Lately, I have been asked several questions about hole finishing. Many are concerned about the best method to use. Should I use a boring bar, multiple cartridge boring head, reamer, or what is the best method to finish my part?
As you know, numerous things will help determine an answer. We’ll need to look at the amount of stock being removed, the finish required, the total tolerance we must work with, the machines we have available to produce the part, and any fixturing issues that may exist.
The most common mistake I see from customers is the length-to-diameter (L:D) ratio used when boring parts. The best practice is to use the largest diameter boring bar that fits into the bore. This will also give you the most stiffness and eliminate tool deflection. The second consideration is the depth of the bore and again the diameter of the bar. By using the larger diameter bar, you’ll achieve greater depths as well.
Tooling suppliers offer a wide range of boring tools. Most of them offer tools with diameter adjustment and at least two cutting heads. This type of tool maximizes metal removal while providing a more stable cutting condition to help eliminate tool deflection. Single head or pocket boring bars offer multiple pocket designs that allow you to change the geometry of the cutting insert and provide the flexibility you need to produce your parts. Most of these tools come in steel or carbide shanks with replaceable heads.
Another area of concern is the machine tool you’ll use. Often, we see machines that are too small or lack the horsepower to produce the parts. In these cases, we must look at the safety of the operator first and make sure we safeguard against machining a part that is too large for our machine.
So, what’s the answer to our original question? There’s no one answer. Variables are numerous. All questions must be answered to determine the best way to bore the part. In some cases, reaming may be the best approach, a dual-headed boring bar may be best, or a plain single-head boring bar may be the answer. However, we should always look at our L:D ratio and maximize the diameter of the boring bar we’re using. Consider chip removal and use through-the-tool coolant, if possible, to help chip washing.
I suggest working with your tooling supplier. They have the application expertise and can help guide you to the proper tool selection. Go ahead and lead a boring life!
Do you have specific topics you would like addressed or cutting tool challenges? Email me so I can address them in a future column.
Mike Ramsey, president of CMR Consulting, retired from Kennametal Inc. as vice president, global machine tool industry sales, after 39 years of service in sales and marketing. He can be reached at miker2468@aol.com.
The AcuGrind air chuck features a built-in actuating cylinder (no hydraulic cylinder is required) for extreme tolerances during turning and grinding applications.
Designed to handle precise finishing, AcuGrind provides 0.000078" accuracy and is ideal for miniaturized components that require extreme tolerances and for machining abrasive materials such as powder metal or carbide. AcuGrind can perform both ID and OD clamping using a boring ring and pin. Its case-hardened base jaws allow for extra rigidity and repeatability within 0.002mm.
Available in 80mm to 250mm, AcuGrind comes fully sealed as part of Proofline Series chucks, reducing overall maintenance. Permanently lubricated, these oil-filled precision chucks help maintain consistent grip force. Other advantages include a case-hardened body and internal parts for high resistance and extended life.
The Vito filter line offers high efficiency and uses all types of oil- and water- based lubricants.
The Vito filter is placed inside the basin where it filters the liquid automatically in pulsed filtration cycles and ventilates water-based coolant to avoid tramp oil from building a surface layer. Using a cellulose filter, the pressure flow-filtration removes chips and solids from any coolant lubricant. It filters the coolant while machinery is in operation to ensure a sufficient and smooth process of maintaining the lubricant.
The filter decreases running cost for tools, increases the quality of lubricants for more accurate workpieces and better cooling, and reduces machining center maintenance.
The expanded range of True-Lok toggle clamps includes four versions with an additional locking mechanism for added security. The added feature ensures the toggle clamp will remain in the closed/hold down position for maximum security in workholding applications. Additionally, it also ensures that the clamps remain in the unclamped/open position to facilitate part change and operator convenience.
True-Lok toggle clamps are available with flanged-base in either steel or stainless steel and are suitable for numerous applications in many industries. The secondary lever that actuates this feature has been designed for thousands of cycles and to be easily accessed and engaged by the operator. Holding capacities range up to 7,700 lb. Twenty-five new line items are offered in total.
The HPX-DR 2329 GK detector has a 75µm resolution offering powerful image capture for miniscule defect detection. It’s suitable for inspecting critical parts and assemblies to identify defects including small cracks, porosity, and flaws.
Designed for high resolution to meet stringent industry standards, the detector also expands the variety of parts that can be examined and improves the accuracy of each inspection.
Calypso 2021 software includes more than 60 new functions and improvements, leading to significantly better performance in quality control. With improved mathematical algorithms, measurement results are 20x faster.
O-Inspect reduces unnecessary travel paths and increases the possibility to sort measurement elements, significantly speeding up optical measurement processes. It also combines as many measurement elements as possible into one camera position, automatically determined according to the pre-set zoom level, optimizing measurement time up to 270%.
