main body is in four parts, glued together.
parts will need to be scaled up and aligned to the print bed surface. the main screw, handle and caps required a brim for support. 3x .25-20 screws also needed.
I also added a main body stl file incase you want to try and print it as a single feature.

Quick Grip Trigger Clamp
This is a fully functional Quick Grip Trigger Clamp. C-Clamps have become very popular prints but the clamp allows quick single hand adjustments. This design was created with fusion 360 and printed on a Prusa i3 MK3.
Everything on this clamp is printed with exception to the springs which make it functional.
Springs can be found in this great spring assortment on amazon:
https://amzn.to/2DAFIbd
Springs needed are:
0.035"x0.25"x0.5" for the release trigger
0.041"x0.437"x1.062" for the clamp trigger
The kit has enough springs to make 6+ clamps.
Filament
The printed version shown in pictures is printed in three different filaments:
Black parts: https://amzn.to/2Dt6xho
Ziro Carbon Fiber PLA (One of my favorites to use)
Grey parts: https://amzn.to/2DqNS5J
Prusament Galaxy Silver PLA
Orange parts: https://amzn.to/2VXMHSm
Amazon Basics PETG

This is a quite robust 3d-printable machine vise. It's 100% 3d-printed - no screw or other piece of hardware is needed to hold the individual pieces together. Pieces clip and snap together.
It's a demonstration that it is very important to consider forces and material properties already when designing a mechanical object. Hints about proper design are presented in my video:
https://youtu.be/mziT7KV-fRI
The video also includes explanations how to assemble this vise.
For 3d-printing it's recommended to print 3 shell layers. 35% infill is sufficient. All the forces for clamping a workpiece are only active at the outer surface - more infill doesn't make the vise more robust. Layer height is 0.15 mm (maybe screws are better printed with 0.1mm layers). No support material needed. Printed with 0.4 mm nozzle.
Assembly: https://jig.space/view?jig=1216 (thanks to http://www.thingiverse.com/greenlig)
Designed with Fusion 360: http://a360.co/2juhSUG
If there are difficulties to print the threaded rods vertically, I've designed…