Vac-Exact Precision Drilling: Setup and Operation

Back to E-Drill Academy

Understanding the Vac-Exact System: Setup, Alignment & Precision Drilling

The Vac-Exact system is a portable, vacuum-locking drill guide designed to give technicians precise, repeatable control when drilling, reaming, or correcting holes on aircraft structures. This Academy post explains how the system works, what each component does, and the fundamentals needed before performing more advanced tasks such as repairing damaged holes or pulling a hole to shift a misaligned centerline.

This guide supports the Vac-Exact Setup & Operation video and is intended to help technicians build a strong understanding of the tool before using it in specific applications.

Vac-Exact Overview

Vac-Exact combines three key elements into a single system:

  1. Vacuum-Locking Locators (Standard & Offset)
    Provide stable, repeatable surface contact on both flat and curved structures.
  2. Optical Bombsight With Aperture Rings
    Allows precise visual alignment over holes, marks, or new centerlines.
  3. Drill Bushing Adapters & Precision Bushings
    Guide the drill bit along the correct axis and prevent bit wandering.

Together, these components allow technicians to achieve drill-press-level accuracy anywhere on the aircraft — without clamps, templates, adhesives, or multiple extra setup steps.

Understanding the Locators

Vac-Exact includes two locators, each useful for different geometries:

Standard Locator

  • Best for flat or near-flat surfaces
  • Fastest to set up
  • Ideal for access panels, skins, or bench work

Offset / Contour Locator

  • Designed for curved surfaces and tight areas
  • Includes a spherical washer stack and an adjustable neck to match complex contours
  • Provides stable, perpendicular contact even on compound curves

Setting the Contour (Offset Locator Only)

When using the offset locator on curved or angled surfaces, the contour must be set:

  1. Place the locator in the general area where you’ll be working.
  2. Loosen the top adjustment knob to free the spherical washer stack.
  3. Adjust the neck until the locator head matches the curve or angle.
  4. Hold the head in place and retighten the knob to lock the contour.
  5. The contour remains fixed as you reposition the tool along nearby locations.

Correct contouring ensures the locator seats cleanly on the surface, enabling accurate alignment and drilling.

Vacuum Operation & Lever Control

Vac-Exact uses a venturi vacuum pump, powered by standard shop air.

  • Vacuum is ON by default when air is connected.
  • The side lever is spring-loaded.
  • Pressing the lever releases vacuum, allowing the locator to “float.”
  • Releasing the lever re-engages vacuum and locks the locator in place.
  • Light feathering allows for precise micro-adjustments.

This “float and lock” mechanism gives technicians fine control over alignment without losing the contour or overall position.

Optical Alignment With the Bombsight

The optical bombsight is used to align accurately with:

  • Existing holes
  • Center markings
  • Target locations for oversizing
  • New centerlines when pulling a hole

Steps:

  1. Select the correct aperture ring for the hole or feature.
  2. Press the aperture onto the bombsight.
  3. Insert the bombsight into the locator.
  4. Position it over the built-in magnet to activate the LEDs.
  5. Use the lever to float and align the locator precisely.
  6. Release the lever to vacuum-lock the locator in position.

Once aligned, replace the bombsight with the drill bushing adapter to begin the drilling phase.

Installing Bushings & Preparing to Drill

To convert from locating to drilling:

  1. Remove the bombsight.
  2. Insert the drill bushing adapter into the locator and lock it.
  3. Choose the appropriate drill bushing for your drill size.
  4. Insert and twist to lock the bushing into the adapter.
  5. Optionally attach the debris reduction accessory to collect chips.
  6. Drill through the bushing for a controlled, perpendicular hole.

Bushings ensure the bit remains centered and prevent walking — critical when repairing damaged holes or pulling a hole.

Use Cases Covered in the Video

  1. Repairing Damaged or Oblong Holes

Vac-Exact allows technicians to re-center and re-round damaged holes while maintaining control over the diameter and alignment.

  1. Pulling a Hole (Shifting Centerline)

When a hole is mislocated, Vac-Exact makes it possible to establish a new center and drill a controlled oversize hole on the correct centerline — without relying on clamps, glued blocks, or complex fixtures.