Extrude Precision and precision in general

I am going back and forth trying to get a body extruded to a precise length 1016mm. But everything I do gives me a fraction. When I try and remove just that fraction it removes some other value larger ( i am using the pad to key in my values). It looks like it might be double but not always. I assume this is a bug? I am using an iPad.

What would be useful, and maybe there is a way to do this that I have not found, is to be able to set the precision. For example if I am working in mm, for my application, I don’t need things moved, sized or positioned in fractions of 1mm. I understand others might.

Can you share the workspace or a screenshot? I tried but I can’t reproduce the problem.

This sounds like another vote for constraints on bodies/extrusions…

The model is not very exciting so I can send you the shapr file if you like.

Well I am voting for specified precision. :grinning:

Please send the file to me (istvan@shapr3d.com) or to support@shapr3d.com. Also a screenshot of the issue would be szper helpful.

Any thoughts on this? It is really a pain that I can’t size things without guessing what number shapr is going to come up with.

OK. I just tested this with a body that has square or rectangular face. When I try and resize I am always give the option to enter the whole size. After I chamfer the edge to 45 degrees - I am making mitered carcasses - I am given the option to move the face by an amount relative to the current size. When I do that shapr starts to introduce rounding errors, that after a few attempts devolves into full on errors.

For example. If I have a panel that has an outside edge of 450mm and inside edge of 430mm, I select the top face and reduce the size by -10mm my outside edge is now 435.858 the inside edge is 415.858, the material is 20mm thick. I expected the outside edge to be 440mm and the inside edge to be 420mm.

Can you please post a screenshot?

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I already sent you a model. Here are three screen shots. You should note that the new size is random, or maybe a ratio of the size of the panel I am sizing.



This is the expected behavior. Using the offset operation offsets a face in the direction of its normal, so when you are offsetting that face it won’t move in the Z direction. If you want to move that face in a certain direction, you can use the Move/Rotate tool to move it.

Fine. But can I move it with precision? I mean sometimes it is out by 5 or 10 or 50mm. I mean I need to make that board a certain length. Otherwise how can I layout the furniture for with any accuracy. And this is simple stuff.

Yes, absolutely. That’s what the Move/Rotate tool does. You can precisely move faces, edges and bodies with it.

OK. But for clarity. You are saying that offsetting by 14mm when asking for 20mm is the expected behavior when using the offset face.

And in case it is not clear, I really like Shapr3D, so far. Just a bit confusing.

No, that’s not what I mean. Offsetting 20mm a 45° chamfer will shorten your edge on the side by exactly 10 * √2. Offsetting does not move the face in the Z direction, but in the direction of the normal of the face.

Offset (blue) vs move (red):

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Thank-you. I am progressing… Getting the hang of it.

Extrusion is the forming of an aluminum material by heating it until in soft condition, then pressing it through a matrix or die to produce profile lengths. Profiles are ubiquitous wherever you find movement; the machinery industry, the automotive industry, medical applications and the aviation industry are excellent examples.