The acquisition of North American Tool Corporation extends custom product capability into the threading space, a new offering for GWS that adds a powerful dimension to the already robust product and service portfolio.
TAVARES, Fla., Feb. 4, 2020 /PRNewswire/ -- GWS Tool Group is pleased to announce it has acquired North American Tool Corporation (NATC).
"NATC is an exciting add for us," said Rick McIntyre, GWS' CEO. "Their customer service model is one of the best in the business, and their focus in taps and threadmills fits in like a perfect puzzle piece to our dynamic and holistic offering. We are very excited to be continually expanding our value proposition for our customers with highly additive acquisitions like this," McIntyre continued
"North American Tool is very excited to be joining GWS Tool Group, a company that embodies the attributes that have long made us successful," said Curt Lansbery, NATC President & CEO. "A customer-centric approach to business rooted in a commitment to quality and quick delivery marry perfectly with our model here at North American Tool. We have no doubt that this move to join GWS will be positive for our associates and will ensure the continued growth of the legacy that we have worked to develop."
The team at NATC will continue to operate from the Illinois facility as a manufacturing arm of GWS Tool Group, and the company expresses intent toward continued investment in the facility, machinery and equipment, and human resources. Customers of NATC are said to expect continuity of the NATC offering and customer service disposition under cover of the GWS ownership.
About GWS Tool Group
GWS Tool Group is a U.S.-based, vertically integrated manufacturer of highly engineered custom, standard, and modified standard cutting tools, primarily servicing the aerospace and defense, power generation, automotive and medical sectors. GWS Tool Group has acquired multiple businesses in the course of its growth, which now serve as the respective manufacturing divisions of the Company.
Retention Knobs are the critical connection between your machine tool and the tool holder and they are the only thing holding a steep taper tool holder in the machine’s spindle.
Techniks has recently introduced their MegaFORCE retention knobs that have some rather unique features when compared to standard pull studs. Before delving into the features of the MegaFORCE pull studs, let's review some things that you may not know, or think about, on a daily basis.
However, if you're running multiple shifts, 24-7, making lots of tool changes, making very heavy cuts with long reach or heavy cutting tools, and/or have ball lock style grippers instead of collet type grippers used on the retention knob, you will probably need to replace your studs at least every six months.
Given the spindle speeds that we are running at to remain competitive, retention knobs are not an item that you want to take a chance on breaking. I can tell you firsthand that 5 pound toolholder with a drill in it flying out of the spindle at 23,000 RPM is not something you want to experience.
Metal Fatigue: Why they fail
Pull studs encounter catastrophic failure as a result of metal fatigue. The metal fatigue can be caused by a number of reasons including poor choice of base material, engineering design, machining process, poor heat treatment, and, sometimes, they have just met or exceeded their service life. We're going to dig into each of these reasons below but first let's look at some threading fundamentals.
That is why the length of engagement of the thread on a pull stud is generally limited to approximately one to one & a half nominal diameter. After that, there is no appreciable increase in strength. Once the applied load has exceeded the first thread's capacity, it will fail and subsequently cause the remaining threads to fail in succession.
Retention Knob design
Repetitive cycles of loading and unloading subject the retention knob to stress that can cause fatigue and cracking at weak areas of the pull stud.
The most common failure point for a retention knob is at the top of the first thread and the underside of the pull stud where the grippers or ball bearings of the drawbar engage and draw the toolholder into the spindle.
Remember, bigger Radii are stronger than sharp corners. More on that soon.
Not all retention knobs are made from the same material, however, material alone does not make for a superior retention knob. Careful attention to design and manufacturing methods must be followed to avoid introducing potential areas of failure.
MegaFORCE retention knobs are made from 8620H. AISI 8620 is a hardenable chromium, molybdenum, nickel low alloy steel often used for carburizing to develop a case-hardened part. This case-hardening will result in good wear characteristics. 8620 has high hardenability, no tempering brittleness, good weldability, little tendency to form a cold crack, good maintainability, and cold strain plasticity.
There are some companies making retention knobs from 9310. The main difference is the lower carbon content in the 9310. 9310 has a tad more Chromium, while 8620 has a tad more nickel. Ultimate Tensile Strength (UTS) is the force at which a material will break. The UTS of 8620H is 650 Mpa (megapascals: a measure of force). The UTS of 9310H is 820 Mpa. So, 9310H does have a UTS that is 26% greater than 8620H.
