gr5

Your model is also about 5mm across. Is it supposed to be 5cm? Maybe all your dimensions are off by exactly 10X? STL files have no dimensions. The standard in 3d printing is that everything be in mm but some CAD expoert in cm or inches.

Alternatively you can put this off, lol. Just lower the speed to about 1/4 speed when it's getting close to the bad spot. 1/2 speed is often not enough.

Where it happens is irrelevant. What is happening is at that spot in the print there is a slightly higher acceleration or jerk. More important to figure out the cause of the shift. First make sure to oil the 6 rods - as printers age friction can go up. Feel how much friction it takes to move the head around. Really feel it so that you can remember it. Then add one drop of oil to each of the 6 axes and feel it again. Most commonly it's one of the 6 set screws on the axis that is slipping (12 in total). You may have gotten a nice hex driver with your printer (or maybe not). If you did you can access all 6 without taking anything apart. If you *do* have to take anything apart it would be to remove that corner cover (only 2 screws) and pull out the stepper to get at that hardest of them. You can also mark each shaft and each pulley to see if any of them are slipping but it's usually the one on the motor which is also the hardest to get to.

cura 15.04 was created april of 2015 (04 is the 4th month, 15 is the 15th year since 2000). Cura 4.X is quite new as of February 2020. Cura 15.04 works great for Ultimaker 2 and Ultimaker Original printers. I still use it sometimes. Cura 4.X should not be slow - it's fast for me. Try a different computer - sometimes the presence of a strange network drive or removable drive confuses cura and it runs very slow. Or a virus scanner could slow it. Maybe try mac/windows/linux or different versions of the O.S. For most people it works fine on all operating systems.

You'll have to look at each parameter but the most likely ones: layer height line width infill percentage shell width print speeds (there are like 7 speeds)

Probably the layer height. A difference of 2X usually means a layer height difference of 2X.

It would do this by the way (show it below the bed) in Cura 15.X or Cura 4.X.

cura 15.04.5 is an EXCELLENT version and has many advantages over the latest Cura (and vice versa). Your problem has nothing to do with cura or the "origin". for some reason that is all there is to the STL file. Try opening the STL file in a different viewer such as meshlab or meshmixer. I think you will see the same result. If it was an origin issue then you would see the part extending BELOW the print bed as kind of a shadow.

For a part like you show, where everything is symmetrical around a center, you can use quite a large nozzle size. For example a 1mm nozzle would save you a lot of time printing and the outside walls would be just as good quality. The most common nozzle hole diameter is 0.4mm (second most common is probably 0.5mm). So upping to 0.6mm is smart but 1mm is even smarter. or you may not like the look of the top and bottom of the part with such a large nozzle. Line width should match nozzle hole diameter. So 0.6mm line width (there are several line width parameters in Cura - I force them all to the same value). You should then set the wall width to a multiple of the line width so if line width is 1.6 then wall width should be 1.2 or 1.8 for example. Not 1.0 or 1.5. The layer height should be no more than about 2/3 of the nozzle diameter. I recommend no more than 1/2 of nozzle diameter. You are going to have to decide how much you care about the look. If you don't care about how it looks then go for thick layer heights as that saves lots of time. For .6mm nozzle a 0.3mm layer height is nice and FAST. As the layer's get thicker the quality goes down. For functional parts you probably won't care. You are just going to have to experiment and then come back to this forum and ask more questions. I notice that there is a hole through your part. That will print about 0.5mm small so add 0.5mm in CAD to the diameter of that (and any other) vertical holes. This has to do with the properties of liquid plastic (kind of like mucus or snot where it sticks to itself) which acts like a rubber band while printing and it gets pulled inwards. You might find that adding 0.5mm is slightly too much and you only need to add 0.4 or so.

To get the core to be recognized push it back into it's slot - particularly by the clear part. And then you probably have to power cycle the printer as it's probably locked in some state. To get the filament out, heat up the core and while it's heating up pop the bowden off the head: remove the little white horse-show ring, and put the head in a corner so you don't bend the rods through the head. Then while pushing down firmly on the collet (the white ring) lift up firmly on the bowden. I have done this easily 100 times. It is time you learn to do this. now once the core is above 120C you should be able to pull the filament out and then you can cool down the core and slide it out if you want. The bowden comes out of the feeder in the same manner. Sometimes I have to remove both ends of the bowden to get the filament all out.

