Install a CMM close to a vibration area

S

Shakib

We just bought a brand new CMM (ZEISS), the first one for our company. The CMM dimensions are 3 feet X 3 feet and its weight is 850 pounds. The volumetric precision of the CMM is 0.0055mm (0.0002 inch). To operate the machine (according to the manufacturer specifications), we must have a temperature of 20 degrees Celcius +/- 2 degrees. Furthermore, the temperature variation cannot be more than 0.8 Celcisus degrees per hour and 1.1 Celcius degrees per day.

Our needs: we bought the CMM to measure production parts with a precision of about 0.025 mm (0.00098 inch) but it will be use sometimes to measure our tooling which is more precise (0,010 mm i.e. 0.00039 inch).

Installation: The CMM will be install in our QC laboratory ("laboratory" according to the QS-9000 definition...) and the dimensions of this lab are about 12 feet X 22 feet. Close to this lab (about 12 feet), there is a 180 tons press in a pit of 8 feet deep. The press is mounted on a concrete base of 8 feet X 6 feet X 3 feet height (we installed this new press about 1 month ago).

Vibration comes from the press and that has an effect on our optic comparator (we can see the vibration at the screen). This vibration is important enough that the QC technician takes his measurement between the press movements.

We have 2 alternatives proposed by the CMM dealers and a local engineering consultant firm to reduce the vibration: an independant concrete base (independant floor) OR an air cussion to be placed under the CMM (this solution is for the CMM only in opposite to the first solution that can be done for both the CMM and the comparator). Both solutions are quite expensive (in comparison with the CMM cost...)

There is also a significant flow of employee in the lab (2 QC technicians, formeman, process engineers...) that use the only door.

Will we be able (with a fast solution..., we don't want to build a new lab...) to eliminate the vibrations and to control the environmental conditions (Temperature and Humidity).

Thank you in advance for your help.
 

Marc

Fully vaccinated are you?
Leader
Have any vibration studies been done at the location where you want to put the CMM? It's hard to say what will work to isolate the CMM if you don't know how 'deep' the problem is.
 
S

Shakib

Originally posted by Marc Smith:
Have any vibration studies been done at the location where you want to put the CMM? It's hard to say what will work to isolate the CMM if you don't know how 'deep' the problem is.
Note yet.It is under evaluation.
 
E

ed bloedorn

definitely a problem that needs a seismic reading to determine the magnitude of the problem. once these readings are analyzed an appropriate isolation system can installed which will eliminate your problem.
 
P

Patrick.Riordan

If the vibration is severe enough it will cause your probe to phantom trigger and give you bad readings. Most of these machines come with some type of vibration dampening system. I ran a Zeiss Prismo Vast for a while and that had it's own air cushion built in the unit. It could survive right out on the shop floor. The uncertainty of your machine is such that I would question using it to measure tooling. It appears that it will have a gage uncertainty for this purpose of about 50% which in most applications is unacceptable.
 
K

kimkolora Pen

i use a CMM Zeiss in my plant, yes the least vibration may cause some error on the sensibility of the probe,i changed the head probe because of that.
 
S

Shakib

What kind of head prode did you have ? Which one do you have now ?
 

DuncanGibbons

Involved In Discussions
Have any vibration studies been done at the location where you want to put the CMM? It's hard to say what will work to isolate the CMM if you don't know how 'deep' the problem is.

What type of vibration tests are typical for assessing the facility?
 

Marc

Fully vaccinated are you?
Leader
I haven't been involved in any laboratory equipment location vibration tests so I can't help with that. My experience is dated. I was tangentially involved in assembly line equipment vibration tests some years ago, mainly for big metal forming presses as the responsible quality engineer. The engineering department was responsible for parameters and I remember the CMM manufacturer had a rep involved. I remember the calibration lab had to be isolated. If I remember correctly they kept the lab isolated from the production floor by cutting the concrete so it rested on it's own slab. The places where I saw serious laboratory isolation were all metal forming facilities with big metal presses.

I am sure this is a highly specialized field so an expert would be necessary to determine what test(s) would be required. You might be able to do some basic stability tests with an accelerometer setup of some kind but if it's really a critical issue I'd call in a professional person.

What kind of head probe did you have ? Which one do you have now ?
Sorry you never got an answer. This discussion is from 2001 and I'm sure you and kimkolora Pen have "moved on" to greener pastures, but maybe someone here can respond /help now anyway.
 
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