yellowshark

I use Repetier Host to control my printing which has this facility. The first thing I do before every print is to extrude some filament until I am happy it is running smoothly and consistently.

What is the diameter of your part? I have a similar one, which I will print at your diameter, and post my settings.

You can use your Lulzbot, assuming it is a "normal FDM Bowden printer, by adding a Custom printer

Hi as mentioned earlier set your speeds the same - you have print speed and outer wall speed that are different. This is vital, you need to keep nozzle pressure consistent. I would drop all print speeds to 30 mm/s; your goal is to get a decent print, get that and then you can always play with speeding it up if you want to. Temp. is meaningless unless we know speed and layer height. If you are printing hot that will not help you either. Were the parts in you pic printed separately or were they all on the print bed at the same time?

Hi, yup agree with 100% with @gr5 comments. You do not mention it but set max. fan at 100%. Also walls, I suggest you go for at least 2 walls assuming a 0.4 nozzle. I normally use 15% overlap between infill and walls. Using a skirt to get the filament flowing consistently before starting the model can only help if you are not using a brim.

probably; I print via Repetier and they call flow % too.

That seems strange; does it not take differing pressures to push the same amount of filament through a 0.4mm nozzle vs a 0.8mm nozzle?

You might want to look at Repetier-Host. RH lets you control - bed temp.; extruder(s) temp.; print speed; filament flow rate and flow %; fans speed; all during the print. You can also send individual lines of g-code to the printer (whether this works during a print I do not know). I have used it to control my prints on my 3ntr for the past 4 years. It has a server version too which allows you to control multiple printers and provides remote access/control. Cura and other slicers can be invoked. It also provides velocity painting to change the look and feel of the object surface but I have not tried that yet, although the pics look good! https://www.repetier.com/

Ok I think a bit of testing would help. Beware I have never used Polysmooth! My inclination is that your speed is too fast. For now I will assume your extruder temp. is correct. Halve your print speed and double your layer height. ( I am thinking that will give you a similar pressure requirement and therefore the extruder temp. will be the same). In Cura sink your model on the Z axis so that the circular area does not get printed and waste your time. Print the leaning arms. Does that look better? Hopefully so but even if not better, repeat the print and take 5 degrees off your extruder temp. Maybe repeat again with another 5 degrees taken off. You will know if it is worthwhile or pointless. I probably should have asked this first but when the two leaning arms are being printed I am wondering what your layer time is? Perhaps it is under your minimum layer time (10 secs?) and causing the print speed to slow down substantially and that is your problem? Using a priming tower would help with that. Infill failure – you do not say what you are using so difficult to understand what might be happening. Personally I would tend to go with 40% to give those arms some strength. I am thinking you need to be watching those arms as they are printed so that you can see what is happening with the infill.

Hi all this is just a call to you all to help us help you. After every Xmas there is the rush of new 3D printers to our forum, which is great. You have no or little experience or maybe you have but none with Cura. And for many the forum is the first point of call for help, which is expected and great that you think we can help you. And there have been a lot of you during the last couple of months. To help us help you! 1. Please tell us your Cura settings; key ones are filament (type/manufacturer), bed temp.,1st layer filament depth and print speed, filament depth, extruder temp., print speed(if you are using different speeds for different parts of the print please tell us), infill % and pattern type, cooling i.e. fan settings; retraction settings 2. A pic, or several, can be really helpful in letting us see what is going on. 3. The old forum use to display the country you lived in but is seems the new one does not. If you could note that in your post it would give us some idea as to your native language and whether you may struggle with English ( of course some big assumptions there); knowing that just prompts us to try and be intelligent with the words we use when replying. Of course it is not mandatory but just misunderstanding one word can make all the difference.

Well you probably want to go slower and cooler but without knowing your settings it is difficult to be definite. Strange though it may sound I had a model with a convex overhang and I found that changing from a 0.4 nozzle to a 0.8 model changed an OK curved overhang to a perfect overhang.

Oh and also it may be worth trying a different filament; possibly just a different colour from the same manufacturer. I have not done any serious research on filament vs dimensional accuracy but I do know that certain filaments print better than others (from the same manufacturer) and if accuracy is key then I will use one of three filaments from the 20-30 I have tried over the years

Hi, lots of good points there from @mastery. I do think you can achieve a better result than100-300 micron though; it will though depend on the model and its geometry. Also bear in mind that circles will always print smaller and you need to adjust for that in your design. You could consider the following. 1. Speed is the killer so slow right down; probably no more than, 30mm/s. 2. Print cool; get your extruder temp. right down until it under extrudes then add 5 degrees 3. Oh you do not mention the material you are using; I am assuming PLA 4,. Environmental temp.; try to have it warm, at least 20c, 25c could be arguably better 5. Z-gap; if you really have your 1st layer squashed down for excellent bed adherence then this may well affect your z-axis measurement. It might be possible to adjust the design dimension to compensate. Alternatively you may need to adjust the z-gap distance a bit to give a bigger gap. 6. At end of print, leave the model in situ and close your printer door and cover top and leave you model their until the bed tem has reached the ambient temp. I.e. go away and have a coffee and cake and leave the model to cool down as slowly as possible. I can normally hit better than 50 microns and guarantee 50 microns. Of course for a prototype I will advise the client that if he is happy with 100-150 microns then I will increase the print speed which reduces the price.

