Thread: Bessey Duoklamp 45-8 Slipping

Brian, can I ask how old, could they be covered by warranty?

Well, of course, I no longer have the receipt But I have had them for a few years and they haven't had a lot of use and when used, I've appreciated that they are not terribly robust so haven't tended to crank them up too much. Also, the spreading function is generally used much less often than the clamping one.

I've contacted Carbatec where I bought them and they have said they will discuss the issue with Bessey Au and I have emailed Bessey in Germany. Awaiting replies but was hoping for somebody on the forum to have solved the problem already.

I can’t vouch for the Bessey units but having been with Irwin for 25 years before their sale to Stanley I know that if you reverse the clutch plates you can sometimes extend the clamps life if they have started to slip.
In some cases I have seen slippage start to occur where clamps are used to clamp materials of the same thickness all the time.
This however tended to happen more with f type clamps where the serrations one the bar wear.

As far as I'm aware, the clutch plates in the Irwins and Besseys are different. I think the Irwins may have two clutch plates together, whereas the Besseys have two plates separated by a spring arrangement to allow for either clamp or separation operaction. In any case, I did try not only changing one plate for the other but also turning them upside down. What I haven't tried yet is to try the whole plate assembly block upside down.

Not sure this all makes sense in general but it will to those who may have needed to operate on their Bessey DuoKlamps. Perhaps I should add some images.

Awaiting responses from Carbatec, Bessey Germany and the Australian Bessey agent (Hordern & Co). In the meantime, I will submit these images that might help clarify the issue:

clutch plate assembly.jpg
This is what the clutch plate assembly looks like. The spacer below the top plate is, as far as I can work out, simply there to locate the springs. The plates themselves are twofold - one for the clamping operation and one for the separation direction operation.

Filed contact surface.jpg
The shiny bit on this (blurred) image is where I have filed the contact surface (between the clutch plate and the bar) because it was showing some wear and I assumed because the wear wasn't even, the plate could not contact the bar appropriately. This assumption may well have been wrong and my filing has made it worse! In any case, I'll see if I can figure out a way to fit a shim between the clutch plate contact surface and the bar.

I can't believe this entire system looks so simple and yet it's causing me so much frustration!

Well, I received a response from the Product Manager at Bessey, Germany who provided some helpful advice regarding ensuring the bar was clean and free from oils, greases and silicone. He further advised that if I had taken care of those issues with no improvement in function I should then contact the Quality Manager whose name and email he attached.

In the meantime, I had had a final lunge at the clamping clutches and, with some difficulty, was able to insert some shims (brass) between the clutch contact surface and the bar and what do you know? Voila! The clamp works perfectly

I informed the Quality Manager of this progress but nevertheless he has arranged for their sales department to send me a new clamp free of all charges! Now that's service and a credit to the Bessey Company, don't you think?

Dear Dovetail, we know how important the tools are to you and to all woodworking people. We know you treat the tools well and with respect and it is an honour to see such enthusiastic people working with our clamps. It was the least we could do for you.
Try out the KRE30-2K as well in the package. They are my favourit in doing the carpentry.

Korpuszwinge-REVO-KR150-2K_1553e.jpg

Wow great result.

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