0.05mm straight edge measurement method ?
0.05mm straight edge measurement method ?
(OP)
Hi,
I dont know if im in the right area but heres my problem
I need to accurately defining the profile of a sheared edge of a piece of sheet steel [pressing]. my sheared edges have to be within 0.05mm of straight (if you butted something perfectly straight up against it)
how would i measure this? I read something about optical shadowgraphing?
Has anyone got any tips?
Thanks
Dave
I dont know if im in the right area but heres my problem
I need to accurately defining the profile of a sheared edge of a piece of sheet steel [pressing]. my sheared edges have to be within 0.05mm of straight (if you butted something perfectly straight up against it)
how would i measure this? I read something about optical shadowgraphing?
Has anyone got any tips?
Thanks
Dave





RE: 0.05mm straight edge measurement method ?
If you have access to an optical comparator or shadow graph or maybe just a light box all may do the job. The comparator will measure the gap, the shadow graph is a Go::NoGo, the light box is a judgement call.
What is the size and shape of the part, especially the edge that needs to gauged?
Can you better explain your straightness requirement.
Is it the largest deviation to be measured form the standard?
Do you need a measurement or just a Go::NoGo assessment?
RE: 0.05mm straight edge measurement method ?
RE: 0.05mm straight edge measurement method ?
[IMG]http:/
The average size of the parts are about 500 x 350 mm . Sheared edge should be as straight as possible. is high tensile 2.0mm material
thanks
RE: 0.05mm straight edge measurement method ?
thanks
RE: 0.05mm straight edge measurement method ?
2mm is very thick for getting a very perpendicular cut edge. At 10% clearance you need 0.020 between the punch and button. That eats almost half your tolerance.
You might try fineblanking, there is far less clearance on a fineblanked edge. I dont think high hardness materials lend themselves to fineblanking.
As for your inspection try googling a few of these resources:
Optical Gauging Products
Optical Comparator
etc... suggestions from above.
If you only need to do a few inspections you can prepare metallurgical mounts and polish them. It will then be simple to measure using a relfected light on a shadowgraph.
Nick
I love materials science!
RE: 0.05mm straight edge measurement method ?
thanks again
RE: 0.05mm straight edge measurement method ?
RE: 0.05mm straight edge measurement method ?
(50um in 2mm is 1.43degrees. so the tolerance for perpendicularity is 88.57 to 91.43) <--is the following correct?
RE: 0.05mm straight edge measurement method ?
Im still researching optical gauges
Thanks again
RE: 0.05mm straight edge measurement method ?
RE: 0.05mm straight edge measurement method ?
thanks
RE: 0.05mm straight edge measurement method ?
Optical comparators would work as well, but the length of the workpiece may be prohibitive if you're trying to check the entire length at one time.