The Cylinder liner

One can see from the out set that this will be a very long job as one is creating a cylinder liner from solid uncored stock. There will be piles of cate iron.

The photo shows the basis set up for the machining and in fact the external parts have been machines to size.

The drill has already drill it full length and I have already bored out the end so that the tail stock can enter the bar and the drill pass right through the part that is to be the cylinder liner.

In the four jaw chuck the bar has remaining static and so far after 6 hour work the bored hole measures about 28mm and needs to be 42mm. As I can only take gentle cuts, as I have no steady. it takes 5 cut to enlarge by 2mm, each pass takes about 10 minutes ( if not longer) so I guess at least another 2 hours solid work ...

After all the work of above was achieved I parted off the liner and set about making up packing pieces that would bring the liner parallel to the saddle and the right height over the saddle.

I then found that my boring between centres was too short so I set about extending the bar by putting 1/2" x 40 threads on both ends and then making up stub pieces internally threaded 1/" x 40.

With this complete the final setting up could be achieved as shown in the photo. This was achieved by calculating the amount of packing to put below the piece and then checking accuracy but adding / removing sheets of paper, to get it as good as I could vertically  so the DTI was used to check error top and bottom and I was satisfied with the result.

With all the checks made the boring could commence.

The boring bar has an advancement screw which is 40 turns to the inch so one turn is 25 1000th if an inch so very small cut can he carried out by say a 1/4 turn of 6.25 thousandth of an inch.

Then lastly a chamfer had to be put on the outer end so a new cutted had to be ground to give the 30 degree angle specified. This has caused slight chatter marking which will be cleaned up later.