Breaking supports during print

I’m trying to work out what i’ve done wrong.
I’m trying to print out the below. I’ve had 3 attempts that have all worked, but have had many more failed attempts.
My assumption is that it has something to do with the ball and the supports needed.
Can anyone offer some help on this one?
radiator rounded v3.stl (1.1 MB)

Printing standing up

Are you printing with any bed adhesion? That’s a lot of support material for those arms, I could see them being problematic.

When does it fail? Pictures of the failures will help. It’s a different problem if it fails before or after the arms are printed. If it’s before, and the print head is ripping the supports off the bed, a brim wide enough to connect all the supports should fix it. If it’s after, a brim could still help, or you might need to enable Retraction and Z Hop When Retracted.

[Edit to add] if the failure location is inconsistent, that points to something else.

@clewis I think you’re onto it with the brim.
It fails at about the same time every time. It starts the bottom of the ball at the end, and I think that motion pulls the support off the bed.
I don’t have any pictures of failures though, just testimony of my swearing when it happens.
I’ve had 3 prints work perfectly, but I must have fluked the support position and thickness for those ones.

Will brim this one up and see what happens today, but I think you’re on the money with it needing a brim. Thought of that after I posted yesterday afternoon.

Increasing the support size, brim, and using the z hop has got me a print that I wanted.
thanks for the heads up. Still learning, but great help.