axsdenied

I finally got hold of some red Colorfabb XT, hopefully to avoid using ABS when printing some large and tough enclosures. I managed to improve the quality quite a bit but I am stuck with several problems. Any hints would be greatly appreciated. 1. Stringing: There is leftover plastic on the sides where the head retracts and does a "jump" to the other side. See bottom of the image. Combing was off. Retraction was set to 40m/s, length = 4.5mm as per Colorfabb's guide here. Travel speed was 200 mm/s which helped remove stringing a bit. I even tried 250 mm/s but it did not improve things. Temperature 245 and 240 degrees (not much difference). I also tried without fan and with fan at 30% (I am using dual fan mount), again I did not notice any difference. XT is not supposed to need much fan? I am not sure what else to try... 2. Infill The infill looks very bad at places, big sections are missing. I don't think there was underextrusion (no stepper clicking) and the outer layers look fine. The infill was printed at the same speed as the outer layers. Fill density was 25%. Any thoughts what happened? Settings: Layer height 0.2 Shell thickness 2.0 (for extra strength) Bottom/top fills 2 (for extra strength) Fill density 25% Print speed 50mm/s (also tried 30mm/s for the outer shell) Travel speed 200 and 250 Fan off and on Temperature 240 & 245 degrees, bed at 70 degrees. Flow 100% and 105%, it did not seem to make a difference for the infill but 100% helped a bit with the point 1. Retraction speed 40 mm/s, length = 4.5 mm

All three articles should be pinned on the top of the forum, not only "A few tips for getting better tips". I wish I have seen them all a month ago when I got the printer. It would saved me lots of grief, wasted time and filament. Thank you Robert!!!

Did you try cleaning the Bowden tube? Push a small piece of cloth or paper towel through it using the filament. Sometimes you get small fragments of filament in it creating friction.

I am trying to print an enclosure with posts that will be tapped so the screws can be used. Unless I use 100% fill the posts are printed in honeycomb with a "circular layer" on the inside and outside. When a tap is used to cut a thread it is not strong enough. Solid fill of the posts would (probably) solve the problem but then I would need to print the whole enclosure with 100% fill. This will take a very long time. I am probably asking too much but anyway... is it possible to have different fill density for different parts of the print? In my example to print the enclosure with, say, 20% fill while the posts are printed with 100% fill. I also noticed that in cura changing the shell thickness improves things a bit. The post will have more inside/outside "circular layers" which helps when tapping the holes. However, even if I set shell thickness to a very large number cura still insists to use honeycomb inside the posts.

I have an UM2 which is about a month old. Since day one every now and then the text on the LCD display quickly moves sideways and then comes back. It happens very quickly but clearly the text shifts by several millimeter and then goes back. It does not happen very often, probably every few minutes. But often enough that I keep noticing it. Is this normal? As I said it has been happening from the day one. Apart from this the printer works fine.

Some people said PLA was not strong enough and that it was snapping, even at 100% fill. Some people suggested that ABS is not good if you are printing PLA as filament rubbing on the feeder may result in small pieces of ABS going into Bowden tube and eventually into extruder which may block. Using a small piece of Bowden tube inside, for example, Robert's feeder can help with this. Personally I use PLA (20% fill) but keep a spare feeder, just in case. Printed over 20h so far with no issues. If it starts breaking I will consider making it in ABS.

Beginner here. I had UM2 for about a month, so my experience/knowledge is not so great. Few days ago I swapped to Robert's feeder hoping to solve underextrusion which is progressively getting worse. 1. I definitely like the "openness" of the design. Much easier to clean, to see what is going on and to insert filament. Especially for beginners this is a ++++++. 2. I am still trying to find the correct tension for the spring/length of yoke. I am getting a lot of feeder-stepper-clicking when trying to print faster. 35mm long screw may be the answer to reduce the tension further (thanks Niko). I never touched the tension on the original feeder and currently it is (still) performing better than Robert's feeder on the extrusion test (also less clicking with the stock feeder). 3. One thing that I keep fighting with is the position of the tension adjustment screw. I am using a pan-head screw and it is difficult to squeeze a screwdriver into position due to the spool holder. Yes, I know the position can't be changed easily, I will need to look for a screw with a different head :-) Hopefully I will be able to tweak the tension more to improve the performance further.

You are possibly mixing up the shell thickness with the bottom/top thickness. The default cura settings for shell thickness is 0.8mm. The bottom/top thickness is 0.6mm (which is 6x the default layer height). (on Cura 14.12.1)

Can the depth of the "tracks" on the filament be used as a guide for the right tension? What about when changing filaments and then going back to the original filament? Do I need to discard the section that was already in the bowden tube and that has "track" marks on it? Can the feeder have a good grip on already used section? I am getting occasional clicking from the motor skipping and some underextrusion. I also had to clean the bowden tube from the small pieces and strings of PLA.

