On Sun, 28 Oct 2012 20:31:26 +0000, alan
wrote:


I'm looking for an alternative, or a different design, for a cam buckle
to tighten a 25mm webbing strap. With the metal cam buckles I currently
have I cannot get enough tension in the strap.
http://www.webbingbucklesstraps.co.uk/cdata/36514/img/36514_1499739.jpg

With this type as the tension in the strap gets tight the friction
between the buckle and strap becomes too great for it to be tightened
any further. Are there any other types that work better. I only need a
tiny bit more tension in the strap.

I've experimented with a 25mm mini ratchet tensioner and while they work
well they are mechanically too large.
http://www.theratchetshop.com/Mini-Ratchets

I've seen US adverts for roller cam buckles that claim to allow
tightening to x4 to x10 better than conventional buckle but they are i)
very expensive, ii) don't ship to the UK and iii) don't seem to have
many stockists in the USA (and none in the UK or Europe).

My experience with this stuff ranges from strapping loads onto the
roofs of cars and lashing double-basses together while the glue dries.
I'm using normal polypropolene webbing and the buckles in your first
example. I don't know what you are using it for or why the mini
ratchet tensioner is too large in your situation but I'm inclined to
think that a limiting factor is the stretchiness of the polypropolene
webbing rather more than the friction on the buckle.

I "lock" the buckle end of the webbing against a corner while I
stretch the rest of the webbing round. It takes several goes to take
up all the slack. In the final stages I grab the taut webbing running
through the buckle and pull it towards the buckle whilst at the same
time pulling the slack away from the buckle on the other side. However
tight it is pulled there's always some elasticity and I've never met a
situation yet when I can't get my hand between the webbing and the
load to grip it for that final shove.

Nick