Then started doing this...
This is someones idea of a fan grill. All it seems to do is cause a load of turbulence. What I need is air flow.
Look at those tiny holes! Way too small to let air in.
Let's start drilling.
That hole needs to be made bigger with a step bit.
A little 3 in One makes your bits last longer.
Now just bolt the two halves of the punch together through the hole...
I took off the sleeve part way through cutting to show the cutting head.
Out it pops clean as a whistle...
Well apart from the oil and swarf (I said there may be swarf)