Nicolinux

Ok, you might be right. But since my threaded rod is deffinitely not centered on the brass nut and the z-coupler, what are my options? I took care to let the brass nut move only horizontally. I hoped that any vertical movement would be constrained by the backpanel of the z-stage. But you are right, if the nut spins it would not move upwards hence screw with the z height (if you catch my drift) Does the brass nut in your Ultimaker move at all?

Weird, I thought that smaller nozzles were able to print small perimeters. If my nozzle can realistically do .2mm, then for 5mm it would take roughly two perimeters. But since Daid said that it is not designed to do so now, I'll accept it. I just wanted to print this single wall object to check the wall alignment and as a quick & dirty test for z-wobbling. For now, I am using this object instead: http://www.thingiverse.com/thing:17991

I meant issue number (2. Ridges / Seams) I clicked too early on post the first time and added more content afterwards. If you were notified about my first post by email it wouldn't containt the whole post. Sorry for that :/

Hi, I've got one of these led rings and would like to mount it using this thing: http://reprapteile.de/elektronik/led-ring70mm.html http://www.thingiverse.com/thing:117345 Where would I connect the led ring? I think it needs 12V. Thanks, Stefan

Oh nice, good to know about the split option... Thanks for the tip with temp set to 0. I will try that. I guess it will also solve the issue with the skirt sometimes sticking to the nozzle and messing up the first layer. I almost always find myself trying to snatch the surplus filament strands around the nozzle. Do you happen to have an idea about issue nr. 2? Right after those ugly blobs, that the biggest remaining thing for me (for now). thx.

There seems to be a problem with the latest official version. When I try to slice this object, it just says "0" for minutes, meter and gram. It creates an almost empty .gcode file where the body with the movement and extrusion instructions is missing. There are only comments with the layer number instead. https://www.dropbox.com/s/m0ge0axij98uug9/0.5mm-thin-wall.stl https://www.dropbox.com/s/icfcfsua5wof04t/0.5mm-thin-wall.gcode I tried different combinations of infill, shell thickness and bottom/top thickness but it still fails.

@gr5: Since the object was printed together with others, I checked the layers view to look out for positioning moves. It is true that blobs form near those areas, but it is not consistent. There are not always blobs when there is a non extrusion move. But other then that, string seems to be really annoying... I have also checked if the blobs line up with the infill pattern, but that's not the case. But if those blobs are due to bad z-movement, how can I track it down? @Nick: The travel speed is at 150. I have also tuned the temperature for my filament. Just printed a high object and changed the temperature every 10mm. I have found that the lowest temperature was around 185° at 50 mm/s speed. However since the first layer won't stick at this low temperature, I changed it to 195°. The treefrog and the "good" trilobite element were printed at 195°. How do I avoid over-extrusion? Right now I print everything at 50mm/s because I don't have a feeling yet for the connection between temperature and speed.

@gr5: Thank you for the ideas. I have created another post and added your answer there in order to keep the topics separate. http://umforum.ultimaker.com/index.php?/topic/2786-please-analyze-my-prints A little update: I measured the extruded filament while it moved through the bowden tube only (and not the nozzle). It was only 1mm off so I calculated the new value and set it to 844. I have also calibrated the x, y and z steps and now my calibration cubes are spot on when measured with a digital caliper So this problem is solved now. Thanks for all the help guys!

gr5 already posted an answer to the first issue in another thread where I posted the first image. Here it is:

