As appeared in Manufacturing News, November 2021
Compared to conventional machining systems, Swiss-style and screw-type machines pose a few different challenges in terms of tooling and toolholding. Most of these stem from the fact that the machines often require long job set-up times and frequent tool changes, both of which shops constantly strive to shorten. In addition, these machines offer very limited room within their work envelopes, and the room they do have is typically packed with tools positioned in extremely close proximity to each other.
Set-ups on Swiss-style machines can take anywhere from six to eight hours. Many screw machine shops do not mind this because large batch sizes/job runs justify the long set-ups. However, what they may not realize is that today’s advanced quick-change toolholders can help shorten set-ups while also making for faster tool changes.
When cutting steel, stainless steel or high-temp materials on a Swiss-style machine, tools wear more quickly and must be replaced when they get to a certain point. Unfortunately, every part requires several tools to machine it, and those tools do not all wear at the same rates. On top of this, one broken tool can lead to other broken tools. For instance, in a drill/ream/tap sequence, if the drill breaks, the machine does not know it and will send the reamer or tap into an incomplete hole, causing that tool and any others that follow it to break until the operator notices the problem.
All of this means that tools need frequent changes, and while that is happening, the machine sits idle and unproductive. For this reason, an increasing number of shops incorporate quick-change toolholder technology that allows them to loosen a worn or broken tool, remove it, insert a new one, tighten it and be back up and running in the shortest possible amount of time.
Not only do today’s quick-change toolholders reduce machine downtime and increase productivity, but they also provide higher accuracy and repeatability and eliminate the need to touch off tools after a routine change-saving even more valuable production time.
“Quick-change tooling, such as SwissQuick ER-to-ER adapters from REGO-FIX, enables shops to preset tooling offline and replace worn tools in seconds on Swiss-style machines,” said a REGO-FIX spokesperson. “Additionally, because such adapters are short ‘miniature’ toolholders, they save valuable machine space as well. In fact, SwissQuick tooling incorporates a larger solid ER body on the back end that remains in the machine and a smaller ER series cavity in front-essentially two holders in one for the shortest, most rigid ER-to-ER reduction available.”
In addition to fast changeouts, shops want repeatability in their Swiss-style machine toolholding. From assembly to assembly, holders from OEMs such as REGO-FIX provide high repeatability. Through that company’s solid ER body style, its SwissQuick adapter improves machining accuracy with a taper-to-collet cavity TIR of less than 0.0001″. The body also allows the adapter to be repeatable within 0.0004″ on tool length. Because they are made from high tensile strength case-hardened steel, SwissQuick adapters provide reduced wear for increased tool life.
With tools located only about a half inch apart from one another on Swiss-style machines, tool changes often prove both dangerous and destructive. Any slip with an ER collet nut wrench can potentially damage neighboring tools and, worse yet, cause operator injury. To prevent operator injury and tool breakage, shops turn to special recently developed locking-type nuts, such as the intRlox Mini Nuts from REGO-FIX.
Specifically developed for Swiss-style machines, these nuts use an anti-slip locking design engineered to prevent the locking wrench from slipping off the nut during assembly and disassembly. They use milled slots on the outside diameter of the nut that mate with corresponding features of the wrench to prevent slippage during the tightening and loosening processes. REGO-FIX’s design includes a special surface treatment to enhance clamping forces and extend the life of the nut by protecting against corrosion.
REGO-FIX also offers an extension tube accessory for its intRlox nuts, with the same profile as the mini nut wrench at one end and the anti-slip profile at the other. With the extension, operators gain a deeper reach between tooling and additional room for the wrench because it is further away from the cutting tools. To ensure proper nut tightening, the extension provides enough room to use a ratchet type wrench as well as torque wrenches.
As Swiss-style machine shops continue to produce job lot sizes in the hundreds of thousands, today’s toolholding designed specifically for those machines can help reduce downtime introduced through frequent tool changes. Taken a step further, advancements in toolholding also provide safety for Swiss-style machine operators and prevent accidental tool breakage during those changeouts.