There are (fortunately) only 2 standard filament sizes. 1.75mm and 2.85mm (often called 3mm). UM uses the larger size. Makerbot gen 5 used the smaller size. I sell a conversion kit here for UM2: https://thegr5store.com/store/index.php/um2-175/1-75mm-conversion-kit-without-bowden.html But I'm not sure it's worth the trouble. How many spools are we talking? How much money is it worth to you? The good news is that you can set the filament diameter on the UM2 itself and cura doesn't need to know your filament diameter. PLA lasts for years (basically - I could explain in more detail about this subject for 10 minutes but I've printed 6 year old PLA with no serious issues). So maybe you should hang on to this filament for your next printer? Or donate it as prizes to students who have a 1.75mm printer (quite common size). Or donate it to another department in your school system as 1.75mm is more common than 3mm.

Yes, absolutely but requires removing the bottom cover. Talk to your reseller. For a while they would only let you downgrade UM3's and S3s because the S5 has deadly voltages inside but if you promise to be careful and demonstrate competence you can downgrade S5 as well now. They really really really don't want you to kill yourself. You will need a micro SD card. Here are the general instructions but only the resellers know where to get the images:

I'm pretty sure you can do exactly what you are asking. First create a cube in cad. ANY dimensions. I recommend something small like 10mm on a side. Then you can scale it to any dimension and place it to any location in Cura. So have your part in cura, then add the cube. In "preferences" "configure cura" uncheck "ensure models are kept apart". Make the cube overlap your model. select your cube by clicking on it. On left side of screen in "per model setting" change mesh type to "modify setting". click the select settings button and add the things you want to change (speed, etc). If you can't add it then... sorry about that. This is the only way I know how to do this. Then modify the speed for portions of the print within the modifying cube. This may sound involved but it's actually very easy and quick to do with a tiny bit of practice.

However once you show a photo of the bottom I may retract my second answer as well. It's important to show a photo of the problem.

Well you didn't show us what the bottom of the part looked like (from the bottom). You showed it from top view. so I gave you the wrong answer. First of all I didn't mean EVERY time you print you adjust the bottom layer - I meant just once or twice until you get this dialed in. Second of all - I retract everything I said. You didn't mention that the bottom looked bad (or at least there was no photo). Maybe include that photo? I'm guessing you have oil on the glass and it's not sticking. Use glass cleaner. See if that helps.

By the way, if your part is only one layer and this is both the top layer and the bottom layer then there is an "ironing" feature to fix these blemishes. Look at all the cura "ironing" features. I've never used it. But ironing won't try to smooth internal, invisible layers, lol. That would be a waste of time.

This isn't normally considered a problem as the layer above wil cover this up. It's caused by overextrusion which is desirable on the bottom layer as a little overextrusion gets the part to stick better and having a part come loose can be a disaster. Particularly on a UM3 you can get a head flood which takes an hour with a heat gun for an experienced person and often you need to replace some parts in the print head. So the glass is not 100% pefrectly flat. Plus if you used the glue stick that can create some height. You only need about 0.1mm extra height to create these "blemishes". The best way to get rid of them is to ONLY do manual leveling and to level on the fly with the 3 knobs while it's printing the brim. To get rid of these blemishes will be very hard to do but if you see them then the glass is just a tiny bit too high (maybe half turn? Maybe quarter turn?) on the nearest leveling screw. But again, having the glass too low can be an epic disaster.

Or maybe your extruder is not build properly. It should be able to fight against around 10 pounds of force (around 5kg). So try moving the extruder and pulling back on the filament until it slips through the extruder. Then hold a 10 pound weight and compare (very rough is good enough). If the problem is your extruder it will slip at less than 1 pound.

First of all you don't need a raft. That's a waste of time. Maybe you need it right now, lol. Anyway your problem is you have massive underextrusion. You are extruding at about 50%. Which is about what is expected if you have 1.75mm filament and your slicer thinks you have 3mm filament (actually closer to 37%). Try setting the flow to 265% on the printer and see if suddenly it is working great. If so then somehow you have the wrong filament diameter in Cura. The fix has something to do with materials settings but I forget how to do that. You have to create or find a material that has diameter 1.75 instead of 2.85mm. I notice you set flow to 130%. That's crazy normally. If you have things set up properly you should never go over 110%. I always set the flow to 100%. Alternatively maybe your printer doesn't have the steps/mm setup properly. You could move the filamnet 100mm and then measure to see how far the material moved (use a marker and ruler or something).

