We Claim:
1. A mechanism for reducing build volume of a powder bed fusion apparatus,
comprising:
a cover plate (119) mounted on a base plate (101) of the powder bed fusion
apparatus;
a riser block (111) fixed to a primary heater plate (107) of the powder bed
fusion apparatus, wherein the primary heater plate (107) sliding relative to a
primary build housing (103) of the powder bed fusion apparatus;
a secondary build plate (117) secured to the riser block (111), wherein the
secondary build plate (117) having an area of cross-section less than an area of
cross-section of the primary heater plate (107);
a slot (121) provided in a predefined shape on the cover plate (119);
a housing (113) fixed on the cover plate (119) extending towards the primary
heater plate (105) for enclosing the riser block (111) and the secondary build
plate (117), wherein the housing (113) aligned with the slot (121);
the riser block (111) including the secondary build plate (115) sliding relative
to the housing (113) based on the sliding of the primary build housing (103);
and
the secondary build plate (115) positioned in the housing (113) relative to the
cover plate (119), provided for receiving powder for manufacturing a part,
thereby reducing the build volume of the powder bed fusion apparatus.
2. The mechanism as claimed in claim 1, wherein a powder spreading apparatus (105) sliding relative to the base (103) for spreading powder on the secondary build plate (115) through the slot (121).
3. The mechanism as claimed in claim 1, wherein a secondary heater plate (115) mounted on the riser block (111) and the secondary build plate (117) mounted on the secondary heater plate (115); and

a heating means provided in the secondary heater plate (115) for heating the powder spread on the secondary build plate (117) for manufacturing the part.
4. The mechanism as claimed in claim 1, wherein a shape of the housing (113) is
hollow cylinder; and
the predefined shape of the slot (121) is circular for enclosing the housing (113).
5. The mechanism as claimed in claim 3, wherein a shape of the secondary build plate (117) and the secondary heater plate (115) is circular.
6. The mechanism as claimed in claim 1, wherein the riser block (111) is provided for supporting the secondary heater plate (115) and the secondary build plate (117) and positioning the secondary build plate (117) inside the housing (113).
7. The mechanism as claimed in claim 1, wherein the cover plate (119) provided for restricting spreading of the powder to the secondary build plate (117) through the slot (121), thereby minimizing powder consumption.
8. The mechanism as claimed in claim 1, wherein the pre-defined shape of the slot (121) is based on a shape of the housing (113).
9. A method of reducing build volume of a powder bed fusion apparatus, comprising the steps of:
mounting (201) a cover plate, including a slot, on a base plate of the powder
bed fusion apparatus, using a fastening means;
fixing (202) a riser block on a primary heater plate of the powder bed fusion
apparatus, using a fastening means;
securing(203) a secondary build plate to the riser block, wherein the secondary
build plate having an area of cross-section less than an area of cross-section of
the primary heater plate, using a fastening means;

fixing(204) a housing to the cover plate, using a fastening means, wherein the housing aligned to the slot and extending towards the primary heater plate; and
positioning (205) the secondary build plate relative to the cover plate by sliding the riser block relative to the housing, thereby reducing the build volume of the powder bed fusion apparatus. 10. The method as claimed in claim 9, wherein the method including spreading powder on the secondary build plate through the slot, by a powder spreading unit, for manufacturing a part; and
heating the powder on the secondary build plate, by a secondary heater plate, mounted below the secondary build plate.