Monday, October 26, 2015

Kuroda Jena Tec : Principles of Ballscrew Repair

Kuroda Jena Tec's ball screw repair technicians can recondition or repair ballscrews of any make or configuration with a range of transfer systems. At our specialised repair and testing facilities, we can recondition ballscrews up to 15m in length and 200mm in diameter. Additionally, we can replace ballscrews, offering a re-engineered matched replacement utilizing our existing inventory, up to 80mm in diameter.
Every repair evaluation includes a health check and free of charge assessment report. Our skilled technicians will disassemble, clean, inspect and determine cause of failure. The ballscrew is initially inspected for shaft straightness, bearing journal total indicated runout (TIR), fine thread and journal condition and wear to the shaft.
The ballscrew is then stripped and all parts are vapour de-greased and checked internally for Ball transfer system damage, Brinelling, fatigue, corrosion and damage to raceways. Each individual ballscrew shaft raceway is then polished, fine threads are cleaned and dressed out if necessary. The ballscrew is reassembled using new, high quality chrome steel balls to the correct pre-load specification. Lastly, the ballscrew is put through a series of tests and one final inspection to ensure precision and quality. If it is predetermined that the ballscrew is beyond economical repair, Kuroda Jena Tec offers reverse engineering and will quote for a replacement ballscrew manufactured in accordance with the sample. This should also be considered if the ballscrew is in a poor but running condition. Ballscrew sizes in diameter up to 80mm and in precision grade are held in stock in the UK and USA which can be retrofitted for replacements. Sizes over this diameter are supplied through Kuroda Jena Tec's German facility supported by the regional technical office. Warranties offered on repair services are dependent on repair assessment, ranging from zero warranty (where a replacement is recommended) to 6 months maximum. For more details on how Kuroda Jena Tec can supply your requirements please visit our websites on

Kuroda Jena Tec : We Make Other Stuff Too!

Kuroda Jena Tec is increasingly known as a manufacturer and supplier of linear products for high precision ballscrews. However what is less widely known is the full range of high quality components for the machine tool and automation manufactured by the Kuroda Jena Tec group globally summarised below.
Motorised and belt driven spindles are designed and manufactured in our UK facility and provided globally to high calibre machine tool customers for grinding, milling, turning applications. An experienced and established design team works with OEM customers to meet the exact customer design specification. Utilising precision grade bearings spindles can be offered in a variety of round body or prismatic housings up to 100,000rpm with numerous additional technical features including ATC, Through spindle coolant, HSK, ISO, BT tool interfaces. Design and manufacture of multi head spindles for transfer lines remains a core competence of the UK team as well modular grinding heads for use on VTL’s or turning machines to grind complex components. Specifically related to the UK, Kuroda Jena Tec is the exclusive distributor of GMN spindles in the UK and Ireland and provides sales and service support for this popular and high quality German range.
Precision Gauges - Since its founding in 1925, Kuroda Precision Industries Ltd. has continued to advance with the history of gauges in our country, and has been striving for improvement in the product quality and reliability. As a result, Kuroda Jena Tec has successfully received the highest class evaluation as a pioneer of gauge manufacturer, such as an authority to indicate JIS "Grade 1" thread gauge mark for the first time in Japan and a production license for API gauges first time ever in the East. The importance of gauges has been recognized anew, because they play a significant role in quality control and quality assurance and the traceability of measurement has become a necessary condition in the quality management system represented by ISO 9000 Series in recent years.
As an authorized company for length section calibration, Kuroda Jena Tec believes firmly that it will be of service to the establishment of traceability of customer's measurement equipment to the national standard through the calibration and certification of gauge blocks and other various gauges as well as measurement equipment. In addition, our ultra-precision machining technology accumulated through the development of gauges is the essential technology contributed to the expansion of all of KURODA's products, and this technology is efficiently employed in tooling, precision grinding ball screws, pulse encoders, CNC surface grinding machines, super polishing machines, surface profile measuring systems, precision press dies, etc. Spindle Test Bars - Kuroda Jena Tec’s range of precision gauging also allows our Japanese production facility the capability to produce high quality spindle test bars in HSK, ISO or BT taper interface.
MQL Systems - Kuroda Jena Tec manufacture MQL systems in Japan and supply to leading global machine tool manufacturers. MQL as an acronym (Minimum Quantity Lubrication) is becoming slowly more understood in the machine tool industry as its clear technical and cost benefits start to be delivered for users looking to reduce consumption costs and improve technical and environmental factors for their machining processes. Previously MQL had limited applications and was frequently associated with specialist processes such as turning or specialist mould and die finishing with ball end-mill applications. MQL utilises a soluble and/or bio-degradable cutting oil delivered in a fine mist to the machining area via either externally delivered nozzles or via integrated tooling to the work piece. It is used as an alternative to either dry machining where tool life is reduced or in place of high pressure flood coolant. Firstly, the disadvantages of flood coolant are numerous such as the high running cost of coolant pumps, maintenance of coolant systems, cleaning of the work area of the machine tool and particularly in summer or warm conditions the unpleasant odour sometimes emitted by poorly maintained coolant systems. It is probably a common viewpoint in the machining industry that a frequent observation of machine shops using flood coolant require a high level of maintenance not only in monitoring coolant condition but also clearing up spills from leaks and so on that present a health and safety hazard in the work place.
While therefore it would be ideal to implement dry machining the effect on tool life, heat management and process performance means that this is not possible in most cases. Where dry machining is successfully employed, the process performance can be inhibited by the need to balance productivity against surface finish and tool life and maintenance costs. Therefore even where users have a defined dry cutting process, MQL can potentially assist with extending tool life and increase machining performance in terms of surface finish, cutting forces and process capability. Inverter Drives - As a spindle manufacturer, Kuroda Jena Tec is also frequently asked to package spindle inverter drives and supply a package of components to the customer. With in-house electrical design capability, Kuroda Jena Tec UK provides a complete design, supply and commissioning service for inverter drives systems related to precision motorised spindles. This is particularly useful when considering a modular grinding attachment or retrofit and modernisation of a machine tool. Kuroda Jena Tec can therefore provide a complete solution for your retrofit installation.
Hydraulic Work Holding - One of the major challenges in machining operations is the ability to clamp and hold workpieces reliably and repeatedly. Kuroda Jena Tec in Japan have over 20 years design and production experience providing hydraulic clamping utilising thin walled expanding shells to clamp components with 1 micron repeatability. Typically used in grinding operations the constant hydraulic pressure reduces workpiece distortion avoiding twisting or buckling once the workpiece is released.

