Problems to verify Position of holes

[[An...]]

Hello,

I have a small problem with the position calculation of holes and hope you can help me.

According to the standard, the position can be calculated using the following formula:

 

 

Position = 2 × √(a² + b²)

 

 

For some results, this works correctly:

 

However, for others, it does not match at all.

Do you have any idea where my mistake might be?

 

Greetings André

 

[[Ma...]]

Problem can be, that you report YZ distance, but don't forget height and A1/A2 angles for that feature.

Also norm is not comming directly from axis of that element but individual sections from measured data.

You can enable detailed TP, so you would see deviations also for axis.

[[An...]]

Thank you for your fast reply.

For the position we're only using a circle. There shouldn't be deviation in angle as you can see here:

Hope that picture helps.

 

Greetings André

[[Wo...]]

You need to enable additional printout on those positions. You are reporting Simple distance which may not be the same as your DRF.

Go to characteristics setting editor - Report - additional report - and change to "On" on those position.

It will show you correct Y and Z used for position.

[[Ma...]]

OK so then i think use correct evaluation - tangential element - that can do a lot.

[[An...]]

Hello again,

the additional report helps a lot as you can see:

I will invest it further with new maschined parts.

@Martin Jánský  To be honest i don't understand the use of a tangential element in that case. The roundness of the element is 0,001mm so i'm not sure if it makes sense to switch. And i'm quite not sure where to switch to tangential element.

 

Greetings André

[[Ma...]]

OK,

TP is from D-AB - is that an alignment or filled datums?

According to norms - datums have to be tangential elements and perpendicular to higher datum.
If you have an alignment and you are measuring YZ from that alignment, then you should have same numbers.
Otherwise you will have different numbers.

[[An...]]

Here are some further information:

The change to tangentialelement seems not to change the results

 

Greetings André

[[Ma...]]

I think you should use outside tangential instead of inner ( i think it's in/out of material - not a definition of a hole/stem )

Form of KreisD_1 is also that little like 4H8?

Then only reason for that would be difference between base alignment and TP datums ( and/or your second feature in distance measurement )

[[An...]]

I tried to be creative 🙂

 

Will have a look later on the tangential element(switch to outside) and look for differences between base-alignment and TP datums.

 

Thank you for your time and support.

 

Greetings André