FREE SAMPLE PROCESSING * CONTRACT FINISHING SERVICES * TURN-KEY FINISHING SYSTEMS
For additional information or sample processing information contact:
by Dave Davidson – Deburring/Finishing Specialist
SME Manufacturing C248 – Spokane, Washington

Advisor: Machining/Material Removal Technical Community 
dryfinish@gmail.com  |  509.230.6821
https://dryfinish.wordpress.com

Below are some process video footage demonstrations of high-speed centrifugal isotropic finishing.  These automated edge and surface finishing methods are capable of producing very refined low micro-inch surfaces that can improve functional part performance and service life.

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Isotropic Micro-Finishing Part Photography by Mark Riley, BV Products

Centrifugal barrel finishing

Centrifugal barrel finishing (CBF) is a high-energy finishing method, which has come into widespread acceptance in the last 25-30 years. Although not nearly as universal in application as vibratory finishing, a long list of important CBF applications have been developed in the last few decades.

Similar in some respects to barrel finishing, in that a drum-type container is partially filled with media and set in motion to create a sliding action of the contents, CBF is different from other finishing methods in some significant ways. Among these are the high pressures developed in terms of media contact with parts, the unique sliding action induced by rotational and centrifugal forces, and accelerated abrading or finishing action. As is true with other high energy processes, because time cycles are much abbreviated, surface finishes can be developed in minutes, which might tie up conventional equipment for many hours.

barfunc
Centrifugal Barrel Finishing principles – high-intensity finishing is performed with barrels mounted on the periphery of a turret. The turret rotates providing the bulk of the centrifugal action, the barrels counter-rotate to provide the sliding abrasive action on parts.

The principle behind CBF is relatively straightforward. Opposing barrels or drums are positioned circumferentially on a turret. (Most systems have either two or four barrels mounted on the turret; some manufacturers favor a vertical and others a horizontal orientation for the turret.) As the turret rotates at high speed, the barrels are counterrotated, creating very high G-forces or pressures, as well as considerable media sliding action within the drums. Pressures as high as 50 Gs have been claimed for some equipment. The more standard equipment types range in size from 1 ft3 (30 L) to 10 ft3, although much larger equipment has been built for some applications.

Media used in these types of processes tend to be a great deal smaller than the common sizes chosen for barrel and vibratory processes. The smaller media, in such a high-pressure environment, are capable of performing much more work than would be the case in lower energy equipment. They also enhance access to all areas of the part and contribute to the ability of the equipment to develop very fine finishes. In addition to the ability to produce meaningful surface finish effects rapidly, and to produce fine finishes, CBF has the ability to impart compressive stress into critical parts that require extended metal fatigue resistance. Small and more delicate parts can also be processed with confidence, as the unique sliding action of the process seems to hold parts in position relative to each other, and there is generally little difficulty experienced with part impingement. Dry process media can be used in certain types of equipment and is useful for light deburring, polishing, and producing very refined isotropic super-finishes.

Below: SME Webinar Presentation on Centrifugal Isotropic Finishing by Dave Davidson (SME Tech Advisor) and Jack Clark (Surface Analytics.com)

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Further reading:  Internet resources

(1)  “Isotropic Mass Finishing for Surface Integrity and Part Performance”,  Article From: Products Finishing, Jack Clark, from Surface Analytics, LLC and David Davidson, from SME Deburr/Finish Technical Group, Posted on: 1/1/2015, [Barrel, vibratory, centrifugal and spindle finish can improve part performance and service life.]  http://www.pfonline.com/articles/isotropic-mass-finishing-for-surface-integrity-and-part-performance

(2)  “Turbo-Charged Abrasive Machining Offers Uniformity, Consistency”  Article From: Products Finishing, by: Dr. Michael Massarsky, President from Turbo-Finish Corporation, and David A. Davidson, from SME Deburr/Finish Technical Group.  Posted on: 6/1/2012.  [Method can deburr, produce edge contour effects rapidly]  http://www.pfonline.com/articles/turbo-charged-abrasive-machining-offers-uniformity-consistency

(3)  “Turbo-Abrasive Machining and Finishing”. MANUFACTURING ENGINEERING – Aerospace Supplement, by: Dr. Michael Massarsky, President from Turbo-Finish Corporation, and David A. Davidson, from SME Deburr/Finish Technical Group. [Method first developed for the aerospace industry can improve surface integrity and part performance]  http://www.slideshare.net/dryfinish/turboabrasive-machining-me-aerospace-supplement-reprint

(4)  “The Role of Surface Finish in Improving Part Performnce”, MANUFACTURING ENGINEERING, by Jack Clark, Surface Analytics.com and David A. Davidson, from SME Deburr/Finish Technical Group.
http://www.slideshare.net/dryfinish/november-2012-f4-deburring-1-final

(5)  “Free Abrasives Flow for Automated Finishing”, MANUFACTURING ENGINEERING, , by: Dr. Michael Massarsky, President from Turbo-Finish Corporation, and David A. Davidson, from SME Deburr/Finish Technical Group. [Exciting new methods of surface finishing that go beyond deburring to specific isotropic surface finishes that can increase service life]  http://www.slideshare.net/dryfinish/october-2013-f2-deburring-1

(6) Turbo-Abrasive Machining Demonstration Video:  https://www.youtube.com/watch?v=jYxqCxMIHNo

(7) SME Spokane, WA Factory Floor video, Centrifugal Finishing in the Precision Machine Shop: Demonstration)  https://www.youtube.com/watch?v=dUdKjaysTYM

 

AUTHOR BIOGRAPHY –  David A. Davidson, [dryfinish@gmail.com]

Mr. Davidson is a deburring/surface finishing specialist and consultant.  He has contributed technical articles to Metal Finishing and other technical and trade publications and is the author of the Mass Finishing section in the current Metal Finishing Guidebook and Directory.  He has also written and lectured extensively for the Society  of Manufacturing Engineers, Society of Plastics Engineers, American Electroplaters and Surface Finishers Association and the Mass Finishing Job Shops Association.  Mr. Davidson’s specialty is finishing process and finishing product development.

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2 thoughts on “Centrifugal Isotropic Finishing Operations on Precision Parts [video]

    1. Hi William: Thanks for your inquiry about deburring and polishing of large aluminum parts. (By the way – how large is large? Can you give me some over-all dimensions for example?)

      This sounds like it might be a really good application for Centrifugal Isofinishing. I am in fact finishing up project on large aluminum parts in LA that involves hand deburring minimization and polishing. I don’t think that the 16 or 32 micro-inch RA requirements will pose that much of a challenge.

      Do you have some of these parts available for (Free) sample processing and feasibility testing? Would it be possible to get some smart-phone pictures of some of the parts so I can make an initial assessment? Please let me know, and I will work to make arrangements for this and give you a shipping address. Here is a project I was also involved with where the company purchased centrifugal isotropic finishing equipment initially for the deburring and polishing of aluminum parts. (SEE: https://www.youtube.com/watch?v=dUdKjaysTYM ) We offer both equipment with process development as well as contract finishing services (though I don’t have a San Jose location for that)

      Please let me know if you have questions or if there is a way I can be helpful.

      Best regards,

      Free Sample Processing
      Contract Deburring and Finishing Services
      High Energy Finishing Equipment and Process Development
      ________________________

      Dave Davidson
      Deburring/Finishing Specialist
      SME Tech Community Advisor
      dryfinish@gmail.com | 509.230.6821
      https://dryfinish.wordpress.com
      http://about.me/dave.davidson

      Like

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