Brim line width insufficient

[Crusty 0]

I am new to 3D printing and use an entry level Anet A8 with increasing success the more practice I get. I use a 0.4mm nozzle, now at 205deg.C and the bed at 70deg.C, these settings seem to work well with my PLA on a glass bed with extra firm hold hairspray.

I designed a component with an 8mm wide brim which seemed to print very satisfactorily, the brim being a quite sturdy solid mass which measures between 0.31 and 0.37mm thick. The brim has 10 growth rings visible which are all fused together and 0.8mm wide each. I printed off two of these components and then my son had a look at my computer which was taking a long time to boot up. He identified the problem as being caused by Cura 4.0 which  I must confess, after an awkward installation, seemed to tie up with the time at which the computer was playing up. He uninstalled Cura and reinstalled it after which the brim of this component would no longer print as before. It was now printing a brim with 20 lines each 0.4mm wide, the lines would not fuse together so adhesion was not good enough to hold.

I delved a little more into the workings of Cura and found that as there was no template for an Anet A8 printer I had to specify my own custom printer and settings, taking advice from the fly out message boxes for each individual setting. I have set all line widths to 0.4mm except the brim line width which I set to 0.8mm and the initial layer line width at 100%, which seems to be the default setting. If I increase that to 200% then the box just turns orange so I left it at the default of 100%. The brim speed is 30mm/sec and the brim line count sets itself automatically to 10 for an 8mm brim width. All would seem well with no reason why it should not print these components as it did before the re-installation. However it now prints a brim of 10 single separated lines which measure up between 0.24 and 0.27mm diameter.

Under the ‘extruder’ tab of ‘machine settings’ I change the filament diameter from 2.85 to 1.75mm as that is what I use but after I have done my slicing and I look again at the extruder settings I find that it has reverted to 2.85mm. The other interesting thing is that if I open the G-Code file so generated, in a Word document, then the second line of instructions for the skirt specifies E0.01485 for the 0.4mm brim line width and  E0.02934 for the 0.8mm brim line width. These are figures I would guess to be correct for printing a nice sturdy fused brim but it still prints out 10 single spaced 0.4mm lines. I’m at a loss now as to why I can no longer print just ten 0.8mm lines. Can anyone help please?

By the way I have been using a 0.1mm layer thickness and 100% infill density.

[mrdindon 0]

same issue here ... did you you had it fixed ?

[Crusty 0]

I never did get to the bottom of the printer settings but then I ran out of hairspray and replaced it with a different brand. The new brand acted more as a release agent than an adhesive so I then started using Kaptan tape which I found to be so good that I no longer needed to start with a brim. I needed a wider tape so I bought some from Ebay but beware! What was listed as Kaptan tape was on a reel printed Kapton and it was as much use as a non-stick frying pan. The moral of the story is:- Experiment with different combinations of materials, suppliers and temperatures and write down everything that you do. When you find something that works just stick with it.

[mrdindon 0]

got mine fixed yesterday night.... just had to increase "Skirt/Brim flow rate". now brim lines touch each other..

[Crusty 0]

That's great mrdindon.

I seem to remember altering skirt/brim flow rate but without success. I think I was using Cura 4.0 at the time but I am now running Cura 4.3 so maybe that will allow me to to alter flow rates.

I haven't had the need to check this out as I'm having success now with the Kapton and I no longer need to print a brim.