OT : Chassis punches

[Dave G4UGM]

> -----Original Message-----
> From: cctalk [mailto:cctalk-bounces at classiccmp.org] On Behalf Of tony
duell
> Sent: 15 December 2014 19:53
> To: General Discussion: On-Topic and Off-Topic Posts
> Subject: RE: OT : Chassis punches
> 
> > I don't know about the hydraulic part, but I've had really like my
> > Greenlee punches.
> 
> That is the sort of thing I've read elsewhere. Greenlee are not cheap, but
> they do the job and last. The brand we used to use in the UK was Q-max [1]
> but they don't do the sizes I need
> 
> [1] Again a good brand IMHO. I convinced my father to buy me the 5/8",
3/4"
> and 1+1/8" ones about 35 years ago. I am still using them. Of course those
> are the sizes for B7G, B9A and Octal valveholders... I think the company
> started out making RF (and IF?) coils, hence the name.
> 
> The ones I am looking at are the conventional 'tighten the bolt' ones
albeit
> with a thrust type ball race on the bolt to reduce the torque needed. The
> published specs exceed what I need to do (they are specified to punch
> 1.6mm mild steel, the thickest I want to do is 1.2mm).
> 
> The hydraulic thingy seems to fit in place of the nut and pulls the punch
bolt
> through the metal into the die. Nowhere can I find info on what advantage
it
> gives. If it's just quicker then I am not going to get one.

Well the manual says the foot pump also allows you to use both hands to
position the punch. 
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.
These days being old and feeble I think I might buy the hydraulic version...

> 
> -tony


Dave
G4UGM