Mirror Back Door G4

[minihack]

MBD G4? Yes……

This is my latest conversion to a Mirror Drive Door G4 PowerMac.

I have done a few different versions of the MDD and these machines pose a unique challenge - which is probably why I keep coming back.

First of all they are one of the nicest looking Apple cases out there (in my opinion), but infuriatingly they also have a lot of problems when adapting them to fit PC parts to.

The front looks great with a bit of mirror polished steel on the front panel, with a lovely simple central switch and two opening panels for DVD drives etc.

The door mechanism is better than every other G4 - no terrible piece of plastic, just a good solid "clunk" when you click the door shut.

Slimline PSU case cleverly integrated into the sidewall.

Sleek looking back with flat panels and large holes for ventilation (although cooling was always the Achilles heel of the MDD).

The problems?

1.The rear IO is back to front - PCI slots on the left.

2.The back panel has a step in it, so that the usual approach of slapping a microATX shield onto the door panel just doesn't work.

3.The back panel is structural so if you machine it away, you end up with it looking awful and floppy (PCI-e cards flapping around in space is not pretty).

4.The central DVD drives are placed exactly to block almost every microATX board known to man as the RAM sticks crash into the drives. Even short drives usually get in the way.

5.Where to place the PSU? The origin slimline one is great, but an ATX PSU just seems out of place in the case and closes down the cooling options remarkably.

6.The front panel - looks great but mostly needs to be removed to get some air into the case.

I could go on…..but you get the picture. All these compromises mean that this G4 is the least modded of them all. Most of them also are not very pretty when you look at the back - as understandably, making it neat at the back is hard without access to specialized equipment. I am lucky as I do have such access as part of my business. Even so, this case has frustrated me up until now!

So my mission was to create something that will fit an MDD without to much effort required and preserve the original feel of the case AND look stunning from behind.

The MBD PowerMac G4

So I present - the Mirror Back Door G4 case conversion in what I consider to be an advanced prototype form.

Stunning stepped mirror door

Here it is with my trusty workhorse GA P55M UD4 board fitted.

Inside the test build

Plenty of space for mATX board

Cut down front drive support

Original PSU case and 2 drive holder

Fan inside the door panel

Clean front look

Behind the mirrored front - room for a DVD drive (slim)


Things to notice about it:

1. The 2mm polished steel back panel is a 3 part construction that fits into and around the original door frame to give a door that is as strong as the original (in fact heavier!) and follows the external outline completely.

2. One of the three parts to this is a flat IO shield which sits as far back in the case as it is possible to go - by having a panel like this instead of the usual sunken rectangular IO slot you gain vital millimetres at the front which allows (dependent on your mATX board) a slimline DVD recorder to occupy one of the front slots.

3. The back of the case is stepped, like the original, with the rear section sliding into place as the door closes.

4. The door step incorporates space for a slim 15mm fan and can be used to house the original 60mm fan that was attached to the MDD door.

So that is a sort of introduction to the mod. Here now are the meaty bits behind what you see above.

Drive Support

Firstly, I'll deal with the front drive support. As original this is huge and blocks just about everything to do with conventional boards:

However I did not want to get rid of it completely as I wanted to still have a chance to use the front dual drive cage - so I cut it down to a more convenient size:

Basically I took drilled out the rivet fixings in the case, then cut out a great big chunk from the middle of the support and riveted the front to the back to "cut and shut" it.

To give this:

and then to tidy it up I used an adhesive sheet of compressible seal material.

I then cut down the drive cage itself so that I could do this with it:

So that gave me something that can be fixed in the original way to mount drives, and a fan, but in a more slimline fashion so it'd not interfere with longer GPUs or with the motherboard.

PSU

Another feature of this build is using a shuttle PSU inside the original PSU case. I have used this before in previous mod.s and it is a relatively easy re-body job.

This is the shuttle PSU that was used:

and basically just took the outer case off and shoved it into the original MDD PSU case - cooling being front to back, there is little else to worry about.

I have also (for fun?!?) re-wired an original MDD power supply so it can actually be used as an ATX PSU. If you are tempted to do that then this page is essential reading:

http://atxg4.com/mdd.html

Over there you will find details of how to use an ATX supply for an original MDD BUT the wiring diagram of pinouts is enough to give you the know how on how to re-wire in the other direction. The MDD supply is similar in many ways to an ATX and the colour coding used on the iwres is the same (except for the 25v wire...) and so it is not too hard to remove the wires from the MDD plug and then re-purpose them into a standard 24pin ATX plug. The catch though is this:

The maximum draw on the 12v line is 16 amps (i.e. 192 Watts) so it means that if you decide to re-wire an original MDD power supply you will NOT be able to use a discrete graphics card over about 60 watts. So for integrated GPUs and old single slot lower powered GPUs you should be fine, but higher performance is not available.

Of course you could instead of re-using the PSU case of the MDD use an ATX supply instead, but I didn't simply because I already had the Shuttle converted supply and that give me more room to have, for instance a taller CPU cooler (even though in my test build here I am using the Intel Stock cooler!).

