Do I have to remove everything when I'm cutting holes?

Pjotor · Post by **Pjotor** » Fri Jul 25, 2003 2:34 am

If you use a machine tool, and especially when using a Dremel, you definitely want to clear the computer out. The risk for getting metal slivers on the electronics is not worth taking.

OTOH, if you use tin snips, you can leave everyting inside, as long as you're careful where the cut-off metal falls. I have done this and never had any problem, although I have had to use a magnetic screwdriver to fish out slivers of steel from tight places.

Good luck!

ruprag · Post by **ruprag** » Fri Jul 25, 2003 4:05 am

Please remove everything, it is so much easier and safer to work with it then

The front bezel is fastened by 6 plastic tabs (3 on each side).

You can see them when you haveb the case open, you just need to push 5 of them a bit and they will come out easily the last one (topmost on "back" side) is a **** since it appears to hit some metal obstruction, I found that I needed to use force to get it loose

(it is just a matter of time before I break it)

Post by **Ralf Hutter** » Fri Jul 25, 2003 4:58 am

Emtpy your entire case out and clean it real, real good when you're finished. Remember Murphy's Law. It's real hard to control where all those metal filings will end up and you can only imagine what would happen if some ended up across the traces on your MoBo or HDD PCB.

POLIST8 · Post by **POLIST8** » Fri Jul 25, 2003 5:17 am

When I use tin-snips I just leave everything possible in the case. Just be sure you get ALL the filings/trimmings out before you power it on, as to not short anything.

chiahaochang · Post by **chiahaochang** » Fri Jul 25, 2003 7:05 am

The times I cut holes in cases I tend to remove everything. Depending on how lucky and lazy I feel. A few times when I was feeling really lucky and really lazy, I didn't take everything out. I was also looking for an excuse to upgrade my PC, so that's probably really why I didn't clean out the case.

Either way I also mask off the case with tape and newspaper to keep the majority of the metal dust/shavings from landing inside the case. Makes the cleaning job much easier.

Zhentar · Post by **Zhentar** » Fri Jul 25, 2003 7:10 am

I mask it off to save time, but a lot of filings still get by so I have to get out the shop vacuum and make sure I clean it up very well.

POLIST8 · Post by **POLIST8** » Fri Jul 25, 2003 7:17 am

I'm lazy as a MF.

Bluefront · Post by **Bluefront** » Fri Jul 25, 2003 9:01 am

If you use a super nibbler there is no need to remove anything....one small starter hole and uou can cut the rest easily with no chips. In the picture it's the larger of the two. The other one is from radio shack....

Super Nibbler

Another hole with a super nibbler

marc999 · Post by **marc999** » Fri Jul 25, 2003 10:11 am

Bluefront,
Where can you get a Super Nibbler ?

Bluefront · Post by **Bluefront** » Fri Jul 25, 2003 3:53 pm

My "super" nibbler is actually an auto body shop tool. I got mine at an auto parts store a few years ago....about $20 if I remember correctly.

Here's another supplier. Search for nibbler....this looks a lot like mine, but way too expensive.

The really good thing about this nibbler is it's ease of use. Say you want to enlarge a 80mm hole to 92mm....easy draw the new hole on the case, and carefully cut it out, no chips, no metal filings. Only takes a few minutes and you don't remove anything.

jafb2000 · Post by **jafb2000** » Mon Jul 28, 2003 12:04 pm

Do not subject the PSU to vibration from a Dremel or power tool or
hole-saw or even drill bit. They do not like it and will fail then/later.

Nibblers are a useful tool, hole punches are preferable but it is very
unlikely you'll find an economicaly one for 80-92mm even on Ebay.
By that size you are rapidly entering hydraulic-only versions.
--
Dorothy Bradbury

Bluefront · Post by **Bluefront** » Tue Jul 29, 2003 2:57 am

jafb2000......I'd sure like to see any evidence that drilling a small hole in a computer case can hurt a PSU. There're no parts in a PSU that I know of that are more fragile than those in a motherboard. Vibrations from some optical drives can be as great, maybe worse than a drill bit. And for sure a cdrom vibration will last for a much longer time than a vibaration from a drill bit.

I'd say most PSU failures happen because of heat, some because of faulty manufacture, and none because of a drilled hole in another part of the case.

jafb2000 · Post by **jafb2000** » Tue Jul 29, 2003 3:19 am

Go drill a hole with a holesaw in a case with a PSU in it,
the chance of your PSU failing shortly after is not low.

From experience with 280$ 460W 1U PSUs to redundant PSUs to
Antec to Sparkle to the cheap no-name 10ukp units. They don't like it.

