thanks for all replies, Having read them back, I think my explanation needs clarifying!
so, I have been drilling 3mm holes into some ally bar, little project for a friend, its my first project, making some king pins for a large rc truck (big job for me!! ha ha). I used a centre cutter to start the hole, everything fine, then changed to what I thought was a good quality 3mm drill bit, slid the tailstock up, locked it in place, and used the handle to cut, nice and slow, and backing off to let swarf out. The entrance to the hole is fine, as I am just putting the drill bit tip into the centre hole, but after 12mm into the bar, (the lenght of the kingpins) the hole exits off centre.
When the tailstock is loose on the bed, there is movement noticeable back and forward movement, if I hold the tail and push pull towareds and away from myself, this motion being at 90 degrees to the bed, the tail will move, so when being tightened I have doubts it is being pulled down to the bed centrally or square to the bed, as there is only a small plate under the tailstock securing it to the bed. As mentioned, there are two small screws at the back of the tailstock, no idea what they are. The lathe instructions are useless, no explanation at all regarding setting up anything!
I have joined the yahoo group, but got a bit lost as I couldnt find any sort of titles for topic threads, so was really hoping someone here would say they have such a lathe, experienced the same problems, and suggested a fix, and explained what the two screws where for, I have tightened and loosened, nothing seems to happen