KESO 2000S Omega ABS disassembly

[tomasfuk]

I have got a KESO 2000S Omega double cylinder in the Euro profile. It has the plug pull / drill protection at the outside cylinder.
I have found the description of the common cylinder, including assembly/disassembly instructions here: http://wiki.koksa.org/KESO_2000S .
Unfortunately this does not work for the cylinder with ABS (pull/drill protection). Even if the key is in, rotated, the plug is being held and cannot go out of the shell.
What is blocking it?
Obviously it cannot go to the front (key) side - it's the purpose of the pull protection. But why it doesn't go to the back (cam) side? The key stop is not the reason.
Here are the pictures of this stuff:
(the left cylinder is the outside one)


Detailed views:

You can see 2 rods inserted into the front face - on both sides of the Ω symbol. I suppose that are the anti-drill inserts. The right one is ferromagnetic (hardened steel?) and the left one is paramagnetic (tungsten carbide?).


You can see again two rods inserted from the back side. Unlike the surrounding material which is magnetically inert, the 2 rods are ferromagnetic but less than the left rod in the front face. Thus, I suppose they are stainless steel. I don't think these two rods could hold the whole anti-pull thing at the back of the plug. At least if it was so, 4 rods (rivets) should be there.

Does anybody know how to disassemble the outside cylinder?

[tomasfuk]

P.S. the rods on the front side are not so hard as I thought. I stuck on them with a punch and it left dinges there. Thus, I'll replace them with tungsten carbide afterwards.

[mh]

I believe one of the purposes of the steel rods is to damage a screw that someone would drive into the keyway, to then pull on that screw. The idea would be that the screw could dig into brass, but not into these steel rods; then the threads of the screw become damaged and cannot transmit the pulling force into the core.
But I never tried it myself.

[tomasfuk]

I don't think so. The pulling screw will not reach them. But let's not discuss the violent attack here - I'm interested in how to disassembly the thing.

[mh]

I don't think these two rods could hold the whole anti-pull thing at the back of the plug.

Not sure if I understand you correctly. But the plug of this version will not go through the housing at the front, it is loaded from the back. There's no separate part attached to the back of the plug, it's one plug with a shape that only goes in from the back.

[tomasfuk]

Yes, but the plug does not go out to the back. Something is holding it in and I don't know what it is. The key isn't it - even if I push on the key strongly (rotated to any position), between the key stop and the housing face remains a gap approx. 150 µm.

[mh]

I don't know either, and my KESO box is currently borrowed to someone else.
But I think it might be friction, i.e. the side elements have been pressed into the housing.

[tomasfuk]

The side elements are being pressed into left, top and right side bars which are inserted only. In addition, if the key is in and rotated, the key pins are in the plug, blocking pins are hidden in the side bars and do not block anything. The only thing which holds these side bars in the housing is the back part of the plug which has bigger diameter. If I push on the key, the side bars still can move (some 100-200 µm) in the axial direction. Thus, the side bars are definitely not the thing holding the plug in.

[mh]

You are right. I checked again and found the explanation:
At the end of the assembly, the two inserts that are visible at the front are pushed into the core. This will push two blocking elements to the side which hold the plug in the housing.
Therefore, disassembly is practically impossible, unless you find a way to get these drill protection inserts out.

[tomasfuk]

Thus, disassembled now. The plug has been held in place by the inserted anti-drilling shield plate which stands out off the plug (3/4 mm) when fixed by those two rods in the front face.

[tomasfuk]

You are right. I checked again and found the explanation...

Thank you for finding it.

I'm a little bit disappointed with it. The outside plug has only 14 pins in it unlike the inside one which has 15 pins. I suppose it's for easier assembly which is more difficult here.
Maybe I'll drill the chamber for the missing pin in the plug afterwards (and take the pin stack from the inside plug).

[mh]

How long are these two rods in the front face?

[tomasfuk]

How long are these two rods in the front face?

Approx. 8 mm and the holes are ø 1.5 x 11.5 mm what is a weakness which enabled me to disassemble it. I pushed the rods deeper in. I measured the length/depth by tasting the rods with a small neodymium magnet.
Now I'm thinking of:

a) as this plug is made of some kind of bronze (probably the mystic Sidra metal ), to drill small holes at the end of those rods, push the rods back, remove them, recap the new holes and replace those rods with tungsten carbide ø 1.5 x 10.5 mm. Drill the chamber for the missing 15th pin.

b) as I wanted to have the plug made of CrNi steel (the cylinder has been sold to the previous owner as being such - the locksmith duped him), to throw the plug away and to get a new one.

I must check the possibilities of getting the parts, I need another cam too.

[tomasfuk]

While making the place for new fixing rods in the front face I realized that the right rod was made of mild carbon steel - not hardened. It was easy to drill it with HSS Co5 bit. I can confirm the 8 mm length of it now, the hole depth is 11.5 mm.
Tomorrow I'll work on the other one which seems to be stainless steel.

[tomasfuk]

BTW, the two rods pushed into the plug from back are approx. 23 mm long, ø 2 mm.