In most centreless grinding conversations, the grinding wheel and the work-rest blade take centre stage. They are the most visible consumables, and they tend to get replaced or refurbished most frequently. Formers, cams and cam followers, by contrast, are often treated as background components - checked occasionally, replaced when they are obviously worn, and rarely identified as the primary cause of quality problems until significant investigation has already taken place elsewhere.

This is a costly oversight. Formers and cams play a direct role in controlling component movement and profile during grinding. When they degrade, the effects show up as dimensional variation, inconsistent surface finish and poor repeatability - problems that are easy to misattribute to the grinding wheel, the blade or the machine setup.

What Formers and Cams Do in a Centreless Grinding System

In centreless grinding operations, formers and cams are used to control how the workpiece is presented to the grinding wheel during the grinding cycle. In cam-driven machines and certain in-feed grinding applications, they govern the infeed movement of the grinding wheel or workpiece support, controlling the rate and profile of stock removal.

Cam followers translate the cam's profile into mechanical movement during the grinding cycle. The accuracy and condition of all three components - former, cam and follower - directly governs whether each cycle delivers the same depth of cut, the same dwell period and the same withdrawal movement. When this chain of components is accurate and well-maintained, the result is consistent part dimensions across a production run. When any element degrades, that consistency breaks down.

How Wear Manifests and Why It Is Often Missed

Wear on formers and cams tends to be gradual. There is rarely a single moment of obvious failure. Instead, the working surfaces slowly lose their profile accuracy, and the dimensional output of the grinding process drifts with it.

Common signs that formers, cams or cam followers may be the root cause of problems include:

• Gradual size drift across a production run - Parts that measure correctly at the start of a batch but gradually move out of tolerance as the run progresses, despite no changes to wheel dressing or machine settings.
• Inconsistent diameter variation between parts - Random, non-repeating dimensional scatter that does not correlate with wheel glazing or blade wear patterns.
• Loss of repeatability between setups - A process that previously settled quickly after a changeover now requires repeated adjustment to achieve acceptable parts, suggesting the cam or former profile is no longer holding the setup correctly.
• Increased cycle-to-cycle variation - Measurable differences in dimension or surface finish between consecutive parts, even within a stable production run.
• Visible surface damage or pitting on cam or former working faces - Even small areas of damage on a cam or former surface translate into localised variation in the grinding cycle.

Because these symptoms are shared with other grinding system problems, formers and cams often only come under scrutiny after the wheel specification, dressing regime, blade condition and coolant system have already been investigated and ruled out.

The Case for Proactive Inspection and Regrinding

The more effective approach is to include formers, cams and cam followers in a structured maintenance and inspection regime rather than waiting for quality problems to signal that something is wrong.

Regrinding worn formers and cams restores their original profile geometry and surface condition, returning the grinding cycle to its intended accuracy. At Workblades & Formers Ltd, this is a core part of our refurbishment service. We regrind and refurbish formers, cams and cam followers to bring them back as close as possible to their original specification, using the same precision approach we apply to work-rest blade regrinding.

The economics of regrinding are straightforward. A well-executed regrind at a fraction of the cost of a new component restores full functionality and extends service life. For high-cost tooling - which many precision formers and cams represent - this is a meaningful contribution to reducing the overall cost of running a centreless grinding operation.

Reverse Engineering and Custom Former Manufacture

One practical challenge with formers and cams is that replacement components are not always available from the original machine manufacturer, particularly for older centreless grinding machines or machines that are no longer in production. In these cases, procurement of replacement tooling can be difficult or prohibitively expensive.

Our in-house design and manufacture capability addresses this directly. We can produce custom formers, cams and cam followers to specification - either from engineering drawings if they are available, or reverse-engineered from a worn component where original documentation no longer exists. This approach is particularly relevant for businesses running older Cincinnati, BSA, Tschudin, Wickman Scrivener or Lidköping machines, where original spares support may be limited.

Custom-manufactured formers can also be produced to modified profiles where a machine is being adapted for a new component range or where the original tooling did not deliver the required size or form accuracy.

Cam Followers: A Frequently Overlooked Wear Item

Cam followers are often neglected in tooling maintenance programmes, despite the fact that they are the component in direct rolling or sliding contact with the cam surface. A worn cam follower introduces play and inconsistency into the mechanical drive of the grinding cycle - even if the cam itself is in good condition.

Inspection of cam followers should be included whenever cams and formers are assessed. Where followers are worn or damaged, replacement or refurbishment should be carried out at the same time as any cam regrind to ensure the complete system is returned to tolerance.

Integrating Former and Cam Maintenance into a Wider Servicing Programme

Formers and cams do not operate in isolation. Their condition interacts with the condition of the work-rest blade, the grinding wheel specification, the control wheel, and the machine spindle. A regrinding programme that addresses only one element of the system while others remain degraded will produce limited results.

Our technical team can support customers in reviewing the full tooling system - including workblades, formers, cams, cam followers and diamond dressing tools - to identify where maintenance or refurbishment will deliver the greatest improvement in process consistency. We supply and service customers across the UK and Europe, with the ability to turn around refurbishment work efficiently to minimise disruption to production schedules.

If your centreless grinding process is producing inconsistent results and you have already investigated the more obvious causes, it is worth looking closely at the condition of your formers and cams. Contact the team at Workblades & Formers Ltd to discuss inspection, regrinding or custom manufacture of centreless grinding tooling.