Recent content by sammcc

probably plenty of spare time if you are able to come onto the forum and write a post about it?

when is a burr not a burr, if the drawing states it should be free from burrs and sharp edges then it should be.

So, the general limits on 1.00" dimension is +/-.010 I have drawn a quick sketch to show the functionality of the part. It is part of a test fixture and is mounted to a base plate via a mounting block so part of face A is the only face that comes into contact with...

Dave & Chez Datum surfaces B and C are not functional or mating in any way. Datum surface A is the mating face, it is where this block attaches onto another smaller block. The contact area is minimal but I do think I will add the flatness tolerance back into datum surface A

So, I have reviewed my datums with a view to the functionality of the part bearing in mind the outside profile sits in mid air with no functionality at all. I think this looks more sensible for what I need. Thoughts...

mkcski- this forum is a great place for having queastions answered and I dont want to become a pest either, but a great way of learning is by asking people who know. I am a long time reader of this forum. Also, we make these parts in small qtys so while coordinate guessing machine is a...

i am back from a 4 day GD & T course (TEC-Ease). But as you have just said- application and selection of datums is complex and the only way I will learn is by doing examples. Looking at examples that are already done is one thing but applying it to parts that dont have it is a completely...

Confused. I was aiming for location per Fig 4-2 So then, what I need to do to correctly apply this is to move my datum B of the FCF and onto the horizontal line to the left of the 2.540 dimension line. Does this make my SEP REQT call out legal?

Do the 1.00 , 3.155 & 2.540 dimensions not allow the caliper test to be carried out? What am I misunderstanding?

mkcski- with reference to 1.3.32.1 does that not make the 3 datum faces features of size? Also, is the sep reqt call out not legal as per 7.5.4.2? Thanks

mkcski- I'm finished work for the day I will read 7.5.4.1 tomorrow morning and re-evaluate this. AndrewTT- Yes I understand, I have re looked at this and I think I understand the rules around this although I might be back with a question to confirm my understanding tomorrow morning.

Andrew- your right so I have called out datum A. Should I then reference datum C on the M6 holes for the same reason as this is the face on which they are derived? Also, the 3X R.130 basic dim covers the additional rad in the U shaped profile mkcski- both your points are taken on board and...

Hi Andrew & all, For manually measuring threads we in the case of these would use a pin with the same diameter as the minor diameter of the thread and check the position that way or if not manually then CMM I have updated the drawing as follows: -Removed the last of the leading zeros from...

The thing with this part is that it is in full view when in use and aesthetics are important so a non functional deature is probably best to ensure consistency. I guess I could add a rad or chamfer onto one of the top internal corners of the "u" shape profile, this would remove the symmetry.

Hi All, Many thanks for your responses. I think I should have explained what this part actually does and what the critical features on it are. So its a block, the real critical features are the 2x dia .201/.197 holes in section x-x. Two photodetectors are fitted into these and their alignment to...