A Print-in-Place Battleship with Gun Turrets that rotate once broken free after printing. At standard size the Battleship is 11cm long. They print in approx. 90 minutes on a Replicator 2 and 2 hours on a 5th Generation Replicator (Uses 24gm of filament).
This print has been tested on a Replicator 2 / 5th Generation Replicator and Z18 so should print well on most machines with PLA and a filament fan. Getting a great result with ABS may be more challenging due to to the low angle of the gun barrels (60 degrees from vertical... PLA machines with a filament fan can print out on more extreme angles than machines with ABS and/or no filament fan). .
However, the fine clearances required may also be a challenge for other machines/slicing applications. If your prints are stuck together and the Gun Turrets will not free to spin/rotate after gently wriggling them from side to side to break them free, try increasing the scale uniformly as this will increase the internal clearances.
Print-in-Place models are popular because they are a one piece print with moving parts that are built inside each other. This is another great example... print one or a whole fleet!
UPDATE: A version with fixed turrets (Refer 'Fixed' .stl file) has been added for anyone who experiencing difficulties with the turrets moving during printing. This could be caused by the slicing application and/or machine not dealing with the detail as is required to get the turrets to print well and break away the internal support easily post printing with a gentle twist of the turret.
PLEASE READ THE INSTRUCTIONS BEFORE PRINTING
Note: If you like this check out all my other designs!
As this has internal moving parts that need to be strong I recommend using 4 shells and 30% fill as a minimum. Use Raft but No Support is required.
On a well set up/accurate machine the Gun Turrets should break away relatively easily by pushing/wriggling them from side to side until they crack free. Twist/rotate a few times until they rotate freely.
If the Gun Turrets do not break free increase the scale uniformly by a few 3 - 5% which will increase the internal clearances.
In summary this prints well as follows:
PLA / Raft / 0.20 Std. Resolution / 4 Shells / 30% infill / No Support