poshman

Thanks for input gr5 !!.. Good points!

So - regarding resolution, isn't it another way to set things up to obtain what is requested?! IF - guess there's an awful lot of job behind that - but if we could divide the perimeter into e.g. 0.02 mm layers, finish 5 of those - and then make the infill in 0.1 mm... That should save a lot of time but still get us the surface finish we want.. Is this possible?... From my point of view most likely a nice to have thing as 0.1 mm resolution is very fine for me.. Of course, chamfers and radius would look better in higher res. But with this method it should be possible to speed up normal prints as well. Perimeter at 0.1 resolution and infill with 0.2 or 0.4 ?!

Nope, not reasonable... I have made the same observations but not in the same way. I put each pulley up in my lathe and watched them. On one hand I just clamped them into the chuck and looking at the center hole - how much it moved. Secondly, to really reveal the truth I put them up on a fitting shaft and then looked at the cogs moving. They are not well made. They are off center and the outer pieces that are pressed onto the center part (the cogs) are not centered either. However, the outer parts to not matter but the off center of the through hole matters. On top of this - the through hole is to big so the pulleys will be off center when attached to the shafts. I have now bought new GT2 (5 mm) and drilled them to close to 8 mm and the last part I sanded to get the perfect fit.

I have to test that - hollow parts - to identify how the shrinkage occurs. If it comes down to shrinkage I definitely have to do something about my fan. It is way to "unfocused" . I Think I will try some variant of cross-flow maybe combined with a improved fan shroud. Have you improved your fan, and in such case - did you see any improvement? Regarding the major improvement in precision I believe that in my case it comes from changing the pulleys and getting new shafts. My old pulleys wobbled a due to the through hole being 0.1-0.15 to big, and not always centered. Moreover, the original shafts were not straight enough. Besides from that, If the short belt arrangement would have been sturdy enough I would have kept them. Now I do not have to think about belt tightening. I never had any problems with it though.

Thanks, I did all the changes at once. The pulleys on the UM i received were not reaching for high precision... so I bought the GT2 instead. In the old config I printed the rest of the parts and then I started the rebuilding. The PLA will not get affected by the PSU. It leaves very little heat and as I have mounted it vertically the excess will not pass the PLA in high degree. If I would consider the PLA being affected it will not result more than tops 1/2 degree.. Nothing to worry about. The next step is to modify the tension devices a bit. I'm thinking of making one of the sides fixed and just one being used for tension. The only drawback from this is that it will be slightly more difficult to mount the belt. Or - I will just change the holding mechanism so the they are straitened out more and so that I perhaps do not need the clips over the belt. However, the clips works fine.. One thing I'm curious about is how come the holes are affected and not the whole part? If the PLA shrinks all of the part should shrink. Now the outer measurements fits perfect but the holes do not. 1+1 does not add up here... or have I missed something?

So finally I got around installing UM upgrades. Calibrated my machine and I'm very happy to say I reach a resolution of +-0.05 mm. Actually more of measure error... So what have I installed: Direct drive. I bought a set of GT2 pulleys, belt and new 8 mm axes. I created a simple but sturdy enough holder for the motors. The setup allows for mounting the brackets first, attaching a part to a motor and then fixing the motor. Also leaving a bit of self adjustment due to some slack in the holes (just for alignment during mounting). I installed Chopenmeister "twister blocks" and design a new belt clamp that fixes and gives tension to the GT2 - belts. However, I do want to redo the fixing of the parts. For now it is satisfactory. and then I also installed my heated bed in a bit more professional way. Well, could have looked a little bit better but what the heck, the machine is supposed to deliver prints, not good looks.. :smile: After everything was installed I calibrated the x-and y-axis regarding traveled distance to number of steps. Now when I print a part that is 100x100x10 mm I get a very good reproduction. 100.2+-0.05 in x-direction. 100.6+-0.05 in y-direction, and 10.0+-0.02 mm in z-direction. An interesting part i have noticed now when I calibrated my UM is that circles tend to be 0.2 mm less in diameter than they should be. I included some circular patterns using the same diameter along x and y-direction. This is quite interesting.. Everything else comes out just fine, but circles are to small. I have tried on other slicer (Simlify3D) and it produces the same results. Is this something that has to do how the slicer calculates circles ???

Sounds great!

