The photopolymerized acrylate products, fabricated using piezoelectric inkjet three dimensional printers, can be deformed under some printing process conditions. To understand and solve this deformation problem, we focus on the drop dynamics of the acrylate resin ink before being cured by the ultraviolet light. We numerically solve the full Navier-Stokes equation with the Volume-of-fluid (VOF) method to investigate the impact, spreading, and recoiling behavior of the resin ink droplet to show how the resin ink flow characteristics result in the shape change of the products. We have successfully developed the numerical models for the analysis of the drop dynamics of the resin ink in piezoelectric inkjet three dimensional printers.