Inserted Centre marks not updating to new Position when hole locations changed.

[Southernpedro2017]

Hi All
I have a question to other users regarding a dangerous error occurring in my drawings. I have posted a request to the help desk regarding this problem but have received no response or remedy for the problem

Background:
Over 15 years using Alibre as my main CAD software for my mechanical design business. I have been using Alibre long before Geo-Magic arrived and departed and have maintained the same process in completing my design for most of that time.

History of fault:
Last year I started receiving feedback from my customers about errors in the dimensions in relation to hole locations on structural members. After a close inspection of the faulty drawings it showed that inserted Center marks had lost there constraint relationship with the hole that had been inserted into. As is usual in my style of engineering 1st Draft sets of drawings are created and then reviewed by the Head engineer. Any changes are then highlighted and changes made to parts which then propagates through to the drawings.

 

[Southernpedro2017]

The problem is that a small change in location of the hole can lead to operator missing the dimension error.

I have tried a number of different drafting procedures to identify which step seems to create the problem. My conclusion from this was this.

1: It only appeared to occur when using the Right click - insert center option on a specific hole on the drawing. This is my preferred method as it allows placement of center marks only on holes I require them without then spending extra time deleting unwanted hole Center lines.

2: Using Right-click insert Centers of a whole view appeared to eliminate the problem.

3: Don't use Center-mark lines in your hole as your dimension reference point.

I have since then used the results of these test to change my technique to eliminate the error that was occuring.

Move forward to last week.

I received a call from a workshop manager who was about to send the drawings out to fabrication shop asking why 2 drawings had different dimensions (2mm difference). A close inspection of this drawing showed that this problem has resurfaced. I had used the Whole View Right Click - insert centers method for this drawing.

This is a very dangerous situation for me as I have to trust that the software will do its job and update dimensions as required. The time and cost implications of having this fault in the Alibre software are to Great If I have to go through every drawing to double check the dimensions have updated correctly.

Warning: Always dimension off the actual Hole not Center marks.

I would like Alibre to please advise what they are doing about fixing this problem and inform there users what is the best way now that we users can use to eliminate the risk until they fix it.

Regards

Southernpedro

 

[HaroldL]

Always dimension off the actual Hole not Center marks.

This is or should be the preferred dimensioning method since the dimension shows the location of the hole feature not the annotation (center mark). When I was working with SolidWorks this issue came up on more than one occasion when the drafter dimensioned to the center mark instead of the hole (circle). So it is not only Alibre that has the problem. My workflow is to apply all dimensions before applying any center marks.

 

[Southernpedro2017]

Hi Harold
Thanks for your input.
I can see this is obvious now but to many people it is undefined in the 2D drawing instructions that this is critical to reduce the risk of error.

It would be good for Alibre to put this detail in the 2D drawing instruction manual.

Thanks again