Flanges

i know there is an auto matic one but i have a mac. is there anyway to put them in manually?

Yeah, you can either find some 3ds Flanges and hand place them, or you can place 2 support nodes next to each other over the existing support and connect them with a tube one size bigger than the support they're going on. Although it would be easier to send your track to someone with a normal PC and ask them to do it for you, it only takes ten seconds..