Need to add a "negative" radius for clearance

[karthur1]

I know that this can be done by creating a sketch and then placing a hole feature, but I am looking for an easier way.  I need to create the "negative" clearance fillet like is shown on the bottom of this part.  Inventor does not allow me to enter a negative value to create this fillet.  I could not find a way to do it with any of the options in the fillet command.

Maybe I am overlooking something or maybe somebody knows a trick.

Thanks

[RobJV]

ifeature?

[admaiora]

Yes, iFeature. Often i have to do a lot of this cuts on sheet metal,then i use this iFeature.

It requests for plane, then 4 points at the the corners.  For single feature i use or another singlefeature-iFeature or this one clicking 4 times the same point corner.

[johnsonshiue]

Hi! Inventor Fillet does not allow negative radius like that. The basic rule in Invnetor Fillet is that the fillet face must be at least tangent to adjacent faces. The negative radius here violates the rule.

Thanks!

[salariua]

I've used hole feature for that but it didn't occurred very often.

[karthur1]

This is something that we do quite often.  I have looked at inserting an iFeature, but it is cumbersome.  I still have to edit the sketch and project the edges of the corners to get the ifeature positioned properly. The click count to insert the ifeature is 14 total (that is not counting the clicks to browse to the catalog location for the ide file).

By the time I do all that, it is just a quick to create a new sketch, draw a circle and then extrude it (12 total clicks).

We use other software here that allows the radius to be entered as a negative number and that flips it around like I want (its not SW, but a profiling software).  It seems that the tools are there for Inventor to do this also. Maybe this could be one of those JDI for the beta team to look at.

I will posted it on the Inventor Idea station here.

Thanks,

Kirk

[LT.Rusty]

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@salariua wrote:

I've used hole feature for that but it didn't occurred very often.

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Yep, same here.  

If I'm milling a pocket in a fixture or something else where I can't make a sharp inside corner but I need to make clearance in the corners, I'll use the hole tool.  Create a new sketch, project the points for my hole centers, and then make the holes.  Only problem with this is that - at least in 2015 - I can't use TO in order to define the bottom of the hole.  Gotta use distance.

[admaiora]

Hi Kirk, have you triend the ide i have attached?

That iFeature allow you tu cut without project edges, just on click for cut (on the cornerpoint)

[karthur1]

I did not see the attachment till now.  I just tried it and that works very well....its much different from the ide that I made.

I guess you have a .ide for 1,2,3,4... etc notches, correct?  How  do you get the ifeature to ask for the point to place the feature?

Kirk

[salariua]

Hole feature doesn't involve to many operations. You can then control the size of all of the notches with one parameter.