silveroranges
Plastic
- Joined
- Aug 27, 2019
First let me start off for saying, I am still learning. If I don't use the right word or terminology please correct me. In college (first year) for mechanical engineering at the same time as being a machinist apprentice to pay the bills.
At my job we are using pin gages to measure depth of a drilled hole on a mass produced part (medical device). Recently the tolerances were changed from (inches) +- .010 to +-.002 for the depth of the hole. I am finding inconsistencies with the pin gages used to measure the part, specifically the break edge on the ends. According the specs used by the gage pin manufacture, ASME B89.1.5-1998-R2009, "Plug gage ends are not required to be perpendicular or controlled." The gage pins' diameter are in spec, but the tapers on the ends are different sizes and lengths, the distances from the small diameter of the taper to large diameter (of the break edge) have inconsistencies as much as .006, at least the ones I have measured on a MicroVu.
Due to the drill tip angle of the drill we use for the hole, (90 degree included angle), the plugs 'fall' in different depths depending on their break edge sizes.
Has anybody encountered this issue before? A fix would be to grind the faces of the pin perpendicular to the axis of the shaft, but then we are essentially relying on a uncertified tolerance, which defeats the whole purpose of buying gages with certificates for NIST.
Looking for some advice and others' thoughts before I go be a pain in the dick for the engineers (who I eventually will be working with, hopefully)
At my job we are using pin gages to measure depth of a drilled hole on a mass produced part (medical device). Recently the tolerances were changed from (inches) +- .010 to +-.002 for the depth of the hole. I am finding inconsistencies with the pin gages used to measure the part, specifically the break edge on the ends. According the specs used by the gage pin manufacture, ASME B89.1.5-1998-R2009, "Plug gage ends are not required to be perpendicular or controlled." The gage pins' diameter are in spec, but the tapers on the ends are different sizes and lengths, the distances from the small diameter of the taper to large diameter (of the break edge) have inconsistencies as much as .006, at least the ones I have measured on a MicroVu.
Due to the drill tip angle of the drill we use for the hole, (90 degree included angle), the plugs 'fall' in different depths depending on their break edge sizes.
Has anybody encountered this issue before? A fix would be to grind the faces of the pin perpendicular to the axis of the shaft, but then we are essentially relying on a uncertified tolerance, which defeats the whole purpose of buying gages with certificates for NIST.
Looking for some advice and others' thoughts before I go be a pain in the dick for the engineers (who I eventually will be working with, hopefully)