That said, Techniks chose 8620 as their material of choice because of the higher nickel content. Nickel tends to work harden more readily and age harden over time which brings the core hardness higher as the pull stud gets older. The work hardening property of 8620 makes it ideally suited for cold forming of threads on the MegaFORCE retention knobs.
It should be noted that some companies are using H13. H13 shares 93% of their average alloy composition in common with 9310.
Rolled Threads vs. Cut Threads
A cut thread, image 1, has a higher coefficient of friction due the the cutting process, while a roll formed thread, image 2, has a lower coefficient of friction which means that it engages deeper into the toolholder bore when subjected to the same torque. You will notice that Cutting threads tears at the material and creates small fractures that become points of weakness that can lead to failure. Rolled threads have burnished roots and crests that are smooth and absent of the fractures common in cut threads.
Rolled threads produce a radiused root and crest of the thread and exhibit between a 40% and 300% increase in tensile strength over a cut thread. The Techniks MegaFORCE retention knobs feature rolled threads that improve the strength of the knob by 40%.
megaFORCE GeomEtric design
There are some claims that a longer projection engages threads deeper in the tool holder preventing taper swelling. While a deeper thread engagement can help prevent taper swelling, applying proper torque to the retention knob is an effective way to reduce taper swelling.
An over-tightened retention knob may still cause taper swelling regardless of how deep it engages the threads of the tool holder. Additionally, the longer undercut section above the threads presents a weak point in the retention knob.
Magnetic Particle Tested
Each MegaFORCE retention knob is magnetic particle tested to ensure material integrity and physical soundness. MegaFORCE retention knobs are tested at 2.5X the pulling forces of the drawbar.
Retention Knob Best Practices
In order to maximize the life of your retention knob and prevent catastrophic failure here are some technical tips to keep your shop productive and safe.
indication marks on Pull Studs
There have been some who claim that drawbar gripper fingers and/or ball marks that appear on retention knob head after several tool changes is normal.
It is NOT. THAT IS FALSE.
According to Haas CNC, ball or gripper marks on the edge of the pull stud indicate that the drawbar does not open completely. If you see these indication marks you should check your drawbar and replace these pull studs immediately.
Now features a Universal Fixture Kit.
Check it out in the new 2021 catalog below!
Our customers in turn receive the solutions they need most. If you have machining challenges, you’re sure to find a solution with Blue Photon’s workholding system.
They also offer fixture design and engineering for milling, turning, grinding, electrical discharge machining (EDM), 3D printing/additive manufacturing, laser, inspection and assembly applications for the aerospace, medical, optical, and robotic industries.
You can view or download the catalog below.
In 2002, a new management team was established. One of the goals the team set during its first few months was to find a permanent location for Horn USA. Large buildings in the light industrial zone are not commonplace in the immediate area of Horn USA, so it took a while to find the ideal opportunity.
Finally, in 2016, 10.76 acres with a 101,000-square-foot light industrial building became available. In typical Horn fashion, advantages and disadvantages were analyzed and finally one came together to the conclusion that this real estate among other things because of its proximity to the existing plant, provided the ideal solution to the next stage of expansion.
In the third quarter of 2019, construction began to bring the facility to the standards expected of Horn. In total, this meant an investment volume in buildings, conversion and technical equipment of approx. 29,000,000 dollar (approx. 25,000,000 euro). Nearly 400 people in all have been involved in the 14-month construction project. The new building has a total area of 11,000 square meters and can accommodate up to 300 people. Horn USA currently employs 120 people.
According to Andreas Vollmer, President Horn USA,
“The new building in the USA makes a clear statement and demonstrates our commitment to the American market. Other than our home market of Germany, this is our strongest international market and has been for a long time. It is also one that holds huge potential for our solutions in the future. The new building provides us with the space we are going to need for this. We are very proud of taking this step and are convinced that it will ultimately benefit our customers as well — in the form of increased production capacity, larger training rooms and our new demonstration centre, for example.”
to the challenges of traditional holding methods
written by Dan Billings & Shannon Osborn, Blue Photon
In both fixed and rotating applications, the vacuum is often applied with a rotary union. Once the workpiece is loaded into the fixture, the vacuum is turned on to allow the part to be pushed into the fixture by atmospheric pressure. The vacuum is turned off to remove or release the part.
