gr5

Usually the filament gets ground down flat if you have too many retractions. Do you have tons of retractions? I had a part that had 40 retractions in a layer and that caused the filament to grind flat. I changed the "minimum extrusion before retraction) to a higher value and that fixed it. If you set that to say .45mm then it will do no more than 10 (4.5mm / .45mm) retractions on a given spot of filament which should be fine.

Extruder won't turn until temp is over 170C but I believe preheat only heats to around 170C, right? So just manually set the temperature using the ulticontroller to the temp you want to print at and then start the print. You might want to check the temp to make sure it isn't commanded to 0C or some other wrong temp. In cura did you select UMO+? For my UMO I always select 0C for the nozzle temp such that I can just set the desired temp on the ulticontroller and start the print when the temp is close enough.

That "nozzle hole" in your part is really bothering me. I've never seen that before and I have to agree the only thing I can think of to cause it is if your Z moves suddenly and forcefully for an extended time (maybe 2 seconds) in the wrong direction. I definitely like the idea of lowering the Z current because that is so easy to do but most people see the power simply turn off with that issue. Still it's worth trying. But for me I think I would ask for a new PCB from Ultimaker. If you go this route contact them at support.ultimaker.com. One other possibility - if the part came loose from the glass and the head was dragging it around for a while but the part was tilting a bit back and forth at the same time? Could that cause the head to dig into the part. Probably not. Your part is very tall and thin so I think it would more likely just fall over.

From looking at your part I don't think the corner-warping could have lifted the part enough to cause the head to melt a hole in it. However what you describe - corners lifting - is a common problem and pretty easily solved. But not what you asked about earlier (bed moving up and down for no reason). There are many solutions that work great. The problem is that PLA shrinks as it cools and the upper layers are pulling very hard horizontally which lifts the lower layers. 1) Make sure the glass is clean if you haven't cleaned it for a few weeks. You want a very thin coat of PVA glue which is found in hairspray, glue stick, wood glue. If you use glue stick or wood glue you need to dilute it with water - about 5 to 10 parts water to 1 part glue. So for example if you use glue stick, apply only to the outer edge of your model then add a tablespoon of water and spread with a tissue such that you thin it so much you can't see it anymore. wood glue is better. hairspray doesn't need to be diluted. When it dries it should be invisible. This glue works well for most plastics. 2) Heat the bed. This helps the plastic fill in completely (no air pockets) so you have better contact with the glass. For PLA any temp above 40C is safe. I often print at 60C bed. 3) heat the bed (didn't I already say that?). Keeping the bottom layers above the glass temp of the material makes it so the bottom layers can flex a bit (very very tiny amount) and relieve the tension/stress. For PLA 60C is better than 50C. 70C is even better but then you get other "warping" like issues at the corners where they move inward but if you are desperate it's worth it. For ABS you want 110C (100C is good enough). 4) rounded corners - having square corners puts all the lifting force on a tiny spot. Rounding the corner spreads the force out more. This is optional if you use brim. 5) Brim - this is the most important of all. Turn on the brim feature in cura and do 10 passes of brim. This is awesome. 6) Squish - make sure the bottom layer is squishing onto the glass with no gaps in the brim. The first trace going down should be flat like a pancake, not rounded like string. don't run the leveling procedure if it is off, just turn the 3 screws the same amount while it is printing the skirt or brim. Counter clockwise from below gets the bed closer to the nozzle. Don't panic, take a breath, think about which way to move the glass, think about how the screw works, then twist. This may take 30 seconds but it's worth it to not rush it. You can always restart the print.

People have had bad luck with all metal head. PLA sticks to it too easily and it is even a more pain in the neck than replacing the white teflon part. Instead consider getting an i2k at my store (and some of those teflon parts): http://gr5.org/store/index.php/um/i2k-insulator.html I only have one left but have more coming in hopefully Monday. Here's the teflon part (cheaper in my store): http://gr5.org/store/index.php/um/pair-duptef-couplers.html

Nice! I'd love to know how much weight it can lift. A UMO or UM2 can lift about 5kg or about 10 pounds: https://ultimaker.com/de/community/view/5222-pulling-force-of-um-extruder?page=1

I was wondering the same thing. If the part came loose and the head dragged it around the bed then it would explain a few things you experienced. A good way to clean the nozzle is with an "atomic pull". Google around for more info on that. Also called a "cold pull". https://ultimaker.com/en/community/view/5118-blocked-nozzle#reply-34691

Oh - and these pictures are much better. that does *not* look like underextrusion. I don't know what that is.

It's definitely a slicer issue because it's fine on the layer with the hole through it. Notice that? Those layers are perfect! then when the hole is done it starts doing it again. I don't know what the issue is. Try Cura maybe? did you try the lower temp? 240C works okay for me as long as there is zero fan! And layers not too thin else they won't melt the layer below. .2mm is good.

Oh - and just to be clear - you have to replace the entire assembly which includes the temp sensor and the cable. It's not hard. Like I said, I sell them.

I just saw your photo - yeah - no wonder you wrecked it. You didn't remove the bolt that holds those 2 things in there. Get that out first!

