The model is a hollowed sphere. Make sure that you print it using PLA (Polylactic acid) and it is a Solid Print.
Turning_Point_Ball(mm).zip (45.7 KB)
so this ball is the same size with near accurate weight?
Yes
No PLA?
yes xD. My bad xD
Can’t edit now for some reason xD
For the record, posts cannot be edited after 24 hours. I’ve got you covered though. 
xD
The print came out fairly accureatly
It is supposed to be 3in in diameter and 0.12lb according to the game manual
so I looked up the the specs on the ball. its suppose to be 55g +/-10. That’s a 18% tolerance and could amount to as much as a 36% swing from ball to ball.
How is that an acceptable tolerance for a plastic part?
For reference the 335g cap has the same tolerance.
Considering the fact that the density different from manufacturer to manufacture and the fact that that we have 3 failed print before this. I would consider this as the best we could do for now. We are using the ball mostly for size fiting, not for projectile testing. If that is the case, we also have to account for the surface friction of the ball.
If you’re planning on using the 3D printed balls for just size fitting, why not simply buy the VEX IQ Bankshot balls while they last 
. To make sure that I get the Bankshot balls to be the same weight as the ones for Turning Point, I opened them by the crease with a knife, then glued small pieces of plastic which is distributed evenly inside of the ball, then glued the balls back together. It worked better than I expected, and I should be prototyping some time next week (Which I may be posting a video of the bot when finished, but only if I feel like I am fine with it).
But anyways, that’s a really nice attempt at printing a ball with an acceptable density for prototyping.
- [TVA]Connor 1814D
Your 3D printed Part is fine. The fact you got it inside of the 18% is commendable.
I’m talking about Vex’s loose tolerances on the official product. Even if the part is blow molded it aught to be tighter than that.