Prototype "Universal" fan mounting grid

[arturbecker]

Hi,
I quickly searched the forum but didn't find an obvious solution to the following problem:

Being able to mount fans of different sizes (say 120mm or 140mm) on the same panel, without special mounting holes for each. And expanding that to 240mm or 280mm radiators.
By "no special mounting holes" I mean the same grid of holes on the panel that allow air to pass through can provide mounting holes for the fans.

A tentative solution:
Mess with the tolerance of the panel holes so that you can fit both the 105 and the 124.5 hole pitches on the same grid. Making this work for two fans in a row (i.e. for use with a radiator) is a bit less trivial because 120 fans have 7.5mm "margin" and 140mm fans have 7.75mm.

Edits:
Several good solutions came up in this thread.
I am working in one of them now (first prototype with dimensions in this post, new dimensions here)

 

[Colinreay]

I'm excited to see where this goes! I've made a uniformly spaced slotting design before in CAD - I think I made the slots 6 or 6.5mm wide and the 105/124.5mm mounting holes wouldn't exactly sit in the middle of the slot, but were close enough to center for screw clearance. If you'd like, I can try to get those dimensions to you for reference (mainly trial and error in Fusion/Excel).

Have you considered making the mounting holes slightly elongated/slotted? I wonder if a few slightly oblong holes would detract from the overall design provided they were small. That might get around the margin issue?

 

[arturbecker]

Hey! Glad you're excited!
I think by trial and error we came up with nearly the same thing. A hole spacing of 6.566 seemed to work for me, with under 5mm diameter holes.
But now I realize the holes should probably be larger to accomodate the standard fan screws. I googled around and found 5.5mm as a "standard" diameter for fan mounting holes.
Then, supposing 5.5mm diameter is correct, the problem becomes finding the spacing that spawns a series of holes which matches three points: 0, 105 and 124.5, within a certain tolerance. I'm not sure what would be a suitable tolerance at this point...
At least that's how I'm thinking about it now, but any suggestion is appreciated!

I also thought of a pattern alternating holes and slots. That would solve the problem for one dimension, but it is not so simple to solve for both dimensions, I think. Like, in 1D you elongate a hole and it becomes a slot, that can fit both 105 and 124.5mm pitches. But in 2D you'd have to either widen the slot or skip some, and have a variable pitch in the second direction.

 

[arturbecker]

I think we're getting somewhere:

Now for radiators, it's a bit trickier but if we make it mandatory that the rad is mounted to the side panel, we can take advantage of the slimmer screws that go on them (6/32 instead of 7/32):

 

[REVOCCASES]

Just a quick idea, but why not go for some universal adapter which could be used for mounting any fan/rad on any panel? Then people could use this on many cases and would not need to replace the whole panel.

Maybe something like this:

Or if you want to stay with the panel design: did you try + shaped cutouts with a o shaped hole in the middle?

 

[arturbecker]

Hey Till, I think your idea is very good. Do you have the model for your adapter? If you'd be willing to put it in the Resources, then it could probably be readily used by people with access to a 3d printer or laser cutter.

I am working on the panel design as part of my own case project, since I want to be able to eventually be able to fit a 240 or 280 rad, or switch 120 to 140 fans without much hassle. As far as I understand, the adapters would increase the thickness of the assembly a little bit, and even more so if adapting from small fan mounts to large fans.

 

[REVOCCASES]

Was just a quick draft I did in five minutes to show the idea I had in mind so we could discuss this further if you are interested.

Yeah, something like this can be made easily with a 3d printer or on a laser cutter. Probably 1mm thickness would be enough if you use threaded inserts for the M3 or M4.

this would also work for bigger fans on smaller fan mounts if you choose the right screw length (not touching the fan blades) .

if there is a need for such a part we can work on this and design one together. Just let me know.

 

[Shatrod]

I also had an idea for this. If you don't intend to mount a radiator and want a fan only, why not embed magnets into the mounting holes of the fan? Then it can snap onto any mesh anywhere

 

[arturbecker]

Thanks a lot for all the input!

Or if you want to stay with the panel design: did you try + shaped cutouts with a o shaped hole in the middle?

Sorry I forgot to answer this! Yes + shaped cutouts (or maybe x shaped?) seem like they would work. Thanks for the idea! I will try it if there's no optimal solution with regular holes

I also had an idea for this. If you don't intend to mount a radiator and want a fan only, why not embed magnets into the mounting holes of the fan? Then it can snap onto any mesh anywhere

I would definitely buy that Sadly it wouldn't work on aluminum cases so for my current project it's not ideal. But I think both a magnetic "screw" and the adapters proposed by Till solve the problem (for steel and aluminum cases respectively)

I am still curious if there's a numerical solution for a grid though! Working on it with our in-house Optimization PhD (meaning: I'm quarantined with my brother)

 

[REVOCCASES]

Do you have the model for your adapter?

It just occurred to me, that I also need some bracket like that for one of my case designs. So I've finalized the drawing and uploaded the model here on SFF.NET

 

[arturbecker]

Apparently Sliger has a thing or two to say about this issue:

Their solution is called the "Infinite Vent" and apparently allows for mounting fans 60mm to 140mm.
I believe they solve the 120 to 140 conundrum with that lone slot line with odd spacing as you can see in the image above, front panel, to the right.
That means the solution is 1D, i.e., it's perfect for this use case, but wouldn't generalize well if there's a need to adjust a 140mm fan in two directions.

