Smooth blending between two parts

roger_blain · July 2021

I have this part, where I need to need to create a smooth transition between the parts. I have tried various methods, and keep ending up with chinks missing.
I need to have the part machined, and don't want these gaps machined into the part.
Any ideas?

Here is the link to my project:
https://cad.onshape.com/documents/3a718191eadfe8f03f24048e/w/d3099d26b7a842a9d19efd48/e/90c24cd5407f7885f1371c94

Image: https://us.v-cdn.net/5022071/uploads/editor/av/inmvdh8413tv.png

Alex_Kempen · July 2021

Here's one method, using some 3D fit splines and surface lofts to generate a smooth transition. There's definitely better ways to do what I did, but it's hard to be more efficient since your model isn't fully constrained and has multiple broken features. If you want a more optimized solution, I would suggest fixing it up first. Otherwise, it's garbage in, garbage out, and there's only so much people will be able to do to help you.

https://cad.onshape.com/documents/3147daba19e6fe8c5333612f/w/60f6b5f6ff2524c6d71355c8/e/b10f5c9166e46d5bf365e226

Image: https://us.v-cdn.net/5022071/uploads/editor/k2/zwlvry9dsdiy.png

Alex_Kempen · July 2021

Here's one method, using some 3D fit splines and surface lofts to generate a smooth transition. There's definitely better ways to do what I did, but it's hard to be more efficient since your model isn't fully constrained and has multiple broken features. If you want a more optimized solution, I would suggest fixing it up first. Otherwise, it's garbage in, garbage out, and there's only so much people will be able to do to help you.

https://cad.onshape.com/documents/3147daba19e6fe8c5333612f/w/60f6b5f6ff2524c6d71355c8/e/b10f5c9166e46d5bf365e226

MichaelPascoe · July 2021

Here is an excellent place to learn some good modeling techniques:
https://learn.onshape.com/catalog?labels=%5B%22Self-Paced%20Courses%22%5D&values=%5B%22All%22%5D

stephanos_androutsellis_theotokis · July 2021

Hi Roger,

There's a new cloud app in the Onshape App Store called Phi that specialises in freeform design. I gave this problem a try and I created a short (2 minutes) video showing how you could tackle it with Phi. I am not sure if this is exactly what you were after, I chose one approach that seemed reasonable to me but you could probably also try other ways. If you want to learn more about Phi you could have a look at the material on the product web site: https://phi3d.com/ .

So the suggestion would be to shorten the one part as shown in the video, and then place the join that was designed in Phi in between the two blocks. Alternatively you can of course also build a freeform joint as the two parts are currently, but it may not have an ideal shape.

I hope this may be of help,
Stephanos
PS. Full disclosure, I'm part of the team that created Phi, so apologies if this counts as self-promotion :-)

steve_shubin · July 2021

@roger_blain

Here’s another version

The main thing about this way is that it uses all PLANAR surfaces. It starts with flat surfaces, near half rounds and holes. Then fillets. The primary tool was extrude. Loft was not used. So everything is easily defined

The main surfaces lineup pretty close to what you have

But I did use different size fillets, for a different take on your part

https://cad.onshape.com/documents/3437b508bc3b373ccdd7bf80/w/e58357f2ae6c0a05a597991b/e/6bc27960c9f460533a926e83

steve_shubin · July 2021

@roger_blain

Look in Assembly for a comparison between the original part and the alternate

roger_blain · July 2021

Thanks Michael, I will !

roger_blain · July 2021

Alex_Kempen said:

Here's one method, using some 3D fit splines and surface lofts to generate a smooth transition. There's definitely better ways to do what I did, but it's hard to be more efficient since your model isn't fully constrained and has multiple broken features. If you want a more optimized solution, I would suggest fixing it up first. Otherwise, it's garbage in, garbage out, and there's only so much people will be able to do to help you.

https://cad.onshape.com/documents/3147daba19e6fe8c5333612f/w/60f6b5f6ff2524c6d71355c8/e/b10f5c9166e46d5bf365e226

Thanks Alex, some valuable techniques I can use !

roger_blain · July 2021

Thanks Steve, a useful approach!

roger_blain · July 2021

stephanos_androutsellis_theotokis said:

Hi Roger,

There's a new cloud app in the Onshape App Store called Phi that specialises in freeform design. I gave this problem a try and I created a short (2 minutes) video showing how you could tackle it with Phi. I am not sure if this is exactly what you were after, I chose one approach that seemed reasonable to me but you could probably also try other ways. If you want to learn more about Phi you could have a look at the material on the product web site: https://phi3d.com/ .

https://vimeo.com/572760431

So the suggestion would be to shorten the one part as shown in the video, and then place the join that was designed in Phi in between the two blocks. Alternatively you can of course also build a freeform joint as the two parts are currently, but it may not have an ideal shape.

I hope this may be of help,
Stephanos
PS. Full disclosure, I'm part of the team that created Phi, so apologies if this counts as self-promotion :-)

Well done Stephanos, this is a very interesting approach, thank you.

Evan_Reese · July 2021

Depending on how much control you need, just using one loft might be the simplest way. Note it's not your exact shape since all of the surfaces blend and there's no hard edge.