Piper Jaffray analyst Troy Jensen says 3D Systems (DDD) last night reported disappointing results with weak printer sales being the primary factor in the revenue miss. The weak printer sales are directly correlated with increased competition from HP Inc. (HPQ), General Electric (GE) and others attacking 3D Systems' key product lines, Jensen tells investors in a post-earnings research note. He sees the company's second half of 2017 as "incrementally more challenging" and believes the stock's a "significant premium" to 3D printing peers is unwarranted. The analyst reiterates an Underweight rating on 3D Systems with a $14 price target.