Tube & Pipe dimensions

[sbromley]

Yet another Inventor problem. Tube & Pipe this time.

Why is the centre dimension on my drawing different to the dimension on the model?

And yes units are set to 2 decimal places.

Knock knock. Another nail in the Inventor coffin!

  

[IgorMir]

It is a long shot, but maybe the view in the drawing is not parallel to the viewing plane? To see it - create a projected view from this one and have a look if the pipe's side is vertical in there.

Cheers,

Igor.

[sbromley]

Looks parallel to me.

[IgorMir]

Well, without actually seeing the files - it is hard to tell what's going on.

[CGBenner]

@sbromley 

In the Document Settings of the route file, what is the decimal precision set to in Units?  It could be a rounding issue between the route and the drawing file.

[sbromley]

Thanks for the reply, that's the 1st thing I checked. I never alter this setting. See below.

[CGBenner]

@sbromley 
Thanks for checking,... it was worth a shot.  🙂

If you double click to edit the drawing dimension, and switch to the Precision & Tolerance tab... how does the "Model Value" compare to what the sketch says the dimension is?

[sbromley · Accepted solution]

Apparently one of the horizontal lines is at a slight angle. No idea how this has happened. Isn't it supposed to default to 90°??

[CGBenner]

@sbromley 

Do you mean one of the lines in the drawing view?  If your route part file is not gorunded to origin planes, and you placed the view using the viewcube... it can be skewed ever so slightly.  It all depends on the relationship of the route part file to the assembly origin planes.  I never assume that they are all square to one another or the world... I've had this happen before, and found that the route part file was off by less than a degree related to the origins, and it caused the same problem you are having.

[sbromley]

In the model. I've no idea how to get it horizontal! I can't constrain it to any of the planes without the lot going to spaghetti!

Sod it I've had enough.

[CGBenner]

@sbromley 

In a situation like this, I usually blame one of the system placed constraints.  Inventor makes assumption because it does not know your design intent.  It places perpendicular constraints at 90 degree corners... but doesn't care if that skews the route away from being perpendicular to (for example) your machine frame.  All it cares about is that the corner is 90 degrees so the elbow can be placed.

I always delete these constraints, and then place my own using "include geometry" to bring in some work planes.  An example would be if I want to ensure that my route is perpendicular to the frame, I will delete the perpendicular constraint that Inventor placed, Include a surface on the frame (which creates a work plane in the route), and then place my own perpendicular constraint to that plane.  That ensures that, not only is the corner 90 degrees for the elbow.... but that the straight section is perpendicular to the frame.  Check out this OLD article I did on the topic... back in '14.

[johnsonshiue]

Hi! If possible, please share the files with me directly johnson.shiue@autodesk.com. I would like to understand the inconsistent behavior better. There should be a logical reason. But, without seeing the files, it is impossible to tell.

Many thanks!

[gcoombridge]

Hi @sbromley, @CGBenner ,

I use the include planes approach also but also heavily use the 3D sketch constraints for routing on the previous ribbon tab. Routes are just 3D sketches after all...

This way you can get lines parallel to the X,Y and Z axis...

[sbromley]

OK I'm back to this. I'll get sacked soon if this carries on. It's taking days to produce a simple route.

I've had to start again with this nonsense but the first bend is always 0.8° and not parallel to the base. I'm at a complete loss. We are actually moving to Solidworks and for the life of me I can't imagine it will be as bad is this rubbish!

[gcoombridge]

Can you post a step file of the run. Then we might be able to help with the misalignment...

I'll be interested to know how it goes with solid works. Give us a comparison in 6 months...