First design of a complete novice, MS Surface Pro holder

[dmehling]

No response yet? I didn't think my questions were that complicated. What I really need to know is how thin can I make my tablet holder and how narrow can I make the perimeter section and crossbeam sections. I don't know if these are the best terms, but I think the picture makes clear what I'm talking about. I am considering nylon, but since my last post, I've also been thinking about aluminum. I did several Google searches, but cannot seem to find any info as to weight-bearing strength of these materials. Perhaps I don't know the right terms since my engineering background is essentially nonexistent.

[LambdaFF]

No response yet? I didn't think my questions were that complicated. What I really need to know is how thin can I make my tablet holder and how narrow can I make the perimeter section and crossbeam sections. I don't know if these are the best terms, but I think the picture makes clear what I'm talking about. I am considering nylon, but since my last post, I've also been thinking about aluminum. I did several Google searches, but cannot seem to find any info as to weight-bearing strength of these materials. Perhaps I don't know the right terms since my engineering background is essentially nonexistent.

As I already said ... ABS is not a good choice : as it has a high shrinkage ratio, it warps. Since you intend to make a flat wide part, it is not a smart material choice. Tritan, PETG and nylon are Ok choices, it's mostly about what you have at hand.

Regarding why we are not giving you a solution : the results depend on several branching choices you have not mentioned. You don't need to be an aeronautics engineer to know this : you can trade thickness (to a point) for infill rates, the number of shells weighs in, sharp corners create weak areas ...
But then, your requirements are somewhat blurry. What do you want it to stand to ? What is the max authorized static deformation ... ? What is the load case ?

So, unless you ask with proper engineering parameters, you don't get an engineer answer. ;-)

As a starting point, and given the the overall idea, I would advise you to :
- put a 5mm thickness on your "lateral supports"
- put 10mm on the base thickness
- put 1,5mm of shell thickness
- put 25% infill.
- add 5mm chamfers in all corners

I think there's 95% chance it will work. You want it slimmer & sexier : make iterations, ask with a clear specification or pay for a design. With the new surface 4 out the door, I'm pretty sure people will make stuff. I for one know I'll have to prepare something for my wife. Tell you in 2 months.

As for aluminium : good point but at this time, given your design, better get it machined than 3D printed. Also the cost compared to nylon won't be competitive, and compared to a plastic part that can be honeycombed, it will be heavier.

[dmehling]

I'm not that familiar with much of the 3-D printing terminology yet, so I don't quite understand everything you said. I have created another design where I have indicated the thickness of the sections, just to make sure that we are talking about the same thing.


As far as shells and infills are concerned, is there a scaling principle involved based on the thickness of the material? For example, I read an explanation of shells and infills, and based on the example pictures of a cube measuring 1 cubic inch, three shells appeared to be only a millimeter thick. And a 25% infill appeared to have chambers/cells that were about 2 millimeters across. Now, I can understand using three shells for my design if the vertical thickness is 1.5 millimeter, but with 25% infill, I don't quite see how that would work. So that's why I was wondering if the size would be scaled down. Maybe I'm misunderstanding something.

[MysteryAlabaster]

I'm not that familiar with much of the 3-D printing terminology yet, so I don't quite understand everything you said. I have created another design where I have indicated the thickness of the sections, just to make sure that we are talking about the same thing.


As far as shells and infills are concerned, is there a scaling principle involved based on the thickness of the material? For example, I read an explanation of shells and infills, and based on the example pictures of a cube measuring 1 cubic inch, three shells appeared to be only a millimeter thick. And a 25% infill appeared to have chambers/cells that were about 2 millimeters across. Now, I can understand using three shells for my design if the vertical thickness is 1.5 millimeter, but with 25% infill, I don't quite see how that would work. So that's why I was wondering if the size would be scaled down. Maybe I'm misunderstanding something.

For most printers, if there is no room for the number of selected shells AND infill, the printer will print as many shells as it can, basically rendering the object 100% solid.

Also, if you'd like I can help you out with prototyping.

[dmehling]

For most printers, if there is no room for the number of selected shells AND infill, the printer will print as many shells as it can, basically rendering the object 100% solid.

Also, if you'd like I can help you out with prototyping.

I would definitely appreciate some help with prototyping. I should have realized how complicated my idea was, considering I am not an engineer.