Doing my favorite kind of project. We have a Japanese massage chair that my wife's late mother purchased 20 years ago. When she passed away nobody else wanted it so we took it. Being Japanese it's not a big chair but it's built like a brick and has been helping my bad back (and my wife's) for ~10 years. It kind of an heirloom now and every time we use it it's hard not to remember her mom. Anyway in the last 3 months something broke. It still worked but there was crunching and clunking that didn't use to happen. It seemed pretty clear the chair was dying. We can afford a new chair and no doubt it'll be way better with more features but it wouldn't be her mom's chair. Well today I decided to have at it. Took it apart relatively easily and found that all the rubber coating on the massage wheels had completely crumbled away. Also there were 4 idler gears/wheels that followed rails that had a rubber coating that had completely let go.
Started by modeling and printing the 4 idler roller/gears in black nylon. This was tricky since the old gears were so blown out I didn't have much of an example to follow. I was plowing ahead and didn't take a pic of the idler before I installed it.
Took a couple adjustments but they fits perfectly. Hard to see but the red arrows point at the front pair. The others are on the far side of the assembly. I was fortunate they used such good material for the rails since they didn't have a mark on em. Just clean out the chips of all the other plastic. Yea crap pic I know but here's a LINK TO A HI RES VERSION
The yellow arrows point at the massage wheels. Those are what press on your back when you lean on it. They had a rubber coating that had crumbled off. It was so thin it didn't provide much cushion so I'm just going to print the wheels in solid nylon. They're printing right now. Got about 19 hours to go since I'm doing them very dense.
This is going way better than I anticipated when I tore the chair apart. I expected to be disappointed by total carnage and not just some gears and wheels. Pretty confident I'll be back in mom's chair here pretty soon.