Slip Tables & Multi-Axis Testing: Tips & Tricks

Practical guidance for reliable horizontal and multi-directional vibration testing

Vibration testing is rarely limited to a single direction. In real-world environments—whether in automotive, aerospace, or electronics—products are exposed to forces from multiple axes.

That’s why engineers rely on slip tables and multi-axis testing setups to simulate real operating conditions more accurately.

This guide focuses on what matters in practice:

• how slip tables work

• how to switch between vertical and horizontal testing

• what challenges engineers face—and how to solve them

What a Slip Table Does (and Why It Matters)

A slip table converts vertical shaker motion into controlled horizontal vibration, allowing engineers to simulate real-world lateral forces.

When you need a slip table

• Transport vibration (truck, rail, shipping)

• Lateral loads in vehicles

• Multi-directional stress on assemblies

Without a slip table, your test only reflects part of the real-world condition.

ETS Slip Tables: What Engineers Should Know

At ETS, slip tables are not treated as simple accessories—they are engineered as core system components that directly impact test accuracy, stability, and repeatability.

Two types of slip table are available: a unibase concept that provides a structural steel body to align the shaker and table on a rigid platform, and a standalone slip table design that allows the feasibility of any vertical shaker from ETS or other manufacturers to couple with the slip table assembly.

ETS Solutions Unibase Slip Table Concept

ETS Solutions Standalone Slip Table Concept

ETS Solutions provide also double slip table unibase that allows users to have double configuration of the slip table in order to perform different tests. The shaker system can rotate 180 degree in order to be combined with both tables. In the middle position, the shaker can be combined with the Head Expander in order to perform vertical test. This configuration is suitable for GT Series and BT Series.

Table in table unibase solution is also available. It allows users to have double configuration of the slip table in order to perform different tests. The small and the big tables are integrated in order to save space in the lab. In order to perform the test with the small table, the user has just to detach it from the bigger table. Simple configuration and easy to use. This configuration is suitable for GT Series and BT Series.

ETS Solutions double slip table unibase

ETS Solutions Table in table unibase slip table concept

Key Engineering Features

Precision granite base
A natural granite slab provides a flat, stable reference surface, ensuring consistent motion and minimizing distortion during testing.

Oil film technology (GT Series)
A thin oil layer between the slip plate and granite base enables:

• ultra-low friction motion

• reduced wear

• natural damping of pitch, roll, and yaw

Hydrostatic bearing systems (BT Series)
Designed for demanding applications:

• high load and overturning moment capacity

• superior cross-axis constraint

• stable performance for large or tall DUTs

Wide size range
From 300 × 300 mm up to 2.5 × 2.5 m + special sizes and shapes, supporting:

• small component testing

• large automotive and aerospace assemblies

Low-profile, high-stability structure

• optimized mass-to-force ratio

• vibration isolation (<5 Hz transmission)

• compatibility with environmental chambers

👉 Related systems and accessories:

• Head expanders & fixtures: https://www.etssolution.com/head-expanders-fixtures

• Options & accessories: https://www.etssolution.com/options-accessories

ETS Solutions Slip Table GT Series

ETS Solutions Slip Table BT Series

What This Means for Engineers

These features translate directly into measurable benefits:

✔ Higher control accuracy
Stable motion reduces control error in sine and random testing

✔ Minimal cross-axis interference
Critical for standard compliance and data integrity

✔ Capability for large and complex DUTs
Hydrostatic systems support high center-of-gravity loads

✔ Faster, repeatable setups
Integrated system design maintains alignment between shaker and table

Choosing the Right ETS Slip Table

• GT Series (Oil Film + Bearings)
  → Ideal for general-purpose horizontal testing
  → Reliable and cost-effective

• BT Series (Hydrostatic Bearings)
  → Ideal for heavy DUTs or high moment loads
  → Maximum stability and precision

👉 Key insight:
In multi-axis testing, the slip table often defines performance more than the shaker itself.

Vertical vs Horizontal Testing: Key Differences

Vertical Testing

• Direct excitation through the shaker armature

• Simpler setup

• Higher usable force

Best for:

• component testing

• resonance studies

• standard qualification

Horizontal Testing (Slip Table)

• Motion transferred through bearings and slip plate

• More sensitive to alignment and setup

• Enables realistic simulation

Best for:

• transport simulation

• large assemblies

• real-world mounting conditions

What Is Multi-Axis Testing?

In most labs, multi-axis testing means:

• sequential testing across axes (X, Y, Z)

• rotating the DUT or reconfiguring setups

• combining slip tables with fixtures

Advanced systems may include:

• dual-axis excitation

• vibration + environmental testing

Practical Challenges (and How to Solve Them)

1. Switching Between Axes

Challenge:
Time-consuming setup and reconfiguration

Solution:

• use modular fixtures

• standardize mounting interfaces

• validate setup with low-level tests

2. Alignment and Side Loads

Challenge:
Misalignment causes distortion and instability

Solution:

• ensure precise installation

• center payload correctly

• verify motion before testing

3. High Center of Gravity Loads

Challenge:
Instability and excessive moments

Solution:

• use reinforced slip tables (e.g., hydrostatic)

• lower center of gravity

• add support fixtures

4. Fixture Design Across Axes

Challenge:
Different load paths in vertical vs horizontal

Solution:

• design for multi-directional stiffness

• avoid flexible structures

• validate with sine sweep

5. Cable Management

Challenge:
Cable movement introduces noise

Solution:

• secure cables close to sensors

• avoid loops

• re-check after axis changes

6. Control Stability

Challenge:
Horizontal systems behave differently

Solution:

• run pre-tests (low-level sine/random)

• verify FRF

• adjust control parameters

Tips for Efficient Multi-Axis Testing

• Complete tests in one axis before switching

• Keep sensor positions consistent

• Document every setup detail

• Standardize fixtures for repeatability

When to Upgrade Your Setup

If you experience:

• unstable horizontal tests

• long setup times

• inconsistent results

…it may be time to review your system configuration.

👉 Explore ETS solutions:
https://www.etssolution.com/options-accessories

FAQ

Do I always need a slip table for horizontal testing?
Yes, for accurate and repeatable horizontal vibration.

Why is horizontal testing more difficult?
Because of additional components, alignment sensitivity, and fixture requirements.

What’s the biggest mistake in multi-axis testing?
Ignoring fixture design and alignment when switching axes.

Can one fixture work for all axes?
Only if designed for multi-directional stiffness.

Final Thoughts

Slip tables and multi-axis testing bring your testing closer to reality but they also require more engineering discipline.

Most issues don’t come from the shaker itself.

They come from:

• alignment

• fixtures

• setup consistency

👉 And in horizontal testing, the slip table often determines your final result quality.

That’s why ETS approaches vibration testing as a complete system - not just a shaker, but a fully engineered solution.