Starting a variable fillet at something greater than zero 1

[HomeMadeSin]

Hey, I'm semi-new at SW, but have done enough to know most of the basics. I want to apply a variable fillet to a curved (poly-arc) edge, but I don't want to have the fillet begin at zero radius. If you apply a radius on a given segment, the software program forces the fillet to continue, on both ends, to ITS satisfaction. It would be like applying a radius on the edge of a cylinder, but only say 25 degrees instead of 360 and the part is NOT with a constant radius so YOU CANT do a revolved cut. Make sense?

 

[JNR]

I don't know if variable fillets have changed since I last used them, but you should be able to apply any radius at any point. So if you want the fillet to go out to the ends of the intersection edge at a constant radius (either side of your variable bit), just define the radii at the end points (and maybe any points in between) to be the same as the begining and end of your variable section. That's what I did on the very first part I ever designed on SW. It is an aesthetically attractive, but geometrically nasty casting. It has several fillets that start out constant, go though a variable section (in one case a huge % variation) and then end up constant again. That was back in SW97, I think.

3/4 of all the Spam produced goes to Hawaii - shame that's not true of SPAM also.......

 

[HomeMadeSin]

I've used the variable fillet as you described, but I want to go from zero radius to say 0.0625" radius instantaneously. For example, on any given edge of a simple plate, the fillet be applied from one end to the middle of that edge ...and here's the kicker.... NOT GO TAPER TO ZERO. Just a "sudden" stop of the fillet.

On the plate example, you would just cut-extrude the shape of the fillet along the edge a defined distance. Problem is, my shape is not linear or constant radius.

Both Inventor and SolidWorks force the fillet to zero beyond your last defined radius (if greater than zero).

 

[JNR]

Hmm... well I think I get it now. You are going to have a little "tiangular" blind face at the end of the fillet. I have had this happen when I did not want it! (Nasty geometry around here.....) Does it have a tangent propagation option you can turn off like constant rad. fillets? Otherwise maybe you should make it go constant rad. to the ends then add the material back with a sweep or something using a 3D compound curve. You would need to put the curve in from the edge before the fillet while you still had the sharp edge - or roll back to do it. Or maybe delete face might bring back the sharp corner only over the constant section if you only pick those faces? This might be one for your VAR also. Get some value out of your support fee.

OK, I just tried a test part using both inside and outside fillets. By default I get constant rad, not reduce to zero out to the ends. o try playing with the various options. Turning off tangent propagation might work if the shape of the geometry logially supported it - didn't like it in my quick test, but who knows in yours. Delete face did not like it either. But I was able to define 3D curves from the sharp intersection (before the fillet remember - I actually rolled back to test it). Made sketch profiles on the ends of the fillets and did both cut sweep (on the internal fillet) and boss sweep (on the external) to remove or replace the material - it worked fine. I think I would actually define the constant rad. with a couple of points though just to be sure.

3/4 of all the Spam produced goes to Hawaii - shame that's not true of SPAM also.......

 

[Arlin]

Is this what you are trying to do?

http://www.mtcnet.net/~arlin/swx_files/var_fillet.zip

(Note: in SWX 2004 format)

I had to jump through some hoops do do this, but I seems to work pretty well.

 

[HomeMadeSin]

JNR:
Yes, I want to effectively have a triangular blind face, sort of like the result of a what sweept cut would leave behind. I've tried all of the options and it doesn't seem to work, but I haven't done much with constant radius options yet. Also, don't you mean a cut sweep on EXTERNAL fillet?

Arlin:

Thanks for the file. It took me a while to figure out what you did, and I certainly haven't figured out how to (or if I can) apply it to my model.

It is cool that SW allows a 0.00 surface offet. It actually suprised me as it is hard-headed about other factors being greater than 0.00000384. And I especially hate the zero-thickness error.....but that is another post.

 

[Arlin]

Your welcome for the file. Yes, it is a vit involved and can be confusing.

Could you post your file or a picture of what you want somewhere? I am just wondering if there is a better way to accomplish what you want. I began this by just doint exacly as you asked, 'using a variable radius fillet.' But perhaps other tools (such as a sweep or loft) to get it done.

 

[HomeMadeSin]

Arlin:

The first pick is the beginning of a volute passageway, which will actually be used as a subtracted part out of the actual pump housing.

http://home.earthlink.net/~homemadesin/sitebuildercontent/sitebuilderpictures/698_04_nov_2003.jpg

The second pic is the close-up of the fillet that I highlighted the part of the variable fillet that I don't want to exist. In other words, I want the other surfaces to meet and form a line.

In reality, tools like a sweep function with many sketches, or a lofting feature that actually follows the guides accurately would do what I want, or at least I could tackle it a different way. I guess that is what Pro/E, Catia and UG is for.

http://home.earthlink.net/~homemade...ebuilderpictures/698_04_nov_2003_close-up.jpg

 

[Arlin]

Well, there probably is a better way, but here is my go at it:

http://www.mtcnet.net/~arlin/swx_files/pump.zip

 

[HomeMadeSin]

Thanks Arlin, that looks the part. I'll have to follow the logic, but it looks good. Although, the mirror (last feature) didn't work. Thanks again.