Fixing ye old F clamp

[stringnstik]

Thought Id just share this.

You never have enough clamps?
Was in this predicament the other day and recalled having once had some F clamps. Aptly named too as I never got them to work properly, that is too hold tight.

Anyway I was desperate so I dug around the shed till they surfaced. These are old, McEwans brand old :lol

I fiddled and sure enough the were F usless clamps indeed. I was about to toss em again and thought Ill take it to work see if Im just not using them properly.
I walked into the doorway of the carpenters/modellers workshop and they burst out laughing. They new exactly why I was there.
Long story short. Cheap soft metal, teeth not cut deep enough, too loose.
Not one for tossing things I thought maybe cut new teeth.. hmm long job. then one of them mentioned showed me a real pro like version. I noticed a grub screw on one of the arms that meshed with the teeth on the shaft.....for extra grip!

Well cutting grooves all the way along the shaft was not worth my time but a grub screw..lets meet it half way and see what transpires.
First I filled the knob off that stop the bottom arm coming off.
With the arm loose I could now put it in a vice and drill a pilot hole just back from the inner inside (see photo) I wanted it just right so the thread would be exposed to grip into the shaft. I got it wrong but no fear I redrilled it out from a 3mm to 4mm grub. Tapped the hole.
put my 4mm grub in and slid it onto the shaft again.
Now when you tighten it it pinches the exposed grub thread onto the shafts edge. the unbraco super strong hi tensile grub bights into the woossy shaft nicely and she slips no more:)

[bigbob]

Clever!

[Steven J]

An EXCELLENT solution. I'm impressed.

Steve