6100/G3/HPV Turbo Cooler Hack

[Trash80toG4]

Been very slowly putting together my maxed out 6100 and this little goodie arrived yesterday:

Hole saw mod to plastic chassis required as well as ductwork underneath to funnel entire clipped corner square vent grid into the intake of the blower. May fab it as five sided pyramid with plans to do a smooth transition printed duct some day?

Blower's Airfow is directed straight at heatsink of overclocked G3 accelerator on an overclocked system bus. I is a match made in heaven, the blower housing's top surface is flush with the bottom surface of the HPV PCB and slips right under!

In baseline form the blower setup might be the silver bullet for pathetic cooling provisions in the 6100. Theory is that blower noise will be muffled by the case?

In the day I'd have used a big, fast HDD in an external case. HPV interferes with 3.5" OEM HDD cubic anyway, so no loss there.
This 6100 build is being set up as a low cost graphics workstation retrofit I might have cobbled together while saving up for a PCI generation PowerMac in the back when.

Comments, suggestions?

 

[bakkus]

Just noting that I love that you went back to this idea.
And that I'm following it very closely as I have a 6100, a NuBus G3 upgrade, and a HPV card looking for the exact treatment down the road, so it'll be interesting to see how you do.

 

[retr01]

Hi @Trash80toG4!

One idea I have is to cut out so that you have grill line supports to preserve the integrity of the bottom part of the case. Something like this stock fan vent on the bottom part of my P476 case:

 

[Trash80toG4]

Just noting that I love that you went back to this idea.

Thanks, the original concept would have pulled a bit more air through the intake grate under the HDD, passing it out a vent in the backplane cover plate in a straight thru shot. That would probably work, but in thinking about more I came up with a bit more radical approach?

The aim of this setup would be to overpressure the entire case and should be a lot more efficient? Airflow is forced into the PSU vents as it's pulled out by of the system by the OEM fan exiting the bottom of the case. Higher CFM pushed through the overall system than can be pulled through it by the PSU alone in the standard setup. That it's directed straight across the horizontal vanes of the NewerTech heatsink and splayed across the VRAM SIMMs is big plus.

Original notion:

https://tinkerdifferent.com/threads/adapting-hpv-card-for-compatibility-with-6100-g3.1984/

 

[Trash80toG4]

One idea I have is to cut out so that you have grill line supports to preserve the integrity of the bottom part of the case.

Bottom of the 6100 case is metal. Holesawn vent cutout won't affect any vertical load bearing members.

 

[Trash80toG4]

Lets start off with a trick I came up with to remove the %$#% plastic "inner chassis" without breaking anything. Had I been a little bit quicker about it I'd have wicked 3-in-1 oil down the members sitting on the oxidized bottom plate of the chassis.

No harm done, I used some handy little wedges a bit upside down for the initial removal:

Wedge on right would be inserted up to the line, raising the retaining nubbin out of its slot in the bottom pan. The one on the left shows the approximate profile of the two tools. I was able to get the inner chassis out without breakage, but generously applied candle wax rub to all bottom members of the chassis and to the smooth sides of the wedges which now face down when cycling the parts. Works really well.

Layout for the hole saw mod worked well enough as I used a larger diameter saw than necessary, not perfectly aligned, but unobstructed.

Dropped the dang fan and it popped apart, doing that on purpose would have been so much better for positioning the center for the hole saw arbor's drill bit. This was the approximation method.

Bottom plate of fan would have been so much more accurate, but it worked out all right.

Hole saw worked well with inner chasis in situ, just need to be really careful about rocking it a bit as the multilevel HDD mounting bayonet system can bind up the hole saw.

That's as far as I got yesterday with documentation of the hack, but it's come along rather nicely. Initial problem with larger diameter hole was that remainder needed a bit of reinforcement to prevent parts falling off. but adding an HDD slide plate mount into the mix works wonders. Matche the hole saw opening of the drive sled to the chassis, pretty much sealed up, but a bit of hot glue/caulking will do the trick. Moar pics needed.

Next to look at a bit of ductwork underneath to seal the grating off so the vast majority of the air intake is drawn in by the blower.

TTFN

 

[Trash80toG4]

Finished documenting the installation/mods before work.

Sled/chassis interface seals the top surface pretty well as is:

Detail of sled parts removed. Dunno if it's the correct sled, but found one I'd already modded a bit to hack up some more.

Sled/fan assembly is integrated into the plastic inner chassis, so backside lever is removed to allow motherboard removal, re-installation. Front corner removal provides clearance for latch lever when removing the inner chassis.

Notice the front of the smooth S-curved ducting of the inner chassis. It directs airflow across the heatsink. Cooling there not necessary when G3 puts the 601 to sleep. If running the PC card in lieu of the G3/HPV combo, I'd shift the blower toward the front, chop the chassis/sled back and abutting the left side. Fabbing ductwork directing flow across the heatsink should do a great job of cooling the overclocked CPU.

 

[Trash80toG4]

Off today and the chassis was just sitting ther on the bench upside down, so a bit more about the 6100's cooling intake setup:

S-curves on both sides constrict the surface area of the outlet from the large, low pressure intake grating that's pulled into the system by the PSU fan. This ducting increases velocity and modifies direction of airflow. optimizing cooling effects on heatsink, Cache/ROM DIMMs and expansion hardware.

The mod I'm (very slowly) doing, mimics the cooling setup of the LC series by embedding the centrifugal blower toforce more air into the system with the overpressure making the PSU fan's cooling task a bit less daunting. Blasting airflow straight across the G3 heatsink and HPV card/VRAM SIMMs should help a bit I hope.

I can visualize what can likely be proven via smoke testing here, but that's messy and fluid dynamics would be well above my pay grade. Found a great example of the kinda stuff I've read over the years. Maybe others might like to take a look?

Quest for Performance: The Evolution of Modern Aircraft

ch10-4