Torgeir

Hi samc99us, Sure there is, just open your gcode (the actual one, that's saved to be printed) file in Cura (here Cura 4.6.1). Cura will open the model in sliced mode, so you can only view it manually or replay it. The later versions of Cura will open with selected filament color and shows colored lines or different colored lines if there is some width that's use several lines. Inner wall, infill, outer wall etc. Suppose you use gray PLA, then your model will appear gray if you drag down the layer number slider bar on the right side. If you then pres start replay, the start point where it start printing will be the layer shift point. In multi layer walls it is not easy to see the seam, as this is more a problem for single wall print and here it will be very easy to see the seam. Cura may start with any of the lines in a multi line wall, but at the same point. In your model there's two sharp angels Cura might use, but the one I've used here is on the right side. So, here is a picture of the whole issue, using Cura 4.6.1: (This actual picture here, also show the selector panel for the various "layer type lines" with colors used.) Here you can see the start point of layer 232 -just where the green line start! If you want to find it in the gcode file, use this tool: http://gcode.ws/ (I'm using this one quite often.) I'll hope this clarify the issue. Regards Torgeir

That's great.. You can specify in the menu "Shell" where/how you can "locate" the Z seam. Just put Z in the "search setting" then Shell pop up. Hmm. By using sharpest edge, the seam is less visible at this place in your nice curved object. 🙂 Torgeir

Why not, this is a good way to save printing time, -but now you are in experimental mode! It all depend very much of the heat transfer capacity of the hot end your printer is using. Saying so, I know nothing about your printer for sure. Your model shape should fit well in using 0.6 mm nozzle, I'll think. I would test with a smaller model with same type of shaping angles hole etc. as your original, -but can be used as a test object to tune up the parameters -with max print time say 45 min. (It is a good help in using Cura in playback mode to have an overview of the printing path. In your above example, the center of the wall line was printed 2 times, I.E. this line was kind of doubled or become to high. By studying the path of one complete layer, you could see this very well, I've never seen this before. So seeing your print was an eyeopener to me..) Well, just a thought. Good luck. Torgeir

Hi, This was a great learning example. Thanks Torgeir

Hi there, We've all been there at sometimes, -so this is great inspiration and information to go on! Way to go. Good decision. Thanks Torgeir

Hi Alex, As those wiring is mowing all the times during printing, those wires might break sometimes. This fan is using 5 V DC, also your model is a UM2+ right. So a question, is your printer an upgraded UM2 to + version, -or is it a factory new UM2+? I'll ask this because I'll think the factory new versions aft fan is temperature controlled, -so if this control circuit stop working it's a problem, -but can be fixed. The old UM2 have a fixed 5 V DC, so when power is applied it will start and will stay as long power is applied. Check those small connectors and carefully inspect that the wires is properly connected to the two pin connectors. This wires may also break at the place where it "tends" to bend when printing.. It might be close to the attachment at the back of the printer or quite close to the extruder. But this might not be because of the replacement of the coupler, as your first pictures indicated expanded filament up hi at the "cold" side of the hot end. So if the fan have had this issue for some time, the coupler had suffered due to high temperature and become deformed due to this fact. So as you've tested the fan with external power, the issue may be just a broken (open) connection in the aft "fan wiring". Hope this help. Regards Torgeir

Hi nssorensen, I'm sorry to see all this problem you've had. What brand of PLA are you using? The first picture you put up remind me about my first print using PLA. It was also white PLA! What I see here looks like the filament has absorbed water, also your description indicate this. I had a roll of PLA that was in this condition when I got it. When there is water in the filament, the filament extrusion can look normal sometimes but can suddenly emit water vapor as the water turns to steam inside the heating block. This make printing a nightmare.. As the vapor is out, normal feeding take place again. This can go on for a long time and fool us to think this is an under extrusion caused by other issues (feeding etc.). A "sign" of water absorbed filament is an indication of a filament that's becomes a little brittle. When it comes to the next problem, I'd see you are using another colored filament, what kind is this? The PT100 sensor is a very good temperature sensor and when it fails it might be extremely erratic or become an open circuit. If the latter occurs, printer will stop and it will address "temp probe error". If you replace the PT100 probe with a precision resistor of 100 ohm, the reading on the printer should read 0 deg. Celsius. Here you will find a table of the resistance for a platinum PT100 sensor: https://www.sterlingsensors.co.uk/pt100-resistance-table In the "old" UM2 there was two ADC (analog to digital converters), but I'm not sure if you have two of those, as Ultimaker removed the extra feature prepared for dual head printing in the UM2+ series at some S/N. You can also check the PT100 for correct values by using boiling water (if you live at high level there will be an error as water boil at a different temperature less that 100 deg.C.) or a mixture of ice cubes and water that's stirred to keep a steady 0 deg.C. reference. Here is a reference to a test I made at my printer, hope this may help.: Wish you good luck. Lets know how it's go. Torgeir.

