fillets - how?

Looking at the feature tree this seems to be an imported part so it doesn't look like you have any control of changing or removing fillets from the feature tree.

that being said....

This sounds like a handy job for the "delete face" and patch feature. What I think you want to do since the existing fillets are too small...

control select all the fillet faces that make up the area that you would like to change or remove the fillet in this case. Think of it as selecting all the faces of the fillet that you would like to set to 0 and create an edge. Once you have all these faces of the fillet selected, right click and under the "face" subset there should be "delete face" option. (If it's not there you need to turn it on by custimizing the menu). Once you bring this option up select the "delete and patch" option.

Sometimes you have to play with the order of fillets of some blend into each other. But hopefully if the geometry isn't too complicated it will have successfully set those to sharp edges.

If you were able to get to this point you should be able to just add the fillet size to your liking and life should be good. If you are having issues with the "delete face" feature... you may have already killed one of your coworkers by the time you read this. ; )

Good luck!

bob zee wrote: ...

If bob z. can visualize where bob z. would like the edges of the fillet to be, then bob z. could use split lines to place the edges of the fillets. This might take some time and might require split lines from a couple different directions. Then use Delete Face with the Delete option to remove the faces that are where the fillets are spoda go (between the edges of the fillets). Then bob z. could loft in fillets between the edges. If bob z. lofts the fillet in smaller sections, bob z. can even blend together fillets that collide.

There are magic four letter words bob z. can use to shame fillets into working, but use that as a last resort, along with beating on the Esc key.

Can Bob Z (out on the border) post only the imported surfaces regarding the blend so others may help mano a mano.

Otherwise, what I'd suggest is trying to do a chamfer in place of a fillet and delete the chamfer face(s) then blend (loft).

..

oh.. one more thing. If the egdes were sharp to begin with and SW just won't let you put in a large fillet. Have you tried a "face blend" fillet? If this doesn't work you may have to get fancy and try loft faces together after split lines and deleted faces. But hopefully you won't have to do this.

Don

OUT IN THE WEST TEXAS TOWN OF EL PASO...

bob z. just got corrected by someone up. way up. way up high on that ladder!

bob z.

yes, the edges are sharp. the imported feature didn't have any fillets on it. bob z. has tried the face blend fillet and isn't having a lot of luck with that, either.

bob z.

BOB Z MIGHT HAVE TO LEARN TO USE THE ATOMIC BOMB OF FILLETS. WORKS EVERY TIME.

EXTRUDE A BLOCK OF MATERIAL UP OUT OF THE SURFACE. THE BLOCK IS A STOP FOR THE FILLET. IT MUST BE BIG ENOUGH TO STOP THE .25 FILLET. PLACE THE BLOCK IN THE LOCATION WHERE THE FILLETS HAVE TROUBLE.

FILLET UP TO THE BLOCK FROM ALL DIRECTIONS.

THEN USING THE EDGES OF THE FILLET WHERE THEY INTERSECT THE BLOCK AND ANY OTHER EDGES NECESSARY CREATE A FILL SURFACE FEATURE.

USE THE FILL SURFACE FEATURE TO TRIM AWAY THE PROTRUDING PART OF THE BLOCK.

P.S. This was something Ed Eaton showed me. I don't take credit; I just use it.

PPS If fillets as large as you need were formed there, would any of the starting surfaces be consumed and changed in form? In other words, does doing what you are going to do change the design, form fit and function?

PPPS There are a lot of little sliver surfaces in your imported part. These are not good. Prior to any work did you run a TOOLS/CHECK with Verification on Rebuild turned on? CTRL Q. Import diagnostics. Did you try exporting to VDAFS? VDAFS has a very stringent checker. It may turn up trouble that other means won't. Did you turn on surface curvature shading and look for "whopper jawed" surfaces? This is just GIGO checking.

PPPPS You can always load a trial version of Rhino and fix it. Sometimes I wonder about jobs like this. There is really no design intent issue and history based modeling can get in the way more than help. More than that, this kind of imported geometry more often than not is not conducive to SW way of doing things for many reasons.

SMA realizes Bob Z's pain but cannot help note that Bob Z is designing a die and also concerned about making external radii large. What SMA knows is that external radii on that feature have no value since the internal radii (on the far side) are the things one cares about since the radii are on the "tension"side of the material (internal radii on the die side may be sharp since the radius in question is controlled from the other side of the material - the punch controls material here and the material on the die side - visible here - is in tension and will conform to the punch - the rule is not always true, but looks true here). SMA also notes a painfully sharp draw radius near the flange - SMA envisions a ripped part or a part that will perhaps require an intermediate reduction to get that sharp radius (GRIN).

What SMA has done is steal the faces from the punch side and build a punch block around it with surfaces only (likewise with the die). SMA noted while doing this type of punch and die design that using surfaces made SMA feel very good about life and that trying to carve up a solid part is just pure pain. SMA now uses surfaces only to do this sort of work. SMA suggest that Bob Z. might be happy this way too . . . SMA used to believe that cavity was a good tool for doing complex punch/die blocks from an imported part, but SMA felt much pain in doing this. SMA still totally believes in cavity when the draw has clean straight sides that lend themselves to carving away, but mostly SMA believes in the utility and good behavior of surfaces for editing these multifaceted parts will also make Bob Z. happy if he decides to try this method.