This video from Optimum Tech shows a 120mm fan installed, and down there at the bottom there's only one regular slot left, then the odd spacing, then the lone slot.

 

[Thehack]

You just need to define some slot dimensions that are "close enough" to where integers hit the 105 and 125 pitch.

For this, 9.56 makes sense.

11*9.56 = 105.2
13*9.56 = 124.3

You can run wider slot widths supplying washers, rubber fan mounts.

Technically, 6.56, 4.5 mm slot width is IMO the best method. Depending on the screws and thickness of sheetmetal, the fanscrew may still fit. It'll "screw" in then spin freely, since the thread density is low. You can probably source some for this exact purpose. It will have the proper clearance for #6 screws, or M4/3.5 which are common radiator mount sizing.

 

[Thehack]

What about just using plate adapters?

You would run a standardized hole spacing. Manufacture simple plates that adapts the 140 mm/120 mm spacing.

The hole spacing can be whatever you feel is good for the design. The adapter plates are mass produced by punching and tapping (or pemsert).

 

[REVOCCASES]

What about just using plate adapters?

-->

It just occurred to me, that I also need some bracket like that for one of my case designs. So I've finalized the drawing and uploaded the model here on SFF.NET

 

[Thehack]

-->

There as some noticeable issues

1. Depending on the vent pattern, install may be annoying.

2. It doesn't fix the problem of radiator mounting, which needs to be strong enough and secure enough to support it.

It seems that it'll function as a quick fix, but I wouldn't trust it to mount a radiator.

 

[REVOCCASES]

1. Depending on the vent pattern, install may be annoying.

2. It doesn't fix the problem of radiator mounting, which needs to be strong enough and secure enough to support it.

It seems that it'll function as a quick fix, but I wouldn't trust it to mount a radiator.

1) Why?

2) It's mainly designed for fans, but if you use stainless steel instead of aluminum why should it not be strong enough to hold a radiator?

3) Yes, it's supposed to be an cheap, easy, flexible and quick solution

 

[Thehack]

1) Why?

2) It's mainly designed for fans, but if you use stainless steel instead of aluminum why should it not be strong enough to hold a radiator?

3) Yes, it's supposed to be an cheap, easy, flexible and quick solution

1. Let's say you have a simple grid hole pattern. You would have to make sure it lines up with grid, which be difficult. And if the install area is close to a bend, it can be moved around as you install it.

2. Stainless is known for corrosion resistance. If you need more strength, use regular steel or increase the thickness of aluminum.

Look at the overall shape, there is no strength to it unless you intend to use some thicker sheet metal. Sheet metal by itself with no bends is actually pretty flexible.

With a full single plate, you can stamp some bends in it to give it strength.

But I guess that can be resolved by using 3 mm aluminum, or 2mm steel.

 

[REVOCCASES]

1. Let's say you have a simple grid hole pattern. You would have to make sure it lines up with grid, which be difficult. And if the install area is close to a bend, it can be moved around as you install it.

2. Stainless is known for corrosion resistance. If you need more strength, use regular steel or increase the thickness of aluminum.

Look at the overall shape, there is no strength to it unless you intend to use some thicker sheet metal. Sheet metal by itself with no bends is actually pretty flexible.

With a full single plate, you can stamp some bends in it to give it strength.

But I guess that can be resolved by using 3 mm aluminum, or 2mm steel.

Seems I'll have to make some samples to convince you. Anyways I need these adapters for my project. Give me a few days.

 

[arturbecker]

You just need to define some slot dimensions that are "close enough" to where integers hit the 105 and 125 pitch.

For this, 9.56 makes sense.

11*9.56 = 105.2
13*9.56 = 124.3

Exactly! Would work for fans.
But for mounting radiators unfortunately we start pushing a bit:
12*9.56 = 114.72 (it's a bit far from our needed 120, for 240 rad mount)
14*9.56 = 133.84 (it's a bit far from our needed 140, for 280 rad mount)
and so on for the next.

Thanks for the input on using the coarseness of the screw in our favor. As far as screw clearances go, I'm trying to make it work with the least amount of extra hardware. So out-of-the-box 7/32 self tapping screws for fans and M3 screws for rads. Put it all in the optimization model and hope for the best.

 

[Thehack]

Exactly! Would work for fans.
But for mounting radiators unfortunately we start pushing a bit:
12*9.56 = 114.72 (it's a bit far from our needed 120, for 240 rad mount)
14*9.56 = 133.84 (it's a bit far from our needed 140, for 280 rad mount)
and so on for the next.

Thanks for the input on using the coarseness of the screw in our favor. As far as screw clearances go, I'm trying to make it work with the least amount of extra hardware. So out-of-the-box 7/32 self tapping screws for fans and M3 screws for rads. Put it all in the optimization model and hope for the best.

Try 11 x 9.56, and 13.

Why do we need 120 and 140?

I thought most rads use #6.