IBM 5155 analogue display fault

[Bjørn Vermo]

On 29 May, 2005, at 02:03, Tony Duell wrote:

>>> That is not an excuse. Anyone working on IBM 5155s (or for that 
>>> matter=20
>>> Friden Flexowriters, which are stuffed with setscrews needing 
>>> Bristol=20
>>> Spline drivers) should have a set.=20
>>
>> Are they the ones that are the same shape as a tractor PTO shaft?
>
> Roughly, yes (although I've never worked on a Tractor...). I think of
> them as :
>
> Allen : Triangular wave rapped round a circle
> Torx : Sine wave rapped round a circle
> Bristol : Square wave wrapped round a circle
>
> Very approximate, of course (and certainly not enough to machine a tool
> to fit them), but it gives the right idea.


  http://www.mgs4u.com/bristol-wrench-spline.htm

And at 15 USD for a holder with one bit, I would not say the price is 
unreasonable for a quality tool. About the same as I paid for a cheap 
Chinese set of some 100 bits of useable bot not great bits.
...

>
> 11mm is relatively common. It's 12mm that I find somewhat obscure, and
> which Citroen seem to use to excess...

12mm is one of the common sizes around here.
I never had any problem with tools for any of my Citroëns, except that 
I had to get the socket for the central nut which holds the fan to the 
shaft on the GS from a heavy equipment store. If you have the original 
service manuals, you will see that they include instructions on how to 
make a number of useful special tools. I have heard that their 
apprentice mechanics had toolmaking as an important part of the 
training.

-- 
-bv