It is well known that centerless grinding processes allow parts to be held to tighter dimensional tolerances, achieve smoother surface finishes, and hold high degrees of straightness.
Beyond these obvious advantages, all centerless grinding processes offer the following 5 Not So Obvious Advantages:
The grinding process is essentially continuous, because the loading time, when compared to grinding between centers, is exceedingly small.
The work is rigidly supported directly under the grinding cut as well as for the full length of the cut. This means that no deflection takes place during the grinding operation, permitting heavier passes than grinding between centers.
No axial thrust is imposed on the work while grinding. The absence of end pressure makes it possible to grind long pieces of brittle materials and to grind easily distorted parts.
Because the error of centering is eliminated, a true floating condition exists during the grinding process. This results in less stock needed and longer wheel life / yield.
Large quantities of smaller size work can be automatically ground by means of a magazine, gravity chute, or hopper feeder attachments, depending on the shape of the workpiece.
A few final thoughts: The degree of error in the centerless grinding process (setup or compensating for wheel wear) is reduced by half, since stock removal is measured on the diameter rather than the radius. Centerless grinding is a mature process, with few wear surfaces in the machine, and automatic lubrication, making maintenance a small part of the total cost of this process.
Thank you, readers, for your attention to our posts.
We will continue to post thought leadership, knowledge retention, and emerging issues that face the precision machining industry and all of us in North American Manufacturing. Thanks for paying attention!
This post will help you understand the limited power of financial incentives.
What really motivates us?
AUTONOMY is the desire to be self directed. If we can’t be self directed, if we have to do things “the prescribed way”- then money will be needed to assure performance.
MASTERY all of us have a desire to get better, to improve, to have an area where we are the “expert.” If we have the chance to get better at what we are doing, we will be motivated to do so.
PURPOSE is the reason that we jump out of bed in themorning, rather than just hit snooze. Sharing the compelling reasons for why what it is we all do matters is a key motivator for everyone in the organization.
Guest Post by Julie O’Keefe, Partner, Armstrong Teasdale LLP
PMPA member companies are engaged in making parts that require precision during the machining process of a specific customer order. This necessitates multiple routine adjustments being made throughout the shift. It can involve changing a dulled drill bit or insert on a screw machine or CNC, it could be redirecting a coolant line that vibrated out of place. It can involve adjusting the alignment of a tool multiple times to maintain the needed offset or location.
These kinds of adjustments are routine, repetitive, and integral to the use of the equipment for production. They are necessary so that the parts are produced to the required precision. This is the classic type of situation intended to be addressed by the exception to the LOTO standard, 1910.147(a)(2)(ii)(B) , assuming the worker does these things using alternative measures that provide alternate protection.
Many inspectors do not recognize that this kind of minor servicing, maintenance which is routine, repetitive and integral to the use of the equipment for production is an allowable exception to the Lockout Tagout requirements if the worker is protected by alternate means.
One form of alternate protection may be, according to interpretations published on OSHA’s website (see below for one of several examples), stopping the machine using a control switch (not an energy isolating switch, just a control switch), if the switch is designed in accordance with good engineering practice, controls all the hazardous energy and is placed in the off position, and is under the exclusive control of the employee performing the task.
Kershaw Letter Interpretation:
“…minor tool changes and adjustments, which are routine and repetitive and must be
performed as an integral part of the production process, are permitted to be
performed without LOTO if the work is performed using alternative
measures that provide effective protection. Electric disconnect switches or
control switches are considered effective protection if the
Are properly designed and applied in accordance with recognized and good
engineering practice; and
Control all the hazardous energy and are placed in an off
Are under the exclusive control of the employee performing the
Here is a quote from the Federal register Vol. 54,No. 169 Friday September 1, 1989:
“As was discussed in the preamble to the proposal, OSHA
recognizes that some servicing operations must be performed with the power on;
in these situations, it would not make sense to to require lockout or tagout,
which apply to deenergized equipment.”
