# Linear Pattern suppression of features

• posted

I have a number of holes that I repeat with a linear pattern "n" times. Between the holes I have a smaller hole - this I repeat "n-1" times (because it sits between the larger holes.

Is there a way to use the same linear pattern on both holes and then suppress the last repetition of the small hole?

• posted

Select the "instance" that you do not want and hit delete.

Richard

• posted

How do I "select" the instance? (I have tried to click on it....)

If I make 4 repeats and delete the 4th instance of the smaller hole - can I then change "n" to e.g. 8 - and then still have the 8th instance deleted - or did I delete a the 4th instance specifically?

Steve

• posted

Select the face of the hole, it should highlight. Hit the delete key and a dialog box will give you the option to delete the pattern or the selected "instance".

You deleted the specific instance.

Richard

• posted

I am pretty sure you are just deleting the 4th instance. If you later change "n" to 8, the 4th instance will still be deleted instead of the

8th instance as you intend.

I think the best method of truly automating your pattern is to use 2 separate patterns and then use equations to drive pattern #2 from pattern #1.

• posted

You could have a similar result using Equations.

double click the second pattern select the dimension that is the quantity tools>Equations add double click the first pattern select the dimension that is the quantity type " - 1" now your second pattern will always have one less than your first pattern.

I have used equations for pattern quantity to fill a length of thread. we cut revolve the first thread and then pattern it. so the equation is Qty@Pattern1 = 2 / Offset@Pattern1 this will make a pattern that is less than one thread width from 2" long.

Corey

• posted

Yeah thought so.

I have a part that comes in different lengths - i.e. different n-value, and it is always the last small hole I need to delete.

Equations - that's new territory.... so right now I have just made two Linear Repeats.

Steve

• posted

I would strongly recommend you check out the equations if you want you patterns to automatically update. They really are pretty simple to use.

Basically, you would do the following: Create you first linear pattern n1=8, d1=2" Create your second linear pattern n2=7, d2=2" now create the driving equations: n2 = n1-1 d2 = d1

You can also create equations to automatically center your pattern and/or automatically calculate the number of instances to fill the part.

If you wish, I will post an example part that uses patterns and equations as I have described above.

• posted

This is so simple, maybe it's not a good idea, end of the day and all that.

But, if you dimension your part from the other end then you could always delete the first instance of the small hole!?!

HTH, Muggs

• posted

....how apparently obvious!

But it doesn't work - I just tried it - deleting the first instance means deleting the feature to pattern - i.e. all the following instances are deleted.

Maybe there's another way of deleting the first instance without deleting the actual feature.

Steve

• posted

The "Equations" menu is not active (shaded grey) under Tools. I place the cursor in the #-field of direction 1, and try to select tools-equations - but can't.

What do I do wrong?

Steve

• posted

When you have your part open, click on the "Sigma" icon in the Tools toolbar - this brings up the equations box. Then you click "Add" which opens the "New Equation " box. To add a dimension to the equation, you can either type it in, which is prone to mistakes, or you can click on it out in the graphics area. To get it to show in the graphics area, double-click the feature in the Feature Tree. Then add the other parts like ( ), +, *, etc.

WT

• posted

Equations rule...!

How do I edit an existing formula? (just the one formula - not "edit all")

Can I create a variable and use it in many equations? (now I make the same calculation in all formulas to derive my "n"-value)

Steve

tools-equations -

• posted

Go ahead and select "Edit all" and this will open all for editing. At that point, pick the one you want to work on.

I don't know for sure about the variable - others might. But, you may not need it. Remember that the "n" value, which I presume is the number of holes, is actually a clickable parameter in the graphics area. When you double-click on the pattern, it displays it's information and just as you can then change the number of instances for different configs, you can also select that parameter to insert into your equation.

WT

• posted

Yeah - got that.

How about referring to values in other parts? I have an overall width upon which everything else depends - so if I change it in one part, it would be nice to have it cascade into all other parts.

Steve

double-click

• posted

I suggest that you create a large hole, a small hole and another large hole. then pattern the last two holes.

Joe

• posted

Good thought - this, of course, being based on the "other" end.

WT

• posted

In a programming environment you would set a global variable that could be used later. Here, I think the way you would do it would be to have the length, holes, etc. defined in the context of the assy. Then you could have it follow another existing pattern, or whatever. However, that might not fit with your design or company structure.

WT

• posted

• posted

If it is simple you can select the surface of the hole and right click Somewhere in the menu there is delete face. if it is a hole it should fill the hole and your first instance is gone yet your pattern stays.

Corey Scheich

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