Electronics Help-Needed: Motherboard tray docking circuit

I am working on a project that has one particular requirement that is beyond my expertise.
http://forums.bit-tech.net/showthread.php?t=92646

This picture explains what I need fairly well


Essentially I will be needing two PCBs (2"x12" in size) that will act as a pass-through connector allowing all of the cables from the various parts of the machine to connect in a central location and then interface with the motherboard tray through a second PCB. The two will connect together (using typical sized pins used for motherboard headers) when the tray is inserted.
If there ends up being enough space left over an intergrated fan controller would also be extremely useful. Since the circuit is also extending the power/reset switches and LCD indication from the motherboard a front panel PCB may also be required (8" x 1" in size).

I am more than willing to pay for this to be designed and made and I would appreciate any thought, comments, questions, etc.

Edit: A theorietical requirement that I am not quite sure how to implement would be a locking mechanism that when the machine is powered-on will not allow the PCBs to be disconnected. I would love to hear any ideas on how to accomplish this.

 

The power connections etc. shouldn't be too complicated to do but AFAIK the IDE connections will have to be very carefully designed to ensure all the traces are exactly the same length. I could be wrong about that requirement though.

The locking mechanism could perhaps be done using some sort of spring-loaded solenoid that pushes locking pins through a housing when power is applied.

This is a really cool idea by the way, and make sure you get royalties when case manufacturers start including these as standard!

 

Indeed! I have everything informally copyrighted already and I'll be filing for a patent soon.

 

That's a really cool idea! Man, if I buy a case with this in it I'm gonna be so happy haha. Tell all my friends, "I WATCHED THAT BEING INVENTED!"

 

I've worked out the spacing and arraingement of the plug-bus design. I may ditch two the the SATA pass-throughs in favor of more molexes.

All of the connections that need to be sent to the front panel module will be consolidated to use a single connector on the plug-bus making installation much easier. The two plug-bus halves will most likely connec to eachother through two 100-pin d-sub connectors AND NOT THROUGH MOLEXES. The number of traces that this mechanism will be duplicating from one side to the other is around 175 at the moment.

 

that is a great idea , i think it is going to be very useful

for the lock system you will put two small electromagnets that when you power the PC they receive current and maintains the two circut-boards thogether. I don´t Know if the electromagnets will cause any damage to the system

Captain Slug, i love your work


sorry about my english

 

Getting all the connectors may be a hassle.

As someone suggested earlier, keeping the trace lengths close on the ATA interfaces could be important.

 

I can easily get all the connectors I need from http://www.mouser.com

 

Looking nice just keep in mind the ammount of power flowing through the power headers, might require some special attention.

 

hey
just a few q's!
so your making 2 boards/backplanes, one which is say the female end which is connected to the ports on the mobo +power and all usb and fan headers, and the other end, the male end will be the other end which all the peripherals and power connectors all plug into?
sounds ambitous! no doubt you'll pull it off and with style!
any idea of dimensions? will it be usable on any sort of motherboard,or will it be specific to the motherboard your using?
good luck! will be keepin an eye on this!

 

That is a good idea although it would be a hassle to conform to because all motherboards do not have the same placement of IO and power components on their boards.

Literally every single motherboard made will have to have one of those connectors custom made to fit it. Probably the best thing to do would be to give the processing capabilities over to the manufacturer's of the board themselves so they could include that component with their motherboards.

It would be something similiar to SLI's connector length - most of them are of different dimensions than one another.

 

or, he could make the back plane in such a way that it mounts on his mobo perfectly, but later can incorporate the use of small cables so that the backplane can be put to a side with the cable trailing to it, or mount the backplane to the case somehow.

 

Isn't it just the presence of the right connectors that matters, rather than their exact placement of the mobo? I was under the impression you'd just use cables to go from the connectors on the mobo to the connectors on the ubercard thingumy?

So as long as you've got the maximum number of each type of connector that any motherboard uses, it'll be compatible with every motherboard. Of course when a new sort of connector is invented a new ubercard thingumy would need to be released too.

 

The reason I interpreted it as an absolute alignment kind of connector was because he said the following:

If it were little cables, will it not be a small rat's nest of wires because then you require different lengths to attach to the different components on the motherboard? Being different motherboards, the placement of connectors vary so that there may be centimeters of slack here and there or not enough.

