Diy Hold Down Clamp . Easel is a combined cad / cam / cnc control web app made by inventables. With this done, slide the tops onto the bars and run a zip tie or rivet into the 1/8 hole at the top of the bar. 8mm Metal Quick Acting Hold Down Clamp T Slot T Track DIY Clamping Kit from www.aliexpress.com Pipe) where you want to position the clamps. To install the clamps on a work surface, drill holes with a spade bit (1 in. If you're gluing small things, all sorts of household items can act as mini spring clamps.