I made all kinds of work out equipment for my son.
1. Rice bucket: To me the 5 gal rice bucket is one of the most effective methods of building the forearms and wrists. I would place money in the bottom from time to time to make it "rewarding". Keep lid on bucket to avoid spills and critters.
2. Weights on a broomstick windlass: Use a broomstick with about 4ft of strong 1/4 inch nylon rope and "wind" the weights up and down with your hands. (about 5 lbs)
3. Ball/rope/pulleys/weights: Sounds complicated but really isn't. I drilled a 1/2" hole in a baseball, glued a 1/4 nylon rope in the hole and attached two pulleys to the ceiling of my basement. One pulley in the center of the room and one where the wall and the ceiling meet. The rope would go thru the pulleys and on the other end of the rope I attached a 5 lb (I think) lead weight (plumbers lead). I then attached 6' of 4" PVC pipe (capped off on the bottom) to the wall directly below the pulley where the wall and ceiling join. I placed about 3 inches of sand in the bottom of the PVC to deaden the sound as the lead went to the bottom of the PVC pipe. My son could then go thru the throwing motion (slowly) holding the ball (which pulled the rope) with the lead weight being pulled up via the pulley system --- I know you
at the contraption but his velocity peaked at 94 mph.
4: Pull up bar: I have 10ft ceilings in my basement that allowed a 1 1/2 inch galvanized pipe used for full range pull-ups.
5: Hitting/pitching net: I installed a net that covered one room in the basement floor to ceiling and wall to wall. Winter or summer it got a lot of use for the soft toss hitting and/or throwing into the net. I could also raise the garage door and he could throw from a greater distance from outside into the basement net.
Fungo