Gun slideway screws fouling

[Adrian Harris]

Has anyone made any changes to the M3 CSK screws which attach the metals sheets to the barrel saddles (CN0144), as they foul on the main gun support piece (CN0179) when done up. I could turn the CSK heads down slightly on the lathe but, having done that before, it's somewhat sketchy.

Adrian

[Donald Suttie]

Hi I not sure if we are talking about the same parts but the previous owner of the PAK i now own has countersunk the holes in the steel sheet so allowing the screws to sit flush

Donald

[David M Wilks]

Adrian, as far as have found with my build ,this part of the model does not slide as per full size, the other parts have a tight grip on CN0179 also there are 6 more countersunk screws to deal with, a tight fit at best even with dremel in hand.Dave W

[Adrian Harris]

It turned out there were several reasons for the parts not fitting together correctly.

Just placing the CSK screw in the steel parts showed that the countersink wasn't deep enough to allow the head to sit flush.

So, step 1 was to increase the countersink depth in the steel parts, until the screwhead sat flush with the surface of the steel. This then required step 2, which was to clean up the backs of the holes where the countersink bit had pushed down the metal, so that the parts would sit flat on the saddle blocks again.

When the CSK screws were tightened down, the heads were still proud, as the countersunk part of the screw head was thicker than the steel parts, and the parts weren't being held in place properly.

So step 3 was to countersink the saddle blocks slightly, so that the screw could be tightened down and everything nipped up correctly.

I didn't take pictures during the process as it's too darned cold in the workshop.

Adrian.

[Donald Suttie]

I noticed when i first got this kit,that it was not the screws that were preventing a smooth slide,its the Aluminum connectors that hold the barrel,that appear to be tight
i am in the process of polishing the rails to see if this helps,the working gun would have had highly polished rails with use,but the static display units seen today paint these parts to prevent rust setting in
i also notice from old photos of a gun in service that the metal covers are sometimes missing,and only the supports for the barrel are on show
i know photos help but i am not good at taking photos as i go
ill post when i can

Donald

[Jerry Carducci]

I'm watching this with interest as the Flak 36 has some similar parts and I know they were binding before I took it all to pieces. I've found it best the countersink the thin sheet and what it's to be attached to as a set at the same time so the countersink extends slightly into the thicker part of the union; just as Adrian said.

I also have the PaK 43 so I'll know what to look for when I get to it.

Jerry