Knuckling Under

Being able to firmly secure a workpiece down significantly improves both accuracy and safety.  There are lots of different clamps on the market that engage with the working surface, and work with varying degrees of success.

The knuckle clamp from Woodpeckers is an innovative approach (as is typical for them!), using a reinforced polycarbonate body with seven pivot points to maximise the capacity of the clamp.  Either end of the body is a pivoting foot to ensure the clamp makes maximum purchase on the working surface, and the workpiece.

Clamping down the workpiece

The clamp also utilises the Woodpeckers Multi-knob, which makes gripping the knob and tensioning it up easy.  Not sure just how much load the clamp can take, bit it certainly provided more than enough for the test job here.  They are said to be virtually indestructible, but I didn’t want to risk destroying the ones I had to prove the point!  You can use Knuckle Clamps on all sorts of tools and jigs (homemade and otherwise) which have T track slots. In this case I chose to use the clamps on the Pro Drill Press table from Professional Woodworkers Supplies.  It would work equally as well on other items such as the router table, Incra Mitre Express, the T slots on a Torque Workcentre, and any homemade jigs that you have incorporated T slots.

Work holddown

As a bit of a test for the clamps, I decided to try a partial-width drill with a forstner bit.  Should prove a pretty good test of the hold capability of the clamp.

Partial width forstner bit hole

Clamps held well, without any suggestion of a kickback.  Didn’t know you could even do this with a forstner bit, especially when the central pin was not in contact with the work.  Something you must not do with a forstner bit mounted in a handheld drill – the risk of a kickback is too great.  On the drill press this is achievable, but you must keep hands well away.

Preset Clamp Height

The clamps can be preset, both in position along the track (and locked in position), and also preset for the degree of “opening”.  This is via a second nut on the bolt which has a spring to hold the clamp up.  This nut does not have to be moved while clamping down, so makes clamping, and reclamping work very easy.

Partial width forstner bit hole

After the first cut, I tried a few more with equal success.

Forstner bits are boring 😉

So that is the knuckle clamp from Woodpeckers.  Sold in Australia through Professional Woodworkers Supplies.  They also have kits which includes track to create some useful bench-clamping solutions.