Smooth fillet on solid

[LucasGC]

Hi all,

I've remade a surface model into a solid part, gotten pretty far into it, and now i'm running into a problem with filleting the edges. 

It seems like if i fillet one single edge, mcam extends the fillet along the line, not along the construction plane. 

The result is a bottom edge that lines up, but the top edge has a gap.

Could i get some help making this smooth? Thanks

FILLET.mcam

[crazy^millman]

In a sharp corner never going to happen. Your going to get what you get. How would you machine it? Ask yourself that question first. How will the part look when you're done machining it? Try to model to match reality and not what you see on the screen. Once you model using that as the process you will see it is much easier to make the model do what you need.

[LucasGC]

I guess i was expecting a wedge shape that blends the two. if the fillets stopped at a 90 degree i would think i'd have a nice triangle left. I will try and get it to do what i'm picturing by sweep cut

[crazy^millman]

On 12/19/2018 at 6:48 AM, LucasGC said:

I guess i was expecting a wedge shape that blends the two. if the fillets stopped at a 90 degree i would think i'd have a nice triangle left. I will try and get it to do what i'm picturing by sweep cut

Make a .001 Radius on the model in those 2 sharp corners and then try to go back and add the radius on that edge and you will see a huge difference. Now add the radius you are trying to make on the edge to the inside sharp corner and then add the edge radius and you see something totally different. This is the nature of solid modeling as the constraints are such that geometrically in a locked state you get predicable results. When you start thinking abstract and let the abstract be your process then you can start seeing how to model with free form shapes to achieve what you want to see and not what your getting. Don't trap yourself in the constraints of the formula, but let the ability to free form your results help you come up with the answer your looking for.

I used a .25R and I then created curves on the edges of the 2 Radius edges to the sharp curves. I then drew a line from the edges of those along the angle. I now have all the edges to create a surface of the shape you are wanting. I made a net surface of that and then made a surface from the solid of the .25 along that angled surface. I can then turn off shading and see the U-V Pattern of each surface and it tells me the story mathematically of each entity. Now you have the formula for the surface you wanted all along, but this is not your typical formula this an abstract free from shape that will be what your looking for. I still have to ask the question can you even machine that free from shape? Does the part require this much work? If so and you must then you must, but if doesn't then can you just machine what you can and call it a day?

[crazy^millman]

DP

Edited December 21, 2018 by 5th Axis CGI
Double Post no reason to repeat myself.

[LucasGC]

On 12/19/2018 at 10:35 AM, 5th Axis CGI said:

DP

This did work, definitely an abstract shape. I ended up doing something different, but this is a valuable process for the future, thank you. 

What i ended up doing was I just made the first radius, and then made the second one match the first, and the third match the second and so on. i went up to 6 decimal places on some. this means the fillets aren't equal on most of the edges... but at least they're smooth.

[crazy^millman]

1 minute ago, LucasGC said:

This did work, definitely an abstract shape. I ended up doing something different, but this is a valuable process for the future, thank you. 

What i ended up doing was I just made the first radius, and then made the second one match the first, and the third match the second and so on. i went up to 6 decimal places on some. this means the fillets aren't equal on most of the edges... but at least they're smooth.

That was the other way to get there. There is one more way to get there also. Variable Radius where you have one side of the Radius one size the middle the half way size and then the other end the other radius.

[LucasGC]

10 minutes ago, 5th Axis CGI said:

That was the other way to get there. There is one more way to get there also. Variable Radius where you have one side of the Radius one size the middle the half way size and then the other end the other radius.

variable radius will combine the endpoints for each line, so if you try and change the radius where the two fillets meet, it will just change them both. i tried adding points 2mm from each endpoint to make it blend but it just wasn't the same