Nova Scroll Chuck problem

[Kirwilli]

Hello all, I have a slight problem with my Nova Scroll chuck. Have one stubborn M6 countersunk retaining screw. It will not budge, trouble is that the head is beginning distort and allen key is slipping. Have tried the usual methods, brute force, wd40 etc. Other screws popped out easily, I even smeared grease under the heads to help removal. Any ideas.

Thanks, Henry

[bdar]

Hi Henry, had a similar problem with one on my Vicmarc chuck with distorting. I used a centre point punch and pushed the metal across and was able to get enough purchase with the allen key then. One really stuborn one I had to drill out. I squirt a bit of graphite powder into the thread when I change them now. I didn't use oil or the likes because it will trap dust and then that will cause a thread to bind.

Hope this helps
Cheers
Darren

[hughie]

Hi Kirwilli,

Another method before get stuck into it with the centre punch is to pien over the edge of the Allen key entry point usually done with a ball pein hammer then drive the Allen key in to the hole, usually works 9 times out of ten, Failing that drill out the head using 6mmm drill if its a 6mm screw. be very careful on the depth you drill other wise you might drill out your thread portion of the hole.
With my chuck I pick up a few spare screws and changed them when they looked a bit dodgy. Later I bought several of the chucks to solve this problem.
hughie

[bsrlee]

Another trick you may already have tried: Put the other screw/s back in & tighten 'em up. Sometimes there is a bit of ...stuff... under the plate & when you remove one screw the plate pivots on the ...stuff.... and locks onto the shaft of the other screw. Putting the other screw/s back in & tightening will release the stuck screw - undo all the screws a bit at a time so the plate can't lockup again.

[Cliff Rogers]

I've had to drill the head off one as well. :mad:
The remaining stub came out with a pair of pliers without any problem at all. :confused:

The really annoying thing is that when I went to the local 'bolt' supplier, the head of the replacement was slighty bigger than the old one.
I found an old allan key that would fit in, cut it off so it was a straight bit to go in a cordless chuck, mounted the screw on the allan key bit & spun it against a running grinder til it would fit. :rolleyes:

[Jim Carroll]

Drilling the head of the screw is the easy way out if the top is not able to be peaned over . As indicated only drill deep enough for the drill to take of the countersink head and this will leave enough to grip with pliers.
You need to get the original screws as they have a 10mm head, the ones available in nut and bolt stores have a 12mm head. One differance between Aus and NZ.

[hughie]

Kirwilli,
I suspect the csk Allen screws maybe a special.As they are normally made to a standard. But there are some variations for special purposes ie UNF attachment sizes etc.
Simplest answer is to grind gently the excess diameter from the csk head, if you can sharpen a gouge this will be simple for you. This is not an uncommon practice. [as per Cliffs message ]

Don't worry about the holding capacity as its done on the csk portion of the head.
By doing this you will save on ordering/buying from a special source and it should also be much cheaper.
hughie

[Jim Carroll]

Hughie instead of burning your fingers buy a set of 8 screws [spares for later also]. They are $8.00 + postage of $1.00.
Saves a lot of greif if you stuff up the thread when trying to hold it when grinding.

[hughie]

Jim,
Thanks for the pricing, I have not had to buy any for some time ...several years in fact, and generally dealt with larger Allen cap heads that tended to be expensive. Having an old jar full of various small sizes I just dive in and usually find what I need. But a time will come....

hughie

[haemish762]

Hey there, if you can find a reasonable engineering store, INVEST in an impact driver. Not one of those ones that runs off a compressor, but a hand held one. There have been many overtightened screws and nuts that have been freed by this device.
It's a must for any workshop, it saves a deal of hair loss!
Cheers Haemish

[hughie]

Haemish too late for the hair,its dunna runna already....sigh hughie

[Kirwilli]

Thanks for all the suggestions about the locked screw. I tried a number of them without success. Eventually I tried something new, at least I think its new. I silver soldered an allen key into the screw head, then gripped the key with a small shifter and low and behold the screw loosened. Had to be carefull that the flux did not run over the side of the head otherwise the solder could have flowed into the threads.

:) Henry