[yuliany]

Originally Posted by djh82uk Hi Guys Im having problems holding down pcb's I have a Taig mill with a normal T-Slot bed. Now my problem is that I just cannot hold the pcb's flat enough. I spent ages getting it so that I can have known points on the fixture for doing double sided boards, but when I come to mill it, it is never flat. At the moment I have a piece 1/4" alumimium that I have run a surfacing gcode on with an 8mm end mill, I then used the mill to mill holes that I later tapped around the perimeter of where the board would be. I then made 4 strips of 1mm thick aluminium with holes in the right places. So I place the board, bolt down the strips and it's always out by about 0.002 - 0.003", it's higher in the center as if it is buckling. The board are not really flat when I get them, but I was hoping the strips would help flatten things out. I also had to cut a section out of the baseplate as my pcb micro drills kept snapping when going through the board. My initial plan was to make a plate out of 2 pieces of the 1/4" thick ali, a top and bottom piece that had a recess of half the thickness of the pcb's on each half. i would then bolt these together, but my mill's Y axis travel is not big enough due to the column. I then though to make the strips onto one rectangular piece but faced the same problem to a degree plus I ran out of the alu sheet. So before I buy more, does anyone have any suggestions? I think it may be buckling due to the fact that there should be something the same thickness as the pcb on the outer edge of the strips, but again due to my travel issues, the surfacing gcode was not able to reach there, so it is difficult to guage what thickness that should be. I have also though about making the strips out of the 1.4" thick ali, perhaps in two parts. I have also thought about vacumn holding, but when drilling/milling the pcb's i would be damaged the vacumn bed all the time. Please, any advice appreciated Regards DJH

Dear friend,

A new clamping technology based on adhesives that can fill the gaps you don't need good surfaces, you can fix your PCB with a tensile clamping force of 300 kg/cm2.
Please find it at: www.mts-rnd.com

Yulian.