my thorfire s70s has this wried dimple dead center on the LED shelf, i am not sure the purpose of this design, but it seems counter intuitive for a efficient thermal path, please advise.
Hmm must be from machining
Correct. Typically a hole is drilled with a regular drill bit and then finished with a boring bit. That dimple is an indicator that the hole was drilled a bit too far before the flat was machined. More care in the machining process needs to be taken to prevent that dimple from showing up.
thanks for the information. is there any way i can fix this?
Well air is an insulator so filling it could help (but probably not a real big difference)
And almost anything is better then air so if I wanted to fix it I would probably put some JB weld in there
But if I saw something like this I would probably just smear some thermal grease in it and be happy, it is a small dimple and the larger ledboard on the shelf would still be good enough for me.
I don’t think a small dimple like that makes any significant difference.
I upgraded the s70 to direct drive, so 12A on turbo it shifted tint, figure any little bit will help. thanks for the advice, I filled the dimple with thermal expoxy.
here I sanded the epoxy flat. Didn’t see any noticeable improvement on shifting tint while in 12A turbo 
