Noob needs help making money

I started playing spiral knights about a week ago *starts dancing* and i really enjoy it so far. I have all 3-star equipment but there's a slight problem. I never get enough orbs from the missions to make the parts i need, so I've ended up grinding the arcade for some hard-earned crowns. it's really frustrating the way I have to earn 21k for 3 orbs and I would really appreciate it if someone could tell me an easier way to make money.

Thanks