No32 telescope

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09-11-2016, 08:48 AM
Peter Laidler

No32 telescope

Just been having a browse through my old tatty copy of the No32 EMER and came across a 1952 (could read 1956.....) miscellaneous instruction regarding the PLATE, locking segment. For our purposes this is the little brass cover at the rear of the range turret, held on by 4x (or 2 on the later cheaper Mk3's) 8BA cheese or round head screws. Got it now.........?

The instruction reads in as many words '......where one or more of the locking plate screws fails to engage, is stripped, loose or in any other way unsatisfactory(*?), then the rearmost parts of the telescope will be stripped from the telescope and repaired in the following manner.........

Anyway, then all the screw holes will be drilled clear with a .090" drill and retapped to 6BA. (All screw holes are to be so repaired regrdless of how many holes are stripped). Thereafter the figure 6 will be stamped '....on or close to the centre of the plate to indicate in the future that this instruction has been carried out. Replacement screws will be Z1/ZA-XXXXX SCREW steel or brass, 6BA, round head blah blah blah suitably cut to length!

Naturally, being an EMER and as in all things official, it goes on and on a bit but there it is in a nutshell. And, like all things EMER and official, there's a bit of ambiguity too! I mean, where I add (*?) in para 2 above. Does a butchered screw head mean that the screw is in any other way unsatisfactory? And why not 6BA Cheese head if they were available in the Instrument shop anyway? It also doesn't mention that the holes in the plate will also be bored out to the 6BA clearance size but I suppose that's obvious really

There it is. If you have a small figure 6 on the index plate OR close to the centre (could that be on the tube too?) that's the reason. If you already knew this old guff, then just ignore it
09-11-2016, 05:02 PM
bigduke6

Quote:

Originally Posted by Peter Laidler

then all the screw holes will be drilled clear with a .090" drill and retapped to 6BA.

Whilst having a tinker on my Matchless WD G3L today, I wished they had used that repair on the two studs were the carb fits...... obvious one has been changed at some point as one Course thread and one fine........ then after fitting the carb (a spare one bought on ebay "cleaned and works fine" was the description) it wouldn't stop flooding............ been a while since I worked with petrol so at least the hands are clean and some parts of the bike....... beer time couldn't come quick enough.
09-11-2016, 07:12 PM
Roger Payne

I'd often wondered about that problem Peter (shows how sad I am, that I wonder about such things). I recently repaired a Mk1 by opening out to 7 BA, though 6 is probably better, as per the EMERS, however, it seemed to work alright.
09-12-2016, 05:08 AM
Peter Laidler

While I was reading the EMER I wondered why they didn't suggest a 7BA as the next and obvious size. But looking through the Zeus book, you'd barely have sufficient material to drill-out and re-tap. But a straightforwards and careful re-tap to 7BA would (just) suffice. Maybe 6BA is better safe than sorry. And perhaps the slightly overlength 6BA screw suggested was a readily available screw. The Z1/ code is radio equipment which would make sense. I bet it's from a radio headset or handset!

Don't forget to mark the plate with a figure 7.
09-12-2016, 10:30 AM
Roger Payne

Yes, in fact I did stamp that corner of the plate with a tiny '7' as I didn't modify all four holes. However, I think in future i will as it makes sense for all of them to be the same*. And yes again, I did not drill the stripped out 8 BA thread, I found that the 7 BA tap would go straight down & re-cut the thread to sufficient depth in 7 BA to function quite satisfactorily. Again though, 6 BA would be a belt & braces solution, typical British military!

* & of course, if someone inverts the plate....top left hole becomes bottom right!
09-12-2016, 07:09 PM
Sentryduty

Quote:

Originally Posted by Roger Payne

* & of course, if someone inverts the plate....top left hole becomes bottom right!

You simply need to stamp it "THIS SIDE UP" so the next fellow can put on right orientation but wrong way around, and go on the forums asking what the "serial number" "d0 3815 514L" means and why it won't fit back on the machine...