OT : Chassis punches

[tony duell]

> Well the manual says the foot pump also allows you to use both hands to
> position the punch.

I can see that if you have the type that fits on a bench press arrangement, but
I am looking at the ones where you drill the centre hole and fit the punch one 
side of the panel and the die the other. So not having 2 hands free is not
that important

> The big advantage of the hydraulics is that you will put more of the effort
> into pulling the die through the steel.
> The problem with the bolt version is that the tension in the bolt increases
> the friction between the bolt and the threads.
> This makes it hard to tighten the nut, even with a ball bearing. With this
> system the friction will stay the same.

True. So it might increase the cutting capacity. On the other hand the
instructions for the hydraulic pump warn time and again about 
trying to go through too think a panel. apparently if the bolt breaks it's
spectacular. 

> These days being old and feeble I think I might buy the hydraulic version...

Thing is, the punches are around \pounds 100 each (!). The hydraulic add-on
is over \pounds 400 (it fits all the punches, I would only need to buy one). I
can just about afford it, but I don't want to spend money if I don't have to.

-tony