Festool FSZ 120 clamps

[galleywood]

I have had a pair of these clamps for a few weeks and have used them about a dozen times to clamp my track saw rail to the 18mm plywood that I have been cutting.

Despite doing up the clamp to what I expect to be a sufficient amount I find that the clamp becomes loose either before or shortly after using the track saw.

I have tried progressively increasing the clamping pressure alternately on each clamp, only to turn my back and hear the rattle of the clamping handle
as it crabs down the 'L' shaped element.

Do others users experience this problem, is there a knack to applying the pressure?
There does not seem to be any scope to fettle them.

 

[Claud1]

Yes I have the same problem and I have no idea what causes it hope someone comes up with a explanation

 

[Distinterior]

I've had a couple of sets for a good few years,.....never had the problem you both describe.

I slide the clamp into the track, lift the lower section up so it's snug, then just tighten the handle until it is good and firm. There is not normally any need to overtighten them.

The one handed ratchet clamps are easier and quicker to use but are more than twice the price...!

EDIT.
Are they both new sets of clamps..? If so, maybe there is a faulty batch out there.

 

[Claud1]

mine are at least 4 years old but not used on a daily basis but do quite often fall loose when I do use them

 

[Freddyjersey2016]

Tempted to ask if anyone ever had the same problem with the cheaper Bosch system?

 

[SteveF]

I use the axminster version and no issue
also prefer the ratchet ones (again the axminster ones)

Steve

 

[Rorschach]

I have those and used on track and just as normal clamps, never had them come loose.

 

[YorkshireMartin]

The only time I've had them work loose is when I set them at the wrong angle which is impossible to do if being used in the rail slot.

They are ratcheted so that sounds really strange.

Definitely take them back for Festool to have a look.

 

[jw00d]

I have a pair of Festools and the Axy clones and not had any problems with them loosening either.

Jamie

 

[adidat]

they will come loose if not tight enough! they need to be done up pretty tight! also find they come undone easily if the clamp pad is right on the edge.

adidat

 

[galleywood]

I think I have worked out the cause of my problem with the clamps.

This image is typical of how I have been setting up the clamp.

I assume that because the clamp has made contact with the workpiece (in this case a door), that it is held up in it's groove and not achieving the required clamping force.

I now back the clamp off to allow it to seat in the groove.
It also prevents damage to the work.