Unexpected loss of the vacuum during machining can be catastrophic to the workpiece and grinding wheel. Epoxy products can be time-consuming and difficult to remove. Furthermore, the part may require solvents or slow heating after processing to remove the epoxy, which can lead to longer cycle and setup times, as well as environmental issues related to the disposal of those solvents.
A variety of newly available adhesives designed specifically for workholding can eliminate part movement during machining, can speed processing times, and can resolve other challenges created by traditional methods (Figure 3). UV-curable adhesives are well suited for holding parts during processing and they enable easy part removal and quick cleanup. High-viscosity adhesives, which can fill gaps between the surface of a part and fixture, supply strong holding power.
If the optical material is transparent to UV light, the adhesive can be cured through the optical material in as little as 60 seconds. If the material does not transmit enough UV light to set off the curing process, then grippers are used and the UV light is transmitted through the gripper to cure the adhesive from the underside of the part. Grippers are patented, load-bearing, and light-transmitting fixture components that enable complete photoactivated adhesive curing.
With new adhesives, traditional holding processes change. First, a thick layer of adhesive is applied between the part and holding device. Grippers are inserted into a fixture and can serve as the interface between the workpiece and holding device if needed. The workpiece is then secured to the grippers with the workholding adhesive, which is cured with UV light transmitted through the core of the gripper. The average tensile holding power of the gripper is between 200 and 605 lbs per adhesive joint and based on the size of the gripper selected.
When the workpiece is loaded, UV light is either passed through the grippers or the workpiece material for 60 seconds to cure the workholding adhesive. Once cured, the workpiece is held in place securely, which allows for aggressive processing. The parts can then be removed from the holding device by hot water soak with a temperature between 170 and 200 ºF. The high temperature eliminates the need for toxic solvents and allows for faster release of the adhesive. Typical debonding time generally runs 2 to 5 minutes. Residual adhesive is easily removed by applying pressurized steam or hot water spray in conjunction with a gentle peeling action (Figure 4).
New adhesives require significantly less preparation than wax, resin, or mechanical clamps, and setup times can be reduced by as much as 75%. For example, once a workholding adhesive is implemented, hours per day can be saved just by eliminating the waxing process, which includes several time-consuming steps: warming wax, mounting the workpiece on wax, allowing the wax to cool before machining, and degreasing wax to clean parts.
New adhesives reduce setup times, eliminate scrap and toxins, enable the operator to have precise control between operations, and ensure the surface integrity of the optical workpiece.
Meet the authors
Dan Billings is president and CEO of Blue Photon Technology & Workholding Systems LLC. He has worked in manufacturing for more than 30 years in the aerospace, medical, optics, and additive manufacturing industries. He is also experienced with the challenges of holding difficult parts for machining.
Shannon Osborn is marketing manager and works on product development at Blue Photon Technology & Workholding Systems. She has a bachelor’s degree in visual communications from Kendall College of Art and Design.
If your operation requires you work with tough, difficult materials, HSSE taps may be the solution that you’re looking for. Engineered to withstand even the most challenging materials and applications, Allen Benjamin’s high speed steel taps offer unparalleled tool life and increased wear resistance.
Because of this, they’ve become the go-to solution for applications that demand a durable, lasting solution. In today’s post, we’re going to discuss three reasons you should consider taps from Allen Benjamin.
Designed to tap even the hardest materials, HSSE taps are made from high speed steel, which contains a higher concentration of cobalt and vanadium. This composition lends incredibly high resistance to wear, resulting in much longer average tool lives. Due to this, you can be confident that you’re purchasing a lasting, durable solution.
When selecting taps, the number of available options can often be intimidating. To address this, Allen Benjamin color codes all of our products. With six color rings available, you — and your employees — will be able to easily locate the exact tap that they need, when they need it, thus reducing downtime, increasing efficiency, and preserving profits.
When you source from Allen Benjamin, you can rest easy knowing that you’re working with the industry’s most trusted supplier of HSSE and carbide taps. Just like F&L Technical Sales, Allen Benjamin is committed to treating our customers to a better experience, we focus on delivering high-quality products and — more importantly — attentive, knowledgeable customer service.
