Question

sls: moving parts
use the information below to answer the question.
sls printing can be used to make moving parts. there is no support structure other than the powder that is in the powder bed.
moving part considerations
consider the thickness of the shafts and the mass to avoid over - sintering. in general, if the print has a shaft that is less than 1 cm in diameter, there can be a clearance of 0.15 mm on each side. the mass will not build up too much heat, so it wont over - sinter. if the shaft needs to be 1 cm, the clearance will be 0.25 mm on each side. it is important to note that there will still be powder in between and it can over - sinter.
reduce surface area
to avoid over - sintering moving parts, a redesign that reduces the surface area and contact is a good choice. there will be much less heat build - up, and the possibility of over - sintering is reduced greatly. the clearance in the center will be 0.4 mm, and an escape hole can be put in to allow the powder to get out.
a redesign that reduces the surface area and contact of an sls print can have which of the following benefits?

• more balance
• less heat build - up
• increased detail
• more support

Explanation:

The text under "Reduce surface area" states that a redesign reducing surface area and contact leads to "much less heat build - up". The other options: "more balance" isn't mentioned in relation to this redesign; "increased detail" isn't associated with reducing surface area/contact; "more support" is incorrect as SLS has powder as support and this redesign doesn't relate to more support.

Answer:

less heat build - up