Modified PCIe 8-pin connector

Thehack

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Made some CAD progress on how it might look.
Not convinced on my hook implementation yet. I'm still thinking some sort of snap fit to secure the connector.
Maybe also make it a PCB that is soldered, but then removing the connector would be very hard since solder isn't flexible.
With a 3D printed part you could snap it on or off when needed. Not very tinker friendly but hardline watercooling also isn't tinker friendly right?

Right now I'm sitting on 2 0.6mm PCBs that would be 1.2mm in total. in theory a 0.6mm PCIe connector could exist.
QinX' XVULPPCIe connector
Current version


Yesterday's version

If it is a pure 2d piece, we can use layers of acrylic, which can be much cheaper to 2d laser cut than to individually 3d print. We need to do a test to see how much height the solder takes up on average and then build around it. We can also employ a nylon screw to hold the acrylic backplate to cover the PCB.

I think it's reasonable to have it require up to 5mm of clearance, much better than the current 15mm clearance for the PCIe power connectors.

 
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QinX

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kees
Mar 2, 2015
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If it is a pure 2d piece, we can use layers of acrylic, which can be much cheaper to 2d laser cut than to individually 3d print. We need to do a test to see how much height the solder takes up on average and then build around it. We can also employ a nylon screw to hold the acrylic backplate to cover the PCB.

I think it's reasonable to have it require up to 5mm of clearance, much better than the current 15mm clearance for the PCIe power connectors.

Require is such a big word. Do you really need those 5mm? Be honest. you'd be able to lose 3.8mm off volume! You could save 150cc on a 20*20*20 case! 150cc!!!!

Just kidding man, I see where you're coming from. If this is doable you'd already be looking at a big win, maybe not for smaller cases. but for fitting bigger cards in already small cases.
 

Thehack

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Require is such a big word. Do you really need those 5mm? Be honest. you'd be able to lose 3.8mm off volume! You could save 150cc on a 20*20*20 case! 150cc!!!!

Just kidding man, I see where you're coming from. If this is doable you'd already be looking at a big win, maybe not for smaller cases. but for fitting bigger cards in already small cases.

Yeah. It'll for sure help cutdown case sizes by a good amount. But we have to be reasonably safe and practical when producing it. Yes we can make it soldered board, no circuit protection, but then you can easily leave the wire unpluged when doing a test and fry your board.

I'd rather put it this way, it requires very little effort to keep it at 1-2 mm, we can just go with a simple design, or we can make it more accessible for everyone and compromise at 2-5mm.
 

iFreilicht

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Maybe also make it a PCB that is soldered, but then removing the connector would be very hard since solder isn't flexible.

I thought about that as well. The Fiberglass is flexible, so if you design the two PCBs in a way that they are press fit and most of the load is taken up by the fibreglass, not the solder, this could work.

EDIT: Additionally, instead of using two PCBs, you could actually have blind holes with pads like here: https://hackaday.io/project/3117-a-even-smaller-nanite
 
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QinX

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kees
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Yeah. It'll for sure help cutdown case sizes by a good amount. But we have to be reasonably safe and practical when producing it. Yes we can make it soldered board, no circuit protection, but then you can easily leave the wire unpluged when doing a test and fry your board.

I'd rather put it this way, it requires very little effort to keep it at 1-2 mm, we can just go with a simple design, or we can make it more accessible for everyone and compromise at 2-5mm.

I've just seen your drawing and while I understand the idea. it doesn't add to safety compared to the secondary PCB.
The SMD Shielding PCB would have no electrically connected copper on the back side, so nothing can short out. the SMD PCB functions only as an end cap for the PCB that holds the connectors and cables.

The two possible problems I do see is that when the connector is not plugged it it is a hazard for shorting. But outside of implementing the mold for the current PCIe connector I do not see a way to prevent that without some elaborate design.
The simplest way of implementing would be to cut the PCIe connector and try to glue it to the PCB, which might work really well actually. I'm just not really seeing myself dremeling all those PCIe connectors :s.

The second problem is without the PCIe connector over the crimp for protection is bent crimps. those would be prone to metal fatigue very quickly and break.

I thought about that as well. The Fiberglass is flexible, so if you design the two PCBs in a way that they are press fit and most of the load is taken up by the fibreglass, not the solder, this could work.

