It was probably the ancient Greeks who first classified six simple types of mechanism: the lever, an inclined plane, a pulley, a wedge, screws as well as the wheel and axle. Even though things have moved on slightly after a few thousand years, I’d guarantee that one, all or a combination of those simple mechanisms can still be found in any machine that you’d care to examine today, even the keyboard of an iMac!
Of those six, the inclined plane is one of the simplest: a ramp up which you can move a heavy load. Make the area beneath the ramp into a solid object and you now have a wedge; wrap the wedge round a stick and you’ve made a screw, but wrap the same wedge round a pivot point and you’ve invented the cam.
Apart from its use in all sorts of other machines, a cam is another handy method of securing something flat onto the workbench, usually one that’s awkward or difficult to hold in any other way. A wooden chair seat is quite a good example where it needs to be held securely on the bench whilst the centre section is shaped.
The one disadvantage of using a cam is that a screw needs to be used for the pivot point and if, like me, you’re slightly disinclined to bang nails and screws into your pristine workbench top, you then need to come up with an alternative and that’s to use a large sub-base made from some scrap material.
The pic shows a well used and fairly mangled bit of 18mm mdf which has had innumerable holes, chisel cuts and router slots inflicted on it over the course of time, but for this purpose it’s ideal for the job.
The UJK Technology Cam Duck Clamps are based around the traditional workshop clamps with the very useful addition of a locking screw through the duck’s ‘eye’.
A standard cam is liable to vibrate free when the job is subjected to vibration from sanding or routing, so in this respect they hold the work a lot more securely. They’re CNC-machined from 12mm thick phenolic laminate and, in order to hold your work properly, four are needed.
The other interesting addition to the UJK range is a pair of Dog Rail Clips. On the face of it, these may seem a little superfluous, but I could have done with some of these little widgets last year when I made a pair of multi-purpose storage units using the power tool table I’d made earlier.
During the course of building the storage units, I had to cut all the rails to identical lengths and ensure each one was square. A single cut with the TS55 was the way I decided to do it and, much to my surprise, it worked. Every rail was the same length and cut dead square.
That, however, was only due to my unusually meticulous setting up procedure. Check everything’s clamped tight, the saw is set to the right depth of cut, extractor connected and the track rail tight against the Parf Dogs etc.
Except that on one or two occasions, the track had shifted away from the Parf Dog by a few mm (arrowed) and, had it not been for my eagle eyed observations and subsequent checks, all the rails would have been cut incorrectly.
Using a pair of Dog Rail Clips would have removed that possible area of inaccuracy as they force the side of the track onto the Parf Dog; as a consequence there’s no room for any error to occur.
If you have a saw/track combination and use a Multifunction Workbench, or have built your own version as I did, a pair of these Dog Rail Clips is an almost indispensable accessory and highly recommended.