Okey, I tested that - looks are really nice!!.. But, I think I got misunderstood, or I didn't find it. The thing I like in Simplify3D I'm asking for is - without importing any model or anything else - being able to connect to the printer and control it. Maybe I did something wrong but I didn't find a way to bring up the printing interface without submitting a model to be printed. Nice to do bed leveling in a personal way depending on how your table is setup. Well, of course I can just do it on the Ultimaker but for me it feels nice to do it on the screen.. Of course this will be of no function printing from a SD-card.... so maybe it's just a nice-to-have thing... :smile:

Ok - I fold. You mention one thing that I didn't think of. That is the corners. If that would not have been an issue I would gladly have proved it to you. And - having that in mind I concur that the triangle hex infill is much better.. Will that be up for selection in the future or is that put on ice? Thanks for valuable input!!

Thanks Robert !

Thanks for input! The hexagonal fill pattern I would like because it is the strongest fill pattern. I don't have the exact numbers but e.g. using an infill of 20% rect could be interchanged to 15% hex pattern - still yielding the same strength of the part. Faster printing and less material. The part becomes much more resistant to twisting as well. Good considering warping. Prove it - well - The hexagonal pattern is much better resisting collapsing of walls as the stresses are distributed in more directions. Short description. This is my job - I do load-stress simulations. Well - of course, if one does not care of the strength in that way - not caring of the weight of the part - then a rect pattern works fine.

Thanks for reply/comment. RC's - where do I find them. I looked at Github but did not figure out where to find it and what to do... I then looked in the Cura 14.01 I run, and followed the preferences and expert settings leads you gave. Did not find anything there, so I guess I have to download a development version to get these properties ?

I've been using both Cura and Simplify3D for some time now. The print quality is absolutely the best in Cura as it seems to have much better compensation for changes in acceleration. However, there are some things I would like in Cura: 1) A machine interface so that when you start Cura you can push a button to connect to the printer and thereby control the bed and nozzle so that things get setup while you are doing other stuff. 2) A way if controlling print speed between different layers. Maybe the program could automatically calculate so that the print speed would be proportional to the time spent on each layer. Thereby the temperature distribution between the layers would be better. Is this done by the "Layer time settings"? 3) Different setups for the infill, especially a hexagonal pattern. 4) A weaker support structure that is much simpler to break of and that does not use as much filament. Ideally it would look like a fishing net of some kind. I think this could be done by making the support structure like infill but having each layer shifted sideways by 2 times the extrusion width so that no layers can interconnect to the other except in the crossing points. 5) A way of selecting areas for which to generate support, or as in Simplify3D, a way of manually entering support structures before slicing. Well... this surely will keep the nice guys creating Cura occupied for the next year... :-) Thanks guys for a great program!!..

I'll come back as soon as I have testet. I have found a place where I can buy natural anodized aluminum having a coating thickness of 10-12 microns. However, The first test I will do is just to cook the aluminum in hot water for 1/2 to 1 hour. This will give me a thin oxidation, which is approximately the same as anodization. However, the thickness will be 0.1 microns, tops.. I will try again printing without any tape and to see if I can get any control of it.. :-)

I have updated the heat bed with a copper sheet under the basalt bed. By doing this I have decreased the temperature spread. I Now have a max 5 degrees difference to the center of the platform. Nice - will lead to much less warping. However, the thermal difference to the center of the platform varies over the surface - not being a constant drop of as a function of distance from the center of the plate. This implies that the thermal conductivity varies quite significantly over the plate. Measuring the temperature I find that in one corner I have a temperature 1 degree below the center of the platform. In another corner I have a drop of 5 degrees. Turning the plate does not change the behavior for that specific corner so it does not have anything to do with the heating materials under the basalt block. Moreover, I have done a lot of testing for adhesion and what I can conclude that some filaments stick much better to the basalt than others. Golden PLA (UM) sticks very good. White ABS, at 255C ok, but not sufficient. Silver PLA not at all. But, I have found a nice system that for PLA works fine. I use pink TESA tape ("the tape that does not stick to wall paper"), tape it to the platform and then clean it with alcohol until it feels to start to get sticky. Finishing the printing the tape comes of easily of the platform and the part. Nice.. But, I now will consider changing the heat platform to aluminium in order to increase the uniformity of the temperature and to speed up heating and cooling. One thing I will test, and I don't know if has been tested, is to use anodized aluminum - and not use tape.