RP part surface quality versus build orientation: when the layers are getting thinner

Open Access


Surface quality is a very important factor to be considered in determining part build orientation in rapid prototyping (RP) processes. Previous research has shown that parts built with inclined planes or curved surfaces along the build orientation have large staircase effect, thus have higher surface roughness compared to parts built with only vertical surfaces. However, as layers are getting thinner in rapid prototyping processes, the opposite might be true. In this study, a number of experiments and measurements are conducted first. In a single machine setup, two cylinders are built, one along axial direction and the other along transverse direction using an Objet® machine. Measurements have shown that surface roughness of RP parts built along the transverse direction is better than those from the axial direction. Through analysis and observation, the authors can conclude that when layers are small enough, surface curvature or slope along the build orientation may no longer be a major concern for RP part surface quality. Instead, the authors have observed that on-the-layer contour layout may cause even more serious surface quality problem. In other words, surface quality is not only dependent on build orientation, but more on scanning orientation on layers.


Rapid prototyping Build orientation Surface quality Scanning orientation 


  1. 1.
    Gibson I, Rosen DW, Stucker B (2010) Additive manufacturing technologies: rapid prototyping to direct digital manufacturing. Springer, New YorkCrossRefGoogle Scholar
  2. 2.
    Cheng W, Fuh JYH, Nee AYC, Wong YS, Loh HT, Miyazawa T (1995) Multi-objective optimization of part building orientation in stereolithography. Rapid Prototyping J 1(4):12–23MATHCrossRefGoogle Scholar
  3. 3.
    Fadel GM, Kirschman C (1996) Accuracy issues in CAD to RP translation. Rapid Prototyping J 2(2):4–17CrossRefGoogle Scholar
  4. 4.
    Reeves PE, Cobb RC (1997) Reducing the surface deviation of stereolithography using in-process techniques. Rapid Prototyping J 3(1):20–31CrossRefGoogle Scholar
  5. 5.
    Hur J, Lee K (1998) The development of a CAD environment to determine the preferred build-up direction for layered manufacturing. Int J Adv Manuf Technol 14(4):247–254CrossRefGoogle Scholar
  6. 6.
    Pham DT, Dimov DT, Gault RS (1999) Part orientation in stereo-lithography. Int J Adv Manuf Technol 15(9):674–682CrossRefGoogle Scholar
  7. 7.
    Xu F, Loh HT, Wong YS (1999) Considerations and selection of optimal orientation for different rapid prototyping systems. Rapid Prototyping J 5(2):54–60CrossRefGoogle Scholar
  8. 8.
    Campbell RI, Artorelli M, Lee HS (2002) Surface roughness visualization for rapid prototyping models. Comput Aided Des 34:717–725CrossRefGoogle Scholar
  9. 9.
    Kulkarni P, Marsan A, Dutta D (2000) A review of process planning techniques in layered manufacturing. Rapid Prototyping J 6(1):18–35CrossRefGoogle Scholar
  10. 10.
    Byun HS, Lee KH (2006) Determination of the optimal build direction for different rapid prototyping processes using multi-criterion decision making. Robot Comput Integrated Manuf 22:69–80CrossRefGoogle Scholar
  11. 11.
    Ahn DK, Kim HC, Lee SH (2007) Fabrication direction optimization to minimize post-machining in layered manufacturing. Int J Mach Tool Manuf 47(3–4):593–606MathSciNetCrossRefGoogle Scholar
  12. 12.
    Galantucci LM, Lavecchia F, Percoco G (2009) Experimental study aiming to enhance the surface finish of fused deposition modeled parts. CIRP Ann Manuf Technol 58:189–192CrossRefGoogle Scholar
  13. 13.
    Canellidis V, Giannatsis J, Dedoussis V (2009) Genetic-algorithm-based multi-objective optimization of the build orientation in stereolithography. Int J Adv Manuf Technol 45:714–730CrossRefGoogle Scholar
  14. 14.
    Objet Geometries. http://www.objet.com/. Accessed in December 2011
  15. 15.
    3D Systems. http://www.3dsystems.com/. Accessed in December 2011
  16. 16.
    Chen YH, Chen ZZ (2011) Joint analysis in rapid fabrication of non-assembly mechanisms. Rapid Prototyping J 17(6):408–417CrossRefGoogle Scholar

Copyright information

© The Author(s) 2012

Authors and Affiliations

  1. 1.Department of Mechanical EngineeringThe University of Hong KongHong KongChina

Personalised recommendations