Accuracy issues with an Excellon Uniline 2000

[sam.price]

Hello

i`m a trainee electronic test fixture manufacturer from Liverpool currently working with an Excellon Uniline 2000 for drilling purposes.

I`ve been having a lot of problems lately with accuracy issues i have to drill through 15mm fibre glass material (or G10). because the machine runs with an ABW110 spindle which is air bearing i have to drill through this material in two runs one 8mm through the top face, then flip the material and drill through the remainder of the material from the back.

The problem im having is the holes i am drilling (usually 1mm/1.4mm/1.75mm wide holes) have a slight step in them and the holes are tight this suggests to me the holes haven't quite met in the middle after flipping the material.

I have spoken to an expert and he seems to think it could be something wrong with the tooling strips i use to hold the material in place, they are very worn and could be causing the problem.

I have included pictures of the machine i`m working with, the bed of the machine which quite clearly has seen some wear and tear, the tooling strips which have also seen better days and one of the holes i have drilled with a very obvious step in the middle. the pictured hole is not a small diameter but is a 19mm hole which is drilled on the machine out of hundreds of 4.35mm holes.