Please help, trying to create a lip and groove for a snap-fit enclosure, getting errors

[hamzanabi123456]

Hi,

I'm new to inventor and have previously used the lip feature (plastic) in order to create a lip and groove on two bodies (top and bottom half) so the enclosure snap-fits together. However, i've changed the design slightly and now the feature gives errors and i don't understand how to resolve it.

Therefore, i was wondering if there is another method for creating a lip feature maybe by using a sweep or something similar, i've tried to sweep cut the profile along the face but it results in errors.

I would greatly appreciate it if someone could create this lip feature on my design along with other possible solutions.

I've attached pics to help visualise the problem and attached the part. Thanks.

[TrippyLighting]

You've been shown exactly that in a previous thread with this very model. Can you elaborate why that did not work for you?

It would make little sense for us to repeat the same thing here if that did not work for you!

Also, working with a dumbed down model without timeline I usually have to resort to different workflow than I would use in a native Fusion 360 model with a timeline.

[CGBenner]

@hamzanabi123456 

Are you trying to model this in Inventor, Fusion, or both?  Sweep would most likey be the correct tool in either case.  You say you tried this and got some errors, can you be more specific?

[hamzanabi123456]

Hi CGBenner and Trippy,

I'm actually modelling in both which is not ideal as if i need to make changes in the design, i have to then export the model to inventor to make the required changes (lip feature).

I had to previously use inventor because i used the lip feature in order to snap-fit the top and bottom half, this is the only reason i had to rely on inventor as fusion doesn't have this feature readily available and the way around this in fusion proved to be quite challenging, @TrippyLighting is correct and had provided me with a method which i attempted but unfortunately couldn't successfuflly replicate (must have not done one of the steps completely correct), that method didn't involve sweeps though.

Since i only have access to fusion at home as its cloud based (inventor is only available on work pc), i want to be able to model in fusion from start to finish, therefore i would need another way of creating that lip to snap-fit the case.

Another member also suggested a sweep in order to create a lip on one of the halves, i managed to follow this and did it correctly in inventor. However, for some odd reason that same exact sketch and sweep doesn't work in fusion (it doesn't sweep across the entirety of the guide face) and gives a compute error, this i find really odd. 

I've attached the inventor file with the timeline, i would appreciate if someone could try this in fusion like i attempted but ended up with the error, it's a simple sketch and sweep feature across a 3d sketch on the guide face.

I would also appreciate if you can comment on wether my sweep attempt is correct.

Thanks again guys.

[CGBenner]

@hamzanabi123456 

Thank you for clarifying; I was a bit confused.  🤔

I leave you in the capable hands of our Fusion experts (I'm not one of them!)  Good luck!

[laughingcreek]

sweep doesn't work here for a variety of reasons.  the most glaring is the presence of "near tangency" conditions at these locations-

that problem most likely originates with the initial profile sketch, which isn't present in the model provided.

I'm also curious to know what is expected with a "snap fit".  @hamzanabi123456 -are you expecting to put a snap fit profile along the entire edge of the lip?  I would think that would be problematic in terms of function since the lip isn't perpendicular to the pull direction in all areas.

[hamzanabi123456]

Hi @laughingcreek,

Thanks for the reply, it's still odd because inventor will actually sweep that same geometry across the profile to create a lip but fusion will give errors (different modelling engine maybe?). I've attached the fusion file (with timeline) below and would be grateful if you analysed it.

I basically want the top and bottom bodies to snap-fit together, they are plastic parts for injection moulding (so tolerances need to be accounted for), someone has mentioned that If i want to match snap-fit perfectly, it would be better using the boolean tool. For a multi-body part, the difference can be made all at once. For two files, its possible to derive the finished body to the second part and then subtract.

I'm not quite sure on this, all help would be highly appreciated. Thanks again

[CGBenner]

@hamzanabi123456 

Fusion's Product Design Extension has some tools for working with plastic parts.  I have no experience in this area, but maybe some of our forum experts here have worked with these tools and can advise if this would be worth looking into.  The extensions do cost extra to use.  (Snap Fit preview)