Completed Corners and frames for 3D printer

matt3o

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Jun 29, 2017
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The project is completed! Jump to the second post for details!

I'm finally working on my custom SSF case and I want to put my 3D printer at good use. I've seen the very good project by @Thehack who designed the corners and the case is held together by the sides. @jottwehh instead went ballistic and 3D printed the whole frame (great project btw!).

My idea is to create a system of modular corners and frames for easy and fast prototyping, so that at the very end you can print or laser cut the sides of any material you want.

Being a super-noob I often make mistakes and miscalculate some distances. With a system like the one I have in mind you just need to re-print a couple of frames, not the whole case from scratch.

This is the very first prototype.


The frame is held to the corner with countersunk screws so the screw heads are flush on the plastic bit. Everything is covered by the side panel. For easy access the screw holes for the side panels should be threaded... or better use a threaded insert like one of these.



The side walls thickness is parametric (defaulted to 2mm) so I can change it to any value and the model is rebuilt accordingly.

So far the thing looks like this (the frame will of course be longer, that's just a quick test)



The whole cube is 32mm while just the corner is 25mm. It looks pretty darn good already even if printed at low res :)

Other than the outer frame I will also design a "plate" to hold the mini-itx motherboard and few other things (eg: PSU holder).

Suggestions? Ideas? Suggestions?

PS: I was not completely sure where to put this post... hope this is fine
 
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matt3o

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Jun 29, 2017
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Project Goal

Consumer grade 3d printers have a working area of about 200x200x200mm. Usually a little more, but they rarely reach 300mm on any side. The first goal is to create a series of modules that can be printed on any consumer grade 3d printer, ie: each piece should be max 200-230mm on any given side.

Secondly, printing a whole case in one shot would take hours (possibly 15+) and if something goes wrong you'd have to throw away the whole piece and start over. With my system you can print each piece separately and if printing fails you'd have to redo only that piece.

Thirdly, modularity. Once you have printed 8 corners you can reuse them for all your future projects. Say you want taller CPU cooler, just print the z-frames compared to having to reprint everything.

Lastly, ease of prototyping. A system like this is faster to prototype, I only have to print one piece at the time to check if it works (20mins to 3hours per each piece).

My rig

The project started because I wanted to build a very specific case. One with great cooling performance and that could host an SFX PSU, a decent GPU and a good CPU cooler. The result I believe is the smallest case you can do fitting those parameters.

Components
Motherboard: asus rog strix z270i gaming
CPU: i7-7700k
GPU: MSI Aero GTX 1060 6G
PSU: SFX Corsair 450W
CPU Cooler: Noctua NH-C14S
SSD: 512gb Samsung 960 Pro

Final result without panels



3D Models and Onshape Project

I designed the case with OnShape. You can view the project here: https://cad.onshape.com/documents/3...c0ef899232da68c1de/e/d34046ffc9cd18aaa07e00be

If you are a registered user on Onshape you can also copy and edit the models. Sorry it is very messy... but it's a starding point.

At the top of the features you'll see 4 variables. You can change panel thickness and XYZ dimensions. Unfortunately I made some errors in the constrains PSU support piece and it's not recreated correctly when altering the X axis (but it's a very easy fix if you know onshape a little). I'll try to fix that in the coming days.

You can also download the 3d models from here in STL format ready to be sliced and printed.

On thingverse: https://www.thingiverse.com/thing:2460903

3D Printing suggestions

  • Print all the frames and the motherboard supports with a high infill, 50-60%.
  • The PSU support is very sturdy. 20-30% infill is more than enough
  • Print the corners in "tripod" position using supports
  • Print the frames in a reversed V position with supports
  • Use good size brim for everything
  • Best slicer for frames and corners is Cura! Everything else can be sliced with anything else
  • Use ABS at least for the PSU and Motherboard supports. I believe PLA si good enough for everything else
  • I used 0.2 layer height for everything except the PSU rig that is 0.35. You don't need higher resolution, but you may want to go 0.15 on the corners.

Other things you need

You need enough 2.5M screws and nuts. Length 6mm.

The side panels need these or similar threaded inserts. M3 length 6-8mm. Do not force the threaded inserts into the corners, use a soldering iron to squeeze them in.

You need of course a PSU extension power cord.
 
