# is there an arc length function?

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i need to notate on an idw the length around a pipe (not linear length) from one leg to another and, from one hole to another, is there a way to do that?

i also can't get it to snap to the centre of the hole anyway, is there something i can do about that?

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There is an arc length dimension - but it seems you have three different questions here? Arc length. Length of pipe. One leg to another. One hole to another.

Can you attach your file here?

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Not sure which version you are running but if you start with the dimension command and select the arc and then right click you have the option to either have arc length or loop length under the dimension type. Also to dimension to the center of a circle hover over the circle and the proceed to the center point of the circle and a green dot will appear that you can select. I am including a picture to show all three of these examples.

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they are holes thru the pipe, so all you see is the cross section, but the dimension is around the pipe from the center of the hole to the feet, so i need that view to measure it

here is a picture

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It seems that you are trying to find the flat distance from the hole to the foot axis. I would consider a flat pattern on sheet metal.

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its pipe tho, not rolled sheet metal

it might seem silly that i want a dimension like this, but this is what the welder wants

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It's easy to get the distance. Find the circumference and divide by number of holes. I can see why he wants the dimension, however, that is pretty easy stuff and a welder should know how to find the distance.

KC

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i know, i could even just put a note "evenly spaced" or something to that effect, but he wants it as an actual dimension

but i fiddled with the draft view and got it to work (or something that will work just as well)

thanks for all the help

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..that is pretty easy stuff and a welder should know how to find the distance.

I agree.

An easy lay-out is proper workmanship.

Your welder should learn how to do it right, rather then you adapting the drawing with wrong dimensioning.

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I am really curious about this one as I cannot find anything in the dimensioning routines that allow me to detail the length of an arc. I can easily find the length of the arc between the holes by using measuring tools, but I cannot for the life of me get Inventor to dimension it either in model sketch mode or within a drawing. The only options I get are radius, diameter and angle dimensions.

Right clicking on the dimension type just does not give me the option described in Jdits7's post? Am I missing something here?

I have tried this in both 2010 and 2011 and looked it up in my rather old 2008 Inventor Essentials book without success.

Dave

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I am really curious about this one as I cannot find anything in the dimensioning routines that allow me to detail the length of an arc.

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File as requested.

Dave

Part1.zip

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I still couldn't get the actual arc function to work, so i just replaced the degree measurement with the arc length, cheating sure, but it looks just fine on the drawing which is what matters most

and also, sometimes it doesn't matter what makes the most sense or is easiest, sometimes you just do what your told

on a side note, looks like i will actually be cutting threads on some pieces instead of using the thread tool, at least until it becomes more obvious how much it slows down the use of the full assemblies

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Hi Gargoyle27,

Unless you have quite a large number of thread cut parts I doubt you will see much difference in speed.

Attached is a very small example of an assembly of a condenser microphone capsule that I created some time back. As the threads on the capsule itself, the perspex locking ring and slug are all 40 TPI Brass Thread, plus the adjusting screws are 10 B.A., I had to cut these myself. I don't suppose it's something I would want to do for every screw thread but it does look good. Generally speaking I don't mind the simulated thread look, but on these small parts it was just not right.

If your boss is wanting to impress a customer with photo-realistic images or you haven't the time/inclination to add a new thread database then it has it uses.

Dave

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Is this what you were looking for?

I created some Work Axis and Work Points off those Axis to align your sketch better.

In the drawing I used "Get Model Sketches" by RMB on the part in the tree and then just used the Dimension command and switched to Arc.

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That's what I was trying to do Mark, but I am not sure about the original poster. I had gone several stages further and created the arc you see on the drawing plane by using f7, projecting the cut edges and adding a little sketch geometry. That's as far as I got as I could not find this arc dimensioning function.

BTW - "I created some Work Axis and Work Points off those Axis to align your sketch better." - I had removed all unnecessary geometry and your actions should not have been necessary.

And yes, your dimension is correct, although I was reading mine in metric at 44.975mm by dint of the measure command.

OK, I have got to the stage of applying the dimension as you have above, now using the annotate menu -where is this ARC selection in the dimension function??

Dave

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Start Dimension command, select the arc, then RMB before placing it. Select Arc Length

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Sorry Mark, those options do NOT appear in the RMB menu. Everything else does, but not the dimension type.

I suspect the original poster is seeing exactly what I am seeing. I also suspect you were thinking we are a bit dumb and that it should be obvious :-)

What version are you using?

Dave

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Are you getting the radius to appear first? If you get a green dot, then you won't get an option for this.

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Do not pick the endpoints of the arc - select the arc itself when dimensioning, then RMB....

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