What is the correct tension for the filament feeder? There is conflicting information on the Internet and also there is talk of different feeder models requiring different tensions. My printer is about 2 weeks old and the white tension pointer is in its top-most position (I never changed it). When the filament goes through the feeder a series of "marks" can be seen on it, as in photo (click on it to zoom in to see what I am talking about). I am suspicious that the tension is too high but I would expect a new printer to be setup correctly??? Also in the photo you can see how the filament got ground away so the feeder could not grip it any more. This happened twice so far. - First time when I was trying to print something with lots of retractions so I could kind of see how it happened as the filament was moved forwards and backwards a lot. - This time it was just a solid block that was printed, no retractions. The printer was not used for 4 days and now I came to this. Could the tension be so high that the pressure weakened the plastic in 4 days? Thanks for any help.

Temperature was 210 indeed. Will try going higher. Thanks.

Why would the side peal off like this? It seems to go all the way down to the first layer. Printer did have underextrusion problems (too high speed as it was just a test print for size). Is underextrusion the reason? Why? Printed on UM2 in PLA, layer 0.2mm, shell 0.8mm, speed 50mm/s (changed to 30mm/s half-way into the print once I noticed the underextrusion issue). Thanks

I am trying to print a large flat-ish object close to the maximum build size of UM2 (230x225mm). I am failing to convince Cura to get even close to that. The maximum size I managed to print so far is 200x200mm (190x190mm touching glass due to rounded bottom edges). Removing skirt gives me extra 2mm in each direction but it is still far off the mark. Cura refused to even do 200x200mm until I added a brim of 3 (or less). Larger brim did not work. Raft seemed to work as well. If I reduced the size of the model it worked without brim/raft. Why does adding brim increase print size? The 200x200mm printed object is offset to the front and left on the glass while in Cura it seems to be centered. Why? I am guessing that left comes from the left nozzle but why is it offset forwards? There is a fair bit of space on each side: 10mm towards front to glass (5 mm to clip) 18mm towards back (13mm to clip) 23mm on left 32mm on right (because of space for 2nd extruder???) How to get access to this? I am aware that Cura won't let me print in between the clips but there is lots of unused space inside the allowed region. What is the safe way to convince Cura to do larger prints? Do I need to change the maximum width/depth in the Machine settings (in Cura)? Default values are 230x225. How far can I go? Is there a safe way of testing the limits. Thanks in advance

Thanks for everybody's replies. Lots of wisdom in your words that will help me with this print and in the future. I printed it with 0.33 (0.34 did not work) and it came out OK. Actually better than I expected. Again, thanks.

Thanks for your reply. I have tried "Fix horrible" before without success. However, you tip about the shell thickness was the answer. Setting 0.4 still shows no mesh but setting 0.3 works although Cura marks it yellow to complain that it is too thin. So, I printed it with shell thickness of 0.3 but I used 100% fill density to compensate for the weak walls. 2h to print, looking good so far. Thanks again.

Hi I am trying to print an ABS particle filter. In particular I am having troubles with the file 3dprintexhausttop2.stl from that website. The file looks normal in Cura. However, when I do slicing and view layers, the mesh disappears. Same when printed of course. Photos below. I have tried playing with the settings in Cura but without success. Any ideas how to get this printed? I think that the guy who made it managed to print it on UM2 as this filter and the whole enclosure is designed for UM2. Thanks again for your help.

It was a pulley. All fixed now. Thanks a lot!!! A bit disappointed that I needed to do a repair on a 2-days old printer. Now back to printing :-)

Hi I got an UM2 two days ago. I was quite happy with it until today I found a spare screw lying under the build plate. A photo is attached. UM2 seem to print OK. The screw has about 4mm diameter and it is about 4mm long. It needs a hex key to be tightened. Any idea where it came from? Thanks for any advice

Every solid releases vapours (atoms/molecules) all the time. This is usually called/described by vapour pressure which depends on the ambient temperature. Heating plastic will make it release more molecules and this is what you can smell. This is what they meant by nanoparticles. By the way, dust is way too big to be considered nanoparticles. Biodegradable does not mean "not harmful". It just means that it will be broken down within a reasonable time. Nothing to do with toxicity.

Thanks to everybody for replies. They were very helpful and I have decided to get UM2. I can probably reduce the size of the box by 10-15mm. korneel: The material does not have to be ABS but it has to be quite tough (impact resistant and rigid). I will also order and try out Colorfab XT as Zoev89 suggested. The specifications seem to be quite good. izo2: Did you print a brim around your box? Again, thanks!!!

Hi I am considering getting the UM2 but I need a bit of advice first as the object I want to print is not the easiest. Is it possible and how difficult would it be to print a box/enclosure which is about the maximum size of the UM2 build volume, i.e. 220 x 220 x 120mm? It has to be in ABS with about 5mm thick walls (can be thicker if needed). The lid will be about 8mm thick. Has anybody done something similar? I am aware that I will need to build an enclosure for the UM2 first. Future support for printing soluable supports would be of a great advantage (for a window in the box). Any advice/hints is greatly appreciated. Thanks