Hi UrsLoher, Welcome in here. First, I do not have an UM3, but with all the thing you've done to in order correct this -it's sure kind of strange.. I'm just wonder could this grinding of the filament occur due to high number of retraction? As there's some load on the feeder and in combination of a little lo pressure setting at your feeder. It might be one of these two issues or the two in combination that can grind down the filament, then the feeder wheel start spinning but cannot move the filament anymore. (I'll think this have happen before.) Just a thought, because of the fact your printer do not need any maintenance after this fail.. Good Luck Regards Torgeir

Hi cesern, You've already got good advice here, -but maybe a little analysis can save you some work. I would like to know if this occur on the X or Y axis? Is this time or bed height related? Did you try to print another known good print to see if it fails here too? If you measure all failed prints with a slider, is the height of these equal? (Just a small note: If you print to fast with your printer it may loose step, this is due to the fact that the torque decrease as a function of the stepping speed. This is because the magnetic fields cannot build up fast enough and loose its torque as speed increase. So every stepper motor have a max speed. This kind of loosing step may happen when the stepper change direction.. So yes I've done that, by purpose.. Edit: I've forgotten to mention that, such an error can be located to a single fixed point in your printed object. Just so it is mentioned.) Can you share the gcode file for us to see (the file that's on the SD card)? I can look at this file and even print it if needed. Regards Torgeir

Hi @IRobertI I agree with you here, but the thing is that I've tried to explain the "break away" in general, this since the filament type breakaway from Ultimaker was mentioned a little higher up in this tread before. So, sorry for any confusion.. The filament Breakaway from Ultimaker is is a special filament to be used in S3 and S5 variants only. This filament is to be printed as PVA in general, however if it stick to your primary filament you may put "some" more air in between the support and the printed object. I've read some place that one can use (0.1 to 0.27) as space here, but I have never printed with Ultimaker Breakaway filament. Thanks Torgeir

Hi 3d_rockstar, Ok. I see, You may use a standard NEMA17 200 step/rev with a 5 mm shaft, just order with the same connector type installed. You will need adapter(s) to match the connection between the stepper and the multi coil shaft types you want. Also you may "offer" some space under the bed to make space for the adapter. With such a setup you might consider to use an upper bearing for support of this shaft.. I would use the "new" plastic nut as they have less friction and are very smooth in operation. (Yes, I'm using such a bearing and have 5 brass ones never used, grin.) It is possible to adjust the stepper a little down for more space. I'll think that Igus might be the best place for a good selection of various Z shafts and adapters that's needed. Sure, there's chines shops that can deliver such stuff, but you never will be sure that the tolerances will bee good enough for your printer. The firmware setting is very easy, so no problem there I'll think. Anyway, good luck in hunting new parts. 🙂 Regards Torgeir

Hi donogh, Try to set "layer height" to 0.04 mm, this is better for layer addition in printing "high overhang". Scroll down in the menu to experimental and select "use adaptive layers". Only this two changes should work well. This should improve your vase some as it may print up toward 90 deg overhang before lack of support. In general less layer height improve overhang max angle to just around 90 deg. (Better angle (you can actually close the top without using support) can be made by increasing wall thickness and decreasing layer height, but not in spiralized mode.) Anyway, a little offside.. Good luck. Torgeir

You're welcome. 🙂

Hi netminder, Just looked at your print project as I've also have an UM2. If I'd read your project file right, you're printing with a 0.6 mm nozzle and speed at 60 mm/s? Right? If so, this is way to fast for such a nozzle with such a detailed object I'll say. Also the flow request for this is very high. In order to print all this details you should use a 0.4 mm nozzle, a much better match for your print. Your printer can print this object very well. For Cura 4.6.1, use default fine, select your infill and select skirt. Reducing "print speed" is very effective in order to avoid issues in the object (resonance/shadows etc.). This should work well for your printer. (Actually I'll think your printer worked very good in spite of this to high demand 🙂). When it come to elephant feet, it is much better to have those -than a print come loose from the bed, oh yes, tried that.. Some use to reduce first layer in the original 3d drawing in order to reduce this effect. Hope this help Good luck Torgeir

