Scalper with Blade

Bed Scraper with Quick-Change Blade

A parametric scraper for getting prints off the bed. It uses replaceable, double-edged blades that you print yourself. The blade slides into a pocket in the handle and clicks in place with a latch. It's angled slightly down so its tip sits level with the bottom of the handle, which means it scrapes whether you hold the handle flat or steep. When one edge goes dull, flip the blade over. When both are dull, print a new one.

Keep spare blades in the matching Scraper Blade Dispenser.

Parts

• Handle: a flat handle with a wide head, a top chamfer down to the blade, a grip with honeycomb cut-outs and an optional name on top.
• Blade: 45 × 20 × 1.6 mm with an edge on each long side. Each edge is bevelled down to a small flat so it prints cleanly, and the center window is what the latch catches.
• Name (optional): a separate solid for dual-colour printing, either inlaid flush or raised.

Blade edges

Each blade has two edges, and each one can be straight, serrated or scalloped. By default, edge A is straight and edge B is serrated, so one blade gives you both: flip it to switch. Turn on Flip blade to preview edge B sticking out.

How the latch works

A U-shaped slit in the pocket floor frees a springy tab with a small ramped bump on it. As the blade slides in, it pushes the tab down until the bump drops into the blade's window. To change blades, press the tab down from underneath and slide the blade out.

Printing

• Print both parts flat, as modelled.
• Print the blade on a smooth build plate. The side that touches the bed is the scraping side, so a smooth plate gives the sharpest edge.
• Use 0.2 mm layers, and a first-layer line width of at least 0.5 mm for the blade.
• PLA works for the handle. If your bed runs too hot for PLA, print the blades in PETG.
• The roof over the angled blade pocket slopes, so its underside prints as a series of bridges about 45 mm wide. Good bridging settings help it stay clean.
• Turn off Blade assembled under Layout to lay the blade out flat in front of the handle for printing.
• For a two-colour name, export the handle and the name together (3MF works well) and give each its own filament.

Customize it

Drag the handles in the viewport for the quick changes: blade width, blade exposure, head length, grip length, grip width and handle thickness. Every setting is also in the configurator:

• Blade: width, depth, thickness, bevel length, angle and how far the blade sticks out of the handle.
• Blade edges: the profile of each edge, plus tooth spacing and depth for serrated edges and scallop spacing and size for scalloped ones.
• Fit: clearance at the sides, top and back of the pocket. Tune these to your printer if blades are too tight or rattle.
• Latch: window size, tab width, slit width, bump height and bump clearance.
• Handle: head length, grip width and length, taper, thickness and the top chamfer.
• Grip pattern: honeycomb on or off, hex size, web width and the solid rim around it.
• Name: text, font, size, depth, position, rotation and style (engraved, inlaid or raised).

Some settings have limits so the scraper keeps working:

• Blade exposure is limited so the latch window stays inside the pocket. For more blade showing, make the blade deeper first.
• The blade angle can't be so shallow that the lip under the blade gets too thin, or so steep that the pocket breaks through the top.

Goes with: Scraper Blade Dispenser, a holder for 10 spare blades.

Inspired by ThreeD-Michael.