Now, custom built for one's own motherboard, that would be quite wonderful. I think it was that Orac3 computer that had its own custom built motherboard shell to increase conformity between components while allowing the connections to have an area to enter/exit.

 

That is going to take a TREMEMDOUS ammount of force to completely couple. It takes enough force to just connect 1 atx connector, expect a coupling force of several hundred pounds. I would suggest using some sort of screw arangement to pull the ends together.

Also, you're going to have lag issues with a PCIe extension, as well as possibly the SATA, and ATA.

 

This is in no way a new idea. It actually exists in some really old Macintosh computers, i have seen it. So forget all plans to patent or otherways protect this idea.

Allso, i have been drawing on one of these constructions, but in my case, i was going to use the same type of connector that is used for connecting paralel cables to printers and removable HD trays to computers since these are low force connectors. I would allso make 2 strips of PCB with identical, but mirrored, contact setup, and short wires to connect everything from the motherboard to the PCB.

But this project was given up because it would have been too expensive.

 

Compaq did a similar thing on some of their machines. I used to have an old 'all-in-one' machine where the monitor was part of the box and the motherboard tray used a docking type connector. But this was more daughter board style, and I can't remember if the power came in from a header.

For docking and undocking I have seen lots of daughtboards docked by hand force and then undocked using a type of lever assembly to the motion is nice and smooth (and easier)

On the docking front have you though of looking at laptop docking stations? They pretty much employ this idea, you have extra devices and ports routed back to the laptop.

 

On the practical side of thngs the SATA and PCI-e connectors are going to have a spaz at you for doing that most likely. SATA in particular is heavily sheilded and very sensitive to resistance. The cables are designed to be a specific resistance and there is a terminating resistor at the drive. If you change this resistance you will have signal degredation e.t.c For teh PCI-e I dont know off the top of my head how sensitive it is to resistance but I assume it is pretty sensitive given its high clock speed.

 

Your idea is very original. The modding subject needs this kind of fresh and bright ideas. I wish you luck with your magnificent project. Suscribed.

 

Gah! I'm gone for 36 hours because of doctor's appointments and this thread explodes. I'll try to answer everyone's questions.

1. Yes, everything that's attached to the motherboard tray will connect to side of the plug-bus that's also attached to the tray. The power supply, drives, switches, and LEDs will connect to the half of the plug-bus that's attached to the case.
2. Each half at the moment is around 12x1.5 inches in size and in the case design they'll attach to the motherboard tray and a docking plate in the case (picture shown below).
3. Since this is basically just a connection duplicator it's just acting as a junction box. It should work with any motherboard, power supply, drive, case, etc. I want it to be as interoperable as possible so that I can upgrade motherboards and power supplies. This could also presumably be offered as a stand-alone retro-fit for other cases.

This plug-bus is not meant to plug into the motherboard itself. The plug-bus will interface with short cable extensions for the various interfaces. The motherboard tray half of the plug-bus will simply be installed next to the motherboard and near the end of motherboard tray. See image below.

1. The plug-bus halves DO NOT connect with the molexes. They will interface with eachother using 2 100-pin d-sub connectors. This should allow the two halves to interface with minimal force, but still remain securely coupled. On half interfaces with just the motherboard through short cables, and the other interfaces with the rest of the machine. The two halves then connect together acting as a signle omni-connector.
2. The PCIe connectors labelled on the image are for power only.
3. I'm not yet sure how the implementation of the SATA connectors will go or if they will even be feasible yet.

I've seen similar mechanisms, but not for this type of application. I'm making a modular motherboard tray that still allows for a wide variety of motherboard options. There are no similar products available for this purpose so in that effect it's unique. Pin interfaces are designed all the time and all have the same purpose, but the design varies and each new interface is someone's invention (and therefore patent). I'm only trying to protect my idea in the effect that a manufacturer doesn't steal it without asking me first.

I have done some research and the cabels themselves do not need a specific resistance, but they do have to be under 50ohm.

I'm only sharing this with everyone to solicit advice, so thanks to everyone so far. Most of the questions have been relating to misinterpretation of my designs but that's understandable since they're quite sketchy at the moment.

I'm entirely out of my league as far as this part of my project is concerned and I have no serious experience with electrical engineering. I desperately need a skilled partner to help me make this happen. The power duplication and switch connections are quite simple and I'm sure I could manage those myself, but this device simply wouldn't be the same without all the drive connections.