Common Mistakes: Trough Saddles and Feet for Screw Conveyors

When designing or installing a screw conveyor, most of the attention is typically placed on screw diameter, capacity, horsepower, and material characteristics. However, one of the most common, and costly, mistakes we see in the field has nothing to do with the screw itself.

It comes down to improper use of trough saddles and feet, which are critical components of the overall troughing system.

At ISC Manufacturing LLC, we frequently encounter screw conveyor issues that trace back to incorrect trough support selection or placement. While saddles and flanged feet may seem like minor components of the troughing, they play a critical role in:

Maintaining alignment
Preventing structural issues
Ensuring long-term reliability of the conveyor system

Understanding the Difference Between Saddles and Feet

Before discussing the mistake, it’s important to understand what each trough support is designed to do.

Flanged feet are bolted to the pre-flanged ends of trough sections, typically at trough joints. They:

Provide stable, fixed support points for the troughing
Are commonly used at standard section intervals

Saddles are welded directly to the bottom of the trough and are used for intermediate trough support between joints.

Providing support where needed between flanges
Allowing designers flexibility without being limited to joint locations

Both supports are effective when used correctly—but problems arise when they are treated as interchangeable within the troughing system.

The Most Common Mistake: Improper Support Strategy

The most common mistake with saddles and feet is using too few trough supports, or using the wrong type, based on conveyor length, loading, and operating conditions.

This often shows up in one of two ways:

1. Relying Only on Flanged Feet for Long Conveyors

In longer screw conveyors, relying solely on flanged feet at trough joints can lead to unsupported trough spans that are too long. Over time, this can cause:

Trough sagging
Misalignment of the screw and hangers
Increased wear on bearings and flighting
Premature component failure

Without intermediate support, the trough can deflect under load, even if the screw itself is properly sized.

2. Adding Saddles Without Considering Alignment and Installation

On the other end of the spectrum, saddles are sometimes added without proper planning. If saddles are not installed level or are placed on uneven foundations, they can introduce misalignment into the troughing system.

This misalignment may not be obvious during installation, but it often results in:

Increased power draw
Abnormal noise or vibration
Uneven wear along the trough and screw

Saddles must be positioned and installed with the same care as any other structural trough support.

Why Proper Support Matters

Screw conveyors rely on precise alignment between the screw, trough, and bearings. Even small deviations caused by poor trough support selection can compound over time.

Proper use of saddles and feet helps:

Maintain consistent screw-to-trough clearances
Reduce stress on hanger bearings and end bearings
Prevent trough distortion under load
Extend overall equipment life

Ignoring these troughing-related factors can turn a well-designed conveyor into a maintenance headache.

Best Practices for Saddles and Feet

To avoid common trough support–related issues, ISC recommends:

Evaluating conveyor length, diameter, and loading when determining trough support spacing
Using saddles for intermediate trough support where joint spacing alone is insufficient
Ensuring all trough supports are installed on level, structurally sound foundations
Verifying trough and screw alignment after installation and before startup

Support selection should never be an afterthought; it should be part of the overall conveyor and troughing design process.

Engineered Support from the Start

At ISC Manufacturing, troughing, saddles, and feet are selected and placed during the engineering phase, not left to chance in the field. Our experience designing and fabricating heavy-duty troughing systems allows us to account for:

Loading conditions
Span length
Installation environment

By considering trough support strategy early, we help customers avoid installation issues, downtime, and unnecessary wear.

Small components make a big difference when it comes to long-term performance.

If you’re designing or troubleshooting a screw conveyor system, our engineering team can help ensure every detail, including troughing and supports, is done right the first time.