You'd think it should be a very rugged device:
o Components are discrete, braced & soldered
o Many components are *sealant braced* against vibration

The answer lies in the specs of the G testing:
o Compare the G/msec specs for PSU (eg, top IBM units)
o To the G/msec vibration figures for hole saw through steel

Remember the PSU is bolted to that violently shaken surface.

Now, by comparison, laptop SMPS are much more rugged.
In shock-proof flight cases they need far less cushioning and the
military tend to prefer them for that reason. Conventional PSUs by
contrast end up using variants of sorbothane in addition to foam/ABS
suspension systems in rack designs to better dissipate impact energy.

There is nothing particularly different between a laptop SMPS & desktop,
although one can argue the quality is sometimes considerably higher.
It might be there is less height in components re leverage etc.

Usually the PSUs fail by refusing to turn on or off ever again, and it
degenerates from there - so it could well be poor soldering etc. The
QC testing of PSUs is generally hot-soak & not vibration testing. It
is worth realising DOA on the cheapies /from vibration/ in surface
shipping can be 30-40% or more - having passed at the factory.

Nibblers are the only safe tool with electronic components about,
and the risk then is one of waste material conductivity v 330VDC.

Shock loading of hole-saws which are often eccentric to the arbour or
mandrel and often eccentric in not being round is quite considerable.

Don't be lazy - unplug the PSU when using hole-saws or big drills

jafb2000 · Post by **jafb2000** » Tue Jul 29, 2003 3:32 am

Unplug = remove, not referring to the power cord.

Yes, some simple solutions:
o Vibrationary isolate the PSU from the case
---- sit the PSU on a mouse-pad or folded towel
o Seal the PSU by a simple plastic bag
---- stops any debris getting in

Just don't use a holesaw with a PSU bolted tight to the case.
All that violent high frequency vibration will exceed the shock ratings,
confirmed by an IBM Almaden colleague who did their HD/PSU testing.

Sadly most quality PSUs are temperature tested, but they are not
all shock tested - as many a suppliers knows on receipt re DOA. The
handling of surface shipping doesn't work too well for PSUs.

My 48V-DC 2kW PSU supplier will not ship surface, only air.
Surface is ok by UPS within the USA, but not outside re DOA.

There are some PSUs which N+1 the laptop style units (recase),
they have higher spec ratings I note - so I do suspect it is a function
of component height (& sub-boards) from the base PCB re inertia.

Only takes a little common sense, why pay for a quality PSU only to
subject it to a condition that are at least biased to shorten its life?

futureweaver · Post by **futureweaver** » Sun Aug 03, 2003 1:36 am

There's a story about an HP unit which had a high DOA rate. They spent ages checking assembly, QA, etc. Finally they tracked it down to a speed bump immediately outside the plant gate.

I use a hand drill & punches for putting small holes in cases. Use the hand drill to drill a tiny hole, ream it out to the size of the punch guide bolt, then use the punch. Despite Dorothy's post above, I'd place the limit for hand punches at 50mm - my largest is 30mm and that takes quite a bit of effort.

I'm also about to get a nibbler - £6 from Machine Mart http://www.machinemart.co.uk/product.asp?p=040212700. This appears to be the "super nibbler" discussed above. I have seen an even more super one, but it was 3x the price.

jafb2000 · Post by **jafb2000** » Sun Aug 03, 2003 2:51 am

You have to use a ball-race on the above-50mm punches, which adds
to the cost - and they are very rare indeed on Ebay. Yes, by the time
you reach 80-92mm fan hole sizes it's hydraulic punch time.

That nibbler is fine, price determines longevity and it's not going to
be used to do a Picasso on a load of cases - so should be no problem.

Don't get carried away tho

Bluefront · Post by **Bluefront** » Sun Aug 03, 2003 2:54 am

futureweaver .....Yeah, that's my super nibbler. You'll be happy with it. I wouldn't mind a new one. After hundreds of cuts mine is getting dull. If I could find a cheap USA source, I'd replace it.

futureweaver · Post by **futureweaver** » Tue Aug 05, 2003 2:53 am

Bluefront,

If I could find a cheap USA source, I'd replace it.

I got a couple of spare blades with mine for an extra £4.69. They weigh 38g, under 2oz, so if it's really the same nibbler you might persuade Machine Mart to stick them in an airmail envelope. OTOH if the anvil is worn I suppose the only thing is to replace the nibbler. The nibbler is by Clarke, which is a US company - quite a lot of MM's stuff appears to be sourced in the US - I have a Clarke concrete mixer from them too. Hmm, that gives me an idea for some really heavyweight case damping

.