|
Holding down thin sheet material can be quite tricky. Multiple clamps can be used but they are time consuming to setup and quite often get in the way while machining. If you need to repeat the operation multiple times you are more likely to introducing errors with positioning. The Clamptable is simply a block of 12 mm thick aluminum with threaded holes in a 20 mm grid and fixing holes to bolt the unit to the milling machine bed. I have chosen a size of 120 X 200 mm but could easily be made larger or smaller as desired.
The other part of the table consists of the clamp bars. There are two types, a fixed bar and an adjustable slide bar.
By using two fixed bars at right angles to give a fixed reference point and an adjustable slide bar on the opposite edge, you can easily repeat work over and over. There are two Clamp table nc files to drill the hole matrix. It is recommended that you first use a 2.5mm center drill drilling to a depth that will open up the ends of the holes slightly. The will help in tapping the holes and prevent raising of metal on the block surface. The second nc file will drill fully through the block. The third file will machine the ends and slots. You can open up the extra end holes manually by hand if required.
The clamp bars are made from 25 mm or 1” X 1/4 material for the fixed bars and 32 mm or 1 1/4” X 1/4 for the adjustable clamps. Three edges of the bar are stepped in 1 mm increments allowing for different material thickness adjustment.
|
