Measure questions about accuracy

[jameswcurtis]

My first question is, why would you want to use anything except 0 precision?

Second question is why would a length in the measurement tool be different from the length in the bottom right context menu? 

In the sketch, it is a straight line that was 45mm, but I changed the length in the sketch to 45.5mm.  Clearly the same line is selected.  

When I had the settings for the tab and the hole both set to 45, when 3d printed it fit too tight to be easily put together or taken apart.  I changed the tab side to be 45.5 to allow some clearance.  Is there a better way to do this in Fusion?

[jameswVTJ5V · Accepted solution]

The precision in the measure tool is how many decimal places you want to measure to.

0 precision will round up or down accordingly. So 44.5 becomes 45 whereas 44.499 would become 44

The precision in the measure tool has no bearing on the actual geometry.

[g-andresen · Accepted solution]

Hi,

1. In my point of view, the central problem lies in the positioning of Tab and Hole.

2. create a new design from scratch and use "offset face" for clearance > avoid base feature!

günther

[jameswcurtis]

2 excellent answers to my questions.  Now it makes perfect sense that Precision refers to the number of decimal points.

And the video on using the Offset Face was what I needed and wasn't smart enough to ask the correct question.  I'm 3d printing tests with the values back to their original setting, but using the offset face command.  Sorry I posted the 1st answer as the solution, I thought I would be able to do both as answers.

[Drewpan]

Hi,

In answer to your question about precision - it is how many decimal places you want for accuracy and when the

numbers are rounded up or down.

If you are 3D printing these parts then your problem may not be with the software but with the actual prints. There is a

certain amount of shrinkage typically with 3d printed parts. The actual amount of shrinkage depends on several factors

including the size and geometry of what is being printed. The printed material also has a bearing on shrinkage and the

geometry that the slicer has selected to create the print can also have an affect. Literally printing something upright

or laid down can affect the end result. There is often also an amount of variation between individual printers, even of

the same model.

With 3d printing there is often a certain amount of massaging and failed prints before you get it right. I have had

prints fail because I left the door of the printer cracked open a fraction. Sometimes you just have to play around with

your design and your slicer settings.

Cheers

Andrew

[jameswcurtis]

Thanks for the feedback. I've been 3d printing a lot of things, but I wouldn't call myself an expert by any stretch of the imagination. I'm impressed with how accurate my Bambu x1 Carbon prints. If fit together when the pieces were made the exact size, it was just difficult to get them to move in place. I just needed to know if there was a better way to make a 'tolerance' for lack of a better word. The offset face should work for what I needed. I printed some scaled at 50% and they worked great.

[g-andresen]

Hi,

Be aware that the offset is also scaled when scaling.
You should therefore do not define the offset until after scaling.

günther