explained what "XL" is: XL Spools 2.2 KG * XL Spools are made to order, each item will have it's own lead-time.

XT is nice stuff, but wildly expensive, and is only sold in .75kg spools, so there is a lot of end-of-spool wastage. ZeniKinetic.com - has good prices, consistent size, and same ABS plastic source as all the other quality US-made filament, but their spec is 3.0 +/-.05, and that can cause friction in the Bowden tube and bad resulting prints. My current supplier is Ultimachine. Good filament and selection.

This is my second .5mm UM2 nozzle, and this time I did it the easier and more precise way. In order to print stronger structural parts, and to print them faster, you need a larger nozzle. The larger thread of plastic is stronger, and the back-pressure to the extruder motor is less, so you can print faster. In trying to enlarge a UM2 .4mm nozzle the first time, I took a new .4mm nozzle from Ultimaker, and used a drill press to drill out the hole, and then sanded the tip very lightly by mounting it in the machine and then moving it around very lightly on 2000-grit sandpaper on the build plate. This gave me a slightly oversize (probably .53mm or so) nozzle and with a wider flat on the nozzle than necessary, and which had a habit of accumulating overheated plastic around the flat, and then letting it go while printing, leaving brown/black spots. This time I rethought the process, after realizing that I was only trying to remove .1mm (.004") from the inside of a very short tip. It doesn't need a motor to drill that little brass, and a drill-press or lathe is prone to drilling a slightly oval hole due to misalignment with the center of the .4mm hole. So this time I simply took the drill bit, which is a near-perfect fit inside the 1/8" upper part of the nozzle, let it self-center in the original hole, and spun it with my fingers for about 20 seconds. It drilled right through, leaving a perfect hole, and no enlargement of the flat, so it prints without building up melted plastic chunks that release into the print. This nozzle works much better as a result. The drill bit I used is this one: http://www.mcmaster.com/#catalog/121/2447/=vm0pxl It's a #76 wire-gauge size, with a 1/8" shank. About US$5.00. If I wanted an even larger nozzle, I'd drill it to .5mm first and then enlarge that to .6mm with a larger bit, using the same technique.

Set the KS bed center on the machine tab to X=115, Y=112.