make a long precision hole

[Arne]

I want to make a truck coupling servo cylinder. (Weak knee - too old :-)) I have a cyl with rod through and standard ends to place in the push link from the foot plate. I want to drill a diam. 16 mm hole, cut the ends and use a new rod diam. 16 mm with small holes and o-rings at centre to work as valves. But I am stuck making the hole with good surface inside. I have lathe and mill ok, but just normal drill bit lengths. What are the steps to make a hole 16.01 plus 0.03 and minus 0 and very straight in cyl rod centre some 200 mm long. Steel is medium quality. I can use a file on it. I have the 16.000 mm new centre rod with cromed surface. What play and inner hole surfacce can I handle without going to a pro? Grateful for hints. Regards Arne

[Thrud]

You can use a reamer with an extension to take it through the entire bore or you could line bore it in your lathe.

To line bore it, it is clamped to the cross slide and a bar is turned between centres to accept a bit. The bar is positioned between the centres and driven by lathe dog. It enters and exits the work with sufficient space to advance the carrage completely past the cutting bit. This can produce a pricision bore if the time is take to do it carefully. This is the traditional method used in the UK for boring steam chests by model engineers.