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iFreilicht

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Feb 28, 2015
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Oh, very interesting! With the way you've set the frame joint up, it would also be easier to join multiple bars together to make decently sized cases even with very small printers.

I'm not sure about threaded inserts. In my experience, regular hex nuts do the same job, are easier to source and most often much slimmer. Additionally, with 3D printing, hex nuts can move around so printer accuracy isn't as much of a concern, and you don't risk splitting parts as you do when hammering threaded inserts into the holes. There's also no danger of a hole being too lose or too tight with hex nuts, so I'd definitely go for that solution.

Stability and rigidity is of course a concern. It might be a good idea to print the bars like this /\ instead of this |_ to make sure that no delamination occurs on the vertically printed screw holes. Though that might be risky on some printers. Using hex nuts already helps with this concern, but it may still be an issue.

Aesthetic idea: Why even have the corner show on the outside? I think the contribution to rigidity is relatively low with that, and having it not peek would not require cutting the panels at angles.

Aesthetic idea in the other direction: Why not have the bars show as well like on the LZ7?

PS: I was not completely sure were to put this post... hope this is fine

It is :)
 
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matt3o

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With the way you've set the frame joint up, it would also be easier to join multiple bars together to make decently sized cases even with very small printers.

absolutely! The idea is to also create mid-joints that can give XY stability to a bigger case.

I'm not sure about threaded inserts. In my experience, regular hex nuts do the same job, are easier to source and most often much slimmer.

If you have all screw/nuts it becomes a little difficult to open the case. When the case is fully closed how do you hold the nut? I believe it could still work, but possibly one of the sides should be held with threaded inserts or maybe magnets. Anyway it's just a hole, you can choose to use any solution!

In my experience ABS is pretty safe to "hammer" :) You have to be a little more cautious with PLA for sure.

Stability and rigidity is of course a concern. It might be a good idea to print the bars like this /\ instead of this |_ to make sure that no delamination occurs on the vertically printed screw holes.

This is a very good point.

Aesthetic idea: Why even have the corner show on the outside?

Initially I thought the corners were actually nice to see (apart from adding a neglectable stability), but I can surely release both versions (with and without corners). Without corners the print is notably easier/faster.

Aesthetic idea in the other direction: Why not have the bars show as well like on the LZ7?

Mmmh I like the idea, it would require some additional work though. I feel it would require more plastic too (ie: longer print times). Let me complete these two versions (w and w/o corners) and I'll think about your idea.
 
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iFreilicht

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If you have all screw/nuts it becomes a little difficult to open the case. When the case is fully closed how do you hold the nut? I believe it could still work, but possibly one of the sides should be held with threaded inserts or maybe magnets. Anyway it's just a hole, you can choose to use any solution!

In my experience ABS is pretty safe to "hammer" :) You have to be a little more cautious with PLA for sure.

I was thinking about having a hexagonal hole that you can put the hex nut into, maybe secure it with glue if necessary. Another option would be to slide the nut into a slot from the side, so you couldn't even push it out with a screw. A cross-section would look like this:

Code:
 C C
 C C
SSNC
 CCC
 CCC

S = Screw, C = Cornerpiece, N = Nut. So you'd slide the nut in from the top. The slot would then be of such a size that the nut can not turn inside.

Initially I thought the corners were actually nice to see (apart from adding a neglectable stability), but I can surely release both versions (with and without corners). Without corners the print is notably easier/faster.

Mmmh I like the idea, it would require some additional work though. I feel it would require more plastic too (ie: longer print times). Let me complete these two versions (w and w/o corners) and I'll think about your idea.

That's correct, you do lose on print time. On the upside, having no overlaps might look a lot better, and it's not as easy to make mistakes cutting the panels.
 
