In order to help you with the preparation of model for the printing process, we created design guidelines considering our printing technology. There are recommended and minimum values in the guidelines. The latter are possible to achieve, but usually will have a negative impact on the print quality. The guidelines concern printing from PLA, ABS and PETG. Restrictions for TPU are bigger.
The guidelines are important for you especially, if you need a precisely made part, e. g. part, which must fit to another part.
Please keep in mind, that thermo-plastics shrink a bit in the printing process, therefore the printed object will always be slightly smaller than computer model. PLA and PETG have the lowest shrinkage. It’s below 1 %. ABS has higher shrinkage.
SIZE OF A PRINTED OBJECT
Maximum size of a printed object: 500 x 300 x 300 mm.
Larger elements can be printed in parts and then combined.
Recommended value: x ≥ 1 mm
Minimum value: x = 0,5 mm
Possible deviation from nominal dimention is ± 0,2 mm, and for thin walls even +0,3 mm. Deviation depends on wall thickness, nozzle size and filament type.
The thinner the wall, the higher risk of wall getting warped and higher relative deviation from nominal dimention (because of deformation of extruded strand of material and the Barrus effect).
ANGLE OF DIAGONAL OVERHANG
Recommended value: x ≥ 35°
Minimum value: x = 20°
Printing of overhang below 35° will cause the deformation of the lower surface of the overhang (visible, uneven strands of material, decrease of print precision).
The lower the layer height and bigger nozzle size, the better is the quality of the overhang.
Sometimes we can avoid the problem with overhang, by rotating the object during preparation of print.
WIDTH OF HORIZONTAL OVERHANG
Recommended value: x ≤ 0,8 mm
Maximum value without support structures: 1,2 mm. In this case single strands of material will probably deform.
Above 1,2 mm there is a necessity to use support structures and there is no limit of the overhang width. The bottom surface of the overhang will be deformed.
DIAMETER/WIDTH OF A HOLE
Recommended value: x ≥ 2 mm
Dimentions of holes in printed parts are smaller by 0,2 – 0,3 mm from the nominal dimentions. The smaller the hole, the higher the risk of disappearance of hole in the printed part. It is possible to print a hole with a 0,7 mm diameter, but it should have about 1 mm in the computer model.
DIAMETER/WIDTH OF A PILLAR
x ≥ 1,2 mm for pillars with height h ≤ 10 mm
x ≥ 3 mm for pillars with height 10 < h ≤ 30 mm
x ≥ 5 mm for pillars with height h > 30 mm
The above values are approximate. Please keep in mind, that the thinner and higher is the pillar, the lower is its strength and worse appearance.
SIZE OF CONVEX LETTERS AND GRAPHICS
Recommended value: x ≥ 0,4 mm
Minimum value: x = 0,3 mm
Recommended value: h ≥ 0,2 mm
Minimum value: h = 0,1 mm
Using values lower than recommended may worsen the readability of text and graphics.
SIZE OF CONCAVE LETTERS AND GRAPHICS
Recommended value: x ≥ 0,5 mm
Minimum value: x = 0,4 mm
Recommended value: x ≥ 0,2 mm
Minimum value: x = 0,1 mm
Using values lower than recommended may worsen the readability of text and graphics. Dimentions of concave letters and graphics are smaller by 0,2 – 0,3 mm from nominal dimentions.
CLEARANCE BETWEEN COOPERATING ELEMENTS
Recommended value: x ≥ 0,2 mm for each side.
The clearance is necessary, because of the decrease of size of holes and other print inaccuracies.