[vcf-midatlantic] Zilog System 8000

[Dave McGuire]

On 11/17/2015 11:49 AM, Herb Johnson via vcf-midatlantic wrote:
>> Your tape drive has also a capstan which went to goo over the past
>> 30 years, so please do not just put them into the drive without
>> fixing that first.
> 
> The following are suggestions I'm not implemented, but they seem
> plausible to me based on other's discussions and some related
> experience. Please report any results.
> 
> Consider making another capstan, otherwise called a "pressure roller".
> In the end, it's a stiff rubber wheel on a bronze bearing with an
> internal diameter to fit on some roller. Examine your drive or others of
> same brand and model to determine dimensions. Keep in mind: it's the
> metal drive roller which determines tape speed, not the roller.
> 
> It's possible a piece of bronze can be machined to be the correct size,
> then rubber molded around it, and then carefully machine the rubber to
> the correct diameter. There are two-part rubber compounds which when
> mixed and cured are quite stiff.
> 
> Or, obtain another larger roller and cut it to fit. Rubber can be
> abraded in a lathe at low speed. Stiff rubber pieces are often sold as
> furniture bumpers or "corks" for pipe and "test tubes".

  Most types of rubber can be machined much more easily if frozen using
liquid nitrogen or dry ice.

               -Dave

-- 
Dave McGuire, AK4HZ
New Kensington, PA