![Smile :)](./images/smilies/icon_e_smile.gif)
It wasn't until recently that I also got a feeling for this e-steps related underextrusion that becomes very visible with the ruby.
That explains why printed things always ends up quite much lighter than they were supposed to be, which actually has been a big question mark for us when we try write scientific articles on 3D-printing.
When you for example print neutron shielding and your objects always ends up 10% lighter than the theoretical weight, people start asking questions..
![Confused :-?](./images/smilies/icon_e_confused.gif)
I am considering to order the next batch of rubies with slightly larger shoulder to make them more forgiving, but at the same time I hesitate to trade overhang quality for better top layers, as the problems with the top layers are not really caused by the ruby, but by lack of precision/calibration in the Ultimaker feeding.
Here is an example of what an UM2 can do with 1.75 mm filament, the direct feeder and a ruby nozzle (printing slow of course and with PID-bed temp control): My main issue is if I want to aim the ruby nozzles towards the Ultimaker machines with their lack of feeding precision, or towards printers with higher precision direct feeders and 1.75 mm filament. (Or sell them together with a 1.75 mm Olsson block kit and a direct feeder kit maybe
![Smile :)](./images/smilies/icon_e_smile.gif)
Regarding the E3D hardened nozzle, I did some comparisons and thought I had photos, but I can not find them right now.
Anyway, the performance on overhangs was worse with the hardened E3D nozzle than with normal brass nozzles in the tests I did.