yellowshark

If you use the standard settings I think they are but lol if you use my settings they are not. Quite possibly faster speed causing under extrusion

Ok so the fact that I never touch my tension, unless I am occasionally maintaining the knurled brass wheel, is actually a good thing! Maybe the point is set the tension to a an appropriate tension so it is not slipping nor gouging, then leave it alone. I touch mine probably once a year. Oh and in case I inferred otherwise, I rarely touch my e-steps; only when the accuracy goes outside my limits, which is very rare. Then I will check everything else and only go to the e-steps as a last resort; playing with the firmware always raises my blood pressure😡

Personally I would go to the Taulman website and read their papers on printing with T-glasse. If you put your nylon in the oven to dry before printing then beware, T-glasse has a very low glass transition temp for nylons, as I found to my own cost when I put three samples in the oven at Taulman 645 temps. The website also has good stuff on T-glasse design objectives and transparency and reflection, or should that be refraction?

Interesting as I have never used combing. Looking at your pic I suspect your retraction settings would benefit from a tune as a complementary or alternative option. I use 5.5mm for PLA/PHA and 6.5mm for nGen. with a 0.4mm nozzle and running cool

Hi @conny_g thanks for that, good work you are doing there J. There is some work I do which has a 0.05 tolerance so it is a subject close to my heart. Interesting point on the feed tension, that is something I had never considered. Interesting also on the 5 degree temp increase, assuming that the previous temp. was pretty optimum, as I have always worked on the basis of slow and cool for accuracy (and consistency). My process now when accuracy is paramount, having played with this for several years, is a) Always use the same filament – i.e. manufacturer and colour b) Always use the same slicer and slicer settings c) Get as close as I can to my normal ambient temp. i.e +/- 1.0 c d) And then use e-steps to dial in the accuracy if needed e) Check every few months and immediately before the 50 micron job, with the reel that will be used which will either be new or hardly used, so there is no impact by the wind on the reel. And now I will need to focus my mind on the feed tension and see what I think. Excluding the latest models, as I do not know much about them, I know that the feed system on my printer is better than on the Ultimaker’s but I still set the tension by feel, i.e. if the filament surface feels right then it is right! Maybe I should get more scientific on that one 🙂 At the end of the day my view is get everything optimum and consistent and then fine tune with e-steps if need be.

Your print speed, nozzle width and layer height define the volume per sec of filament that needs to be extruded. As the volume increases you need to reduce the viscosity of the filament, which is done by raising the extruder temp. As the filament starts to become too viscous for a given volume you will start to get under-extrusion. As an adjunct, manual/hardware problems with the filament and feeder sub-system will lead to the same problem. The reverse of all the above applies; if the viscosity is too low then that will lead to over extrusion. So whenever you change one of the three variables above you need to consider changing the extrusion temp. so that the viscosity matches the volume per sec. required to be extruded. Now if you were to, say, change the print speed from 50mm/s to 60mm/s or the layer height from .250 to.260 it is extremely unlikely that you would need to worry about the extruder temp., unless you are already way off the optimum temp. and the small change pushes you over the edge. But if you were to double the print speed or double the layer height it is highly likely that you would want to increase the extruder temp. Finally the filament being used has an impact and I am including here a PLA filament from the same manufacturer but in a different colour. For sure if the optimum setting on YOUR printer is say 4mm nozzle, .300 layer, 30mm/s at 190 temp. then just about all PLAs will go through OK with those settings. But that does not mean you are at the optimum settings, which is probably fine if you are at concept modelling stage but probably not if you are in final production. If I buy a filament I have never used before I always test it to establish the optimum settings for a range of print speeds and layer heights. And may I endorse @Smithy comments on unifying all print speeds. The only time I would change that would be if I had something with a large surface area, > 50% of the print bed, maybe a plinth and it just did not make sense to print the infill so slow.

Lol it is all electronic via Repetier's GUI, no mucking around with wheels

Indeed 🙂 @geert_2 has listed the likely causes for you. You say you have 3 printers but it is not clear if you area suffering with all 3? If you are then it is more likely to be your Cura settings than a hardware problem. Vice versa if it is only 1 printer with the problem. It could also be the reel of filament you are use so worth trying nother reel also.

In no particular order... Print speed - the faster you go the lower the quality Resolution, i.e. layer height - the thinner you go the better the quality Extrusion flow - i.e. tuning speed vs layer height vs. extrusion temp. I.E. within arrange of, say, +/- 5 degrees there is an optimum temp. for a given combination of layer height and print speed. When I am testing a new filament I will gradually reduce the extruder temp until I see under extrusion and then I will increase by 5 degrees. If that is good I will reduce by a couple of degrees and see which is the best between the two; if the same I will always go with the cooler temp. Keep all print speeds the same - yes there will be certain models where you will just not want to do this, but every time you change speed this will affect the pressure needed in the feed system and the stabilisation of this is not instantaneous so you will briefly under/over extrude which can cause surface artefacts Filament quality - you get what you pay for; cheap filaments give you cheap results Different filaments - from different manufacturers often need different optimum settings for the same print; the same applies to different colours from the same manufacturer, the colour dyes impact performance. Hardware - maintain it so it is performing optimally, particularly the feed system (again filament quality can affect this)

I do not have any problems.

