Pipe Hacksawing Guide Clamp

I needed to cut some 25mm pipe with a hacksaw, because I'm making an [MPCNC](http://www.vicious1.com/). But I couldn't get the cut straight, and the saw kept skipping.

So I designed this little guide clamp device: you put two guides surrounding where you want to cut, with two protective shims between, and the saw can only go along the line of the guides. The guides are tightened with an M4 bolt.

The shims ensure a sawblade-width gap; they are intended to be cheap and sacrificial, preventing the saw from eating the guides. When the shims are worn, print more. They have a little stand-off built on to them to help set the channel for the blade (mine was 1mm wide) - without the stand-off, it's hard to judge the separation, and the shims tend to stick together.

You need to fit an M4 nut and (~20mm) bolt for each guide so you can tighten them onto the pipe. The OpenSCAD file is included, so you can easily change the bolt size, or adapt it for different pipe diameters.

### Instru