Is this your model? Or did you download it from somewhere? If it's your model then you can fix it in your CAD software. What CAD software did you use? If not, try the mesh tools as nallath suggests or you can use the netfabb repair service (free web service but you have to create an account). Also you can mess with the standard mesh options in cura. I would try unchecking "union overlapping volumes" or checking "extensive stitching". just toggle them all.

Bath interferometers. I have made about 20 of these for people who use them to test their telescope mirrors. They are amazingly accurate and can do better than a $40,000 Zygo PSI optical tester. These can test to almost 1/1000 of a wavelength of light although having the mirror within 1/10 of a wave is more than good enough. Basically anything in the photo you suspect is 3d printed - is 3d printed. The screwdriver is not and the tripod that holds it is not. Everything else plastic is 3d printed. Mostly PLA, some parts on the interferometer itself are nylon as they need to bend. 3 nylon parts you can see in the zoomed in version - sticking up the highest (not the knob which is higher I suppose) is the nylon lens holder, the cube holder also and the mirror holder which has a spherical pocket that goes around that sphere on the post. I've made quite a few of these and I keep tweaking the design. The original design is not mine but got it from thingiverse.

I don't know - look at the settings in Cura - try to find out how the filament diameter is set. I did this once and it took me an hour I think. It was confusing. I had to change it in 2 places - both in the materials (the materials have a diameter) and in the printer settings. I may have done more work than necessary. Once I understood that it was critical to fix this in Materials it didn't take long. I then just had to find a way to get cura to accept the material for my printer.

For example check out this graph at 6:02 into this video (link should jump you to 6:02)

Yes! Any opportunity to do some serious measurements is a good thing! 🥰 Keep in mind that PLA is solid below 52C and around 52C it becomes like clay (aka plasticine). Also 3d printed parts are a bit weaker in this "vertical" direction and my suggestions 1-4 will potentially make a large difference in strength. Anything that makes it print better at the ends has the potential to also make the part weaker (not as good layer adhesion). PLA softens at such a low temperature that it tends to be almost as strong vertically as horizontally but when you switch to higher temp materials like Nylon or ABS you get much weaker layer adhesion unless you do the opposite: turn fans off or very low, don't print 2 at a time, raise air temp by covering the machine. There is a CNC kitchen video (search for that on youtube) about this subject - adhesion layer strength - how to improve it.

1) Of course it will look better if you print flat. Which way are you going to pull it apart? PLA acts like a liquid rubber band as it comes out of the nozzle - it shrinks very rapidly as it cools - in mere milliseconds and it also sticks to itself like snot. So it's coming out like an already-stretched rubber band pulling with some force between the nozzle and where it last attached well to the print. So when it gets to the ends it is being pulled inward (before it becomes solid) so your print gets narrower as you go up. Also because you have too much PLA to fit in the planned volume (which is smaller now that it is stretched inwards) you also get some sideways overextrusion on the ends. 2) One fix is more cooling - make sure you fans are at 100% but I'm 90% sure your fans are already there. 3) You can get more cooling by doing thinner layers or printing a bigger part or: 4) by printing 2 or even 5 objects such that each layer has more time to cool before the next layer is placed down. But that might invalidate your experiment? Or maybe your experiment is invalid because people would be printing larger parts normally? And larger parts would have more time to cool down before the next layer is applied. 5) It might also help to slow things down. Try printing at say 35mm/sec or 20mm/sec. ALL printing speeds. I hate that most cura profiles have different speeds for infill and wall, etc. Your part is all one type of infill (not sure which type? shell?) so there's really only one speed I suspect 6) Unrelated to cooling - by default the printer has very low values for acceleration and jerk. This makes the nozzle pause much longer at the ends than the middle - visually it seems very fast but if you timed it and watched it in slow motion you would realize it's just hanging out on the corners "like forever". You can reduce this a lot by unchecking "acceleration control" and "jerk control". It will also print faster. This will reduce the overextrusion on the two ends of travel. The other bumps in the middle of the wall - I never really understand what causes those as there are so many causes but almost all causes of bumps are fixed by printing slower.