Our F&L Technical Sales team will work with you to understand your application, recommend potential solutions, and supply you with the taps that you need. So, if you’ve been considering a new supplier for your operation’s carbide taps, HSSE taps, or smart tapping fluid, be sure to browse our website and contact us with any questions you have.
Original GMN parts, precise measurement devices and tools, along with the expertise and experience of GMN's highly qualified staff guarantee that their spindle repair service meets our customer’s expectations of quality, reliability and performance.
GMN uses this same method when servicing spindles supplied by most other machine tool spindle manufacturers as well.
GMN USA utilizes only the best components when refurbishing spindles. The use of GMN ABEC 7 and higher quality bearings assure the best possible accuracy and reliability for their spindle repairs. Motors, clamping systems, sensors and other critical parts supplied by vendors must meet strict GMN quality standards. All this attention to detail ensures that spindles are returned to our customers with “like new” performance and reliability.
GMN USA is equipped with a variety of grinding machines that cover all of their grinding requirements. All spindle component grinding operations are completed in their facility to ensure high quality and a quick turnaround time. The GMN USA assembly and test departments utilize state of the art spindle drives and vibration analysis equipment to confirm that each spindle meets very exacting demands.
The experienced team of engineers, machinists and spindle technicians at GMN USA is focused on providing the best possible service and technical advice to our customers.
Their spindle repair service includes an accurate evaluation of incoming spindles, replacement or refurbishment of damaged components, dynamic balancing, extensive testing and vibration analysis.
Below is a video showing GMN USA in Farmington, Connecticut going through their spindle repair process. It is the most comprensive repair process in the industry.
In addition to a comprehensive range of standard spindle types, GMN also will design and develop special spindles to meet the specific requirements of our customers.
GMN is a market leader for spindle technology worldwide, especially in the field of innovative solutions for precision and high speed machining.
Give us a call with questions!
Shrink fit holders are the most accurate for TIR as the toolholder engages completely around round shank tools with a bore tolerance of -0.0001" to -0.0003". As high performance end mills have tightened shank tolerances to the same range of -0.0001" to -0.0003" they have used finer and finer grain grinding wheels which give the shanks a 'shiny' appearance.
Shiny means that the superfinished shank has a lower coefficient of friction. So, although the TIR is tighter, the shank is more "slippery". End mills traditionally had surface finish of about 8 μin on the tool shank. But that's changed. It's been recommended that tool shanks used in shrink fit holders should not have a finish finer than 16 μin. for optimum holding power, but tell that to the guy who just superfinished the end mill to a super cocncentric tolerance that you don't want it looking that good.
Everyone know that the last thing you want is for the end mill to slip in the middle of a heavy cut or on the finishing pass of a high tolerance part. These 'hi performance' end mills, often times have higher helix angles which are great for ejecting chips but also create a higher pull out force on that slippery shank. And reducing the helix angle is not the answer.
We already know that the gripping pressure is a function of the interference between the tool shank and the shrink fit toolholder bore. Most shrink fit holders have a already bore surface finish of between 12 μin. and 16 μin. So they are ground to a very high tolerance and have about the same surface finish as the toolholder shank.
End mill manufacturers and machinist have tried a variety of methods over the years to stop the tools from pulling out. This has ranged from grit blasting the shank to rubbing chalk on the shank, but most everyone in the industry has felt that the problem really needs to be addressed by the longer life toolholder rather than the replaceable cutting tool.
Techniks arrived at their 4x the holding power comes from torsion testing vs. a standard shrink fit toolholder. They used a ¾” carbide gage pin in a standard holder and found the torque at which the tool will spin in the bore.
They then tested the ShrinkLOCKED holder using the same test.
According to Greg Webb, at Techniks,
"We actually could not find the point at which the tool would spin in the ShrinkLOCKED holder as we broke the carbide gage pins at 4x+ times the torque of the standard holder. The holding power is greater, we just have not found a way to measure this, so we kept our claims conservative at 4x."
The challenge was to achieve both hard and soft cost savings, as well as time spent on drilling flanges from one side, chamfering the backside and creating a controlled chamfer on the top surface which was a secondary process.
We designed an indexable drill with our rear cutting carbide deburring insert along with a fixed pocket chamfer insert to create the precision top chamfer that was required. The spade drill insert also had a special feature that allowed it to chamfer the top side of the bottom hole that was pre-drilled.
