Fastest way to make chips

So I'm sitting at 49/50 beskar droids needed for the shipyard, and I need either a legendary beskar Opti-Strk or Mecha Droid. But even tho I'm running 6 minute missions constantly, I'm not having any luck. So I thought maybe my only way to get them is buying a legendary and upgrading it with chips. But that costs 12k chips and I never had anything close to that. Rn I'm just building and selling decent droids for the chips, but it's taking forever.