On 05/06/16 23:33, Jim Wilkins wrote:
"David Billington" wrote in message
...
On 05/06/16 04:19, Jon Anderson wrote:
On 5/06/2016 12:10 PM, Ed Huntress wrote:

Would something like a fly press (screw press in the US) do. I have
one and love it and a few years ago acquired a decent set of metric
and inch sized punches and dies off ebay. Fly presses in the UK are
quite common but the punch and die sets not nearly so but round ones
aren't that expensive to buy new. I had used them before at a
company I worked at but when I got my own set working I was amazed
at how much quicker and easier it was to use the punches and dies
compared to drilling for making holes in sheet metal. All the
punches I have have a centring pip to pick up a centre pop and so
once located a quick swing and you have a nice clean hole that
doesn't require cleaning up.

This is the common small press he
http://www.engineering.uiowa.edu/ems...nt/arbor-press
A different machine, we have arbor presses here in the UK but a fly
press is different and can hold the punch and die accurately whereas an
arbor press is largely for pressing items in/out and isn't accurate,
especially the likely Chinese version you provided a link to. A typical
fly press here
http://www.ebay.co.uk/itm/Sweeney-Bl...-/331870208098 will
hold a punch and die accurately and allow for quick swapping of punch
and die once the bolster is set up to allow for quick changes of hole size.

They are generally rated from 1/2 to 3 tons, perhaps more but I
haven't encountered those. In New England at least, used ones are
often modified with punches and dies to install swaged hardware in
circuit boards.

I've seen only the one bench-sized sheet metal hole punch I mentioned
in a company shop and none in used tool stores, if I had I'd own it..
The ironworkers I examined didn't have enough throat depth.
http://www.scotchman.com/ironworkers/

In my experience the usual small-run precision sheet metal punch press
was a Strippit:
http://www.strippittech.com/Strippit..._Machines.html

--jsw