Ratchet ScratchIt

Scratching an Itch is important to all of us, so I have designed this modular extendable Scratcher with changeable ScratchIt attachments. When closed it is 225mm long, and when extended fully, 370mm.

The Pyramids attachment is for larger areas, like the back, whilst The Claw is for that one persistant itch. The Shards are for areas of chronic itching (eg. from Peripheral Neuropathy) where constant scratching inflames and damages the skin. These are pointy enough to give some relief without scraping the skin.

New Bonus Attachment! I've added The Palm Grip, designed to be used with The Shards whilst in your Palm. This will be good for people with limited grip strength as well as being quick and convenient for sensitive areas.

Printing

I strongly recommend using PLA+ for most of the parts - standard PLA is prone to snapping and layer separation when stressed. Printing on a mix of Creality K1C, Ender-3 V3 and Ender-3 V3 Plus, here are the materials and print settings I used, all in Orca Slicer (similar should be available in Orca-like Slicers eg. Prusa, Bambu, Creality 5.0+):

Frame

• eSun Silk Silver PLA+ (the Silk weakens it a little - I may reprint with a non-SIlk)
• 0.16mm Layer Height
• 4 layers Wall/Top/Bottom with Concentric Surface
• 15% 3D Honeycomb Infill

Rod

• Jayo Black PLA+
• 0.20mm Layer Height
• 3 layers Wall/Top/Bottom with Concentric Surface
• 10% 3D Honeycomb Infill
• A smail amount of support - see image: Normal(manual), Snug, 0.2mm Top Interface Spacing
   
• 

Handle

• Whatever you please. Tested with eSun PLA+ and Overture Sedimentary Rock PLA - there is a separate model if you want a TPU handle (different tolerances, similar settings)
• 0.20mm Layer Height
• 3 layers Wall/Top/Bottom with Concentric Surface
• 10% Honeycomb Infill
• Seam Position: Nearest
• Scarf Joint Seam: Contour and Hole, 20mm Length, 10 Steps
• Fuzzy Skin is a really nice effect, if you have it I suggest you try it: Contour, 0.8mm Point Distance, 0.2mm Thickness

The Grip

• Jayo Grey PLA+
• 0.20mm Layer Height
• 3 layers Wall/Top/Bottom with Concentric Surface
• 10% 3D Honeycomb Infill
• A smail amount of support - see image: Normal(manual), Snug, 0.2mm Top Interface Spacing, 1mm Support/Object XY Distance
   
• 

The Shards

• Jayo/Sunlu Wood-Style PLA+
• 0.20 Layer Height
• 3 layers Wall/Top/Bottom with Concentric Surface
• 10% Support Cubic Infill
• I recommend using an Inner+Outer brim and some bed adhesive for this

The Pyramids

• eSun Fire Engine Red PLA+
• 0.20mm Layer Height
• 3 layers Wall/Top/Bottom with Concentric Surface
• 10% Honeycomb Infill
• Variable Layer Height: Adaptive, 0.5

The Claw

• eSun Pine Green PLA+
• 0.20mm Layer Height
• 4 layers Wall/Top/Bottom with Concentric Surface
• 15% 3D Honeycomb Infill
• Variable Layer Height: Adaptive, 0.5

The Palm Grip

• eSun Dark Yellow PLA+
• 0.20mm Layer Height
• 3 layers Wall/Top/Bottom with Concentric Surface
• 10% 3D Honeycomb Infill
• Print as oriented to avoid support, but do use a brim and perhaps some bed adhesive

Post Printing and Assembly

First take the Rod and, holding the clipped end, work it in and out of the Frame, rotating it each time - you should end up with the Rod moving freely, if snugly. Turn the Rod around and do the same carefully, initially pinching the clip pins together, aligned with the Frame's ratchet holes.

Test each of the ScratchIt attachments in the end of the Rod, they should snap in all four ways around.

Do some fine sanding on the tips of The Pyramids and The Claw, to fully round off the edges. At a minimum, rub some discarded PLA against them, or try my PLA Polishers. You don't want burrs and sharp bits against your skin!

Stretch The Grips a little to put The Shards in place.

Finally add the Handle (might need a little glue, try it and see), and we're done!

By the way, the Ratcheting makes a great sound!

If you like this model, then please:

EdinBearDragon