Four operations were completed in one pass.
The EZ Burr Burr-Free Drill drilled the hole, deburred and chamfered the back all in one step, thus eliminating the secondary step of chamfering the bottom surface on the top hole.
This saved time as well as money, plus the tool life of the Burr-Free Drill achieved a more consistent result and had a longer tool life than the previous method.
Written by Mark Kirby AM Business Manager, Renishaw Canada
Printing is usually not the end of the process. Almost always, after printing and any heat treatment, metal parts require some machining in a few areas.
Sometimes to improve surface finish, more often to allow fasteners to lock the component in place. For example, spinal clamps can expand with living hinges, or a captive ball and socket can be printed as one and locked with a set screw.
In both cases the threads required will be machined rather than printed. If machining is only required in one direction, then parts can sometimes be machined on the build plate. Usually machining is required from multiple directions and it is impossible to access these areas with multiple parts printed on the plate.
The workholding challenge is then how to best hold the component for machining after it is removed from the build plate.
3D Printed Workholding
The main disadvantage of plastic jaws is that they will often distort the component as they are tightened. Although the jaws hold the part rigidly for machining, when the component is released from the fixture any machined bores may no longer be perfectly round, and true positions of features will have moved slightly as the component relaxes back into its unloaded shape.
A recent collaborative project involving Renishaw, University of Waterloo and Intellijoint Surgical investigated a printed alternative design for an optical tracker used in total hip arthroplasty. The tracker provides surgeons with intraoperative measurements, enabling proper establishment of cup position, equalization of leg length and restoration or maintenance of offset and joint center of rotation.
A plastic set of jaws was designed to clamp the part while leaving the machining areas exposed. Although the plastic jaws clamp the part rigidly, they never clamp the part repeatably, so the exact position of the part must be found using a machine probe and best fitting software such as NC-PerfectPart, from Metrology Software Products Ltd. (MSP). Originally developed for machining of high value aerospace and Formula 1 composite structures, this software is perfectly suited to the challenge of precisely locating an organic-shaped AM part with no obvious datum features.
Points are selected on the component in the CAD environment and the deviations from nominal positions are measured by the probe on the CNC machine. The NC-PerfectPart software then creates a best fit alignment that is a 6-axis coordinate transformation—both translation and rotation. This coordinate shift is automatically recalled into the machine controller before CNC programs are executed.
The machine probe is also used to automatically achieve very high tolerances by employing a “cut/measure/cut” strategy.
Features are semi-finished, measured and compensation automatically applied to achieve tight drawing specifications on final machining passes.
This approach allows for variables such as cutter/part deflection under load, and tool variation from programmed size.
Problems and Solutions
In order to machine the part accurately it was essential not to bend it with mechanical clamping, but at the same time it was equally important to add rigidity.
The solution was to use Blue Photon’s UV activated adhesive and grippers. By gluing the part onto four gripper posts (that transmit UV light to cure the glue in approximately 90 seconds) the hip tracker was held firmly but still in the free state.
An aluminum block was machined to hold the four gripper posts in the correct positions for the tracker body. Initial machining was successful on the three posts directly bonded to the grippers, but one post was cantilevered above the gripper and vibrated during machining. A plastic support block was printed to hold this post and eliminated this problem. By cradling the part, the support block also allowed for more accurate positioning of the tracker prior to the glue being cured. The glue thickness is optimally around 1mm, and after machining the part and fixture can be separated by simply immersing the assembly in near boiling water for a few minutes, and then peeling apart.
The only disadvantage of using the glue grippers appeared to be the extra work to design and machine the gripper fixture. However, on a subsequent project for an industrial impeller Renishaw used plastic printing to produce the gripper fixture instead of machining. This proved that the manufacture of a robust, custom workholding solution can be reduced to an overnight desktop print.
Refining the Procedure:
The cranial plate is also defined as an obstacle that must be avoided. A preserve ring would be defined, and constrained, to enable the completed fixture to be held in a chuck. Loads are added to the gripper bushing preserve regions to represent machining forces that must be resisted. The software can then solve the structural connection of all the parts for maximum stiffness.
One of the barriers to adoption of patient specific solutions is the high design cost typically involved. Using generative design coupled with plastic printing is an innovative solution that largely automates the workholding process with Blue Photon’s adhesive grippers.
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