Problems with Offset Faces

[tombushey]

I'm having trouble with the Offset Faces command recently. When I select a face the CPU monitor on my computer spikes with Fusion activity. It takes minutes to type in a distance for the offset and then takes minutes to complete the offset operation. As soon as it completes the CPU usage drops off back to a low level. 

I'm using release 2.0.1975 on Mac OS 10.11.4.

[jeff_strater]

Hi @tombushey,

Can you share your design or a screencast?  If the face you are offsetting is complex, this operation can certainly be slow.  Is this a Patch (surface) offset, or a Model (solid) offset?  Also, if your design is parametric, and the face you are offsetting is early in the design, and Offset is set to "automatic" or "modify existing feature", this can be slow as well.

But, with some more info, we can take a look.

Thanks,

Jeff

[tombushey]

I've attached a screencast showing my workflow. Initially I performed a split face for each element from the sketch I created from an imported SVG. At first the splitface operations where fast but got slower each time. I then started dong the offset faces and that was very slow and got slower each time. For the screencast I changed the process and do the offset face command immediately after after each split face. That is worling well initially but seems to be slowing down again. I should mention that over the last year I have created lots of models just like this, with the same amount of complexity without this performance issue. Not sure what has changed to cause the problem this time.

If you have any suggestions to improve my process I'd love to hear them!

[tombushey]

Oops, forgot to add the screencast...

[tombushey]

Here is another screencast showing that the process is getting slower as i do more of them. In the past this was not an issue.

[PhilProcarioJr]

@tombushey

You need to break these apart into separate sketches and operations, for instance do 5 words or so per sketch or operation.

That way it will not bog down Fusion.

You should never do this complex of a sketch all at once.

[jeff_strater · Accepted solution]

I'm not sure that I would approach this problem using Split Faces and Offset.  That technique works for small emboss operations, but you have a lot of those to do.  And, for each subsequent Split/Offset has to work with an ever-increasingly complex face.  So, it's not surprising that it gets slower and slower.  

Here is another way to approach this.  Starting here:

I create a sketch with some text (since I don't have your SVG):

Then, I extruded all the text in one feature and chose "New Body".  This results in:

(yes, I know I messed up the "e", but I was in a hurry)

Next, I offset the top curved face by 2mm in the Patch workspace:

Next, I do a Split Body of all the text bodies using the new offset surface.  You can do this in one operation:

I chose to "Remove" the unneeded bodies, but that's not strictly necessary:

Each of these text bodies, then, extend 2mm into the base.

Then, it's just a question of doing a single Combine operation.  Select the base as the target, and all the remaining letter bodies as tool bodies.  Make sure Keep Tools is unchecked, because you don't need them anymore.  This operation is a bit slow, maybe a minute, but that is expected, and there is only one operation.  This is the result:

Hope this gives you some additional ideas about how to do this.

Jeff

[tombushey]

Thanks Jeff, I'll give that a try tonight. I'll admit the Split Face/Offset approach may not be the most efficient, and the first time I created a model like this it was also very slow. But after an update sometime last year it just started working like a breeze from start to finish. I was able to create several models with variations on this design with no problem. Not sure what has changed. I liked the approach because the engraved text remains normal to the curved top surface of the disk. Will that be true of the technique you described?

[jeff_strater]

You are correct.  My method does not produce offsets that are normal to the curved top face.  It does produce cuts where the bottom of the cut matches the top, though.

Jeff

[PhilProcarioJr]

@tombushey

Could you share the sketch? I would like to take a stab at figuring out a fast work flow for this.

[tombushey]

Given the size of this thing is just 1" diameter, the exact angle of the engraving doesn't really matter! But it's still good to know if I ever tried to make something larger.

I have these cast in bronze by Shapeways by the way.

[tombushey]

I was able to work through this method and it definitely works much quicker. Here is what the resulting engraving looks like as a cross section using the 2 methods. Still not sure if the difference will have a noticeable effect in the final product.

[tombushey]

I thought I'd share the results of Jeff.Strater's suggested solution to my engraved text problem from earlier in this thread. The pictures below show the resulting model as printed and cast in bronze by Shapeways. The diameter of the piece is 1" so you can see how small the text is in the final product. Thanks again for the help Jeff.