To contribute the Clan chest, you can only get crowns on scale (normal matchmaking system), not Challenges, Tournaments or Friendly Battles.
The crowns you win on the scale contribute to both your regular crown chest and the Clan chest. For example, when you get 3 crowns, they will be added to both chests.
Clan chests are available at the beginning of each season. As always, each season lasts 2 weeks but you only have 7 days to fill the chests of the Clan. After 7 days, you can collect the rewards of the Clan Chest. Clan Chest can be opened immediately without any cool down. Clash Royale Hack Cheats
If you leave your clan for these 7 days, you will be put in recharge period. You will not receive any rewards from the Clan Chest until next season. Also, when you are on recharge time, your winning crowns do not contribute to the clan’s chest.
There are 10 levels of safes. You must collect 100 crowns to unlock the first level of the chest. After completing the first level, you can unlock the second level and so on.
There is a chest tab in each clan. In this tab you can see exactly who contributed and how much. Clash Royale Free Gems If you contribute 0 crown, you will not receive any Clan chest reward. However, if you contribute only 1 crown (YES ONE), you will get the full contents of the clan chest won by the other members.
Being in Arena 1 or Arena 10 does not affect the amount of cards you can get from the Clan Chest, but it limits the cards you can win. For example, if you are in Arena 3, you can not get Bowler from the Clan Chest. It takes 3250 crowns to unlock the final trunk, which means that if your Clan has 50 members, each member just needs to get less than 10 crowns per day, in 7 days.