How to MAXIMIZE flowrate: UM2 with 3D Solex Block and Bondtech extruder

[MaxPower 4]

Hi everybody, I am new to this forum and would like to know about your experience with an Ultimaker equipped with an Olsson Block or 3D Solex matchless Block and Bondtech extruder (or other, whatever works).

I am printing large objects with my UM2 extended and I want to reduce the print time by maximizing the flow rate (in terms of mm^3/second coming out of the nozzle). I dont mind thicker layers due to the large objects like lamp shades or furniture.

I think the flow rate is at the end the only important value for max build speed. Sure, I can reduce the numer of outlines and the infill, but I speak about maximize the speed for a given setup (e.g. 2mm wall-thickness and 10% infill)

Bye the way, the used flowrate is shown in Cura if you move the mouse over the "print speed" input field (it calculates the flow rate with the speed, the nozzle diameter and the layer height/ width...).

With the Tinkergnome-firmware (if used, if not give it a try), the actual flow rate is shown during printing when you move the cursor over the flow rate field in the LCD.

You can also calculate it, a flowrate of 30 mm^3/s is equal to 108 g/h (with density 1,0g/cm^3). ABS has a bit higher density, but the print speed is not constant (outlines slower etc.). So lets say:

30 mm^3/s =100g/h - already achieved

60mm^3/s = 200g/h - goal

So far I used five different nozzles on my 3D solex Block: 0,4/ 0,6/ 0,8/ 1,0/ 1,5mm.

I was able to achieve a flow rate of 30..35mm^3/s. Which is already quite impressive.

But I hope to push it further. There is a chart on the 3D Solex homepage (3dsolex.com/matchless-charts) which states a flow rate of 60mm^3/s using at least a 1,0mm nozzle.

Can anyone of you print that fast?

I achieve the 30...35mm^3 with a 0,8mm nozzle or bigger. But increasing print speed (and with it increasing flow rate) lets my Bondtech extruder skip, leading to holes in the print.

I doesn´t seem to be the extruder since it is quite powerful. I think the filament just can not be heated fast enough. If I push the filament in by hand, I can not extrude it much faster since I cant not push harder before breaking something. I already checked the nozzle doesnt touch the sheet metal of the fans. I also used copper paste to install the 35W heater. So I think the heater block is working fine?!

I am printing ABS at between 235 and 260°C.

Maybe the flow chart with 60mm^3/s is made for PLA?

Would be interesting to hear if anyone can print at hyperspeed...

Anyway, Bondtech and Solex-Block seem to be a good choice. I am already printing much faster than with the standard UM2 setup. Now I am experimenting with Simplify 3D - a really awesome Slicer with many cool features I always missed in Cura.

Cheers, Ascan

[DidierKlein 712]

Hi and welcome to the community!

30mm3/s is quite a good flowrate already!

I'm not very experienced in ABS printing but from the experience i have with PLA the obvious manner to achieve more flowrate is to increase the temp. With such speeds the filament has very little time to warm up and melt correctly so higher temp is indeed necessary!

Another way is to increase the nozzle size of course, with the matchless nozzles you can go up to 2mm as you mentionned.

Another way to know the flowrate by the way is this: speed x nozzle size x layerheight

So let's say you are printing with à 1mm nozzle 0.5mm layers and 60mm/s speed:

1 x 0.5 x 60 = 30mm3/s

With the 2mm and the same settings you reach the glory 60mm3/s i'm assuming that the temperature for ABS would be pretty much the max temp of the printer (260°c) in order to work.