Minor servicing or maintenance that is routine, repetitive and
integral to the use of the equipment for production may be covered by alternate protection. As the interpretations on the OSHA website indicate, such effective protection can include stopping the machine using a control switch (not an energy isolating switch, just a control switch), if the
switch is designed in accordance with good engineering practice, controls all the hazardous energy and is placed in the off position, and is under the exclusive control of the employee performing the task.
Guest Post by Julie O’Keefe, Partner, Armstrong Teasdale LLP
Now targeting smaller firms! This year’s notice changes the establishment employee size from 40 to 20.*(Or less see below!)
This program is in addition to 13 national Emphasis Programs and approximately 140 Regional Local Emphasis programs.
This program includes SIC 20-39 MANUFACTURING.
Primary Inspection List Criteria:
DART rate of 7.0 or higher
DAFWII case rate at or above 5.0
Low Rate Establishment in a High Rate Industry (very suspicious, you must be lying)
Non providers of Rate information to OSHA’s last survey.
Secondary Inspection List Criteria
DART rates Greater than 5.0 but less than 7.0
DAFWII case rate of 4.0 but less than 5.0
But wait, there’s more!
Tertiary Inspection List
” If an Area Office completes its inspections of all establishments on its Primary and Secondary Inspection Lists before the expiration of this SST program, it may obtain additional establishments by contacting the Office of Statistical Analysis (OSA); Dave Schmidt by e-mail or at 202/693-1886.
The threshold rates will vary with each Area Office. OSA will randomly select and provide each Area Office with the number of establishments specifically requested by that Area Office. No establishments with a DART rate of 3.6 or lower and a DAFWII case rate of 2.2 or lower will be included. No establishments in SIC 805 will be included. “
* If you have fewer than 20 employees you may still be inspected:
“If an establishment to be inspected under the SST-11 plan has fewer than 20 employees at the time the CSHO arrives on site to begin the inspection, the inspection will still be conducted, provided that the establishment has more than 10 employees and either its calculated DART rate or DAFWII case rate is at or above twice the private sector 2009 national incidence rates (that is, DART = 3.6; DAFWII = 2.2), or records are not available.”
Wonder why employers are reticent to grow, expand or hire new employees? This example of Regulatory Tone says a lot.
NAM and Industry Week Q3 Manufacturing Survey shows manufacturing still in positive territory but the much weaker economy is causing much weaker sentiment looking ahead.
Current outlook– Manufacturers optimism has declined from 86.4% of respondents either very or somewhat positive in their business outlook in the June survey, only 65.4% said the same in the third quarter — a drop of over 20 percentage points.
Economy is top concern –Nearly 65% of manufacturers surveyed said that a weaker domestic economy was hurting their sales.
Regulatory issues are real drag on growth– Almost 61% said that an unfavorable business climate was one of the biggest challenges right now, and nearly 80% felt that government involvement was impeding their ability to grow their operations.
You can see the more results on Industry Week site here.
Aluminum usage in automotive applications has increased every year for nearly 40 years. Automotive Aluminum usage in 2012 is reported to be 343 pounds, up five percent from 2009’s 327 pounds per vehicle, according to a report available from the Aluminum Association. The data was obtained in a survey of automakers by Ducker Worldwide.
Longer term, the report predicts aluminum is expected to double its share of the average automotive materials mix to 16 percent by 2025 with future cars and light trucks reaching a predicted average of 550 pounds of automotive aluminum per vehicle. Precision machining companies are increasingly seeing opportunities to quote parts from aluminum that had prior been steel or brass.
Its Not Just Wheels and Powertrain Anymore
The Ducker- Aluminum Association Survey revealed that the light metal is quickly gaining market share in hoods, trunks, doors and bumpers. Body, bumper and closure content grew by 58 percent from 2009 to 2012, with 30 percent of all hoods on 2012 vehicles being aluminum. This accounts for saving a total of 100 million pounds of vehicle weight across the entire fleet. Twenty percent of all bumpers in 2012 will be aluminum. Aluminum is the key to automotive downweighting.
Other Highlights from the Report
The average increase in aluminum content since 1975 has been seven pounds per year per light vehicle.
