Bar clamp clutch slipping

[Aaron Liebling]

I have a dewalt bar clamp where the clutch now always slips - even if I try to hold it locked during tightening. Nothing looks stripped or obviously broken that I can see.

Any ideas on ways to address it as I'd rather not junk it.

442975

[glenn bradley]

Light duty clamps can be over tightened pretty easily. The screw is an amazing energy transfer machine ;-) I would try removing the clutch plates and installing them upside down . . . that is reverse them north to south . . . am I making sense. I had to do this on some Jet parallel clamps because I used them as if they were Besseys. Jet tech support gave the recommendation and even had a written procedure with pictures that they sent for the fix so . . . not uncommon for them I guess.

If you need some extreme clamping power I would invest in a couple clamps for that purpose (https://www.rockler.com/bessey-tg-professional-series-bar-clamps?country=US&sid=V91040&promo=shopping&utm_source=google&utm_medium=cpc&utm_term=&utm_content=&utm_campaign=PL&tid=pla&gclid=Cj0KCQjw2or8BRCNARIsAC_ppya-euow2TEWc8DLbq_RFCq2fw--nabqa0ViMob4aFqhDmatL3qz3QwaAk8ZEALw_wcB). This is not often required and I think many of us over-pressure things when clamping. I know I now use much less 'crush' than I used to when clamping things. If you try the "flip fix" let us know how it goes. Maybe it will help someone else.

[Mark Bolton]

Yep, Ill bet if you take the clamp apart you'll find that either the grooves on the back of the bar are worn or the dogs (three black bars) are. You can likely touch them up with a triangular file on the bar or a grinder for the dogs (likely hardened).

[andy bessette]

I have a dewalt bar clamp where the clutch now always slips...

That is likely an inferior import.

[Mel Fulks]

Sometimes just pressing a little on those pieces while tightening will makes them grip.

[Aaron Liebling]

No question - it's a cheap clamp I bought from a box store when I was desperate for a few more long clamps for a glue up. It's clearly been abused beyond its limited capabilities. That said, I own it and hate to throw a hunk of steel away, so I'll see how easy it is to dismantle and try to rehabilitate.

I have some of those bessey clamps. They're brilliant, but so much so that they do feed my tendency to overclamp!

[Andy D Jones]

First, look at those three clutch plates closely. Most are stamped out of sheet steel, and will have rounded edges on one side, and sharper, sheared edges on the other, as a result of the punch and die used in manufacturing them. You want them oriented such that the sharp edge of the hole faces the "right" way to bite into the pipe better when the clamp is tightened. A close look at the geometry of the clamp block, the pipe, and the clutch plates should make the right direction apparent.

I have seen some that were (re)assembled the wrong way before, either by the user or the manufacturing/assembly labor.

You can also check to see if the sharp edges show signs of being worn down in use, likely due to cheap, softer steel. If so, a rat tail file can help bring them back, but you have to be careful to preserve the shape of the rounded hole so it engages the pipe correctly, at an angle. Or you can file from the flat side with a big flat file, but that's usually a lot more filing. If you have a light touch with your bench grinder, you might try that, on the sharp side.

-- Andy - Arlington TX