I made an extendo-glove like in the cartoons! Here's how I did it:

Step 1: Materials

You can make these as long or short as you want. I went with 4 sections (including handles), with each length of wood at 14". this was the material I had on hand, but any length of wood works as long as each segment is the same. An additional piece is required for the sliders and I used 2 more for the glove attachment, though plywood could work for the latter.

(12) pieces 14" length 1" x 2" (I used pine, was what I had).

(11) 2" long 1/4" bolts

(1) 3" long 1/4" bolt

(36) 1/4" washers

(24) 1/4" nuts

(2) 1" long screws

Boxing Glove

Wadding (I used a t-shirt) and duct tape (it's a prototype)

Step 2: Drilling and Routing

I Drilled 1/4" holes at 1", 7", and 13" on the interior segments of wood. The handles can be done without the 13" hole.

I then drilled 1/4" holes at 1", 4", 10", and 13" for the sliding segment. I used a table router to connect the holes into 2 slots as shown in the photos.

Step 3: Piece It Together

Each hole takes a bolt, 3 washers, and 2 nuts. One slot on the sliding segment takes a 2" bolt, 3 washers, and 2 nuts, and the other segment takes a 3" bolt, 3 washers, and 2 nuts. I cut an additional spacer of wood between the lattice segment and the sliding segment due to the lattice offset. Loctite or similar will help the nuts to stay in place. The nuts should not be too tight or else you wont get any motion.

I cut two pieces of the 1" x 2" to length to fit into the boxing glove and poke out just enough to attach to the sliding segment. This length will vary depending on your boxing glove.

To secure the glove I wrapped a t-shirt around the wood segments with duct tape. There are better ways to do this but this is my prototype.