Trouble with 3D fillet

[Art K]

I have been trying to put a .187 fillet on the edge of a part and have been unsuccessful.
Here is a snapshot of the part, the blue line on the left side is where I have been to do the .187 fillet. I have been getting this error message. "BL_CAP_COMPLEX: could not find acceptable sequence of capping faces to trim blend face" I had trouble on the bottom of the other side and solved it by turning on variable radius. If i do the other side .1to .187 I can get some fillet on the left side but that isn't what I want.
Art

 

[Lew_Merrick]

Art -- I am thinking ot the edge you want to fillet as being the "bottom of a flat-bottomed V" (for lack of a better descriptor). My first question is, "Other than filing that fillet, how would you make it? Normally a fillet has to have "run-out" at either end of a "blind-enclosed fillet" or somebody has to make it with a file, right? Had the "pre-filleted" surfaces been themselves filleted with just about any fillet radius (because of the internal nature of the join) your fillet would almost certainly followed along quite nicely.

 

[Art K]

Lew,
I have a Tormach mill and was going to machine it with that. If I understand you the square corner on the bottom is the problem and that I need to blend the fillet into the base somehow to get the desired result? How do I pre-fillet the surface?
Art

 

[JST]

Do that fillet before some others. Might then work. Fillets are VERY sensitive to the order of operations, because the blending is a very weak point with the fillet tool.

The fillet would be easy-peasy if a casting, because there is no need to generate the toolpath then, the pattern can be generated with many pieces.

I'd bet your problem is with the fillet along the bottom edge. Put the blue line fillet in first, before that AND maybe before those holes, and see if that does it.

The other issue is the one on the angle, which is a good deal larger radius,

Dunno, did this simplified similar part, and it just worked....

 

[Lew_Merrick]

Lew,
I have a Tormach mill and was going to machine it with that. If I understand you the square corner on the bottom is the problem and that I need to blend the fillet into the base somehow to get the desired result? How do I pre-fillet the surface?
Art

Art -- Another approach would be to consturct (as a separate Part) with Revolved ends that can be BOOLEAN Subtracted from your initial Part. That way it truly reflects the manufacturing process.

 

[GeorgD]

I have been trying to put a .187 fillet on the edge of a part and have been unsuccessful.View attachment 25382
Here is a snapshot of the part, the blue line on the left side is where I have been to do the .187 fillet. I have been getting this error message. "BL_CAP_COMPLEX: could not find acceptable sequence of capping faces to trim blend face" I had trouble on the bottom of the other side and solved it by turning on variable radius. If i do the other side .1to .187 I can get some fillet on the left side but that isn't what I want.
Art

Hello Art,
I would put an Fillet on the edge which results after putting the previous edge rounding betwen the edges. And only then round this edge

 

[Art K]

JST, Hal
Thanks for your help, tried to load your file and got an error that the file version is higher than mine. Could I do that as a revolve cut along the blue line as the axis of rotation? Or can I just move the order of the fillet before all the holes rather than deleting them all and starting over re-installing the holes. I did try suppressing the holes but that didn't seem to work. The fillet radius on all the top edge is all .187 except the part on the right hand side where it blends into the horizontal flat above the 1/2" hole and 4 mounting holes.
Art

 

[JST]

Well, I tried several order of operation, and had no troubles with the equivalent to your blue edge.

I t may just have to do with specific numbers... I have noticed Alibre sometimes has an issue with a particular dimension. The picture shows what I did, just roughly replicating your shape of the edges. There seemed to be no problem no matter what order I applied the fillets. I made the edge fillets different so as to make the most "trouble". Bottom one is 0.5", angled is 0.250", and the small one is your 0.1875"

It APPEARS possible that the rounding function in Alibre sometimes lets differences creep up into the 6th decimal place, so that "equal" dimensions turn out to be different down in the last place. That might cause things not to work in various ways that are not necessarily easy to predict.

At this point I do not know what the issue is, and can only suggest changing the order of operations, because I have found that to fix stubborn issues with the "capping", as your error message shows you have.

Fillets before holes would be a good start. It gets a bit complex down in the left bottom corner, where the hole and two fillets all come together.

 

[Art K]

JST,
Thanks I will try that. I think I could change the angle and give more space for the c-bore in the corner as well.
Art

 

[Art K]

JST,
I tried that. There was a small portion on the bottom and if I did the fillet on that then the blue line it worked just fine. Thanks for your help. Until I looked at it that closely I didn't realize it was a split line.
Art

 

[bigseb]

Art, can you upload your part? Usually helps...

 

[HaroldL]

Try this...

Step 1:


Step 2:


Finished fillet:

 

[DaveD44]

I'm having a similar problem. I can't get a top and bottom edges fillet to take on a flute inside a handle. PRT file attached. I believe that it may have to do with Sketch 10 (drawn first, but since reordered by me in one attempt to make this work) and Sketch 11 and how they align. The problem is that Sketch 10 is made on one plane and Sketch 11 is on another. I don't know a way to make the two sketches share and lock to a common line because Sketch 11 has to lock to the extrusion of Sketch 10, Extrusion 16. Can someone make this work? Is there a better way to make the smaller upward flute? Part of the larger flute?

 

[idslk]

Hello DaveD44,

i'm not sure about the dimensions you've used. Length overall round about 13mm?
I've done it from scratch with different dimensions. Only the first quick try. Ofcourse there are better ways to do it...
Do you have some kind of drawing or sample for this?

Regards
Stefan

 

[oldfox]

Dave,
I wasn't sure what more you wanted in fillets so I added the edges of the handle depression. Look over the drawing and go down the explorer tree and see the sequence I used. You will notice that I have suppressed features that aren't needed at this point. If you need them later, just
un-suppress them. I put the Scale after everything else was completed as I would guess that the intention was to scale the completed wrench.

This is how I handle fillets. Others may have different methods.

 

[idslk]

Hi Chris,

that's also a solution
Haven't been sure about this:


"needed" or not?

Regards
Stefan

 

[DaveD44]

idslk: What I want is pretty much what you drew up from scratch. Yes, it is tiny, about a half inch or 13.24 mm long. It is a 1.6 inch to the foot scaled standard 1/2 inch pipe locomotive drain cock. I'm 3D printing several sizes for use with live steam models. And, after all this, it is too small for many of the features on the prototype to print. Shapeways will not even print this handle with the flute, as it becomes too thin for printing. A screen capture of the handle for the 3/4 inch pipe cock is attached. It is the original non-scaled version and it rendered correctly. I suppose the few changes I made to the scaled version caused it to fail.

Thank you idslk and oldfox for the samples that give me some guidance on how to better accomplish models like this.

 

[oldfox]

You're welcome Dave. I hope it helps you along the long dusty trail.

 

[idslk]

Hello DaveD44, hello Chris,

i've tested the Scale_Part_V01.Py Skript with this (my) part.
I've opened the part in "original" size, started the skript, have choosen "nothing excluded", 10% , ok...
It takes some moments until it was through, but it works perfect - ready was the tiny valve handle

Here are "both", loaded together into an assembly:


Regards
Stefan

 

[oldfox]

Papa bear and baby bear. Well done.