Aerodynamic Tuft Making Jig

This is a jig designed to print on a Prusa MK4 for turning kapton tape and sewing thread into identically sized, precisely spaced tufts for aerodynamic testing. The spacing is adjustable but may cause some issues in the Solidworks recompile so adjust at your own risk. The one uploaded here allows for tuft spacing in 1/2 inch or 12.7 mm increments. The length can be adjusted by mounting the larger tap block and smaller sizing block further apart. The mounting holes are designed to allow multiple units to be lined up on a standard 1 inch optical table use. A future version will be configurable using OnShape whenever I get around to doing that.

I use Isacord's Texlight Glow in the Dark Thread to do fluorescent tufting but any similar weight thread will work.  

See it in action in the recent LinusTechTips video!

Instructions for Use:

1. Print both blocks from the included 3mf file. I used the default 0.4 nozzle speed profile on a Prusa MK4S. So any similarly sized 3D printer will do.

2. Mount the two blocks to an optical table or similar 1inch spaced, 1/4-20 or M6 rigid surface. Adjust the spacing between the larger tape block and smaller sizing block to get the length of tuft desired.

3. Print and mount additional blocks to produce strips longer than possible with a single block. The 1/2in (12.7 mm) spacing is preserved when combining blocks.

4. Securing the thread at one end with a finger or some tape. Start wrapping the thread around each block. Alternating between the tape block and the sizing block. Skip some pegs as necessary to achieve the desired spacing.

5. Apply just enough tension to keep the string taught but not under load on the jig. Apply too much tension and the tufts will likely curl or pop off of the tape.

6. Still holding the string in place. Tape over the flat portion of the taping jig with your chosen tape. I recommend Kapton tape since it is thin and doesn't leave residue on your model. However, any relatively thin tape will do.

7. Run your finger over the tape to ensure it is well stuck down and tightly placed over each thread.

8. Take a razor blade and run it along the grooves along the length of each block to cut the tufts to size.

9. I recommend cutting on the smaller sizing block first, then the tape block.

10. Carefully remove the tape with attached tufts from the block and apply to the aerodynamic model under test. 

11. Be careful when peeling up the tape to press down on the tufts so they stay attached. Static forces may provide some sticking to the jig depending on your climate and the tape used.

12. Blow Air.