'Snow' better way to clean coordinate-measuring machine probes

February 2, 2016, University of Nottingham

Manufacturers in search of the most effective, fast and green way to keep coordinate-measuring machine probes dirt-free and error-free should use a dry ice technique, known as carbon dioxide 'snow' cleaning.

This advice comes from the Manufacturing Metrology Team at The University of Nottingham which has designed and developed an in-situ snow cleaning method specifically for CMM styli after finding general cleaning solutions available on the market today were unfit for purpose.

A CMM is a mechanical system that measures the dimensions of a manufactured object, using a stylus that makes contact with its surface at various intervals to plot and record coordinates.

CMMs are increasingly used to verify the complex geometry of micro-scale components in the automotive, medical and telecommunications industries.

Measurement error can occur if the highly-sensitive stylus tip, contaminated with tiny debris particles, touches a surface. This can lead to errors that are 10 times greater than the standard error margin expected of the instrument.

In the face of a lack of industry-wide solution, Dr Xiaobing Feng, Dr Simon Lawes and Dr Peter Kinnell (now at Loughborough University) from the Manufacturing Metrology Team in the Department of Mechanical Engineering at The University of Nottingham began investigating the problem in 2014.

After testing various cleaning systems, they determined that using a high velocity stream of CO2 gas and small particles, a technique known as snow cleaning, is the best method. The dry ice strikes and cleans the surface, clearing particles and thin layers of organic residue as effectively as solvents, but with the advantage of no chemical reactions or abrasive processes.

Dr Xiaobing Feng explains: "Solid dry ice particles possess greater momentum than air to dislodge and remove any size particles of debris from micro components in precision measuring equipment.

"Snow cleaning is effective and gentle so it doesn't damage the very fragile stylus - which may cost up to around £800 each - and are easily broken. It is also an eco-neutral technique as the CO2 is extracted from air."

The researchers developed the novel technique specifically for on-machine cleaning. As the stylus does not rotate, they used three nozzles, with identical geometry, symmetrically positioned, to clean the entire stylus tip and balance the impact force. The technique also uses short pulses of stream to alleviate a 'snow' build-up on the tip surface, which can obstruct further cleaning.

"A particle just a few micrometres in size can cause significant dimensional measurement errors. Therefore, regular cleaning of the stylus tip is critical in maintaining accuracy and extending life expectancy. As any sacrifice on speed is worth taking as measurements are redundant if inaccurate," adds Dr Feng.

To complement the snow cleaning prototype, the researchers are now working on developing a stylus contamination inspection system for in-line quality control of µCMM measurements.

Their next steps are to investigate and monitor how quickly probes get dirty and how often they need cleaning in different environments.

Explore further: Close-up film shows for the first time how ants use 'combs' and 'brushes' to keep their antennae clean

Related Stories

Cavitation bubbles bursting with cleaning power

January 12, 2016

It's easy to think of soap suds when one thinks of bubbles, but these bubbles can clean without chemicals. These are cavitation bubbles, which are created when air is churned up in water. And what researchers are learning ...

Deep cleaning with carbon dioxide

October 9, 2012

One of the many interesting items on show is a tool that combines – in one step – cleaning with supercritical carbon dioxide and cleaning with CO2 snow.

Mini robot builds NPL probe

August 31, 2012

Precision engineering requires accurate measurements and these are often made using co-ordinate measuring machines, or CMMs.

Manufacturer's cleaning ineffective for suction tips

August 2, 2012

(HealthDay) -- Following the manufacturer's recommendations is inadequate for cleaning suction tips, with residual debris identified after cleaning, according to a study published in the August issue of the AORN Journal.

Recommended for you

Cryptocurrency rivals snap at Bitcoin's heels

January 14, 2018

Bitcoin may be the most famous cryptocurrency but, despite a dizzying rise, it's not the most lucrative one and far from alone in a universe that counts 1,400 rivals, and counting.

Top takeaways from Consumers Electronics Show

January 13, 2018

The 2018 Consumer Electronics Show, which concluded Friday in Las Vegas, drew some 4,000 exhibitors from dozens of countries and more than 170,000 attendees, showcased some of the latest from the technology world.

Finnish firm detects new Intel security flaw

January 12, 2018

A new security flaw has been found in Intel hardware which could enable hackers to access corporate laptops remotely, Finnish cybersecurity specialist F-Secure said on Friday.


Adjust slider to filter visible comments by rank

Display comments: newest first

not rated yet Feb 02, 2016
" It is also an eco-neutral technique as the CO2 is extracted from air."

OK it was an interesting article until this point. First of all commercial CO2 is NOT extracted from the atmosphere it is produced by burning hydrocarbons and processing the flue gasses. Second of all the amount of CO2 that this process releases is so small that it is useless to worry about it.
not rated yet Feb 03, 2016
What really bothered me about the sentence is the fact that every scientific announcement must be punctuated by politically correct phrases such as this. How has this need not to offend or even appear to effect the environment affected scientific research?

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.