Thursday, October 1, 2015

Launch of “Fastmake” DIN Ballscrew Machining Service

Kuroda Jena Tec has launched its “Fastmake” service in Europe and North America to service the needs of the market for high precision ballscrews on short delivery. Kuroda Jena Tec now stocks in Michigan and UK from diameter 16mm to diameter 80mm in various quality grades in popular pitch configurations including precision ground, whirled and rolled and is able to provide standard delivery times of 3 weeks including end machining. For express shipments, delivery can be made within 1 week or for emergency breakdown purposes in one day in some cases. Predominantly in DIN sizes, Kuroda Jena Tec also stocks JTs3 series ballnuts with a slightly softer mounting flange without holes which allows the company to customise the hole pattern quickly and easily to suit non-DIN hole mounting. Further flexibility is offered via JTs7 style ballnuts offering plain threaded end fixing without flange offering even more flexibility in mounting options. End machining customisation includes the facility for hard turning of the hardened stock shaft with straightening and journal grinding capability which offers the customer guaranteed OEM quality whether servicing the requests of OEM or MRO customers. In addition to “Fastmake” Kuroda Jena Tec can offer a wide variety of other sizes and pitches made to order from diameter 5mm up to 125mm with standard or customised ballnuts from their Japanese and German production facilities. For more information please contact your local sales office or authorised distributor via

Kuroda Jena Tec Harmonisation Creates Global Ballscrew Brand

Since the acquisition of Jena Tec in 2012 by Kuroda Precision Industries Ltd of Japan, the company has harmonised and defined its global manufacturing and logistic supply chains to support future growth. Formerly separate brand names of “Kuroda” and “Jena Tec” are now combined as “Kuroda Jena Tec” and registered as a trademark globally. The harmony of the Kuroda Jena Tec brand symbolises the best of Japanese and German quality, accuracy and precision. The Kuroda Jena Tec ballscrew product line up is now one of the most comprehensive in the market providing from diameter 5mm up to diameter 125mm. Manufactured in both JIS and DIN standards, the company is able to offer customised and standard ballscrews in a range of diameter and pitch configurations in rolled, whirled and ground quality. All market sectors can now be adequately serviced by the Kuroda Jena Tec product range including machine tool, automation, PCB, Semi-conductor, packaging, handling, etc. High lead capability is a particular strength of the Japanese product range with many attractive features including maintenance free lubseal options and BTA end adaptors reducing delivery time. Since acquisition, Kuroda Jena Tec has expanded its market sectors and has grown sales through its enhanced sales network into mainland Europe and North America. Expansion has seen investment in new end machining capability in North America as well as significant stock investment in Europe and USA to allow Kuroda Jena Tec to shorten delivery times to same day in many cases. For more information and to find your local sales office or authorised distributor go to