First of all - did you remove the thin screw that holds the temp sensor and heater into the block? That's a crucial step. You will definitely have to buy a new temp sensor. The smaller hole is the temp sensor - that's the one the people break the most often. The larger hole is for the heater. That one doesn't break as often but it can still happen. What country are you in? If your printer is less than a year old you might be able to get free ones although - well you broke it/them. In USA you can get these parts at fbrc8.com - that's the official reseller. But I sell even better parts for less money. I test each temp sensor and heater. I test the temp sensors at 260C as many of these fail at temps above 200C. My store is gr5.org/store/. In other countries try 3dsolex.com. I sell 3dsolex blocks to replace your existing block but once you get the wire out you can get the rest of the temp sensor out with a bolt remove tool. These are inexpensive drill bits that are shaped like a cone and that spin backwards and drill out an old destroyed bolt so you can put a new bolt in the hole. Works great for getting temp sensor out once you have already destroyed it. Same for heater. google "screw extractor".

For other people: if your fans are hitting the side of the printer it's usually because they are bent wrong - this is common - or because the limit switch is off by a millimeter or so. But printing a smaller fan shroud works also and some of these alternate fan shrouds have better, more symmetrical cooling.

Nice post!

Some of what you post is common and some I've never heard of before... The only way filament will ball up and fall off the nozzle is if some other problem occurred a while earlier and the nozzle is up above the print. So this is not something worth worrying about - the main cause of why it stopped is more important. If a piece falls over - this is most likely a totally different problem. This happens a lot. The best fix for it is to get the part to stick to the bed better. I would start with brim - do you use the brim feature? Set it to about 10 passes. If part is still knocked over it is too tall and you need to either rotate it 90 degrees or add some diagonal supports that go from the bed up half way the print. That nozzle hole is scary. I don't know what would cause that and I don't think I've seen that before. It seems like the Z axis - the bed - would have to move upwards into the nozzle suddenly for no reason. This can happen if you print USB - do you print through USB? That is not recommended and not officially supported. Or if your gcode is corrupted (never heard of this before). Having the printer stop printing for no reason is also common. It can happen if your filament is brittle and cracks or if you print too hot (>250C) and too slowly (especially a problem with non-PLA filaments). It can happen if dust/dirt gets into the nozzle. If you have too many retractions and filament is ground to dust at feeder. If you get a tangle in the spool of PLA.

Try slowing it down maybe? Try 35mm/sec. Make sure all your printing speeds (shell, infill, inner shell) are at the same speed. It's hard to tell because it's black but it doesn't look like underextrusion to me. But hard to tell. I would expleriment as it's printing. After you see the pattern, try slowing speed to 50% to see if it goes away. If not then try changing the temperature and let it do a few more layers and see what happens. Usually for best quality you want 20-35mm/sec and 190C to 200C.

Actually I would avoid UM filament for a month until this is figured out. Since you live in USA try printedSolid.com. Then when things are sorted out you can get some UM filament at fbrc8.com.

Once pla is breaking in the tube you need to throw the rest away. Sorry. Get a new roll. How old was this roll of filament? There have been a few reports of bad filament. Usually it takes a year or two for filament to get brittle.

Have you considered flipping this part over? I can't see the whole part but it looks to me like it would print much better if you flipped it over. You would only have to support that small rim. Also I explained why those areas have strange looking support already. Maybe you should start over and read all the posts?

ernest if you want antennas any better you must print 2 things to give the pla a chance to cool down. so either 2 robots or print a tower next to the robot.

Yes. I was talking about the same thing. When you have overhangs you get this exactissue - you get a lip after a few layers and it lifts up and every time the nozzle comes near it pushes the lip back down. This is best fixed with lots of fan. But you can avoid it if you design your model correctly. For example if you flip your part so that *down* is the same as *down* in your photo then you shouldn't have any crucial over hangs anymore.

To add suport in cad just create some kind of pillar that starts at the base and goes up and touches the bottom of (for example) a balcony on the outer 2 corners. Make the support sturdy - at least 1/10 as wide as high so 100mm support should be at least 10mm at base. But where the support touches the balcony it can be down to 1mm in diameter so it is easy to break off.

It's too bad you uninstalled the older version of Cura. Unlike most software with different versions, Cura installs as though it is a completely different app for each version so I have about 8 versions installed and can easily run whichever version I want. Although I usually only run a recent version. So are you saying that when you open the STL file generated from fusion, Cura crashes? Or hangs up? Make sure all copies of Cura are closed and that there is no hung up version of Cura somewhere (on windows you need task manager to determine this). Then start it fresh and try loading a very very simple STL from tingiverse - perhaps a cube? Then clear platform and try loading your fusion STL file. Perhaps you have too many triangles? There is a limit - not sure if the limit is 2 million polygons, 200 million polygons, or what. But at some point cura runs out of it's limited memory so that is my guess as to the problem. If that's the problem you might decide to decimate the number of polygons using meshlab (try googling how to do that). I have found that 1 million polygons can describe pretty much anything you might print in the volume of the UM to the resolution of the UM.

very cool. No pictures? :(

The bad quality at the windows is almost certainly caused by printing too fast and having the feeder speed up and slow down all the time for infill versus shell or for when it slows down at the corners for the windows. Either way have all speeds at 35mm/sec. If you are impatient for a print it's better to go to .2mm height than to go to 50mm/sec (assuming you want quality which is true for this print). The support can be removed with the right tools - get some very small pliers that you can stick in the window and twist it out - then get a set of flat and curved small files that easily fit through the windows the short way to clean up the edges. Also consider using a butane torch but don't use that on this model until you've practiced with the flame on some models you don't care about. You don't actually need support for windows because the UM bridges just great as long as it's a perfectly horizontal bridge which is true for the tops of windows and doorways. The few spots that need support can be done in CAD.