Introduction: Halloween Helping Hand

Let's give COVID the finger!

I just got my first 3D printer a few weeks ago, and I am addicted! Of course the first thing you do is browse Thingiverse or Cults to find awesome things to print, and if you are looking by popularity you will invariably find a slew of helping hands for hands-free pushing of buttons and opening of doors. October is almost upon us, and my family LOVES Halloween...especially my 2 youngest who are not really that young going in to 9th and 11th grades. I started looking for Halloween themed things, and was surprised there were not really many themed designs for these, so I took up the learning curve to design my own!

Supplies

Here is what I used in this adventure:

*Note that the paint is optional...I will probably print more of these using the correct color PLA, then jump to the nail polish.

And for the design element:

  • Tinkercad for the basic design...this recent Instructable was wonderful and opened my eyes to the creative combining and subtracting of simple shapes to do really complex things
  • Vectornator for iPad to create vector art of the skeleton detail to import into Tinkercad
  • Cura for slicing the exported .stl from Tinkercad to run on the printer

Step 1: Design

Not gonna go too in depth here, mainly because I didn't do this project with an Instructable in mind, so I didn't really capture much for in process details, but here is the high level:

  1. Since I wasn't reinventing the wheel, I grabbed a few existing designs from Thingiverse and imported them in to Tinkercad to get the basic size and ergonomics right, then blocked out those elements in my own blank slab.
  2. I wanted to a skeleton hand with a hooked finger, so I found some clip-art of a pointing skeleton hand, thinking since it was an .svg it would be easy to import straight in to Tinkercad...nope. To create a real vector drawing I used Vectornator on my iPad with a stylus. I imported the clip-art as the base layer, then added a layer for each part I wanted to have independent control over to form my model. The result is the included .svg files...one for the closed part of the hand, and the distal, middle, and proximal phalanges.
  3. I imported the .svg files in to Tinkercad, positioned and scaled everything to fit the critical hole and hook, then through creative use of basic shapes carved it out to the overall shape I wanted. The included .stl file is the result of my efforts.

Step 2: Printing

Using your slicer of choice (mine is Cura), load up the .stl on your build plate and use your optimal settings to slice it and create the .gcode file. Here are the basic settings I used on my Mega Zero/SunLu gray PLA...you will likely need to tweak for your printer/material.

  • Layer Height: 0.2mm
  • Infill: 25% using cubic subdivision
  • Supports: Yes
  • Adhesion: Whatever's best for your printer/material

If you are still with me, then you probably know about the thrill of watching your print grow...not much excitement for a few hours. Take a nap, then grab your finished print and clean it up!

Step 3: Finishing

I have to admit my wife (littlebadwren) kind of pushed me out of the way at this point. I was talking about how I could change filament during the print to get white bones on a black base, and she was like "just paint it and be done!"

So what she did was the following (sorry, did not get any pics, but I am sure you can see it all in your minds):

  1. Sanded the base part with fine-grit sandpaper to remove major inconsistencies
  2. Applied the spray primer-filler...I did get to do this part because littlebadwren does not understand why spray paint instructions are so particular
  3. Sanded cured primer with fine-grit sandpaper to smooth things up
  4. Applied orange spray paint
  5. Applied white nail polish to bones after orange paint cured

Step 4: Use

My family was excited to have these in a cool Halloween theme! They work great for opening fridges and getting ice...let's thank my hand model littlebadwren!