PLA gymnastic rings

thingiverse

2019/oct update: 1 year later, I still use it to exercise routinely, many times with 10 to 15kg extra and they are still not showing any sign of danger. Exposed to the sun and rain all this time. Gymnastic rings are kind of expensive around here, so I decided to see if I could print a very strong of my own. For that I put concentric rings inside the print. They ensure that the pieces has a LOT more strength than it would with just regular infill, since they define the direction of the print with the shell of each ring. I tested so far doing 12 pullups on 77kg (67kg + 10kg belt https://i.imgur.com/qB0OMKo.mp4 video of it) using one ring. Normally you should use one ring for each arm, thus not exceeding maybe 50kg for each ring. I can't guarantee it will work with more weights but I will test. The shape is what I assumed it would be a safer shape for plastic. However I will make a new shape as this constricts my arm movements. It is so strong that I think I can have more liberty. I included the gcode just so people can see how I printed. I printed with supports just for that extra toughness and make sure the top layers don't become weak because they fell down a little, but I think I may just have wasted filament. I printed with 4 layers of infill and 120% flow, again for extra toughness but I think it might also be waste of material and overkill. Anwyay I'm open for suggestions from any engineer out there. The objective is just to be able to do body weight exercise, nothing crazy, and be as cheap as possible. After all, if it's expensive it's better to buy the $20 wooden ring which is proven to work. Thanks for any advice.