Recommended settings for 3D printing

Here is my experience with setting up the printer for optimal performance. The correct setting is different for each type of printer and depends on many factors that are often directly related. It happens that a printing problem cannot be eliminated by a single change. Therefore, it is important to properly understand the context and principles of 3D polymer printing.

Extrusion width

In my experience, it is best to choose the extrusion width according to the printed object. Different statues and decorative objects may have different settings than the technical objects for which the optimum print width is specified. For example, my tanks are usually optimized for 0.5 mm, which means the thinnest wall is 1 mm thick, then 2 mm, and more. So the nozzle can go back and forth without having to change the extrusion width. Yes, you can set a variable extrusion width, but quite a few hotend types have a problem with this. Often the extrusion is insufficient or the heatbrake gets clogged. If you have good results with this, you can use this setting.

The optimal extrusion width is calculated by adding the nozzle diameter and the layer height. Often, however, a smaller value will do. However, it is never a good idea to use the same diameter as the nozzle. Having the extruder set up correctly - number of steps, pressure, motor power - is essential to achieve a good surface and ideal interconnection of adjacent perimeters. This may be different for different materials, depending on the tolerance of the string diameter or the stiffness of the matrix. Tanks print with a nozzle of 0.4 mm, print height is 0.15 mm, and extrusion is 0.5 mm.

Layer height

The maximum layer height can be set to 70% of the nozzle diameter. The minimum depends on the capabilities of your printer, but too low values may paradoxically result in worse printing of some details, depending on temperature, print speed, polymer type, cooling power, etc. It will also increase the printing time. The optimum value for a 0.4 mm nozzle is a layer height of 0.2 mm and an extrusion of 0.5 mm.

Print speed

Print speed is, in my opinion, a completely overrated element. The most common question I get asked about my printers is "How fast does it print?".

This cannot be answered unequivocally because again there are multiple contexts. I will list a few key ones here:

  1. Firmware - yes it does, this aspect matters too. The most famous are Repetier, Marlin, Klipper, RepRap, Smoothieware. In terms of print speed, Klipper is the best, and has some great features for achieving quality printing at high speeds. Then there's Marlin, Smoothieware and Repetier.
  2. Printer mechanics - here again there are more elements. Weight of moving parts, type of guides (rails, bars,..), belt tension and quality, driver settings for motors, and more.
  3. Extruder and hotend power - for higher speeds, a sufficiently powerful heater is required (40W or more, 80W or 2x 50W kits are made). This is necessary to sufficiently melt the polymer in the hotend nozzle. If not sufficient, there will be scrubbing of the print, which will not be usable.
  4. Printed object - the shape and size of the printed object are important to allow the print time to set before the next layer is applied or to avoid loss of detail. A large print slowdown for smaller or detailed objects is not a good solution here, as it should be associated with a change in fusing temperature of the filament, where there is of course a large inertia.

Based on these findings, I have come to the decision that print speed is not that important to me. It is better to wait a bit, and have a good quality and detailed print. To maintain a constant nozzle pressure, which fluctuates quite a bit during changes in print direction, I print between 50 and 80 mm/sec, with 300 mm/sec shifts. I have a delta printer, E3D V6 extruder.

So when is it a good idea to use high speed printing?

If you print mostly large and simple objects. It is good to know the limits of your printer. For optimum performance it is advisable to fit a sufficiently sized hotend and a larger nozzle diameter. For example, E3D offers the powerful Volcano and Super Volcano hotends, Slice Engineering - Mosquito Magnum, and others. Suitable nozzle diameters for these hotends are e.g. 0.8 mm and higher.

The technology of 3D printing of polymers is a very extensive field, experience in it must be accumulated through practice, testing and experimentation. However, theoretical knowledge is also very important for the user to be able to use the potential of his printer to the maximum. I have made this short guide to help beginner users avoid basic mistakes and causes of problems during printing. I will be expanding this guide as time goes on.

Luboš Hort