bang off

verb3

1. •
   (informal) To fire (a weapon or a shot); to ejaculate.
2. •
   (informal) To typewrite quickly.

   • I banged off a letter of complaint to the local newspaper.
3. •
   Of an automated loom: to have the shuttle fail to follow its intended path and bang against other parts of the loom.

   • If you use our waterproof bobbins you don't have any looms banging off because of filling yarn breaking on splintered, cracked and split bobbins. — 1915