EDIT: Additionally, instead of using two PCBs, you could actually have blind holes with pads like here: https://hackaday.io/project/3117-a-even-smaller-nanite
Some sort of pivot system would be great, I think we'll get this figured out. I'm just wondering if I should make a batch of PCBs for testing. But I'm impatient like that :eek:

The holes are drilled most of the way through by hand.
So he has SMD pads and drills tiny holes in them? Really cool, but practical for this? I'm not sure, there is quite some current and I do need both sides of the PCB for +12V and GND planes.
 

Thehack

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I don't think we have to worry about the plug coming off.

I just plugged the female terminal onto the male terminal and there is plenty of force to keep it plug, there is no way it'll come off on it's own. The female terminal is designed to grip the male terminal.

The fatigue on the terminal may be an issue, as they may get bent/misaligned if you use it often.
 

QinX

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kees
Mar 2, 2015
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I don't think we have to worry about the plug coming off.

I just plugged the female terminal onto the male terminal and there is plenty of force to keep it plug, there is no way it'll come off on it's own. The female terminal is designed to grip the male terminal.

The fatigue on the terminal may be an issue, as they may get bent/misaligned if you use it often.
Market strategy, It'll be a consumable product designed to wear out with repeated use.

I could argue that with the super slim profile why would you want remove it? You should just disconnect it at the other end of the cable your using. Unless you're upgrading your GPU.

I also feel that there is no real need for the hook, 6-pin should have plenty of frictional force to keep it in place.
 

Thehack

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Market strategy, It'll be a consumable product designed to wear out with repeated use.

I could argue that with the super slim profile why would you want remove it? You should just disconnect it at the other end of the cable your using. Unless you're upgrading your GPU.

I also feel that there is no real need for the hook, 6-pin should have plenty of frictional force to keep it in place.

I agree, no need for the hook, heck, i'll take it as is, as I'm fairly comfortable with risking hardware for the sake of smallness.
 

iFreilicht

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So he has SMD pads and drills tiny holes in them? Really cool, but practical for this? I'm not sure, there is quite some current and I do need both sides of the PCB for +12V and GND planes.

Yeah that's true, the inside probably can't be plated, even if your manufacturer hat Z-axis milling capabilities.
 
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QinX

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kees
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So as a recap on what I'm looking to make right now.
I've got 8 PCBs which would result in 4(8-ish) connector types.
6-pin for GPU's without a backplate.
6-pin for GPU with a backplate.
8-pin for GPU's without a backplate.
8-pin for GPU's with a backplate.

In terms of width they would be the same width as their respective sockets, so a recessed connector shouldn't have any problems.
the PCB's can also be flipped before assembly, so even if the PCIe socket is reversed it'll still be oriented correctly.

So these two configurations would work.



I'm going to forego the "hook" since I do feel that the friction from the 6 or 8 terminals is enough to hold it in place, there should be much less cable weight and if there is it would be pull the connectors in rather than out.
Actual testing should show if it is adequate or not, but I'm confident it will be.

The end result should hopefully be a PCIe connector that is around 1.2mm thick, possible a little thicker.
So these would be the final PCBs unless I'm getting some compelling reason to do it another way :)
 

Aibohphobia

aka James
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Feb 22, 2015
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Thinking about it, there are often sharp leads on the back of the PCB, maybe it'd be better to just have the backplate version only?

That way if there isn't a backplate, the wires are still up and away from the board in case there are pointy bits nearby.
 

QinX

Master of Cramming
kees
Mar 2, 2015
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Thinking about it, there are often sharp leads on the back of the PCB, maybe it'd be better to just have the backplate version only?

That way if there isn't a backplate, the wires are still up and away from the board in case there are pointy bits nearby.

With the dimensions of the current board and where I'm ordering have a 10cm*10cm max PCB size for their prototyping service, the most efficient fit I can get is 3 tall board with 2 short boards. otherwise I would have to go with 4 tall boards.
For a test run I'm getting more tall boards the short boards and I'll see where the demand goes from there.

But I do agree that backs of PCBs tend to be spiky, but whether or not the PCB is tall or short only the PCIe socket pins would be in the way and that could be solved with some sticky foam if you're worried.

Another reason people might want the shorter pcb, although an edge case for sure, is if Xfire or SLI is used. gotta squeeze between those cards somehow :p.

I guess it's more about having the option.
 

R3venger

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Dec 15, 2015
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Very interesting. I don't recognize that smaller connector, anyone know what it is?
This should be the msi Trident Pc.

About the soldered connectors: Just ask any pico psu maufacturer.
The pins of the 8pin connectors and the 24 pin conectors should be the same if im not mistaken.
And on the direct plug pico psu´s the 24pin is soldered onto the pcb.