Are Shops Shying Away from Shrinkfit?

by | Jan 26, 2024

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We, as a global tooling supplier, interact with countless numbers of shops on a daily basis, and lately, many of them have voiced growing concerns centered around safety. These concerns stem from the fact that in tight labor markets, they are forced to hire lesser skilled individuals who lack sufficient experience for certain, more complex, types of toolholding systems.

As a result, we’ve experienced more shops currently using such toolholding systems as those based on heatshrink technology inquiring about safer, easier-to-use alternatives. In the majority of these instances, those shops have ended up switching to mechanical-based systems, such as the tape-to-taper press-fit powRgrip system.

Because there is no heat involved with  taper-to-taper systems, they eliminate the need for operators to handle super-heated toolholders from a heating device with asbestos gloves, load in a cutting tool and place the assembly – holder and cutting tool – in a cooling tower, cooling attachment or on a table top. In turn, there is no longer the risk of anyone accidentally injuring themselves if the heated holders are not properly tagged or isolated or if the operator does not follow the strict handling protocols.

In addition to the safety aspect, shops are drawn to the other benefits of taper-to-taper systems. These include longer holder life, increased versatility, speed, precision and higher vibration damping.

The press-in parameters of a taper-to-taper system are controlled and consistent, unlike heat-based systems where inexperienced operators may alter the heating cycles of a holder. It is  alterations in temperature or length of heating cycle that can damage the heatshrink holder and cause it to wear out faster. Even under optimal heating conditions, the life cycle of the holder may only reach 5,000 uses – which is one quarter of the life of a taper-to-taper holder.

Conversely, properly maintained powRgrip holders and collets sustain their high performance for at least 20,000 cycles. In fact, over time, pressing a collet into a holder slowly burnishes the holder cavity to a more polished, higher precision surface finish that further increases the system’s overall accuracy. 

When it comes to versatility, a separate heatshrink holder is required for each cutting tool diameter, as well as for any long reach options. Also, the holders are not compatible with Weldon-shank tools, so if one is accidentally installed, it could potentially damage the holder or become permanently stuck and impossible to remove. Additionally, small-diameter holders are quite susceptible to overheating and are thus not as effective as taper-to-taper holders over long periods of time.

Each holder in the powRgrip system, on the other hand, holds any collet diameter – in metric or standard units – within its specified range. This drastically reduces the number of holders that must be kept in inventory to hold a wide variety of tool diameters. The holders are also compatible with Weldon-shank tools.

Compared to taper-to-taper systems, the tool load/unload cycles of a heatshrink system take longer. Also, the task of presetting the holders is a complex one because once the tool is inserted, it cannot be adjusted without a special induction and presetter machine.

The powRgrip system provides incredibly fast tool changeouts. Full clamping cycles take less than 10 seconds with the automatic assembly mounting unit. Plus, tools are completely safe to handle and ready to use immediately after that short loading cycle time.

Likewise, Z-level tool length adjustments are equally simple with the tapered collets because each one has a Z-level adjustment screw. On any standard presetter, an operator can easily and precisely adjust this screw using an inexpensive adjustment tool, and the repeatability of this Z-level adjustment is well within 10 µm.

While they ensure safe and easy operation, taper-to-taper collet-holding systems do so without sacrificing precision. For powRgrip, Total Indicated Runouts (T.I.R.s) are typically less than 3 µm. The lower the T.I.R, the less tool vibration, and the less vibration, the longer cutting tools last, which in turn reduces overall tooling costs.

The rigidity and strength of these toolholding systems yield the highest transferable torque against comparable systems. Taper-to-taper holders provide 1,100 Nm of torque on 1” tools, whereas other systems generate just over half of that strength.

In the world of toolholding systems, shops have options and can choose any type of system they prefer. However, in light of the current lack of skilled labor, the best option may be the one that provides safe and simple operation as well as much need longevity, versatility, speed and precision.

Ready to make the switch to powRgrip? Contact us for more information.

By David McHenry, Engineering & Technical Manager at REGO-FIX