Hi gr5, @gr5 You certainly made me thinking.. Those axis types have been using "multi coils" for years.. I wrongly used the pitch 2 deg, -but it should be multiplied by 4 as an UM2 use quad coils. So the real pitch is 8 deg., to be used for such a calculation. I'm going to correct the numbers to avoid confusion.. Thanks for your hint. Regard Torgeir

Hi alexgan, Hmm.. Seems there is something going on at the coupler. How is the coupler, the white insulator that's right above the heath block? If the coupler is too much compressed in between the fixed alu spacer and the heat block, the coupler may shrink and the passage for the filament will decrease. This will create a massive resistance for the "free" feed of the filament. This pressure is set by the stainless tube screw that's attached to the heat block, however if this screw is to loose, it may lead to a leakage of filament into the extruder that will ruin you day.. Do not ask me about how tight is enough, cause I never seen any info about this. I just turn it down until it is only in contact with the coupler, then I add about (5-10) degrees more turn -so that I feel "some" resistance. I usually put one mark on the screw and heat sink so I can see that it is held in the right place and do not move. So yes, there is a critical balance in tightening this screw.. These couplers is a consumable part and we should always have some in spare. Hope this help Torgeir

Hi there, No triplex, but a standard one with 2 deg. pitch. Regards Torgeir

Hi Folks, This tread is kind of old, but here's at last 3 different issues that can happen with any kind of printer.. So, to the first one that's very interesting, cause this is a relatively small round print with an overhang. This problem is not related to the breakaway support, but it is because of to much heat radiation to this part/side of the printed object. As the object is round, you will see that one sector will suffer for lo blast from one of the fan and this is the problem here. This could be cause one fan is not working properly, or just stopped. Also such object may not have sufficient cooling due to the position of the fan and the fact that the object is very close to the bed. To avoid this latter, the only way is to print with blue tape and heat bed off. The break away should have some distance to the "roof" as it should not stick to hard to the print, so around a millimeter or less is what I'm using -but depend a little of filament type as well. The second print with white PLA (I guess), is something else. This color is the most difficult one to print due to it's color, -white. From the thermodynamics this is well known, object with this color do not radiate it's heat energy as well as the object darker colors. So here it is better to be on the low end of temperature advised by the producer. In this print you see some brownish remains that are in the skin of the object, this also indicates to high temperature. With a small content of water present in the filament, very small holes might bee seen in your print. Well, this is just about the old issues up there. Thanks Torgeir

Hi Raymond, This is great information. Thanks Torgeir

Hi Johnny24, Welcome in here. I'll think 48 deg. C., on the outside metal cover is pretty high! This may lead to overheating of the small stepper driving ICS. If it's this hot I would have installed fan just to blow under there while printing. I'll think that there was planned to be a fan or two in the original edition of UM2. Somehow this was skipped, but maybe this was an optional thing for operation in hot countries? On the main PCB there is a connector to be used for a 24 V DC fan.. You may also check that the current settings for the stepper motors is at correct level that's normally 1200 mA. Good Luck Thanks Torgeir

Hi Alex, If the filament is soft and climbing up the tube, check that the aft cooling fan is working. This fan is keeping the cold side of the hot end "cold" in order to prevent such happen. Such thing may also happen if the printer is turned off directly after printing without cooling down. Thanks Torgeir

