This decade had witnessed the tremendous progress in miniaturizing optical imaging systems. Despite the advancements in 3D printing optical lenses at increasingly smaller dimensions, challenges remain in precisely manufacturing the dimensionally compatible optomechanical components and assembling them into a functional imaging system. To tackle this issue, here we report the use of 3D printing to enable digitalized optomechanical components manufacturing, part-count-reduction design, and the inclusion of passive alignment features, all for the ease of system assembly. We 3D printed the key optomechanical components of a penny-sized accommodating optical microscope in 50 minutes at a significantly reduced unit cost near $4. By actuating a built-in voice-coil-motor, we validated its accommodating capability to focus on specimens located at different distances, and further utilized a focus stacking function to greatly extended depth-of-field. The microscope can be readily customized and rapidly manufactured to respond to task-specific needs in form-factor and optical characteristics. This article is protected by copyright. All rights reserved.