eldrick

RepRap w/ Retraction enabled = 4h 3m RepRap w/ Retraction disabled = 4h 3m UltiGcode w/ Retraction = 4h 31m UltiGcode No Retraction = 4h 31m

I notice that the print time estimates change substantially depending on what type of code is generated. With one print the estimated print time was 6hrs. 9min. when set to UltiGcode in the machine settings (for my UM2) vs. 5hrs. 20min. when set to RepRap Marlin. This is with 14.04RC1. Can anyone tell me if this represents real printing time? Does the RepRap flavor of gcode really print around 15% faster than UltiGcode?

I've seen this same behavior with 14.03 on UM2. At low levels the fans are not getting enough of a jump-start to get them moving.

The answer is Yes. You can monitor and set temps, extrude filament, move the head around, etc. from Pronterface/Printrun via USB, and start a print from the SD card using the controller.

Replace the 25mm fan. Apparently the fans in some batches of UM2 were unacceptably louder than others.

A brass suede brush for shoes cleans the nozzle nicely.

Get the UM2. Print from the SD card. Control the machine from a Mac or PC with Pronterface/Printrun (without Cura getting in the way).

BTW, this doesn't work for the outrigger fans - the Smaller MagLev fans don't work with PWM.

They do seem to have some serious logistics issues. Lack of spare parts availability will seriously hurt Ultimaker if it continues.

Actually, Makershed is presently showing "This Product Is Temporarily Unavailable", so apparently they have sold the 75 UM2s that they received about a month ago.

+1 on the support. Online responses from the author? Almost unheard of (aside from the Ultimaker forum)! And MOI is very stable - I haven't crashed it yet in a year of use.

PS - he is focused on multi-extruder support for v1.5...

Tighten the screws. The screw heads should protrude less than a mm from the fan. Or, to improve the cooling and print quality, print a plastic fan shroud to replace the metal one.

Illuminarti's extrusion test is a sensitive test of ringing. You can see the differences as it gets faster up the column, and compare ringing quantitatively before and after a change.

The extrusion test is a good one for a number of issues - it is a sensitive indicator for print echo. I found that echo trailing the text was visible at 5mm/s on my UM2, but was barely visible at 8mm/s after I replaced the OEM metal fan shroud with a 14g-lighter printed version.

I'm guessing that the extruder knurling squashing one side of the filament makes that side longer, and that the indented serrated side will thus wind up against the longer outside of the bowden tube, but that's just a guess. Let us know.

I'd agree with that. Nevertheless it does. There is only about 1mm between the fan-screws and the wall when the carriage is homed, so no room to get the extra mm or two from the endstop position.

My main concerns with this are twofold: - A maximum width piece created by Cura runs the head into the right side of the mechanism - an unexpected hard stop. (Yeah, I know, just don't Do that.) This should be addressed in Marlin setup. - The Cura limitation that the entire area between the clips is forbidden territory is not allowing me to use the maximum width (minus 1mm for X- clearance) on a hexagonal piece I've been working on. I can scale about 3% larger using Kisslicer, but it causes other issues.

Here's what I got when trying to evaluate actual printable volume using Cura: http://umforum.ultimaker.com/index.php?/topic/5447-um2-does-not-meet-its-build-volume-specs/%C2%A0

You could easily test the latter idea. Let us know if it works.

Sorry - bad explanation. It moves to the left-front corner of the volume as before, but then waits until the bed is nearly all the way up before it extrudes the blob, which it drops on top of the left clip, and gives almost no time to remove the excess before printing begins.

On the right and left, it's hardware limits. Between the clips one could get a few more mm, but with the risk of a head collision.

UM2 is stated by Ultimaker to have a Build Volume of 225x230x205. Apparently this is a case of marketing gone wild - the entire size of the glass plate is not available for printing. I created a rectangle with 2mm wide lines, and removed the corners to avoid the clips. I incremented the X and Y size until Cura 14.04RC1 would no longer allow saving the gcode. The actual maximum build plate size object Cura will accept for a printer defined as a UM2 is 228x208, not 230x225. You don't get to print in the area between the clips - those bands are excluded by Cura the full width of the printbed. You also don't get to print in the 9mm at left, or the 23mm at the right side without a second extruder. When you are printing at the X228 position, the black boxes at the ends of the rods are up against the pulleys and squealing, so you actually don't even get that last mm of the 228. If you used a different slicer that doesn't know about the clips you could get another few mm in the + and - Y direction between the clips, but I'd be very skeptical about getting 225mm on the Y axis. Here's my maximum-size test print. http://umforum.ultimaker.com/index.php?/gallery/image/5220-biggest-um2-object/

Then you aren't going to like 14.04RC - it keeps the head in the Home corner instead of moving it to the front before raising the bed, so you no longer have a chance to remove that pre-loaded excess extruded thread before printing starts. This is a real issue for PLA, as the stuff turns brown and eventually carbonizes if you leave the heat on between prints. Flushing out a couple of cm before printing can avoid a lot of clogs and restarts.

I usually manually heat the bed and extruder using Pronterface, then before starting the print I extrude a few mm until I see plastic start to come out. Then I start the print, and use tweezers to remove the excess plastic just before the UM2 starts printing the skirt. Also, having a large skirt or more than one loop helps clear the extruder before it starts the piece.