Curious No32 MkIII, answers on a post card please????

[Simon]

Is it me, as maybe I'm looking at the wrong components, but what I took to be the R&D shoes in the stripped photo's of Simon's scope (I think it is posting number 35) look totally different to run of the mill Mk3/L1A1 shoes? The one I measured looks pretty typical to me - a rectangular brass shoe on a rounded shaft, which is bored out to receive the tensioning spring.

Confused of Sutton Coldfield.

It would indeed appear we are measuring two different things. The dims I quoted are taken from the steel block on the end of the lead screw of the elevation and deflection drums

[Simon]

Right then,

Here's a set of photo's which show exactly what I've measured and the results, I've even gone to the trouble of taking them in that new fangled Metric thingummy. draw your own conclusions

[Peter Laidler]

Thems the lead screw nut then the spring loaded shoe and then the turret housing. As a matter of interest, while they are shown with different part numbers, we could only get the lead screw and nut as a matched pair and even then, due to them being multi start threads, you couldn't be certain that they'd mate-up if you started the thread 180 degrees out. The lead screw nuts had to fit VERY closely fore/aft inside the turret housing or there would be excess rotational slack in the thumbscrew

[Roger Payne]

Simon, you have the measurements from the Mk3 range shoe, but I've now reassembled the scope. However I've got an L1A1 in bits now (ex CT&S Mk3), & the range lead screw shoe measures 0.399" in length x 0.304" in depth x 0.251" in height. Hope this helps. Sorry it's in old money but I work best in that currency, & I could only find an Imperial Moore & Wright micrometer!

ATB.

[Simon]

Simon, you have the measurements from the Mk3 range shoe, but I've now reassembled the scope. However I've got an L1A1 in bits now (ex CT&S Mk3), & the range lead screw shoe measures 0.399" in length x 0.304" in depth x 0.251" in height. Hope this helps. Sorry it's in old money but I work best in that currency, & I could only find an Imperial Moore & Wright micrometer!

ATB.

Rog,

Thanks for that, I've finally got around to comparing your measurements against the ones I took now we know we are comparing like for like.

Starting with a conversion of your measurements we have

Mine, yours, = difference
10.17mm, 10.14mm, = 0.03mm
7.91mm, 7.73mm, = 0.18mm

Or if you prefer an Imperial measurement.

Mine, Yours, = Difference
0.400", 0.399", = 0.001"
0.310" , 0.304", = 0.006"

Are we now allowed to say that they're pretty close?

[Peter Laidler]

Now we're all singing from the same hymn sheet - or talking the same lingo, that's pretty close!