A couple of weeks ago we had an a burglery attempt. Measures had to be taken, so I decided to make a proper way of locking a gate from the inside. This might seem a bit rough to many of you who are used to neat little engines but it might be interresting to some

I started by turning the OD on a pipe to a small shoulder, flipped it over and bored out close to desired dimension

I bored a hole in a square plate to suit the shoulder diameter of the pipe and welded them together. Then I chucked it in the lathe and turned the internal diameter of the pipe to the correct dimension

I also faced of the back of the plate as it warped a bit during welding. Inside the bore there is a 2mm shoulder. The groove inside the pipe is for lubrication later on.

Then I started turning down a 70mm shaft to 40mm in passes with 1mm DOC and high feed, still it took for ages!

The surface was rough and became very hot, not to mention the swarf which didn't break and ended up in blue 2 meter long coils, so I had to fill up the coolant system on the lathe and try it out. It worked a treat, except for a leak where the bed is mounted to the stand in the tailstock end.

Finished bar

It did fit inside the pipe



To make the locking arm i "needed" a somewhat accurate hole, so I bodged up this boring tool

And used it to bore out a hole in a suiting piece of flat steel

A bit of welding later and there you go, I had turned a groove inside the tube and drilled a hole for a grease nipple before I welded it together. Don't want to have to pry the lock open in a few years time


I didn't take any pictures of making the counterpart, but it is quite basic. Due to security reasons the pictures of the lock are a bit reduced. The flat steel is 15mm thick and the shafts are 40mm, should be able to give the next thieves some problems