Hi 3D_rockstar, The best thing to do is just to get a new stepper of same type as used in the standard UM2. Other alternatives will not improve your Z resolution very much. Let me explain, it is not easy to just to swap the axes, this is because they operate with different shaft diameter vs pitch angle.. Edited: The pitch used for the Z shaft calculation 2 deg. pitch and this is to be multiplied with the number of coils in “parallel” in the shaft. An UM2 have a 4 coil shaft. So pitch to be used is 8 mm. Lets look at the shaft UM2 is using. The shaft diameter is 8 mm with 8 mm pitch (I.E. the axis move 8 mm per rev 360 deg.) Meaning we have 8 mm/200 step. Each full step is then 0.04 mm or 40 micron. Standard setting for Z use 8 bit micro step. So standard setting give; 8 mm/200/8=0.005 mm or 5 micron! If you like to improve this, you can install a jumper to use 16 bit micro step. With 16 bit setting; 8 mm/200/16=0.0025 mm or 2.5 micron. By looking at this numbers one can understand why Ultimaker selected 8 bit.. The reason I’m using 16 bit on Z and X/Y geared by two, is simply because I’m mostly print very small parts and most of my parts could be printed with an UM2 Go.. However, printing with this setting is very interesting -but sure kind of experimental. So, all in all, a small mechanical play will easily ruin this resolution by numbers.. But the very good thing here is that most of the resonance shadows in my printed model's is gone. 🙂 The above numbers is recalculated with correct pitch 8 mm/rev. Thank you @gr5 Hope this help you. Torgeir

Hi 3D_rockstar, First I’ll explain my interest in improving the mechanical tolerances. As thermoplastics is very difficult to keep within a given tolerances, I wanted to keep all this other mechanical play at a minimum level. I’ve also tried to get read of as much weight as possible from the moving extruder and the gantry system. This is important in order to have as little resonance as possible, as this often give your print object some shadow/echo effect. This is a typical after rapid accelerating/decelerating movement of the extruder head. Much of this problem is caused by the short belts stretching/flexing during heavy load during this process. This two short belts are the ones suffer due to the high torque that’s needed for this rapid movements. As I used a mechanical “belt gearing” 16:32 tooth pulleys on both X/Y axis, I’ve got higher resolution on those axes, as well I halved the torque on those two axis. You can see how this was done here: https://community.ultimaker.com/topic/31254-changing-an-um2-from-125-micron-to-625-micron-resolution-on-x-y-axes/?tab=comments#comment-257342 When it comes to the height axis Z, I’ve found that the pitch angle is important to leave as it is. This is because G play an important role in keeping the level as steady as possible, if this angle is less steep it is much easier to have issues due to this. I would rather go for the Igus type and the choose a step motor with higher step rate per/rev. But here ofc., using same pitch as the original Z-shaft. I have not printed the 3Dbenchy after I did this modification, but I've one other from before and after mod. I've printed the last one yesterday. An important note here, this two model is printed with the exact same gcode file from 2016! The one on the right side is printed after modification. Click on the picture to zoom in. I've splited the pictures into two part, not as good as it is originally, but you can see the ringing resonance after the /S (sss).. 🙂 Here is another picture of this flow test print of the eight step upward the speed increase. If you zoom in you will see the reduction of the resonance. The only issue after this mod is that the steppers X/Y now running at the double speed from before to keep same speed of printing as before. So the noise level is increased! I'll see if I can find some references from others I've used to collect. Regards Torgeir Edited, by some reason my pictures is much reduced in quality here...

Hi 3D_rockstar, Go for the old type h-stepper with fixed rod, -but if you really want to change this, -the only type that match good enough for an UM2 is the Igus type. The original step/unit for an UM2 is; X80.00 Y80.00 Z200 E282 To improve the resolution on the Z axis you just have to install a link on the 8/16 bit contact on the PCB, then the resolution is doubled to 400 step/unit for the Z axis. As a result of this link, your bed will only rice half of fully up position, so you need to change the number of step/unit in the firmware. By using Pronterface (or other method) and sending the following to the printer: M92 Z400 M500 The first string M92 Z400 change motion step for Z to 400 Step/unit and the second string M500 store the changes to the firmware. (Note: A factory reset will restore to the original setting.) This will improve the Z axe stepping much! I've doubled my step/unit for all tree axis, and my printer is much improved.. 🙂 So my printer setting X / Y is now 160 step/unit and Z is 400 step/unit. My resolution is for X/Y down to 6.25 uM (old 12.5 uM) and h down to 2.5 uM (old 5.0 uM). The result is amazing and I've never been able to make as god print as I do now. Also I can print overhang better due to this modification. Good Luck Torgeir

Thank you. I'm going to investigate this thing for sure.. (But disagree very much in naming our printed objects 2.5 D, they are really 3D object, so I'd rater said; welcome into the digital world... 🙂 ) Torgeir