Tools (4):
Proxxon FMZ vice

Original page created on 31/08/2019.

The FMZ vice

The fixing device is in the form of a C-shaped part whose upper branch fits into the vice’s base. The lower branch is equipped with a knurled screw that acts as a clamp. This attachment thus makes the vice easily movable, but necessarily at the table’s edge. In the event of a fall of the object tight in the vice, there is a 90 % chance that it is found on the ground!

Qualities and defects of the vice

The ball is very practical, but the trouble is that it is not perfectly spherical, and that its manoeuvre is therefore quite hard. In addition, its clamping device has a very limited stroke, so that after a while, it comes to the blocking while the ball is not really tight. So you can force on the screw, your vice doesn’t really hold in place and turns to the slightest solicitation.

Key: ① points of articulation; ② almost zero clamping stroke.

Another problem is posed by the parallel guide rods of the jaws. They are nickel-plated steel, but of a diameter a little too small, and not really rectified. There is therefore a fairly important clearance in the movable jaw, and an illusory parallelism.

The jaws are equipped with V-shaped grooves, horizontally and vertically, which allow effective clamping of cylindrical parts with a minimum diameter of 3.5 mm. Personally, I would have preferred less. They are equipped with removable good quality synthetic rubber smooth jaws: I often use them to solder parts (their property of thermal insulation facilitates the temperature rising), and I found that they resist very well to the soldering heat.

Improvements

Regarding the parallel guides, I bought 9 mm rectified steel rod, in which I cut two lengths of 130 mm. A slight chamfer at the ends makes it easy to insert them into the moving jaw. The guidance becomes much softer, without chatter, which allows to manoeuvre the crank with one finger. Parallelism is better, but not perfect. The disadvantage is that this steel can rust, so it must be cleaned and greased to protect it.

Regarding the tightening of the ball, there are two solutions.

The first, the simplest, is to insert small rectangular wedges of the greatest possible thickness (1 mm seems the maximum) at the joint’s support points. This is quite efficient, at least for a while, until the aluminium parts are deformed a bit more: we are then brought back to the same problem. Here, the wedges are small 10 × 10 mm pieces of glass-epoxy (PCB) 0.8 mm thick.

The second solution is to take the root harm: since there is not enough clamping stroke, increase it by decreasing the thickness of the mobile part by filing or milling (hatched part).

As for me, as long as the first solution works, I’ll stay with it.

To be continued…