Re: ultrasonic cleaning for disk heads

[Curious Marc via cctalk]

> On Jan 27, 2018, at 11:02 AM, Mark J. Blair via cctalk 
>  wrote:
> 
> When it happens, am I correct in assuming that the pack is toast, and should 
> never be loaded again?

Carl would be better qualified to answer that one, but from what he has taught 
me and what we've seen so far, it depends. If it's a mild crash and just 
burnished, it might be OK. A lot of the PARC packs we read had such leftover 
marks from previous mild encounters with a head... Some read just fine, most 
dirtied our heads but were OK at least for archiving once, a few re-crashed. If 
there is a gouge and you can see the metal, forget it.

Marc

Re: ultrasonic cleaning for disk heads

[Noel Chiappa via cctalk]

> From: Mark J. Blair

> I have a single decpack cartridge ... It's marked "decpack 2200 BPI-12"
> and has 12 sector notches in the hub. Does that mean that it was most
> likely used with an RK05 drive in a PDP-11 system?

Yes.

> I hope that I can procure a matching drive for it one of these days

The come by occasionally on eBait; here's the most recent one (October
last year):

  http://www.ebay.com/itm/122452738128

They're usually mildly pricy, alas.

Noel

Re: ultrasonic cleaning for disk heads

[Mark J. Blair via cctalk]

Speaking of these drives, I have a single decpack cartridge which hitchhiked 
along with a purchase of RL02 packs. It's marked "decpack 2200 BPI-12" and has 
12 sector notches in the hub. Does that mean that it was most likely used with 
an RK05 drive in a PDP-11 system? I seem to recall that packs used with a PDP-8 
system would have 16 sector notches. I hope that I can procure a matching drive 
for it one of these days, even though Marc's video makes me think I'd be 
royally screwed if I didn't also manage to procure a good alignment pack to go 
with it, and maybe some spare heads. I don't have any experience with the 
front-loading drives yet.

Labels on the pack indicate that it saw some DEC maintenance on 1/6/84, and it 
was used by somebody named Fred Knight. It's labeled "KMC-LP Testing Pack". I 
know it's a long shot, but it would be neat if any of that meant something to 
anybody on the list.

I don't know anything about how to clean hard drive packs, and that's something 
I'd like to learn about.

-- 
Mark J. Blair, NF6X 
http://www.nf6x.net/

Re: ultrasonic cleaning for disk heads

[Steve Malikoff via cctalk]

I too watched Marc's video with great interest, as I have a pair of Diablo 31's 
identical to his.
Now, I'm a long long long way from getting them operational, but it's good to 
see what has worked for
future reference.

As I'd never be able to find a similar alignment pack, the heads in mine would 
have to stay put for
cleaning. Thus I'm wondering whether it would be possible to place the drive 
vertically so the heads
point down, and use one of those el-cheapo miniature jewellery ultrasonic 
cleaners plentiful on eBay
to dip the heads into the isopropyl alcohol, in situ?

The cleaner would I expect require some modification for it to fit around the 
heads and in the tight
space, plus some mounting arrangement to keep it from falling into the drive.

Steve.

Re: ultrasonic cleaning for disk heads

[Fritz Mueller via cctalk]

Thanks for the tip on heating, Carl.
 
> On Jan 27, 2018, at 11:02 AM, Mark J. Blair via cctalk 
>  wrote:
> Some dumb questions from a guy who has not yet experienced his first head 
> crash on a removable-pack hard drive:
> 
> When it happens, am I correct in assuming that the pack is toast, and should 
> never be loaded again?

I’m fairly new to this as well, but from what I have seen so far, head crashes 
vary in severity from mild bumps/scrapes to deep, brutal gouges. My experience 
with RK05 packs is that media may be recovered after mild crashes with careful 
cleaning, though it takes a good bit of patience and elbow grease to remove 
post-crash smudges of burnt oxide from the disk surfaces and the heads.  
Anything with a deeper gouge will probably just crash again straight away.

I received about a dozen packs with my RK05 drives.  There is a lot of good 
advice in the archives here and over on the vcfed DEC forum about 
opening/inspecting/cleaning packs, and I don’t think I’d try to mount anything 
in my drives without opening it up and giving it an inspection first.  On RK05 
packs this is easy; since they are a single platter you can easily see and 
clean the entirety of both surfaces.  I imagine on a multi-platter pack it 
would be really difficult to inspect or clean without unstacking the platters, 
after which I’d guess alignment and balancing would be problematic?

