Barrel Grinder
Overview
A Barrel Grinder is a building used to grind certain metals (silver and aluminum) into powder. The grinding process takes time and Endurance, and is usually done by a group.
Once started, the Barrel Grinder begins turning. It must be rewound regularly (every 15-20 seconds, roughly) or it will stop turning, requiring a repair cost of 4 leather and 4 oil to restart.
Source
This building becomes available after you have learned the Pyrotechnic Mortar Construction tech at a University of Art and Music.
Cost
Built inside a compound.
Use
The grinder can be loaded with up to 100 Silver or Aluminum metal.
The grinder must be repaired before starting. This requires 4 leather and 4 oil. You then wind the spring and it will grind for 20 secs. If you or someone else winds again in this time period, the timer resets to 20 secs. If the 20-second window is missed, the grinder breaks and must be repaired again before winding can resume. Additional metal can be added to the grinder while it is grinding.
Since winding has an Endurance timer of 120 secs, you need a team, good food and a method to synchronize team members. Endurance of +21 should allow 2 people to wind every 15 seconds. Endurance of +36 allows solo grinding.
10 Silver Powder or 10 Aluminum Powder is produced from 1 metal every 15 seconds and can be used as a timer if your food permits.
Expert tip
From earlier tales: Because a message in a chat bubble remains on screen for 15 teppy seconds, this is the ideal way to time your 'wind' actions. Working with 3 people, with just 9 End I was able to run a grinder indefinately using this (plus about 2 seconds real time) as our guide. ~Juspar