Why cheat rather than fix the problem?! Personally I would not use e-steps as a cheat as that affects accuracy, which of course may not be important to you. Anyway it is far too complicated compared with other options, as @gr5 says Flow is a quick easy cheat. But it is still cheating in my book; fix your problem and I am sure you will get more consistent better looking prints

Well I am not sure how easy it is to do this these days on the new Ultimaker printers but I have used Repetier-Host for over 5 years on my non Ultimaker to control my prints and to do all those things for me, including changing flow speed or print speed mid print. I know Ultimaker users have used it I the past, just have not seen the subject posted for a while.

and I am wondering if you might be stronger with a bigger nozzle; every time you print two adjacent lines you have a join and I wonder if that introduces a weakness. What would be stronger, 10 lines from the 0.25 nozzle or one line from a 2.5 nozzle?

...Maybe it was nGen I used it with.

Hi @giostark funnily enough I was going to suggest trying Coasting in my last email. I tried it when it first became available, 2 years ago?, and recall I met with some success. But I am not using at the moment and cannot recall what caused me to remove it - but worth a try!

With reference to the hole rather than the wall thickness... 3D printers do not print circles, they print straight lines. Lol end of really. The line cuts across the arc so the radius is smaller. No way around that really apart from compensating in your design if dimensional accuracy is important and you have a tight tolerance.

Ok a few comments on your settings; I am not sure that the material would make any difference with these If I were using PLA with 0.5 layer height I would use two top layers to see if that gave me a better top finish. To me a thickness of 0.5 for the top layers seems marginal; but of course I have never used 0.5 layer height so it may be OK. It may be that with this thicker layer height and 60% infill you are OK. I would not print outer wall first. Perceived wisdom is that you are likely to get a better surface by printing outer wall last. I have never used optimise wall printing order and have no idea what it attempts to do. But you only have two walls, with the order specified in the above sentence, so I would be inclined to untick that. Skin overlap % hmn never used that although I see I am doing so unwittingly. The setting is calculated and mine shows 5%. 40% looks awfully high, although with a wall width of 0.8mm you might well be OK; a setting which potentially impacts the outer wall so you might want to try reducing it considerably just to see. Skin expand distance; again no idea what that does, but guessing, why do you want your outside wall (if that is what skin is) to be 4.8mm wide rather than 4mm wide. Again it is one of those settings that looks like it may affect the surface and I would untick for now. Retract at layer change; again another I have never used in 5 years. Might be worth turning off to see. Retract distance 1.5; wow I assume ABS does not leak as much as PLA!

Ah, ABS, all bets are off! I have never used it so you need someone who does to best advise. I would have thought with ABS 210 was too cool; but you need someone who knows what they are talking about 🙂

Hi I am not 100% sure what is causing your problem but I would suggest you try the following settings – you do not list all your settings, so you may be using some of these already. Nozzle width 0.4 Line widths all 0.4 No. of walls 2 ALL print speeds 30mm/s, including Infill (except travel speed and 1st layer speeds (if you want to run that slower, I always use 20mm/s) Outer before inner walls not ticked Horizontal expansion 0 Infill before walls not ticked Infill overlap 15% Infill density 26 or larger Flow 100% Retraction distance of 5.5 will probably be OK, you can try both. I use 6.5 for nGen and 5.5 or 6.5 for PLA, depending on whether I remember to switch 6.5 back to 5.5 for PLA!! I have never used retract before outer wall – not sure why you would want to do that. I have never used a layer height greater than 0.300 so I have no idea if that could have any impact. Ok Z seam. I always use Random; I am not saying that you should. I do not know why you have selected Sharpest Corner – you are printing a cube, all corners are 90 degrees and so all corners are equal sharpness. You do not say what you extrusion temp is, which is rather important! Print as cool as you can to avoid any over-extrusion on corners as the print head decelerates and accelerates.

Actually another and fool proof way is to load the model into Cura. select the model and hit the move icon; the Z parameter should be 0 otherwise it is not sitting on the bed. Set it to 0 if not 0 . Also you could set it to -1mm (say) which means the model will below the build plate and try printing i.e. your first printing layer will be 1mm into the model rather than the actual 1st layer of the model.

If your printer is in good shape and setup properly then dimensional errors on rectangular geometry should be <0.100mm Circular geometry will have a larger error, say 0.300mm smaller because FDM machines do not print circles, they print straight lines and each line in circular geometry cuts the cusp of the arc. For circular geometry you need to design this failing into your model, it is a bit suck it and see. With a well grounded printer it should not be a problem. I can hit 50 micron error easily and can get down to 30 or better but we will only guarantee 50

I would have to say that if Inventor is being used then I would not worry about decimating. I use Solidworks and of course the two are the two leading software companies, arch enemies I guess, with a lot of similarities and attention to engineering and quality. We have not had one problem from Solidworks in the 5 years we have been using it and I would expect Autodesk to be the same.

… oh a quick thought, using a 0.8mm nozzle instead of a 0.4mm might help, it certainly does on curve overhangs; although possibly not on an absolute 90 degree angle, trying to get my head around that😵

A few points ? print the top part separately and glue the two pieces together. I see you have 4 layers on the bottom; can you have 4 layers on the top, or 3? If you are using 0.3 layer height then your final layer should be fine. Of course you may need to do a bit of cleaning up inside the cube, depending on what is going in the cube. The first layer will never be great. Make sure your fans are running 100% to cool the bridge material as quickly as possible. Print as a cold as possible, this will enhance cooling and make sure you are not over extruding Reduce print speed, this will enhance cooling And make sure your printer is in tip top condition. I have bridged >10mm a lot in architectural prints, it is not difficult. Returning to your photo - white is probably the most difficult colour, you may get instant improvement if you change that. And it is easier with high quality filament I bet you are not printing as cool as you can 😎