The dozen or so packs that I received with my drives many years ago had a lot 
of variation in condition.  Some had bad, hard crashes, others just had “bumps 
and bruises”.  The heads of both drives as I received them had lots of oxide 
build up — it doesn’t look as if the previous users (scientists in a lab) had 
very good disk hygiene!

—FritzM.

Re: ultrasonic cleaning for disk heads

[Mark J. Blair via cctalk]

I thoroughly enjoyed Marc's video of the head cleaning.

Some dumb questions from a guy who has not yet experienced his first head crash 
on a removable-pack hard drive:

When it happens, am I correct in assuming that the pack is toast, and should 
never be loaded again?

My removable-pack drives are DEC RL02 drives and a Data General drive with one 
removable and one fixed platter, using cartridges of the same style as the 
RL02. The DG drive has a glass encoder, so I presume that it requires 
realignment after removing the heads for cleaning. I might have acquired an 
alignment pack for it already. But since the RL02 drives use servo bursts on 
the media, do they require realignment after removing and replacing the heads?

-- 
Mark J. Blair, NF6X 
http://www.nf6x.net/

Re: ultrasonic cleaning for disk heads

[Anders Nelson via cctalk]

The most versatile, effective cleaning tool /ever/. Not even sarcastic.

=]

--
Anders Nelson

+1 (517) 775-6129

www.erogear.com

On Fri, Jan 26, 2018 at 3:45 PM, dwight via cctalk 
wrote:

> I always use my finger and finger nail. Your finger is very sensitive to
> even the tiniest piece of crud. I then just need to do a final clean with
> IPA.
>
> Dwight
>
>
> 
> From: cctalk  on behalf of Fritz Mueller
> via cctalk 
> Sent: Friday, January 26, 2018 12:15:34 PM
> To: General Discussion: On-Topic and Off-Topic Posts
> Subject: ultrasonic cleaning for disk heads
>
> I watched with great interest one of curiousmarc’s recent Alto videos,
> wherein they clean a Diablo drive head ultrasonically.  I’ve been
> struggling a bit with my restored RK05 drives to completely clean the heads
> after minor head crashes.  Not being able to get them really sparkling
> clean makes me always worried about running the drives for more than a few
> minutes at a time, and a little nervous every time I spin them up….
> Scrubbing and scrubbing and scrubbing with IPA and kimwipes just doesn’t
> seem to get all the crud off.
>
> I do have an alignment pack that I could use to re-align the heads after
> removing them for a proper cleaning this way.  Decent ultrasonic cleaners
> aren’t terribly expensive and might be nice to have around the shop anyway
> (I could also do all my eyeglasses :-)
>
> In the video, the heads are submerged in IPA in a glass cylinder, which is
> then placed in the ultrasonic bath.
>
> Has anybody on the list here done this and have tips/advice beyond what
> can be seen in the video?  It looked very effective!  I’m also having a
> little trouble sourcing the squat form glass graduated cylinder online.
>
> cheers,
>—FritzM.
>
>

Re: ultrasonic cleaning for disk heads

[dwight via cctalk]

I always use my finger and finger nail. Your finger is very sensitive to even 
the tiniest piece of crud. I then just need to do a final clean with IPA.

Dwight



From: cctalk  on behalf of Fritz Mueller via 
cctalk 
Sent: Friday, January 26, 2018 12:15:34 PM
To: General Discussion: On-Topic and Off-Topic Posts
Subject: ultrasonic cleaning for disk heads

I watched with great interest one of curiousmarc’s recent Alto videos, wherein 
they clean a Diablo drive head ultrasonically.  I’ve been struggling a bit with 
my restored RK05 drives to completely clean the heads after minor head crashes. 
 Not being able to get them really sparkling clean makes me always worried 
about running the drives for more than a few minutes at a time, and a little 
nervous every time I spin them up…. Scrubbing and scrubbing and scrubbing with 
IPA and kimwipes just doesn’t seem to get all the crud off.

I do have an alignment pack that I could use to re-align the heads after 
removing them for a proper cleaning this way.  Decent ultrasonic cleaners 
aren’t terribly expensive and might be nice to have around the shop anyway (I 
could also do all my eyeglasses :-)

In the video, the heads are submerged in IPA in a glass cylinder, which is then 
placed in the ultrasonic bath.

Has anybody on the list here done this and have tips/advice beyond what can be 
seen in the video?  It looked very effective!  I’m also having a little trouble 
sourcing the squat form glass graduated cylinder online.

cheers,
   —FritzM.