After dumping a bunch of media on one of my cubes with a working MO, despite all the usual precautions, the machine built up a fair amount of dust on the drive(s). As we all know, dust kills the drives faster than almost anything else.
That got me thinking about filtering: I'm sure everyone has seen cubes that are literally full of dust because there is essentially no filtration, especially with the fans reversed (in the standard configuration, the grill at the bottom might catch some dust, and of course, the drives acted as a great dust filter :wink:).
I did some experiments with these fan filters:
http://www.newegg.com/Product/Product.aspx?Item=N82E16811999217&Tpk=120mm%20fan%20filterhttp://www.newegg.com/Product/Product.aspx?Item=N82E16811995048&cm_re=120mm_fan_filter-_-11-995-048-_-ProductThe silverstone will mount under the existing cap on the NeXT fan, and the other one replaces the top cap but looks like a standard fixture. The silverstone would be an improvement over no filtering, but the mesh isn't particularly fine grained. The other filter has a coarse foam filter, and I believe would be superior in the long run.
I also experimented with a few modern fans in the interest of perhaps making the cubes a little quieter and to improve airflow. The NeXT fans move a surprisingly large amount of air, but a papst 4412FGL seems roughly equivalent and is almost silent. Other modern fans move more air (for example, a 120mm thermaltake moves quite a bit more air), but are just as noisy.
Bottom line is that on the cubes that I use frequently, I am going to at least put a bgears filter on the standard NeXT fan, and I may even replace the NeXT fan with a modern one.
I recently purchased some of
these filters (
http://www.frozencpu.com/products/2623/ffi-05/120mm_Washable_Fan_Filter.html?tl=g47c223s548) to use on a few PC's and they seem to filter well. The fan cover snaps on to make filter cleaning easier, similar to the second filter that you linked to. I haven't tried it on a NeXTcube yet. I would like to try a modern fan though, perhaps with an
adjustable fan speed controller (
http://www.frozencpu.com/products/9091/bus-191/Manual_12V_Variable_Speed_Controller_-_4-Pin_Molex_Connector.html?tl=g47c17s285).
It would also be interesting to try some open cell foam from McMaster-Carr on the inside floor of a cube to trap dust when using the original fan configuration.
I just put a combination of a papst+foam filter into my main cube, and it's not a whole lot quieter (blame the SCSI), but judging from the amount of air coming out the front, it's on par with the original fan, if not a bit more powerful.
Knowing that it has a lot better filtration will make me sleep better at night... don't want to kill a working MO drive...
For quiet, perhaps we can replace SCSI with a SCSI-to-IDE converter and some form of solid state storage. I saw someone do this in another post here with a CF card. Has anyone investigated what the most suitable form of solid state storage (in terms of number of write cycles, read/write & data transfer performance (I guess the latter could not be a limiting factor with any modern solid state storage media), etc. would be?
What did you use to interface the NeXT fan power connector to the modern fans' connector?
Great idea to install a filter and keep dust out, and very interesting to hear your filtered fan does not impede airflow, or has even better airflow than the original one - I was concerned about that. Is its power consumption (load on the PSU) also not any greater, or not materially greater, than the original fan?
Since we mainly want to keep dust out to stop the cube from overheating, and filters can get clogged up (which non-filtered fans are less likely to do), an eye will need to be kept on the filter to keep it clean(ed).
I use an external HEPA air filtration system in all my computer rooms to reduce the amount of dust build-up. Using one should reduce the amount of dust buildup either on your filter, or in a machine with an original unfiltered fan, without being in any way invasive. Blueair Air Purifiers are inexpensive and seem to work well.
I used a fan with a standard molex connector in order to connect a modern fan to the NeXT, so the fan sits between the power supply and the SCSI drive.
I need to measure the consumption, but I suspect that a modern fan doesn't draw any more than an old NeXT fan. That said, if you have a Dimension in the cube as well, I think you need to be careful.
As for SCSI... I think the SCSI->IDE converters are somewhat expensive aren't they? I do remember a thread recently on the classic computer mailing list where someone had implemented a SCSI->flash device using a fairly simple MCU. Once I get the protocol converter done for keyboard/mouse I might tackle something like that.
Quote from: "gtnicol"I used a fan with a standard molex connector in order to connect a modern fan to the NeXT, so the fan sits between the power supply and the SCSI drive.
You mean - sits logically, as in you split off the power off the PSU with a molex splitter connector, but physically it still sits at the back of the machine?
Quote from: "gtnicol"I need to measure the consumption, but I suspect that a modern fan doesn't draw any more than an old NeXT fan.
I would have thought so ... the original fan will have a spec. I'm sure it's possible to replace it with a modern fan with the same power consumption spec. My concern is if, it being muffled by the filter, you will need a more powerful fan for the same amount of air flow? Modern fans seem to have made some progress with their bearing design, but I don't know if this is only in terms of durability, or also in terms of lower friction.
Quote from: "gtnicol"I think the SCSI->IDE converters are somewhat expensive aren't they?
I think so. I've only been able to find expensive ones. It will not be a cheap solution. But, it should give better performance, be quieter, and consume less power than an old SCSI HD. Also, the hard disk is one of the first things to fail, and there must eventually come a time when the supply of compatible 4GB SCSI HDs will run out. And they don't seem to be too cheap either (especially for what they are).