3 Sep
2026
3 Sep
'26
4:29 p.m.
Good stuff Chris, thank you.
I should chime in that, due partly to fear and partly to laziness, I have sidestepped
Chri’s much better “take apart and re lubricate” method by very carefully heating the
axles of the capstans using an RF soldering station and spinning the capstans by hand
(while quite warm) until they “feel” smooth again. Effective Relube without the risk of
disassembly. No new chemicals.
This has worked on all three tk50s I’ve tried it on and they continue to work after, I
think, nearly two years. I try to use them often so they don’t sludge up again.
—Jake
On Sep 3, 2026, at 19:04, Chris Zach via cctalk
<cctalk(a)classiccmp.org> wrote:
TK50's and TK70's have a bad rap for this. The key problem is twofold:
1) Tapes stored in dungeons tend to be crap and shed stuff
2) The capstans on the TK50 are very important and need to be lubricated
For the first, I go with good quality tapes and before I put a tape into my collection I
clean the heads, then run the tape through a backup or two then check the heads. If dirty
I pitch the tape and clean. If clean I clean the heads again and put it in service. Same
process you should go through with any new magnetic media (RL02, RX01, etc....)
For the second you really need to take the drive apart, remove the bolts on the front and
rear capstans (marking the bolt's orientation and how many turns to take off) and
lubricate the bearings with fine watch oil. They should spin easily the whole problem is
the oil dries out and since they use tape friction to turn and the rear one is connected
to a tachometer having them drag will drive the tape unit insane and lead to unspooled
tapes, read problems, all sorts of insanity.
Remember they don't have tension arms, the capstans are how they figure everything
out.
Aside from that, fine. I use mine as backups with no issues. Just never introduce a new
tape without checking the heads, otherwise the crap will get on your good tapes like an
STD.
C
> On 9/3/26 17:55, Rob Jarratt via cctalk wrote:
> Be very careful when reading them, they will shed and stick to the rollers. You may
need to bake the tapes. See this account:
https://www.magneticscrolls.com/blog/tk50-tape-baking
>
> Regards
>
> Rpb
>
>> On 03/09/2026 10:05, hlep via cctalk wrote:
>> Hi Rod,
>>
>>
>> Do you have any external TK 50 or TK 70 tape drives?
>>
>> I'm working at an archive in Germany and we've got some TK-50 tapes and
we've been looking for some hardware to access them with.
>>
>>
>> Best,
>>
>>
>> Josh
>>
>> On 2026-09-03 08:37, Rod Smallwood via cctalk wrote:
>>> Hi Guys
>>>
>>> My DEC Collection needs downsizing.
>>>
>>> Im in the UK so for the US only the small stuff would be worth shipping
>>>
>>> If you need anything PDP8, PDP11 or VAX please indicate item you might
want
>>>
>>> Rod
>>>
>>>