Disposable Paper Towel Paint Brush Device - Improved (Two Versions)

This is a re-mix of my original brush at the link below. I have used these brushes frequently in my shop, and found them to be very useful. The original design works well, but when I designed it I was new to both CAD and 3D printing - now that I have more experience I was able to create a similar design that has only two pieces instead of three, prints in half the time of the original, and uses less filament. Her is the link to the original design:

https://www.printables.com/model/40484-disposable-paper-towel-paint-brush-device

About the Brush

Sometimes when I need to paint or stain a small area I find it easier to use a small piece of rolled up paper towel as a "brush" - simple and easy to make and just toss it when you're done. Unfortunately the rolled up towel is not very stiff, and it also easy to get paint or stain on your hands.

This print is designed to make it easy and convenient to both make and use a "paper towel paint-brush." There are two parts to the print:

• Handle (with tang): The main part of the brush holder; the tang section adds “stiffness” to the paper towel.
• Collar : Slips around the paper towel on the tang and holds it in place with simple pressure.

The Two Versions

The “short tang” version is a simplified form of my original brush design, which I have used successfully.

The second “long tang” version is somewhat experimental -I have lengthened and tapered (in thickness) the “tang” which supports the paper towel brush. I believe this version will produce a somewhat stiffer brush, but I have not yet tried it out.

How to use (also, see photos) :

• Start with a sheet of paper towel in "standard" size - the paper towel rolls I purchase have sheets that measure 27.9cm x 25.9cm.
• Cut the paper towel sheet into quarters; each quarter will make one “brush.”
• Fold the quarter sheet in half, and with the folded edge toward the handle, wrap it around the tang.
• Slip the collar over the wrapped paper towel (from the tang end) and slide it onto the tang until it grips the paper towel firmly.

You can also take a scissors and cut some slits into the end of the "brush" to make "bristles" (just don't cut into the tang!), although this is not strictly necessary.

Use the brush like a regular paintbrush. When you're done, just remove the used paper towel and throw it away, and you're ready for a new brush. At around 12¢(US) each, it's cheap enough to print half a dozen or so and keep them around for those small paint jobs that crop up from time to time.

Some caveats : I have used paper towel brushes (before I made this holder) for latex paint, oil based paint, polyurethane, and for stains with good results, but the paper towel does not hold up well for large areas, and tends to wear quickly on rough surfaces. The paper towel can also shed paper fibers which may be a problem for some applications.

In the photos for the original version you can see how I used the brush to apply polyurethane finish to some wooden drawer fronts.

Print instructions

Print all three parts at once in PLA using the 3mf file provided; otherwise :

• infill 10% grid
• perimeters = 2
• 0.2mm layer height

I printed on a smooth build plate and did not find it necessary to use a brim.

CAD

The OnShape 3D CAD files for this are here :

https://cad.onshape.com/documents/95a85e69235547417b71a308/w/cdef00a78fe7ae6a4d0c782a/e/9dba126e6160428e0f2628d2