So i got my sentinel from madvapes , and its a really nice mod... When it works. I have had so much trouble with this mod, i have sanded down the contacts like 5 times allready but it will work anywhere from a few hours, to a few days, then it will only fire hard if i turn the button when im hitting it till i can feel that its hitting hard. I clean the contacts like crazy, and ive cleaned the whole mod once allready, but i cant figure it out. I cant keep sanding down the negative contact because ive sanded it so much theres about a 35 gauge kanthal wire sized hole in it... I really dont know what to do about this mod, plus my 510 threading is getting a bit loose. What can i do to fix the connection issues for atleast say, 4 days, before i have to fix it again?