Hi, I am tuning my Ultimaker and I encountered some problems. Please take a look at the following images: 1. Blobs I wanted to print the famous articulated trilobite: http://www.thingiverse.com/thing:28259 When I print all elements together (it is one .stl file), I get very visible (and ugly) blobs. 0.1 layer height, 0.6 walls, 50 speed, 220°, 20% infill When I print only one single element, it is way better. The blobs are almost gone. Some are still there: At the top, the single element, at the bottom the element printed with the others at once. Those blobs seem to arise when the nozzle extrudes plastic for the outer perimeter layers. Right after the infill is done, the nozzle moves to the outer layer and sometimes extrudes too much plastic and a blob forms. I have already calibrated the extruder (E steps) so this shouldn't be a problem. 2. Ridges / Seams On many objects I get those ugly seams where the outer layer starts. Call them regular blobs - but this issue is different because they are very regular. The calibration cubes feature these seems only at the front facing edge. I remember that Slic3r had a setting to "randomize starting points". Bug I guess that's only half of a solution because then those mini blobs would be scattered along the x-axis then. 3. Ugly last drop and bad underside When a print finishes, usually the very last drop that is extruded looks big, squashed and ugly. I suspect that up until now, all my problems are related to overextrusion. Don't mind the poor treefrog - he lost a leg while printing. The layers on the leg curl/warp up a bit for very small layers and have a big chance to be knocked over by the subsequent, circular layer run. Also the underside of the frog's arm is very very ugly. Maybe the small layers didn't have time to cool and that's why the warp up (or it is overextrusion again). I have set the minimal layer time to 7s for all prints. Sorry for the many questions. But I think I am close to a (for my actual needs) finely tuned Ultimaker. Thanks. Stefan

Ok, just for the record - if anyone stumbles over this post. My issue was solved by making the brass nut sliding around left and right. This way it could accomodate the offset to the right of the threaded rod. http://umforum.ultimaker.com/index.php?/topic/2716-cannot-lower-bed-to-reach-endstop/

@gr5: What du you mean with 82% - of what? I can't read the article right now because it seems to be down for me (from Germany). Will try later. @illuminarti: You are right, I was pushing the filament through the nozzle. I will insert it only a little into the bowden tube and try again. By the way, I read somewhere that you shouldn't leave the nozzle hot for too long without extruding because it could lead to plugs. What would be the right temperature and the maximal time to leave hot? About the image - is this really a sign of overextrusion? I printed this object with fairly standard settings (0.2 layer height, 50mm/s, 220°C, minimal layer time 5s). Retraction is always enabled with the defaults (40.0mm/s and 4.5mm distance). I have the "latest" official firmware from march 2013. I know about the bug with the halved retraction speed and I will take care of re-building the firmware later. For now I'd like to get some acceptable prints. After the z-wobble issue, the blobs are the biggest issue for me now. Especially because it is not consistent. Some prints do feature it, others don't. I guess I really need to take a more methodical approach when testing and write everything down...

I am trying to calibrate the extruder but I stumbled on a weird issue. My default E steps value was set to 836 (rev4 kit). I measured 150mm from beneath the extruder and marked it with tape. Then with Printrun (or Pronterface), I set it to extrude 100mm. The weird thing was that it extruded only 82mm. That's pretty far off from 100mm. I calculated the new E steps value to 1019.5 like this: (100mm/82mm)*836 = 1019.5. With the new value the new extrusion accuracy was way better - 98mm. How can this be? Isn't this value way to high? I didn't take off the bowden tube though. I thought that under normal circumstances, the bowden tube is attached and the measurement should be made under "normal circumstances". The reason I started to tweak the E steps was because some printed parts feature very prominent blobs. I thought that might be a sign for overextrusion. With the old E steps value (836) I also tried to extrude directly via gcode following the advice in this post: http://umforum.ultimaker.com/index.php?/topic/1647-extruder-calibration However this failed because the hobbed bolt just ate up the filament and didn't move the filament very far. I used the following gcode(s): G91 ;relative positioning G1 E100 F300 ;extrude 100mm at half max speed G90 ;absolute positioning

You are right, I think it is the dial on the controller and the crappy code. Sometimes I miss menues because the dial moves back and forth althought I just rotated it one notch. Thanks for the idea with the tape - I will try that.

Check out page 7: http://umforum.ultimaker.com/index.php?/topic/1611-fixing-pulley-innacuracy/page-7 You need to contact user foehnsturm: http://umforum.ultimaker.com/index.php?/user/5589-foehnsturm/

Status update: HUGE SUCCESS! Thank you guys. The issue is solved now. I still didn't want to change the parts holding the brass nut, so I printed two new ones. Those are 2mm lower and allow the brass nut to move slightly. Here is my actual print (left with banding and on the right without): I still have problems with the stage not moving up smoothly. When I "auto home" via the UltiController, it pauses every second while moving up. But this seems to be something else - not mechanical. Also the motor sometimes still stops and makes loud noises but only when homing or while moving the stage completely up or down.

