On 01-18-2008, Gerald Voigt of Hawkeye Hobbies wrote about Berna Clamps:
"I've had some for years, though they don't get used as much as I had hoped they
would. They have a major drawback...no lateral support. Apply pressure to a part
and they slip from torsion (twisting). The single rod between the beams just doesn't
keep the clamp in alignment. If they find a way to improve this they'll get more of
my business. What I found better is getting the original mirco 'Quik Grip' from Vise
Grip. I have several which I use a lot. The knock offs are cheaper but stay away! I
once had to crush a model to get them to release. So much for saving a buck."
This answer to a model maker looking for a place carrying the Berna clamps gives me a magnificent opportunity for underlining some important property of these clamps. The Berna clamps reproduce exactly, against the object(s) you want to hold, the force you are exerting with your fingers when you push the jaws close to the beam towards the object(s). This can be demonstrated with a little of mathematics and physics (the demonstration is included in the brochure that is normally given to every user). In other words, you have the exact control of the clamping force. However, this is true only if you do not thrust upon the jaws. If you thrust, the jaws of those clamps refuse to thrust. They twist off. This twisting off of the jaws, if too much force is applied upon, is not linked to the rotundity of the beam, but simply to the fact that the jaws are slightly flexible. These clamps have only been created to apply a gentle pressure on delicate objects and not to crush them. But mind! This anti-damage safety by twisting of the jaws appears only in clamping configuration, that is to say when the jaw buffers are facing each other. As a result in bench-clamp and in spreading configurations, you can press much harder. Control of the clamping force is then only available as a safety.
So on condition you use the Berna clamps as specified above (no thrusting when buffers are facing each other), on top of the exact clamping force control and of the anti-damage safety, you can enjoy all the benefits the Berna clamps offer for holding delicate objects, unlike every other clamp:
Feather lightness,
Very limited extent beyond span, even in spreading configuration.
Instant locking.
Instant release (one finger, moving close to the beam and along it, has just to slide one jaw rear end apart).
Absolutely no marking.
Locking even when a minute force is applied.
Jaw buffers conforming to difficult shapes and as result expanding clamping force on objects and as such avoiding any pressure peak.
Extra-sturdiness as built with materials, such as carbon fibers, normally used for building modern aircraft.
Easy use as a bench-clamp for stabilizing objects that are very unstable.
Easy use as a revolutionary helping-hand with large and parallel span, without any risk of scratching at all, helping-hand that can clamp and spread.
Pressure kept up when glue retracts by drying, which results in excellent bonding.
Maximum span extendable with beam connectors.
All these benefits are explained with photos and drawings in a brochure with directions for use. This brochure is available on request. Please simply send an e-mail to phberna@free.fr, telling that you need the Berna MultiClamps brochure and you should normally receive a copy of it within a fortnight at most.
Thank you for your attention,
Dr Philip Berna