Adjustable Drawer Slide Installation Jig & Helping Hand Platform

I designed this jig while installing cabinet slides in existing cabinet bodies. I needed something to hold up the back of heavy, long undermount drawer slides to keep them level during installation. There are two other common options that didn't work well for my scenario

1. Spacer blocks: This works well when installing slides in many uniform positions. However, I was installing each set of slides at different heights. This would have required a new spacer block for each set of slides creating a lot of waste. 
2. Other jigs that only clamp in the front: The slides I was working with were 21" undermount drawer slides. These slides are particularly heavy. I was not able to get a jig that only supported the front of the slides to stay in place due to the weight of the slides.

This led me to creating a small adjustable platform that could be temporarily, but securely mounted anywhere inside the cabinet.

The design consists of two parts:

Platform – a flat surface supported by a wide perpendicular dovetail, similar in shape to machine ways. The dovetail contains a threaded insert at its base.

Body – a matching groove that slides along the dovetail. It includes three holes: two for cabinet screws that secure the jig to the cabinet wall, and a third elongated hole for a bolt that passes through and threads into the platform insert. Tightening the bolt clamps the two parts together, locking the platform at the desired height.

This setup makes it easy to fine-tune the slide height before driving screws. I didn’t mind the small screw holes this left inside the cabinet, which will later be hidden by the drawer itself, since it made installation faster and more accurate.

Instructions for Use

1. Mark the rough position of the drawer slide using a measuring tape near the back of the cabinet on each slide
2. Screw the jig a bit below the mark on both sides as the platform can be adjusted to be higher up, but it cannot be adjusted lower down
3. Use a piece of scrap, or the drawer slide itself, rest the back on the platform with the front extending beyond the front of the cabinet and add a clamp below this piece to register the front height of the slide. Make sure the clamp creates a level surface from front to back
4. Rest a level on top of the part extending beyond the front of the cabinet to check for level from left-to-right
5. Adjust the height of the platform and front clamp as needed to achieve level from front-to-back and left-to-right
6. Finally, rest the slide on top of the platform and clamp and screw it to the cabinet

Print Settings: PLA with coarse layer high of 0.28 for fast printing

Other Materials:

• Two M6x9x8 threaded inserts
• M6x25 screw
• Two cabinet screws