Good luck man . . .

SMA

Sometimes I have just reconstructed the part from scratch after getting enough dimensions one way or another. I can't tell by looking whether most of the surfaces are prismatic or not.

Working with imported geometry is not my idea of fun. I don't know if I heard whether or not Feature Recognition worked, but I assume it didn't do very good.

Even with prismatic surfaces, Radii have presented a problem for me in getting them to all "work". I have had to spend hours going through complex parts where radii run through dozens of edges and all have to blend together right.

I have changed the order of radii, types of radii and sometimes been forced to add small radii from .01 to .1" on two intersecting surfaces to get a radii at their intersection with another surface to fillet properly. When the angle is slight like a draft angle of maybe 5 degrees, I have at times had to put in a 1" to 5" radii on the meeting of two surfaces, in order to get their edges to Fillet properly with a

Bo

bob zee wrote:

SMA realizes Bob Z's pain but cannot help note that Bob Z is designing a die and also concerned about making external radii large. What SMA knows is that external radii on that feature have no value since the internal radii (on the far side) are the things one cares about since the radii are on the "tension"side of the material (internal radii on the die side may be sharp since the radius in question is controlled from the other side of the material - the punch controls material here and the material on the die side - visible here - is in tension and will conform to the punch - the rule is not always true, but looks true here). SMA also notes a painfully sharp draw radius near the flange - SMA envisions a ripped part or a part that will perhaps require an intermediate reduction to get that sharp radius (GRIN).

What SMA has done is steal the faces from the punch side and build a punch block around it with surfaces only (likewise with the die). SMA noted while doing this type of punch and die design that using surfaces made SMA feel very good about life and that trying to carve up a solid part is just pure pain. SMA now uses surfaces only to do this sort of work. SMA suggest that Bob Z. might be happy this way too . . . SMA used to believe that cavity was a good tool for doing complex punch/die blocks from an imported part, but SMA felt much pain in doing this. SMA still totally believes in cavity when the draw has clean straight sides that lend themselves to carving away, but mostly SMA believes in the utility and good behavior of surfaces for editing these multifaceted parts will also make Bob Z. happy if he decides to try this method.

Good luck man . . .

SMA

bob z. isn't quite sure he has the brain power to pull that one off. :~(

bob z. extended the surfaces far enough to allow for the radii to be formed without consuming the needed surfaces.

bob z. did a 'roundtrip' through IGES and it came back in as a surface with errors - ran the diagnostics and it fixed the gaps and then bacame one imported feature.

bob z. has played with rhino just enough to know that he would/could really screw up this part. :~)>

bob z. is trying to create really large external radii so that the internal radii on the far side are big - so, yes bob z. is in total agreement with you (he thinks, anyway because he has NEVER designed a die before). the painfully sharp radius near the flange will be bigger, bob z. is still in the in-process stages.

bob z. started out with surfaces on this project. we had a wooden check fixture (gage?) that was sent out and an iges file with the surfaces was sent back to us. after going through several iterations, bob z. ended up with what we see in the picture - one imported solid feature and fillets that don't work...

Thank you! You have helped tremendously. :~)>

bob z. is going to try this method right now.

bob z.

if one of these many ideas don't work for bob z. by about noon today, bob z. will post this file somewhere on the 'net for download.

you guys have been way too helpful. everyone that has responded to this thread deserves riches beyond comprehension! you guys rock. all of you. :~)>

bob z.

Sometimes round trips through IGES are not enough. That certainly does not eliminate slivers and slivers are what you have. They are as aggravating in a model as they are in your finger and need to be removed. No automagic way to do that.

My point about Rhino is simply that the problem at hand really isn't one in which "Design Intent" comes into play as strongly as "Get the job out yesterday". Do you have as much time to play with the model as you do to learn another tool?

these slivers are DEADLY. :-(

very good question. unfortunately, bob z. is not sure how to answer.

bob z.

watch out for those Mexican girls...........

good luck with your fillets.

OR:

good luck with the Mexican girls-watch out for the fillets.

you decide.

jk

bob z. just got the fillets MOSTLY figured out. bob z. will stay away from the girls. :~)>

bob z. p.s. they had training. *i* have google.

This was something I picked up from Jason Pancoasts filleting presentation in 2001, and I understand that he got it from Keith Pederson. All I contributed was recognising its power and showing a few more common examples, to dissect the "why's" of it, and apparently most important of all- to tag it with a cute/memorable catchphrase. It also works with drafts sometimes (and shells, and all sorts of other problems) Just want to put credit where it is due (i.e. not on me. As a policy I don't like to regurgitate other folks stuff, but this one was just too darn useful. All my ppt slides say I stole it wholesale from Pancoast) Ed