designing a cast part, strengthening ribs(extrusion/push,pull/planes) advice?

[Anonymous]

Hi Guys,

Looking for a bit of advice. New to f360.

This is a base I'm designing for a machine. The part will be cast steel in the End. 

What I'm struggling with is the ribs to support the round post to all four corners. I'v tried various ways to make them but they're proving to challenge me a bit. 

The method I've had most success with is to sketch the shape of the rib on the the base and push/pull it to the height I want. The vertical surfaces meet perfectly on the radius and will allow me to make nice fillets. The problem is then cutting the corner off. I've tried creating a plane on a angle through the part but when I cut it, the cut carries on to infinity and takes off the round post with it. Also I cant seem to get it to lock onto right angles. I've  tried  sketching guide lines for the planes but they always end up crooked. 

The other way I tried doing it is to create a vertical plane, sketch the side profile of the rib and push/pull it to get the desired thickness. Which worked fine but the ends where it meets the round post and the short end aren't desirable. I can't get the fillets right to the round post as the surfaces don't meet properly. And I can't seem to find a way to trim the small tip of the rib be the corner recess to meet the radius around the bolt hole. 

I'm not sure if either of these methods are a good way to go about this but ideally what I'm imagining is a way of combining both of them. Or just simply a different/better way of doing it if there is one?

Attached are some screen shots , showing the two different methods I've been attempting on each of the ribs.  hopefully my explanation makes sense. 

I plan to smooth everything off with fillets at a later stage. Any help would be much appreciated. 

[Anonymous]

Two solutions for your project as is. One is to make separate components, and make the center post invisible when you make your cut. The other solution is to make your sketch plane on the side face of the rib, not orthogonal to it. Draw the desired shape of your rib profile. The make the area that want excluded 'closed'. Extrude this area in 'cut' mode, and remove the excess from your rib.

I am sure the more experienced F360er's would advise you to compose your separate pieces as individual components, with their sketches in separate models with 3 view sketches, extruded & modified as necessary, and then assemble them as desired.

[Anonymous]

Thanks for the quick response! 

This is helpfull information, I'll have to brush up a bit on making things as separate components. I'm not familiar with that but it does make sense. I'll give it a go when my brains aren't so fried from multiple failed attempts lol 

Also is there a way to get a new plane to snap to grid?

Many thanks!

[davebYYPCU · Accepted solution]

So much better to attach a file- so we demo with your data.

You are nearly there - continue with the back version, replace the plane with a side view sketch, see below.

With out the file - I would build the rectangular web before the bolt landing, so that the bolt landing - extrude cuts - two directions, the bolt landing and the small end.  The tall end is done the way you want it.  For the shape of the top of this rib, draw a cut line on one face, then using that line as the bottom of a rectangle draw the rectangle over the offcut and extrude cut it off.

Might help....

[Anonymous]

Yeah I see what your saying with the bolt landing, that makes sense. I'll give that a try but also just for future reference is is possible to trim it to the existing shape of the landing? Just in case I come across a similar scenario in the future. 

Extrude cut with a rectangle.... has worked a treat!  

I'll work on it a bit more and post an update. I'm getting my head around it though so I'm happy.

Thank you! 

[davebYYPCU]

Yep, presuming your talking about a wavy cut on a wider rib, 

(no file - can't see how the landing shoulder was made,

I'll presume a profile cut down from the top face, and mirrors, but

- there are other ways)

you can go to Patch, and extrude that profile, as a cutting surface,

the use that as the cutter in a Split Body operation,

but the web has to be a separate body to do that, getting too complicated,

use the extrude cuts.

Good to hear the frustration getting lower.

[Anonymous]

Yes sorry I'll get a file uploaded but you are correct, profile cut down from the top face. Just no mirrors did them individually.

That's good to know. Will keep it in mind but I will stick with extrude cuts for now, if I can. Especially as in my eyes these are basic things I'm making here at the moment. I like the concept of it, keep it simple. The machine as a whole will be made up of a few components so I'm sure I'll get into individual bodies and assemblies later on.

The last program I worked with was mastercam 10, which I was quite handy with.... But that was over a decade ago haha things have moved on somewhat since then!