filleting operation

[mmyoung]

It's fairly commonplace for me to join a cylinder to a piece of rectangular bar stock with a 100% weld, which I indicate with a fillet.

If the width of the bar stock approaches the diameter of the cylinder (I'm selecting Tangent Entities), VW won't perform the fillet, or it "works," but it looks terrible; there's a nasty-looking patch where the fillets join.

So, I export to Concepts Unlimited (which also uses the ACIS kernal, but a better version), perform the fillet with no problem, then import back into VW.

Is there some additional trick I can use? It seems like such a simple thing, which other apps do well. I even tried breaking the stuff into NURBS surfaces and using Create Fillet Surface, but no luck.

?Michael Young

2008 SP3; 10.5.4

RW & Machine Design

Edited July 24, 2008 by mmyoung

[AndiACD]

i think you might be flogging another dead horse here with NNA, i've asked many times about a solution but still have had no sign of improvement on the Fillet/Chamfer front.

Something other CAD packs accomplish without flinching, but VW often falls flat on it's face if anything more complicated than a simple but joint is required.

is there anybody out there?

[CADD OP]

I am sympathetic to your pain...I am also fighting with the fillet commands! :mad:

[M.CH]

Are you using solid addition and then using the fillet edge tool?

I am making a rectangular solid and a slightly smaller rod, using fillet edge tool in the 3D modelling palette seem to work fine, do you want to post your file?

[AndiACD]

MCH, yep, that's the simple type of solid i refer to that VW is able to cope with.

It's the moderately more complex stuff when VW trips over it's own boot laces.

[mmyoung]

Thanks for all the replies and symphathy! My workaround (export and solve, then import it) would have cost me a $bundle if I did already own this other bundle. I don't know what someone would do to solve this common situation if he or she couldn't port it to another app. I'm looking into (haven't done it yet) converting to a mesh and seeing if I can cobble something up. Curiosity, mostly, but also to see if it's a viable workaround.

[mmyoung]

Incidentally ? what other categories of filleting problems have you run into, so I know what to look out for? It'd be good to catalog them. Dang, I love VW, and things like this are all the more frustrating because of my general affection.

To be fair, this is actually a tough problem, and though Spatial has solved a lot of it, it can even trip up programs like FormZ and Concepts (now Shark!). But I think there ought to be a short list of common solutions, like this one, which are just routine and listed in the product literature as solvable.

Edited July 28, 2008 by mmyoung

[AndiACD]

e.g. 2 or more cylindrical solids attached to a surface, like gear covers/cases.

the fillet tool runs into difficulties negotiating multiple objects, variable shapes.

[mmyoung]

Well, wooohooo

the Parasolids kernal seems to have put this aright.

[mike m oz]

Parasolids certainly has resolved the fillet issue. In my experiments so far if the fillet is possible in real life it will work.

[AndiACD]

All i can say is, it's about time!

Now lets see if the adding and subtraction of 3D objects is as stable and precise on complex model construction and has finally come of age.

[mike m oz]

Andi, so far all of the boolean operations seem good. One of the things I like is you can now set the Working Plane on a face, draw on it with the Nurbs tools to split the surface, and then use the Extrude Curve mode of the Protrusion Cutout tool to 'push' or 'pull' on the different parts to subtract or add to the object. It is almost SketchUP like.

Edited September 27, 2008 by mike m oz

[AndiACD]

Sounds GREAT Mike, just hope it solves my niggles.

i've always had trouble in editing when subtracting and adding two objects that share an overlapping line. particularly with very small objects including threaded shafts/screws and always having to "Nudge" them until VW accepts their position, hence my "Precision" query. i see there is still an issue with rendering subtracted solids from your attachment. i refer to the patchy surface colour of the hole. Another of my niggles. Nice work nevertheless.

Thanx.

Edited September 28, 2008 by AndiACD

[mmyoung]

I am guessing the surface color of the hole is not resultant from coincident surfaces or dodgy subtraction but might just be a reflection. So far I'm having better luck in 2009 than packages that use the top-end Spatial kernal. I'm really amazed by this thing.

the coincident or near-coincident surfaces thing is a nasty problem in polygon modelers like SketchUp, because the surfaces on the model are really "limit surfaces" like you get in sub-d modeling. I hope this doesn't come up here.

Edited October 1, 2008 by mmyoung

[mike m oz]

Some more fillet examples:

- Tube fillets to a hemisphere end on a larger tube.

- Weld fillet of a tube to a bar the same width as the tube.

Fillets like these couldn't be done in VW 2008.

Edited October 4, 2008 by mike m oz

[AndiACD]

Nice examples Mike.

Thanx

[M.CH]

Also it should be noted that if you make changes which impact on the fillets, the fillets will change.

That is a great step forward.

[AndiACD]

M.CH, so does that mean you don't have to Ungroup the object before editing it now like you used to and reapply the fillet again when your done?

[M.CH]

Yes, it automatically updates

[AndiACD]

Now, THAT, is a step in the right direction.

Good news.

[GWS]

I just spotted this from another thread:

(Re: 2 question for 2009)

'The filleting behaves the same as all other versions, by that I mean in terms of once the fillet is implemented, one can't modify the underlying solid/3D object. One has to get rid of all the fillets alter the object as required then re-fillet. This goes against what the parasolid engine is all about. Weird.'

This comment seems to contradict the one above. Could someone please clarify my confusion please

Kind regards

Guy

[AndiACD]

Hey Guy,

got a trial copy of VW2009 yesterday and opening files from my version has brought up the problems you speak of.

in VW 11 threads subtracted, after a bit of Nudging without too much of a fuss, but although some of the threads work on this front(that's a hick-up on it's own-some do, some don't), there are several symbols i created that have "turned to stone"! Only the bounding box is visible. Going deep into the Edit mode reveals that the threads(subtracted) are the problem. 3 M3x22mm threads turned into 3 square extrusions. After a lot of searching in the pallets, i found the tool i used no longer exists and a straight nut and bolt icon does the trick, or at least it should. But i can't even get the dialogue box to operate(see pic)

So, no new threads.

Sorry no pic. Can we post pics here? How do you do it Mike?

[AndiACD]

'The filleting behaves the same as all other versions, by that I mean in terms of once the fillet is implemented, one can't modify the underlying solid/3D object. One has to get rid of all the fillets alter the object as required then re-fillet. This goes against what the parasolid engine is all about. Weird.'

Well Guy, and all the other contributors here . . . . . .

i have now installed VW2009 and i can back up the quote above. i still have to "ungroup" before editing objects and VW still complains about filleting complicated shapes. i.e. the filleting tool isn't any better than it was in VW11.

Sorry Guys, i did try and there may be a few things that have improved, but so far i have yet to find them.

Oh yes, it doesn't crash, not yet anyway, but then neither did 11.5.1 which used to hang sometimes which 2009 has already done thrice since installing it.

[GWS]

Yes, I have had the same problem with 'imported' solid subtractions where the only thing visible is te bounding box.

I was a little disappointed that the ungrouping/filleting situation hasn't been sorted out as it seems to be alomsot every mechanical part I design has filleted edges at some point.

still I'm sure VW10 will deal with it as well as adding 3d dimensioning of course!!

Kind regards

Guy

[AndiACD]

Hammer Horror story continues . . . . . . . .