Introduction: Quick & Dirty: Negative Battery Terminal Block for LED Hula Hoop

About: Sprite of all trades and master mischief maker. I love to tinker and it shows. STEAM proponent. Open Source lover. LED fanatic. \m/

This guide is for the everyday hooper that has a large diameter LED hoop and would like to downsize it and/or re-tube it. The materials used are items that I feel like are easily accessible and affordable for everyone.

The LED hoops I build daily have a custom designed negative terminal block that is 3D printed at my local makerspace. If you prefer a more polished terminal block, I carry them in my webstore.

A quick shoutout to Scott with Hyperion 3D printed block design is based off of his. He was kind enough to share his design with me and I tweaked a few things in order for it to work well with my process. If you are new to 3D printing, stop by OnShape and learn how to design your own items. It's free and cloud based!

Step 1: Material and Tools.

- 1/2" poplar dowel rod. (This is for a 3/4" hoop. You may need a smaller size if you are downsizing to smaller than 3/4" tubing.)

- Something to cut the dowel with.

- AA size spring. (The spring used in the photo is Digikey part # 36-211-ND.)

- Small flat philips screw. (The screw pictured is a #4 x 1/2" wood screw.)

- Phillips heads screwdriver.

- Approximately 7" of smaller tubing for the sleeve and the connector. (I used 5/8" for this one due to the hoop being 3/4". You would use 1/2" for 5/8" tubing and 3/4" for 7/8" tubing.)

Pardon the photos. I will work towards improving them! :-)

Step 2: Cut Dowel and Sleeve.

You need about 3/4"-1" of dowel rod for each terminal block and 1"-1 1/4" of tubing for the terminal sleeve. Not need for military like precision. Just eyeball it and make sure it is about 1/4" shorter than your sleeve piece.

Step 3: Prep Your Spring.

Take your screw and insert the tip between the bottom rings of the spring and guide it into the small circle at the bottom center of the spring.

Take a screwdriver and screw it down into the small circle until the head is flush with the base of the spring.

Step 4: Whittle Your Block.

Take your preferred device for cutting and shave down the dowel to have one side flattened out.

Next, take the screw/spring combo and insert the screw tip into the center of the dowel you just shaved. Push on the screw with your thumb to make an indention for an easier start. Use a screwdriver to run the head of the screw, to the top of the dowel rod.

Your end result should look similar to the photo.

Take your terminal block and practice fit it into your terminal sleeve (1" piece of smaller tubing).

You are now ready to proceed with my guide to downsize your LED hula hoop!