The z screw is not that high normally, it was just set to demonstrate the offset to the right. It was not inserted into z-coupler at all at that time. I can now insert it all the way into the z-coupler and then it sits well bellow the top plate. I didn't know that the brass nut should/could slide around a bit left/right. It is very tight and does not move a notch. That's why the z-screw is bent to the side a bit. I guess that's the solution then. I was afraid to change the brass nut holder but thanks to your explanation it is clear now. I will post back soon. Thanks illuminarti!

But how will you move the z-motor? You would have to move it only a few milimeters to the side and there is no place for new screw holes without touching the old ones. It may be better to move the brass nut. That's what I tried (see my previous thread) but due to printer inaccuracy the whole z-stage was skewed. I am back to the original parts now, but I am still not sure how to tackle this issue.

Here is a little update for this issue. I didn't like the solution where I had to change the plywood parts so I re-created the brass nut holder in OpenSCAD and moved it's feet one milimeter to the side. But due to my printer inaccuracy the printed parts did exhibit some warping (why? PLA should be safe - or so I thought and the part sticks all to well to the blue tape) so the entiere back of the z-carriage was skewed. Original: My version: The wobbling issue is a little bit better now, but still very visible :( Here is a view from the top (it is exaggerated but you can clearly see that the threaded rod isn't centered): I am at loss here. I don't know what to do next. Fiddle with the brass nut holder or print another batch hoping that it won't warp. In the process of screwing and unscrewing the set screws on the z-coupler (called resilient or resiliert coupling) I broke one bit and now a set screw is stuck forever in the coupler. And even if I unscrew the screws for the z-motor, I can't take the coupler off... Not the ideal conditions for high quality prints I guess.

Hey drumrboy44, do you have any updates on this issue? I think I have the same problem: http://umforum.ultimaker.com/index.php?/topic/2716-cannot-lower-bed-to-reach-endstop/ Stefan

Hi, ich denke ich habe ein ähnliches Problem, aber nicht wirklich eine Lösung... Ich habe im EN Forum nachgefragt: http://umforum.ultimaker.com/index.php?/topic/2716-cannot-lower-bed-to-reach-endstop/ Aber wenn das bei dir auch so ist (und ich schätze du hast deinen Kit auch erst vor kurzem bestellt), dann ist es vielleicht ein allgemeines Problem mit den Platten. Ich kann zwar den Drucktisch einstecken, aber dann ist die Gewindestange nicht mittig zentriert auf den Z-Motor unten. Das führt zum "wobbeln" und zu Spuren auf den Ausdrucken (ähnlich wie hier): http://umforum.ultimaker.com/index.php?/topic/2216-strange-print-artifacts-horizontal-bands-rippling/?hl=%2Bhorizontal+%2Blines Wäre interessant zu wissen was andere (oder der Support von Ultimaker) dazu sagen.

Well, here is my notification - my pulleys are really bad I can send you a video of their wobbling. But I have already ordered the better ones from forum user fhoensturm, so it doesn't matter (at least for me). By the way, there is nowhere a note about the silver set screws. Maybe you could add it to the wiki (or I can do it since it is a wiki anyway).

Sadly the didn't. Pulleys are still bad but don't worry about it just now. You will spend way more time worring about belt tension and asix alignment in order to get good print results. Apart from a nasty z-wobbling issue, I have already good print results and still use the stock pulleys. http://umforum.ultimaker.com/index.php?/topic/2716-cannot-lower-bed-to-reach-endstop/ One more thing. The assembly instruction states that when you put the pulleys on the rods and add the belts, to make sure that the screw holes for the set screws on the pulley face inwards. Do follow this advice and try to align the set screw holes to be at the same angle when facing inwards. Since you will be tightening/loosening those pulleys a lot, it is a great help: http://wiki.ultimaker.com/Ultimaker_rev.4_assembly:_X-Y_axes#Step_4:_Mounting_the_axes

@gr5: Where exactly did you put the shims? Since I need the brass nut to move to the left, I'd put them on the right side. Does this look right to you? thx. I wonder though why I have to do this. Surely the Ultimaker people would have found this issue with a rev4 build. Maybe I made a mistake somewhere else - but where?

Thanks for the warning. I made sure that the short belt doesn't touch the wooden panel. That's why I didn't follow the advice from the assembly instructions and placed the pulley quite close to the motor.