bolt circle and extrude

[bac478]

I have a question of preference that relates to axial patterns. For circular hole patterns, I like to use an axial pattern feature so I get the built in bolt circle in the drawing. However, I run into a lot of "issues" when the spacing of the circular pattern is irregular. This requires the use of a table type pattern which, in my opinion, is a little clunky. They only allow dimensioning from a single reference so angles over 90 deg. or worse, over 180 deg. are encountered. Dimensions like this are terrible to show on a drawing and make everything look messy. I would much prefer to dimension everything using a simple extrude feature, that way I have tons of flexibility. However, I don't get the nice bolt circle in the drawing and I end up having to create a separate sketch just to show the bolt circle and then align all the axes of the holes I created with the extrude.

My question is what method do most folks use to deal with this problem and create irregular circular hole patterns? I am on WF4 currently.

 

[design-engine]

I could talk about this topic for hours and you brought up a lot of points in one long paragraph.

one the bolt hole circle showing in a drawing. Several ways to fake this one is to use a sketch curve on the solid part to illustrate the bolt hole circle. Color it yellow and change the linetype to a centerline. The other way is to place a line entity in drawing mode of the same bolt hole... change the color to yellow and change the linetype (font) to centerline.

probably the pattern of these types of bolt holes should be modified for Creo 3.0 to accommodate the drawing????
Edited by: design-engine

 

[bac478]

So just to clarify, your preferred method of creating an irregular circular pattern is to use a sketch/extrude with some sort of centerline added afterwards?

 

[design-engine]

irregular circular pattern... no I didn't address that.I only addressed how to get the bolt hole circle to show up right...

use the pattern function like normal then select on what features that are irregular and those remove. The white dot showing the pattern.... if you click on a white dot that turns off the pattern feature.

 

[bac478]

Aha, ya I knew about omitting certain instances of a pattern at creation. Sometimes I deal with patterns of holes that don't even follow a regular interval that allows a simple omission. For example, one I am dealing with now has instances at 29deg and -40.5deg, and then it symmetric as well. For a case like this, omitting certain instances wont work.

 

[design-engine]

there was a function in Pro/E v20 and previous that would allow you to unpattern geometry. It was hiding so to speak at the Group Options. Once you UN-pattern the geometry you could modify the geometry at will to the desired dimensions. Not patterned any longer tho. You could try 'copy' then 'paste special' That's a really powerful function that PTC gave Pro/E at the WF2.0 level that beats SW really hard. I consider that function part of my basic set of tricks.

 

[bac478]

I do like the paste special, but it still won't give the bolt centerline in the drawing though right? I usually don't have a problem creating the feature the way I want, I just have problems when it comes time to make the drawing. I just like the idea of having the bolt centerline come in like it was intended for circular patterns. I also like my angular dimensions for a circular pattern to be < 90deg. Unfortunately, the table pattern gets me the bolt circle with awkward dimensions, and the extrude gets me nice dimensions with no bolt circle. That's why I was wondering what everyone else was doing when they ran into such a problem.