Stupid Perimeter question 1

[rtrnka]

Why does Solid Works give a Perimeter value eqal to twice the actual Perimeter when a cylindrical surface is selected?

 

[ShaggyPE]

My guess is that because perimeter is a linear dimension, and you have selected a surface, SW grabs both the edges surrounding the surface and totals the perimeters. In the future, select only the edge you want.

 

[MrPickles]

I think Shaggy18VW is tright. Select just one edge of the cylinder, and the Length is what you want...I think.


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Mr. Pickles

 

[rtrnka]

The reason why this came up is that we were asked the permeter of one of the ends by one of our plating vendors. We have not noticed this before; the perimeter should be available by selecting the edge as one of the given values. I think this is another case of the "would be nice to have" enhancement requests.

Thanks All!!

Rich

 

[Arlin]

I am betting it is grabbing BOTH circular edges at the end of the cylinder.

You could just select one edge and measure its LENGTH
or
Select the end face of the cylinder instead of the cylinder surface.

 

[TheTick]

Tick emerges from his lab...

I just did a few quick experiments on surfaces and the measuring tool. It seems that perimeter isn't really perimieter at all. Perimeter is actually the sum of all free edges of a surface.

I made a square planar surface, 10mm on a side. It's perimeter (calculators ready, everyone!), measured 40mm. When I placed a 3mm square hole in this surface, the surface's perimeter measured 52mm.

If the ladies don't find you handsome, they should at least find you handy.

 

[Arlin]

> I just did a few quick experiments on surfaces and the measuring tool. It seems that perimeter isn't really perimieter at all. Perimeter is actually the sum of all free edges of a surface.

Yep, I actually used this all the time with our laser cut parts to calculate the total cut length of the part. Just select the plate, hit the measure tool, and use the perimeter readout. This includes all edges of the selected surface (thus including the holes).

 

[Roller1]

Perimeter is actually the correct term. The perimeter is the sum of all the boundaries af an area which would include holes etc.

The easiest way to find the outside boundary length is to use 'select loop' before measuring.

Roller1

 

[JNR]

The first answer is correct. (Bear in mind the cylindrical surfaces have two edges).

If you select the CURVED SURFACE (ie. the whole curved surface of the cylinder highlights green) you get what you asked for - the total perimeter of this surface's edges - BOTH ENDS.

If you select the EDGE on the end of the cylinder (ie. the EDGE CIRCLE on one end highlights green) you get its LENGHT - exactly half the previous value and what you apparently really wanted.

If you select the FLAT SURFACE on ONE END or the cylinder you get its perimeter - the same as the last value and half the first one and again apparently what you really wanted.

Seems very simple and logical to me. Ya gotta be careful what you are selecting!! Try it out by making a simple part with one sketch of a circle extruded into a cylinder. You need to watch the little symbol that comes up next to your pointer. A little stick means you are going to select an edge (essentially a linear/wireframe object in a way). A little wavy patch means you are going to select a surface. Other symbols indicate other types of objects.

Incidentally, if you select the entire feature in the tree and then click on the measure tool it comes up blank - very disappointing. I kinda hoped it might give me the volume, etc of that individual feature. Ahh, sometimes I just expect too much from life.....

Be naughty - save Santa a trip.