Initializing Precision Pipeline
SLICING_GEOMETRY // CALIBRATING_BUILD_CHAMBER
“Bringing Idea into Reality within Minutes”
SLICING_GEOMETRY // CALIBRATING_BUILD_CHAMBER
“Bringing Idea into Reality within Minutes”
Overhangs, wall thickness, bridging, clearances, holes, fillets, threads and infill — the eight things that decide whether a print works first time.
MetaFuse3D
Most failed prints fail for one of a small number of reasons, and all of them are design decisions made before the file reaches the machine. These eight rules cover the common ones.
Each layer has to rest on the one below it. Once a surface slopes further than roughly 45° from vertical, each layer is hanging out over air and needs support material underneath.
Supports work, but they leave marks where they touch. Designing chamfers and transitions at 45° or steeper lets the geometry support itself and come off the machine clean.
On FDM, a wall is built from whole extrusion widths. With a 0.4 mm nozzle, walls at 0.8 mm, 1.2 mm and 1.6 mm print as two, three and four clean perimeters. A wall at 0.9 mm forces the slicer to fudge it.
For resin, thin walls are limited by rigidity rather than extrusion width — around 1 mm for a solid wall, and more for a hollow shell, which also needs drain holes so uncured resin can escape.
Bridging is when the printer extrudes across open air between two anchor points. With good part cooling, short spans bridge cleanly; long ones sag in the middle.
Where a span is long, an arch, a teardrop ceiling or a set of supports will hold the geometry better than hoping.
Parts change size slightly as they cool or cure. Two surfaces modelled to touch at exactly 0.00 mm will not slide — they will bind, or fuse.
Build clearance into the CAD: a small offset for a press fit, more for a sliding fit, more again for a hinge or linkage. The right value depends on the material and the machine, so it is worth printing a test coupon rather than guessing on the real part.
If two printed parts have to move relative to each other, the gap between them has to exist in the CAD file. The machine will not add it for you.
Vertical holes in FDM print slightly small, because the extruded bead pulls inward on a curve. If a hole has to take a fastener or a pin, oversize it in CAD or plan to ream it after printing.
Horizontal holes have the opposite problem: the top of the circle is an unsupported bridge and sags. A teardrop or diamond profile keeps the opening round.
A fillet on the edge touching the build plate becomes an almost-horizontal overhang at the very first layer, which prints roughly.
A 45° chamfer in the same place prints cleanly and also helps with the slight bulge at the base — elephant’s foot — that squashed first layers produce.
Printed threads work for light clamping, but polymer threads strip if they are cycled repeatedly.
For anything that will be taken apart more than a few times, design a plain cylindrical pocket for a brass heat-set insert. The insert melts into place with a soldering iron and gives a metal thread in a printed part.
Fully solid infill is rarely needed. It costs time and material, and the internal stresses can warp the part.
A modest gyroid infill gives strength in all three directions and lets air and moisture move through the part, which is usually the better default.
Drop a file into ModelForge, configure colour and material with a live 3D preview, and order it printed on our machines.