The back panels

I started off modelling everything in paper, then acrylic and then I commissioned the prototype from mirror coated 2mm steel.

However, this post is already a bit long, so I'll come back to the next post and detailing the back panel construction after walking the dog and having some dinner (!).

 

[minihack]

So it started with thinking about how I could fit an ordinary IO plate to the original door. You can just see that in this pic.:

The problem with that is that every small amount is important in this case and as you can see from the picture a mATX motherboard (even with the front drive support cut back) still intrudes quite a bit towards the front of the case. On the other hand taking the IO as far back as possible would give another 15mm clearance at the front which could be critical to allowing more mATX boards and GPUs to fit inside the case.

So then I moved to a prototype in acrylic.

This piece showed that everything could fit and was a 4 piece assembly - the front flat plate that you see, then behind that the actual IO shield - those 2 pieces sandwich between them some parts of the original G4 door structure and are screwed through it to one another. Then there is a back piece that goes in front of where the original MDD PCI slots were and screws to that part of the door frame, and then between that piece and the rear of the IO shield was a thick 12mm perspex slab. Arguably this was over engineered but it gave a solid structure that when the door closed and opened conformed exactly to the original principles.

However, it also for stability really needed to have a piece that would make a join between the door frame and the flat door so the next design stage was this:

This is a paper model showing a piece for riveting to the door and forming the IO shield.

The next part was the most important and was realising it in metal and, as it was for an MDD I felt the material HAD to be mirrored steel.

So a few design tweaks later I bit the bullet and ordered my parts.

Here is the realisation in metal of the IO shield:

and one of the parts for the backplate (still with protective coating on):

The first fit up followed and, as I had expected, the standoffs for this conversion must be low to make everything fit correctly. I had to use 5mm standoffs - so for safety sake I have put insulating material under where the motherboard sits. Here it is with standoffs fitted (M3 threaded standoffs - door drilled and then standoffs put in place - and then insulation applied).

To be continued.....

 

[grg3]

Lookin' good! I have been saving a Mirror Door system and I look forward to all ideas for modifying it.

 

[jamba]

great mod..whats that caddy where the slim DVD in mounted in ?

 

[minihack]

great mod..whats that caddy where the slim DVD in mounted in ?

It is this one: http://www.silverstonetek.com/product.php?pid=246&area=en

It's not ideal as of course the doors of the MDD as standard just allow you to use the DVD drive - so you cannot use the hot swap SSD feature or the 2 USB ports. You can though of course still use the integrated SSD mount, just can't eject it through the front slot. I used it though as I had it in my stock pile of bits and I remember I bought it very cheaply as Scan.co.uk were clearing it as old stock. You could I am sure use a different caddy. By the way, the slim drive does have enough force to open the drive door of the MDD when it ejects a disk.

Something like this would probably be first choice though for me for the MDD and you could just square it off at the back behind the DVD drive. Other than that it is cheap and only has metal where it needs to be, so you could probably fill both front slots with these if you wanted http://www.kustompcs.co.uk/acatalog/info_3972.html

 

[rehpotsirhc]

It is this one: http://www.silverstonetek.com/product.php?pid=246&area=en

It's not ideal as of course the doors of the MDD as standard just allow you to use the DVD drive - so you cannot use the hot swap SSD feature or the 2 USB ports. You can though of course still use the integrated SSD mount, just can't eject it through the front slot. I used it though as I had it in my stock pile of bits and I remember I bought it very cheaply as Scan.co.uk were clearing it as old stock. You could I am sure use a different caddy. By the way, the slim drive does have enough force to open the drive door of the MDD when it ejects a disk.

Something like this would probably be first choice though for me for the MDD and you could just square it off at the back behind the DVD drive. Other than that it is cheap and only has metal where it needs to be, so you could probably fill both front slots with these if you wanted http://www.kustompcs.co.uk/acatalog/info_3972.html

Will a standard SATA optical drive fit? The silverstone piece looks to to be around the same depth.

 

[minihack]

Will a standard SATA optical drive fit? The silverstone piece looks to to be around the same depth.

No, the Silverstone case is I guess about 1cm longer than the slim sata drive at 136.4mm, the shortest SATA normal drives are around 165mm I believe and this photo gives you an idea of the distance between the Silverstone and the front RAM sticks for the mATX boards as you shut the door.

So it looks like the very max length of anything placed in the front drive bays (and assuming you push the mATX board back to the very back of the MDD as I have done) is around 145mm - beyond that you'll need to cut the Optical Drive case in the same way that others have done for the earlier G4s to avoid RAM clash. On earlier G4s though the drives are higher so tend to be less of a problem than they are for the MDD.

 

[doctorevil30564]

Holy cow that looks nice.

 

[jamba]

maybe fitting in another 20 mm fan? .. with more dremeling of course..

 

[minihack]

Hmm...I am thinking about extra cooling. MDD is a pita as standard to cool, so I'm chewing over what next to cut!

So I've been spending a while looking at Aquamac and his old original mdd mod.s Heck he is one talented individual as everything he touches looks gorgeous. I pinned a load of his things for inspiration:

http://pinterest.com/laserhive/mirror-drive-door-creations/