Automakers will, on average, seek to lower the weight of cars and light trucks by at least 10% by 2025.
Market factors already in place are projected to push aluminum content to 400 pounds per vehicle in 2015/2016.
Aluminum is gaining market share at the expense of both traditional and high strength steels (HSLA), which are declining as a percentage of vehicle makeup.
Advanced High Strength Steels (AHSS) also are growing at the expense of inferior steels, but gauge reduction with AHSS provides limited weight savings potential compared to using lower density aluminum. Pound for pound, aluminum replaces more than twice as much weight as AHSS.
Which of Your Customers Are Leading the Way with Aluminum?
The latest model vehicles boasting above average aluminum content (more than nine percent of vehicle curb weight) include the Chevrolet Malibu, Cadillac CTS, Ford Explorer, Ford Focus, Ford Escape, Lincoln MKZ, Chrysler C sedan, Honda Civic/CR-V, Honda Accord, Nissan Altima, Toyota Avalon and Fiat 500.
More than nine percent of curb weight is Aluminum!
Want to learn more? Register for the webinar or for more information on the survey and the overall advantages of automotive aluminum, visit AluminumTransportation.org or call (248) 975-2800.
Precision Machining is a subset of Fabricated Metals which was one of the sectors reporting continued strength in August.
Economic activity in the manufacturing sector expanded in August for the 25th consecutive month, and the overall economy grew for the 27th consecutive month, say the nation’s supply executives in the latest Manufacturing ISM Report On Business®.
“The PMI registered 50.6 percent, a decrease of 0.3 percentage point from July, indicating expansion in the manufacturing sector for the 25th consecutive month, at a slightly slower rate.” While the index declined from July, it still remains above 50, indicating expansion.
Ten manufacturing sectors reported growth including: Wood Products; Petroleum & Coal Products; Miscellaneous Manufacturing; Food, Beverage & Tobacco Products; Fabricated Metal Products; Paper Products; Transportation Equipment; Chemical Products; Computer & Electronic Products; and Machinery.
Precision machined products can be found in some fashion in all of these sectors- either incorporated into a product or in the tooling and process infrastructure of these industries.
The ISM reported some areas of concern.
“The Production Index registered 48.6 percent, indicating contraction for the first time since May of 2009, when it registered 45 percent. The New Orders and Backlog of Orders Indexes edged up slightly from July, but both indexes are indicating contraction in August at slower rates than in July. The rate of increase in prices slowed for the fourth consecutive month, dropping another 3.5 percentage points in August to 55.5 percent. The overall sentiment is one of concern and caution over the domestic and international economic environment, which is affecting customers’ confidence and willingness to place orders, at least in the short term.”
While all is not rosy, we are not ready to throw in the towel on what may in fact be just the result of slow seasonality in this report. Anecdotally, PMPA shops are scheduling overtime, and have positive outlook for sales, shipments, and other key indicators over the next three months.
Here’s a secret: While every body thought that going to college was a “must” to have a good career, the fact is that skilled workers are in high demand in U.S. manufacturing shops in precision machining and fabricated metals. Just like our products are.
For those who thought they knew everything that could be known about heat treating steel.
Tooling and Production Magazine reported on this new “Flash Processing” technique that raises mechanical properties by about 7% over conventional martensitic HS steels.
This process is also said to improve formability- drawability or rollability- by about 30%. Obviously, that gives designers quite a bit of potential mass savings- key to lower fuel consumption and higher performance- lighter, stronger, more efficient- in transporation applications where these kinds of steels are typically used.
The structure of the steel after processing shows the expected martensite as well as bainite and an abundance of carbides. Traditional heat treatments try to assure a uniformity of the desired resultant microstruture- anomalous structures are considered bad.
The hybrid structure developed by this flash processing technique is a – dare we say- “composite microstructure” which gives the material bulk mechanical properties of improved strength and increased ductility.
We look forward to the continued development of this exciting new process by it’s inventor, Gary Cola, the research team at The Ohio State University, and National Science Foundation (NSF) Center for Integrative Materials Joining for Energy Applications which is leading a consortium of other universities to develop this technology.