My first chipping of a Nikkor

[richardHaw]

i am actually more concerned about keeping the aesthetics clean and from the looks of what Bjorn Jorde did, it looks pretty clean. 

[Bjørn Rørslett]

A CPU-modified lens should look precisely the same after modification, except for the tell-tale row of signal pins. See the attached picture of my old 15 mm f/5.6 QD.C Nikkor.

[Erik Lund]

I agree with Bjørn here Try to avoid damage to the surface of the mount! and also to the three flange parts.

The drill used for countersinking the holes for the contact block screws should be about same diameter as the screw head 2mm, drill for screw is 1.5-1.6mm the screws are 1.4mm.

If your a little shaky with your hands its best to use a shaft drill with an oversize shaft that fits inside the jig holes.

There is 3.1mm between the flange surface and the three flange parts,,,

The jig is made in Denmark BTW The result of a brainstorm,,, And why is it cut up? Because its the only way to make it 100% precise without a CNC machine,,,

[Bjørn Rørslett]

... Du to some malfunctioning brains at the time, we actually cut the first 3-4 K-rings in the wrong position. Thus had to discard them. Fortunately, I had brought more than a handful with me

[richardHaw]

the kit looks small enough anyway. and yes, most nikkors have enough space under the baffles for this. the F mount was considered big when it came out. 

this 105mm f/2.5 was easy to work with unfortunately mine was a bit of a trouble. the person who assembled my lens put too much epoxy in the rear bayonet screws. i heated them, put acetone on them and tried everything i know. 3 out of 5 screws came off easily but the 2 ones that were left were a pain and one of them snapped my drill in 2!!! the older screws were made of good stainless steel...

the jigs can be 3d printed and cast using a tough resin. an easily available source is the F -> EOS adapter which is really cheap.

[Bjørn Jorde]

Thank Erik & Bjørn for the guidance on the drilling.
Turns out, the drill bit sizes were fine: The small one is 1/16" and the larger 5/64" - who needs the metric system when it's much easier to say, and remember, 5/64 of an inch than 2 mm 
The larger fits between the flanges just fine.
It was a bit sloppy work of me to not aim it right (no jig to help me  ).

Thanks again for all your help.

Oh, I did finish my third lens - the 50/1.4 AI.

[Erik Lund]

Good to hear !

[richardHaw]

i actually love metric and hate standard (for obvious reasons)

so the screws you used are 2mm? 

[Erik Lund]

Head is 2mm and Thread is 1.4 mm, you need to buy the proper ones from Nikon, they have the exact right length and a non standard counter-sunk small head.

[richardHaw]

1.6 is a bit rare here. usually it's 1.7 



flat head screw here is called 皿ねじ or plate head screw. is this the one you are talking about? (counter sunk)

by the way, if you need screws, you can buy one from Sunko (they accept orders of 10,000). they basically make all types of precision screws including those pesky set screws for lens barrels. they are easily destroyed when the metal is old. i hate them so much.

[Bjørn Rørslett]

The correct retaining screws for the contact block assembly are Nikon part number  1K001-082. They come in packs of 5 screws.

[Erik Lund]

It's the first drawing; Described as: A countersunk head with a flat top,,,

Nikon uses so many off standard screws it's amazing,,,

I would never use a non Nikon Screw for this application! Bjørn had some for a while, they where terrible to use, fell of the screwdriver, sharp edges on the head,,,

I also got some Nikon screws designed for the plastic F-mounts. there the head is too large to use on a metal F-mount, had to trim them down, try trimming the head of 1.6mm hardened steel screws,,,

[Hugh_3170]

Richard, the Nikon screws for the Nikon contact block that Bjørn has given you the part number for are stainless steel screws, they are M1.4 (i.e. metric, 1.4mm thread diameter), they are 3mm overall length, and have a 2mm head diameter (as noted above). 

The head is variously described as a cone head, flat head, or counter sunk head depending on what part of the world you are in.

[richardHaw]

http://www.sunco.co.jp/
this company makes screws. i am going to order some 1.4 set screws from them. i am pretty sure that they have equivalent screws that Nikon uses. their inventory is awesome. 
you can order from them if you spend a lot for screws. that would be a lot of savings!

http://www.sunco.co.jp/street/catalog.html

click on the magenta square and it should send you to the catalogs 

[richardHaw]

Richard, the Nikon screws for the Nikon contact block that Bjørn has given you the part number for are stainless steel screws, they are M1.4 (i.e. metric, 1.4mm thread diameter), they are 3mm overall length, and have a 2mm head diameter (as noted above). 

The head is variously described as a cone head, flat head, or counter sunk head depending on what part of the world you are in.

I see. i have some in hand, stainless & the black one. there is a screw shop nearby my studio (i actually bought all of their remaining flat head M2X4's and resold them to some friends). these screws are identical to what Nikon uses. the important part is the pitch. the pitch has to be correct.