Topic: 300% faster print speeds, how is this calculated?

Hi!

Although I already own a 3D printer I have been following the Robox with great interest, especially the dual nozzle system speaks to my love for engineering with the needle valve system.

Inspired by the Robox I have been looking at using two different size extruders for my own printer (I own a SpiderBot) to speed things up and doing some experiments slicing for these in Simplify3D.

Now I read on the website the following:

robox® includes a proprietary dual-nozzle system which can improve print speeds by up to 300% when set against our competitors. A single material feed can be directed out of one of two nozzles – with a 0.3mm or 0.8mm extrusion diameter. This means Robox® can produce highly detailed exterior surfaces for the surfaces you can see, and then quickly fill the object using the larger nozzle multiple layers at a time without affecting part strength or detail.

But I can’t figure out how this “300%” is determined. I found two things, the different size nozzles (0.3 and 0.8 mm) and also smarter slicing, thicker layers on top of each other if they are the same (for example with a cube). The second bit I read here when searching this forum:

http://www.cel-robox.com/forums/topic/killer-features-your-views/#post-4642

My own experiments with several different parts (a simple 2x2x2 cm cube), the Cute Octopus from Thingiverse (default size) and a Batman Boomerang (much outside detail, very little infill) reveal print time reductions from a single 0.5 mm nozzle to 2 nozzles at 0.3 and 0.8 of about 15-30%. What I have not changed is the movement speed for these two those are the same.

Now don’t get me wrong, I’m not here to bash, I think increased print time of 15-30% is great and a lot, but I don’t see the 300% faster bit. Can someone explain, when and how this can be achieved. =)

Another thing I notice with Simplify3D as a slicer is that for more sharper/pointy objects the infill, at a larger diameter does not fill up everything properly. Does the Robox slicer take care of this?