Think about whether you want a quality surface finish. "Fast speed" will not deliver and changing print speeds continually during printing will keep changing the pressure in the filament feed an give poorer quality.

First of all we live in a Health & Safety world. They have two objectives. Firstly to keep issuing warnings to keep their jobs. Secondly to worry you to keep their jobs. Your printer is made out of metals and or wood and/or plastics. You are unlikely to eat it. If it burns you probably have greater worries. I was bought up in the 50s and 60s and spent plenty of time walking through London's pea souper fogs, with plenty of coal particulates, and I am still here with no asthma or anything similar. Do filaments when they melt give of particulates? No idea. I use predominantly PLA which is made from root vegetables, so if you like snacking that is probably good you. Open a window, well yes but difficult in the depths of winter. @kmanstudios makes a good point about buying from a reputable supplier. If the material is dangerous there will be a label on the boxing/reel saying so. Examples are ColorFabb, Ultimaker and Faberdashery. No doubt if you live in a city then staying indoors with your printer will be substantially safer than walking outside in all those diesel induced NOS fumes. Oh and never make a bacon sarnie, you never know what nasty things are in that cheap oil from the supermarket.

Hi, I certainly and I suspect @gr5 too have misunderstood you, although both our answers are still relevant. Are you saying that on any layer, although probably the top layer, you are taking diameter measurements from different points on the circumference and that these are differing measurements which on average show a 0.3 error? I have never seen that though to be fair I guess I rarely take more than two measurements, at right angles to each other. Also how big is the difference between the measurements. Personally I would not be concerned by 10 or 20 microns and depending on my mood might overlook 30 microns - sorry you said that already, yes quite large! Another thing not to overlook, and you might be, but if you are not an engineer (typically) and trained on how to accurately take measurements with a gauge then your measurements will probably not be good enough to get the level of accuracy you seem to chasing. I know; I am not trained and my measurements are always different and wrong compared with my son who is a qualified mechanical engineer. And to reinforce @gr5 's point that if you really squish in your filament on the 1st layer to get good adhesion then yes you will see the errors he notes. If I were to print something with required accurate holes then I would deliberately increase the nozzle to bed distance that I normally use; at the end of the day it depends on how much tolerance you are allowed.

Ah, thanks @gr5. OK got it now; that is a travel move and yes it is not a sound I have ever heard on my non UM printer, the head hitting infill I assume but boy that is loud

No sound at all from the video on my speakers

what did you set in Cura for your seam positioning?

Yup that sounds pretty much like my non-UM printer

I do not think there is a setting in Cura to do this but I have not used vs. 3.n so I could be wrong. It is easy though, just add a command to the end of your g-code file; M140 Snn where nn is the temp. you want. However, you may find you need the bed temp to drop down from the printing temp. so that you can easily remove the print from the surface. Better to wait 5 mins than damage your plate

Hi, this has nothing do you with your printer, probably, but is due to the way 3d printers print circles. I.E. they do not draw circles they draw lines and as a result the diameter of a circle will always be smaller. So you have to give your circle a bigger diameter at design. It may take you a couple of goes to get it right but once you have done it a few times you will get a feel for your printer and will know what increase to make. For straight lines you should be able to hit +/- 0.05mm accuracy. I will not guarantee anything better but can normally hit 0.03 or 0.02. As long as you are well set up then printing slow is the key to accuracy.

Check the icon in the icon strip on the left hand side for Move, I think it may be the one at the top. The Z axis should show 0; if not that is your problem

Sorry I cannot help; I went through a similar experience and end up throwing the reel in the bin. BUT there were a lot of posts on the subject a year or so back on this subject. I suggest that if you search the forum for flexible filament you will find them. Even better would be to use the filament name which was very popular but unfortunately I cannot remember it

Oh for sure, if the print bed is not level then you will not get a consistent z-gap across the bed. That is one of the advantages of using the "on the fly" method because you can correct a bad level using the process. BUT I clearly take a different view on life to you, which is that bed levelling is that. It does not set THE z-gap; it sets A z-gap, by the nature of the process, which is hopefully usable but not THE optimum z-gap; this is done by using the on the fly method or the Cura method. A lot of people will use an A4 sheet or whatever during levelling (bearing in mind that certain countries have A4 sheets of different thicknesses) and then generally lessen the gap to get the optimum setting for them.