120 deg ended Hole depth from the tips

[Wiseco]

Hi,

Is there a way to set the depth from the tip of a 120 deg ended-hole?

When you machined something, you set the tool offset from the tips and not after the taper section so...

 

[solid7]

When you machined something, you set the tool offset from the tips and not after the taper section so...

But when you design something, you call out the length of hole that is useable, in most cases...

You can write a simple formula (with several simple parameters) to calculate/set the depth of the hole based on the angle of the drill point, and the diameter of the hole. Simple trigonometry should yield a formula that is useful for determining your overall depth.

Whether you should blindly trust that Catia is putting in a a true 120 degree drill point at all times is another case. Undoubtedly, someone will come along and say that it works fine for them - but I've seen problems with the math on some drill points in the past. I have several instances where theoretical depth does not match the CAD model by several thousandths, or more. If that's close enough for you, go for it. However, if the depth is critical, do yourself a favor, and design the holes in manually.

That's my $.02.

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[Wiseco]

However, if the depth is critical, do yourself a favor, and design the holes in manually.

Yeah this is what I've done but to compare catia to solidwork, in solidwork you can work with the side sketch of the hole and move the lenght to the tip, this is what I was searching for.

 

[solid7]

in solidwork you can work with the side sketch of the hole and move the lenght to the tip, this is what I was searching for.

I guess it all depends on how you want to define the holes. Here is what I would do, given your situation:

1) First off, I would define the holes by a plane normal to the surface, and plunge them. I would not use a side sketch.

2) For all holes of a given size, define the diameter of the hole with a parameter. (flat bottom hole)

3) create a chamfer on the bottom of the hole equal to 1/2 the diameter.

4) create a formula for each chamfer, and set the formula equal to the radius of the hole. (radius is how holes are defined by formula - not diameter) It would be a good idea to group hole diameters and chamfers logically, so that you don't have to chamfer each hole individually. (although, admittedly, this will make a size change more difficult)

5) For easy measurement, you can put a point in the center of each hole, and make a normal line to it. (to define the centerline) Create a formula which states that the length of the line is equal to the depth of the hole. The chamfer is just cosmetic at this point, so you will get the true depth.

The advantage to this, is that no matter what the depth, you will always have a quick and easy point of reference. You can even attach measures, and leave them in the model, if it helps you out. I do this quite often.

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[Azrael]

I may add that you maybe should consider making your own hole features with udf instead. So so can control it with your own parameters.

Saw some demos on something called BPA (business process accelerators) and the interesting one for this case is called Power Features, appeantly a set of hole features that is more according to the real life with rules and intelligence to the machining workbench. I noticed that it looked like they used udf with rules.