Internal groove measurement

[wmdn]

I am currently quoting a rather large project, several hundred part numbers, most of which have ID grooves ranging fron under an inch in diameter to over 10 inches. Groove widths from approximately 0.05 inches to 0.500. I am attempting to find the best type of gaging for the grooves. I would appreciate any and all comments and information regarding this. We do have a CMM and could do the gaging on that, but as a final inspection. I am looking for a solution to gaging in process, as the parts would be difficult, at best, to relocate on the machine tool to recut.

Thank you for any help you may have in steering me in the right direction.

 

[funnelguy]

Tolerance ranges on the grooves will determine the resolution required for the gages and the accuracy of the master or setting gage.

Adaptor points for calipers are certainly convenient, but not very accurate and very susceptable to operator feel. There are dial gages for the smaller diameters which are pretty good but can require a bit of diligence on the operator's part.

Have a look at the standard offerings of Mitutoyo, Starrett and Brown & Sharpe. Federal, SPI and Fowler also make applicable devices. You will want to give consideration to the method used to set and check the gages as well.

 

[MechEng13]

Expanding on funnelguy...

You will also have to look at calibration of the gages you finally decide on.

You also may come to the determination that nothing on the market does what you want it to. In that case you will need to get custom gages designed and made. Of course these will also have to be calibrated on some set schedule. Don't be afraid of custom gagings up front cost... it can be recouped quickly by reduction of time to check for the operators and easy of use.



Alan M. Etzkorn
Product Engineer
Nixon Tool Co.

http://www.nixontool.com

 

[ornerynorsk]

An internal dial caliper gauge is just the ticket for you. It works on the same principal as a travel dial, has a push button for collapsing the legs for inserting into the bore, and they can be relied upon for pretty good accuracy. It is a comparative instrument, so you need a ring gauge or a master to set it up.