Designing for 3D Printing

The 3D Print tab has what a part made on a 3D printer needs: features that add a nut pocket or a printable hole in a click or two, a check of the part against what the printer can do, and an export laid out on the printer's bed. Every size it uses comes from the part's print profile: a printer and a material.

Its buttons run left to right in the order you work: set up (profile, orientation), add features, check, export.

Print Profile

3D Print ▸ Print Profile picks the profile this part uses and edits your own. A profile holds:

Four profiles come with RazorCAD: PLA, PETG and ABS on a 0.4 mm nozzle, and a resin printer. They can't be changed: Copy… one and change the copy. Use for this part keeps the choice with the part (a copy of the profile is saved in the part file too); Make default is the profile for parts that have none. A change to one of your profiles applies to every part that uses it.

Printer sets the bed from a list of popular printers (Prusa MK4 / MK4S, CORE One, CORE One L, XL and MINI+; Bambu Lab A1 mini, A1, P1S, X1C and H2D; Creality Ender-3 V3 and K1 Max; Elegoo Neptune 4 Pro; Anycubic Kobra 3). Chosen on a starting profile, it makes a copy of it for that printer, used for this part. The Prusa sizes are from Prusa's own pages; the others are from retailers' and reviewers' listings, and the dialog says so when one is chosen: check them against your printer's specifications. Typing a bed size of your own clears the printer.

Slicer program (Windows app): Choose slicer program… picks the program Open in Slicer starts.

Place on Bed, Auto-Orient and Show Bed

The checks, the overhang map and the export all use the part's build orientation : which way up it prints. Until you set one, the part's biggest flat outside face lies on the bed.

• Place on Bed : select a flat face, then click it: that face goes down on the bed.
• Auto-Orient : tries the part with each of its outside flat faces down, and in the 26 directions of a cube's faces, edges and corners, and lists the best three: least support first, then the most on the bed, then the lowest. Use sets one.
• Show Bed : draws the printer's bed (a 10 mm grid) and its build volume under the part.

Features that depend on which way is up (Printable Hole, Bridging Layer, First-Layer Chamfer, Printable Overhangs) keep the orientation the part had when they were added.

Check Printability

Check Printability checks the solid bodies in their build orientation against the profile, numbers what it finds on the model, and lists it:

Below the list: the support it would need (an estimate: columns from each overhang down to the part or the bed), the part's volume, its mass in the profile's material, and the filament it takes. Where a print feature fixes what was found, a button starts it: Printable Overhangs, Split for Printing, Auto-Orient.

Overhang Map and Thickness Map

Overhang Map colours the model up its build direction: green fine (or on the bed), amber within 10° of the profile's overhang limit, red over it (needs support). Thickness Map colours walls red under 2 extrusion widths, green to yellow above. Click again to turn them off.

Nut Pocket

Nut Pocket makes a hex pocket for an ISO 4032 nut, with the screw's clearance hole through (ISO 273 normal fit; untick it to leave it out). Click points on a face, or pick a sketch with points: each gets one. The pocket is the nut's size plus the profile's clearance each side, as deep as the nut plus the clearance (or Pocket depth). Turn the flats by turns it.

Captive slot: the pocket starts Slot below the face inside the part and a slot as wide as the nut runs out sideways past the part's edge (Slot direction), to slide the nut in from the side.

Insert Hole

Insert Hole makes a hole for a threaded insert pressed or melted in (heat-set): the insert's hole diameter, as deep as the insert plus a Relief below it, with a lead-in Chamfer at the top. The sizes come from a table of typical inserts; makers' sizes differ, so check yours and type its Hole diameter and Insert length if they do.

Screw Hole for Plastic

Screw Hole for Plastic makes a pilot hole for a screw cut straight into the print: 0.85 × the screw's size (or a Pilot hole of your own), to a Depth, with a cap screw's Counterbore or a Countersink if wanted (ISO sizes).

Printable Hole

Printable Hole reshapes holes lying on their side so they print without support: their top comes to a 45° point up the build direction (a Teardrop), or the point is cut flat at the top of the hole. Every hole whose axis lies within Holes within this of level is changed, or click the holes to change only those.

Bridging Layer

Bridging Layer helps a counterbore or pocket printed upside down: the printer can't bridge round the smaller hole above it. Click the flat face round the hole (the counterbore's floor). Steps: that face is stepped up one layer at a time, first a strip as wide as the hole across the opening, then a square, so each layer bridges onto the one before. A skin: one layer closes the hole; drill it out after printing.

First-Layer Chamfer

First-Layer Chamfer chamfers every edge on the bed (0.4 mm to start), so the first layer, squashed wider, doesn't stick out.

Printable Overhangs

Printable Overhangs turns rounds facing down, up the build direction, into 45° chamfers of the same size, which print without support.

Fit Clearance

Fit Clearance moves the faces of a part that fit against another part back by a fit's gap: Press, Snug, Sliding or Loose from the profile, or a Gap of your own. A flat face moves in; a pin gets thinner and a hole wider, by the gap all round.

Print-in-Place Hinge

Print-in-Place Hinge makes a hinge that prints assembled. Click the straight edge it turns about: knuckles (Knuckle diameter) are spaced along it, the gap apart; the first, third… carry the Pin all along, the others are bored the gap wider all round and turn on it. Each set is a body of its own: join each to its part with Combine.

Split for Printing

Split for Printing cuts a part too big for the printer in two at a plane (choose a plane, or click a flat face), with Dowels across the cut: holes for dowels (Dowel diameter, the profile's snug fit each side, Hole depth each side), spaced along the cut's longest side and kept clear of its edges. Glue the halves on the dowels.

Export for Printing and Open in Slicer

Export for Printing writes the solid bodies as 3MF (it keeps millimetres and each body as its own object), turned into their build orientation, their lowest point on the bed, over the bed's middle. Export STL for Printing does the same as STL. Open in Slicer (Windows app) opens the last export, or a new one, in the slicer program named in Print Profile; RazorCAD only starts the program with the file.

Calibrate Fits

Calibrate Fits saves a test piece (3MF): a plate with four Ø6 holes and four pegs, 6 mm less twice the profile's press, snug, sliding and loose gaps, left to right. Print it, try the pegs in the holes, and set each fit to the gap of the peg that fitted that way. Save the fits keeps them in the profile (a starting profile: in a copy of it, used by this part).