CNC machining centers continually run at full capacity to produce high-quality parts that adhere to demanding specifications. Expensive dedicated machines' workholding devices experience wear over time due to the forces of machining. Direct debilitating variables include performing in hostile environments, working with complex part geometries, or using demanding exotic material types (inconel, titanium, etc.), all of which can promote the wear on a machine.
These demands on today's unique production operations can often be solved by simple custom-engineered workholding solutions. As specialization has increased, more forward-thinking end-users are demanding one-of-a-kind, affordable workholding solutions with added process efficiency beyond typical live and dead centers.
Riten Industries, Inc. has developed unique workholding solutions, such as the Riten "specials" program, with the goal to assist machinists seeking higher efficiencies for uncommon applications. These specials are engineered to minimize machine downtime and streamline productivity.
Riten Specials Program/Process
Based in a 35,000 sq. ft. facility in central Ohio, Riten's engineering team has three dedicated machines that they run assemblies through for their specials program.
The goal of the program is to minimize machine downtime. The program's process is simple: when a customer runs a machine until it fails, they can send in their damaged assembly for an engineering analysis to determine if Riten can refurbish/repair to like-new condition, or build a completely new unit. Riten also encourages customers using the specials program to keep a complete spare assembly readily available in stock. The goal is to have one on hand at all times to avoid machine downtime during the rebuild process.
According to Mitchell Kirby, Riten's V.P. of Manufacturing, "Generally, there are more replacements than refurbishments or repairs because most end-users often run the machine until it fails. Riten encourages customers to be ahead of the curve on complete failure by scheduling machine maintenance during their down season. It is like repairing an engine, so there is a longer lead time to replace new tools from scratch."
After the engineering analysis, Riten provides a size and cost of assembly job profile, which varies on a case-by-case basis. If it is not too damaged from the wear, the bearing assembly turnaround time is shorter. Typical turnaround time is 2-3 weeks for refurbished, and 10-12 weeks for a complete rebuild project. Riten's National Sales Manager, Kent Hizer, emphasized, "Without the Riten specials solution, and with today's supply chain issues, it could conceivably take up to 4-6 months to deliver a complete workholding solution."
Riten Specials program initiatives may include:
- Rebuild or replace spindle
- Rebuild or replace quill assemblies
- Refurbish bearing assembly and replace the heavy-duty bearings
- Repair tailstock and headstock (lathes and grinders)
- Refurbish or replace all worn parts (including the in-house fabrication of obsolete or unavailable components).
A staff of approximately seven to nine engineers is continually devoted to the specials program for all makes of centers for industry-specific applications in the aerospace, automotive, defense, medical markets, etc.
Union Electric Steel Case Study
Union Electric Steel Corporation (UES), a global producer of forged and cast rolls for the worldwide steel and metal industries has been implementing Riten's customized specials program for over two decades on their existing equipment where the parts do not exist or they need to retrofit, rebuild, redesign headstock or tailstock assemblies.
UES utilizes a wide range of machines with different shapes and size types, both domestic and overseas brands, in their manufacturing of forged and cast rolls for metals and steel industry applications. They make products that range from 4-50 tons, so it is imperative to keep the machine operations running. If a tailstock is not exactly right to meet their applications' load bearing requirements, product quality issues inevitably arise.
UES typically runs their machines for two to three years before they need to use Riten's specials program. Additionally, to avoid costly downtime during this process, they keep a complete spare bearing assembly available at all times. They rarely replace the spindle as their production is not as hard on it. Depending on the application, they try to get 5-10 years of use (or longer) from the machines.
According to Tom Moore, UES Director of Maintenance, "Typically, the age of the equipment will show the need for specials. With age, you start to see the problem-particularly if they have not been maintained well over time. Also, as you use a tailstock over time, repeatedly running the quill in and out, it takes on wear, so the need to retrofit or upgrade is apparent. Implementing Riten's specials program is done uniquely on a case-to-case basis per the machine's wear indicators."
Recently, UES had Riten retrofit a couple of their key machines. They were able to pull off the old tailstock and quill assembly and mounted the spare-which is vital to minimizing downtime. As a result, their downtime was days instead of months. The worn unit was then sent to Riten where they retrofitted the tailstock quill.
Riten's Hizer noted, "We rebuilt one of the quills to a like-new standard so that the machines were identical internally. Also, we replaced the inside parts of the lathe and the worn-out bearing assembly of the machine. In total, we did two assemblies and a spare. Their spindle material is specific to their machines' demanding application requirements, so we set them to those standards."
According to Moore, "The need for implementing Riten's specials program is uniquely case-to-case, as size and cost of the assembly varies. A tailstock specials package might range in the 20-80K plus range. Obviously, this is significantly less than the major investment required for new capital equipment. The program is a good backbone for minimizing downtime, as Riten has the replacement spares on hand so we can keep running. If I sense that wear is breaking it down, I can immediately call them to engineer a solution for us. I then send them the tailstock quill assembly to determine if it is a complete rebuild design or if we can repair/refurbish what we provided. If it is not too damaged from wear, the bearing assembly turnaround time is also much shorter."
Kirby concluded, "Ultimately, for most of Riten's clients, the potential downtime alone would be much more than the replacement costs. The majority of Riten's clients implement specials every two to four years depending on how heavy they run their machines. It is also critical to have a spare in place during this process. In fact, without a spare in place most machines could be down three months or more for most clients."
Moore noted, "Critically, Riten's specials program allows us to swiftly adapt to our specific production needs and unique machining applications to achieve higher efficiencies."
For more information contact:
Riten Industries, Inc.
1100 Lakeview Ave.
Washington Court House, OH 43160
800-338-0027 / 740-335-5353
www.riten.com