A few notes from Dr. Gears himself (No not me, I mean THE Cog):

SCP-914 was not designed as an industrial device. Nor was it primarily a scientific device. Its primary function appears to be as a form of entertainment. After review of the recovery notes, and evaluation of the test logs, it appears that SCP-914 was designed to create the most “novel” items possible, with no regard for practicality or function.

When entering a small pile of parts for a clock on a 1:1 setting, you will most likely get a clock. If you enter blocks of wood, glass, and metal, it leaves a wide degree of room for “interpretation” by SCP-914, with a clock only one of many possible outcomes. If you desire to create a human being with, say, metallic skin, then the best plan would be to create a “suit” of the metal in the exact dimensions of the intended subject, and the same thickness as the subject’s skin. At that point, a setting of 1:1 or Fine may achieve the desired result.

However, there is a high degree of randomness still associated with SCP-914. Patience must be maintained, as it is not being used for its intended purpose, and thus may frustrate attempts to achieve a desired result. A short review of settings, as well:

• Rough: Destruction of the item, often by pressure, heat, or cutting.
  
• Coarse: Disassembly of the item into component parts.
  
• 1:1: Direct integration of multiple items, or “re-interpretation” of singular items.
  
• Fine: Refinement of items, often with a blending or “re-interpretation” of base states.
  
• Very Fine: Total “re-interpretation”, often times using only the base compounds of items.

This is not a simple exchange machine tecolote, review the documentation damnit - _-