How many of you have to dumb your drawings down for people who don't understand GD&T 19

[Eric Gushiken]

Just curious. How many of you have to dumb your drawings down for people, even engineering teams, who do not understand GD&T. I encounter this quite often and it is very FRUSTRATING! I know the ramifications and I want the product or system to have the best chance of success with the least problems during assembly and in service but when you just can't convince people even though you are able to communicate the issue crystal clearly it often makes me wonder if I should just be a people pleaser and try not to cause a ruckus and just make the money or should I just be an ass and fight with them, then move on to the next contract that I'm inevitably going to fight with again.

 

[Belanger]

Or....leave the MMB modifiers and the shirt could say "Shift happens."

John-Paul Belanger
Certified Sr. GD&T Professional
Geometric Learning Systems

 

[Double-Edged]

"dumb your drawings down for people who don't understand GD&T"

Then for whatever reason the wrong people are interacting with the engineering drawings. Train them, hire different people or utilize knowledgeable job shops.

 

[Eric Gushiken]

I've found that, generally, only the aerospace industry seems to have a good grasp of GD&T. However, one of the aerospace contracts I worked with had their own internal machine shop with state-of-the-art equipment but their machinists claimed they could only hold a tolerance of +/-.005". I know this is not true and asked if they meant +/-.0005"? No +/-.005". This was primarily for hole sizes and positions. This was causing issues with a tolerance stackup for an assembly I was doing for them and I tried to convince them that their machines are capable of doing better. They didn't like my attitude and let me go. +/-.005" is a very common title block tolerance for 3 place decimals and I think they had inexperienced machinists who just assumed that that is what their machines were capable of. I'm currently on another contract and the project is late and over-budget. Lots of back-and-forth with the team discussing and debating the GD&T, whether to use it or not, how to use it, etc. We need to use it to ensure the assembly will go together but there is always concerns that whatever shop they send the drawings out to either won't understand it and do a no-quote or jack the prices up way high, then when the parts come in this company's shop says they can't inspect anything with GD&T because they basically only have tape measures (these are large weldments with additional machining).