Improvements in the programming process can save additional time. For example, Zeiss has simplified the workflow for showing deviation flags and introduced numerous improvements for importing product and manufacturing information (PMI).
Designed for complete machining of all six sides of complex parts, the 715 Series machining center fits between the vertical Chiron FZ 08 S mill-turn Precision+ machining center and the Stama MT 733 machining center. It includes part handling automation and storage.
Part size range is bars up to 65mm or chuck parts up to 200mm, with 20kg max. workpiece weight.
The machine platform also integrates digital systems from the Chiron SmartLine portfolio, including automatic condition monitoring, integrated machine and process diagnostics, machining simulation, preventive machine protection in every mode of operation, remote diagnostics and maintenance, and intuitive operation.
White Salmon, Washington-headquartered Sagetech Avionics Inc. has received a $12 million investment from Due West Partners, a Seattle, Washington-based private investment firm. The investment will accelerate Sagetech’s unmanned aerial vehicle (UAV) detect and avoid (DAA) capability.
Sagetech Avionics recently demonstrated detect and avoid on UAV Factory’s Penguin C aircraft as part of a Phase 1 Small Business Technology Transfer (STTR) for the United States Air Force.
Sagetech has been collaborating with the Federal Aviation Administration (FAA) to test algorithms for ACAS X, the next generation of airborne collision avoidance that’s become an international standard. ACAS X uses advanced algorithmic techniques and probabilistic models to obtain the safest and best possible collision avoidance system for all piloted and unpiloted aircraft.
Credit GA-ASI
UK orders 13 additional GA-ASI Protectors
The UK Ministry of Defence (MoD) has exercised its contract option with San Diego, California-based General Atomics Aeronautical Systems Inc. (GA-ASI) to manufacture and deliver 13 additional Protector RG Mk1 Remotely Piloted Air Systems (RPAS) to the MoD’s initial order for three systems.
“The Protector program involves industry across the UK with vital parts of the aircraft manufactured on the Isle of Wight, supporting highly skilled jobs for years to come,” says Jeremy Quin, UK Minister for Defense Procurement.
GKN Aerospace is manufacturing the advanced composite V-tails for the MQ-9B at its center of excellence in Cowes, the Isle of Wight.
GA-ASI’s MQ-9B SkyGuardian is the baseline system being configured for the Royal Air Force (RAF) as the Protector RG Mk1. It includes X-band satellite communications (SATCOM) for automatic takeoff and landing and support for UK weapon systems, as well as the aircraft’s onboard sensors, including its electro-optical sensor ball and Lynx multi-mode radar.
Antavia Ametek, Viking support aerial firefighting
Viking Air Ltd. of Victoria, British Columbia, Canada, has renewed its Antavia Ametek maintenance, repair, and overhaul (MRO) landing gear maintenance support for an additional three years. The agreement, initiated in 2018, confirms Antavia as a factory endorsed component center (FECC) and official repair station to support Viking’s Canadair fleet of CL215/CL215T/415/415EAF with landing gear. The aircraft are used globally as water bombers in combating forest fires.
Antavia’s landing gear maintenance covers more than 60% of Canadair’s worldwide fleet.
Laurent Bouissou, Antavia’s managing director, says, “We know how important it is to return these aircraft to service. We strive to continually reduce our turnaround times by improving the availability of spare parts as well as by investing in our engineering methods and workshop organization.”
In recent years, Antavia has developed a spare parts inventory of $10 million, strengthened its dedicated engineering and workshop teams, and added new machining resources.
Viking Air Ltd.; AvAir
AvAir secures IAI engine asset management
Chandler, Arizona-based aviation aftermarket provider AvAir has contracted with Israel Aerospace Industries (IAI)Aviation Group to provide asset management for more than 20,000 line items, including internal parts and accessories for CFM56-3, CFM56-5B, CFM56-7B, V2500-A5, and PW4000 engines, along with airframe components for the Airbus A320 and Boeing family aircraft.
AvAir offers solutions for customers and suppliers to buy, sell, exchange, loan, lease, or consign inventories with more than 26 million in-stock parts.
MULTI Degrees-of-Freedom (MULTI-DOF) encoders offer machine manufacturers a better way to implement metrology designs to obtain multiple measurements simultaneously and facilitate correcting deviations on the fly. Conventional encoders offer one degree of motion, but these three new encoders do more to serve demanding requirements.
Traditionally, an encoder only measures deviations along a single axis, and although these can be corrected via some controllers, they can still be blind to common but unavoidable effects of guideway error or thermal linear expansion (to name a few) which would cause deflection along multiple axes. Using multiple reader heads enables detection of these deflections, allowing for the necessary compensation at the inception and ensuring machine integrity.
Users of MULTI-DOF encoders can expect high reproducibility and consistent quality in their systems.