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EdZ

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May 11, 2015
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Another option for fixing the side panels: magnets! Add a pocket to the 'inside' of the corner pieces to hold a small magnet, and glue a magnet to the corresponding spot on the inside of the side panel. The same could also be done with the frame pieces for a more secure fit.
In that situation, the exposed corners would be beneficial to prevent the side panel sliding on the face of the frame.
 

jottwehh

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Mar 19, 2016
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Another option for fixing the side panels: magnets!
In theory you are right, but at least for the case i designed, the side panel are elemaental for stability. I mean my design is kind of
minimalist, so maybe a stronger structure will be better, but anyway; since the material is plastic it will be flexible and in my opinion magnets arent a good choice here.
In my experience, regular hex nuts do the same job, are easier to source and most often much slimmer.
I thought about hex nuts too, but i personally dont like any loose parts in my case. on top of that the construction is getting really big. I went for those:

simply "pressed" them gently in with a soldering iron and its really strong this only 3mm wall thickness
 

iFreilicht

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thought about hex nuts too, but i personally dont like any loose parts in my case. on top of that the construction is getting really big. I went for those:

simply "pressed" them gently in with a soldering iron and its really strong this only 3mm wall thickness

Very interesting, thanks for sharing! Yeah soldering irons are awesome for this kind of work, they could easily work for the threaded inserts matt posted above as well. Completely forgot about that.
 
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matt3o

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I thought about hex nuts too, but i personally dont like any loose parts in my case. on top of that the construction is getting really big. I went for those:

simply "pressed" them gently in with a soldering iron and its really strong this only 3mm wall thickness

gosh! I kinda wished AHLTec had an English version! :p
 
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matt3o

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Added version without protruding corners. With both nuts and threaded insert options


Now I just need to confirm screw size and check those wonderful inserts @jottwehh linked (I hope to find them over here).

All versions will be available for download in case anyone is interested.
 

jottwehh

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Mar 19, 2016
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Not quiet sure if i got you right with your nuts insert, but shoulnd int not visable from the front? o_O
I dont know how to explain in english.... but mor like @Thehack s version:

Like you put the nut from behind, but it cant get through.... you know what I mean?

here are some Pictures of the nuts:



I used M2.5
 
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matt3o

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I think what @jottwehh means is that without a thin section of material between the panel and the nut which is smaller than the nut then the nut can pull through the hole?

honestly my idea would be to simply glue them in, but I can put some material on the back to hold it
 
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iFreilicht

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Yeeeees that's what I'm talking about. Maybe slant the corner as well so it aligns a little better with the panel shape? For the round panels, a rounded-over corner might work. I know you don't have enough material on the inside for that right now, but I think it would really help bring the whole thing together.

honestly my idea would be to simply glue them in, but I can put some material on the back to hold it

Ah, I don't know if I'd trust that. I was also thinking along the lines of having part of the cornerpiece between nut and side-panel that way the load is entirely on the piece itself and the glue is just there to keep it from falling out when removing the screws, so you wouldn't have to worry about the glued joint between plastic and metal failing.
 
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matt3o

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Jun 29, 2017
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I've done more work on the latest design.


First of all I reduced the corner to a 25×25mm cube (was 30×30mm). I consequently reduced the frame screws from M3 to M2.5, while we have still room for M3 for the panel screws.

This reduction is pretty important because we have less wasted space on the sides (meaning: the closest to the side you can put the I/O back panel is now 25mm). I believe I can shrink it another 5mm and bring it to 20×20 but I don't want to lose structural strength, so I'm going to print the current version first and check on that.

I've also added the inserts in the frame where we'll fix the support for the motherboard.

Both straight and curved versions are available. Straight is probably easier to deal with (you could hand-cut the side panels), but I kinda like the curved version.

Maybe slant the corner as well so it aligns a little better with the panel shape? For the round panels, a rounded-over corner might work. I know you don't have enough material on the inside for that right now, but I think it would really help bring the whole thing together.

yeah, I'll give those a try as soon as I finalized the model. The rounded corner could be daunting for home 3d printers.

Ah, I don't know if I'd trust that. I was also thinking along the lines of having part of the cornerpiece between nut and side-panel that way the load is entirely on the piece itself and the glue is just there to keep it from falling out when removing the screws, so you wouldn't have to worry about the glued joint between plastic and metal failing.

I'm pretty much sold on the threaded inserts. I was able to find them pretty easily and I'll get them on Monday. If there's really a request for nuts inserts I can certainly work on that too.

Now to the 3d printer! See you in 40mins! :)
 

matt3o

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Jun 29, 2017
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I tried quickly on simplify3d



With 45° overhang angle the sides don't even need support (but I have to check on the print quality). The support in the middle is for the reinforcement I put in the corner. It takes a little longer to print though, due to the many travel moves and it also has to slow down at the top of the pyramid. Anyway I'll make some tests.

Thanks for your help!