PDA

View Full Version : Drill bits slipping in chuck



Clareb
05-12-2011, 05:45 PM
I seem to be having problems drilling small holes in 0.5mm silver sheet. I am drilling by hand with a pin vice and a 0.6mm drill bit but when I put pressure on the pin vice the drill bit slides up straight away. I screw the pin vice really tightly to hold the drill bit and there is no movement until I put pressure on it. Has anyone got any ideas why it's doing it and what I can do as its never done it before

Dennis
05-12-2011, 06:37 PM
Hi Clare,

If you are using the right collet for this drill bit, the cross will close completely with the drill taken out and the collar tightened. If it passes that test, then the problem is only that with time it no longer screws up tightly enough by hand and you must give an extra little turn with pliers. Some DIY pliers with rough jaws are best, but be gentle or the threads of your pin vice will wear out.

These things are sent to try us all. Regards, Dennis.

mizgeorge
05-12-2011, 09:43 PM
Alternatively, switch to using a shank drill bit, which, at 2.3mm on the shank, might be a bit easier to keep hold of (and is longer too)

http://www.cooksongold.com/Jewellery-Tools/Busch-Shank-Drill-0.6mm-prcode-971-020

lilia
05-12-2011, 10:28 PM
I have the shank one, to be honest I find it much more difficult to control, due to bending of the thin part when pressing down. I now only use 'normal' 0.5 drill bits in my hand chuck, takes slightly longer, but a lot of control and no slipping or breaking of the drillbit.

mizgeorge
06-12-2011, 12:20 AM
I have the shank one, to be honest I find it much more difficult to control, due to bending of the thin part when pressing down. I now only use 'normal' 0.5 drill bits in my hand chuck, takes slightly longer, but a lot of control and no slipping or breaking of the drillbit.

If your bits are bending, then you're pressing too hard and they're not doing the job for you. Some cut lube helps a lot, and, rather like piercing, let the tool do the work.

lilia
06-12-2011, 03:43 PM
If your bits are bending, then you're pressing too hard and they're not doing the job for you. Some cut lube helps a lot, and, rather like piercing, let the tool do the work.

I don't put much pressure, but still a tiny bit a pressure is needed to keep the drill bit in the correct place. I don't use cut lube, as it seems to disappear so fast. Rio's own one is so much better.

Dennis
06-12-2011, 08:42 PM
A light mark with a centre punch, or a pit made with a small round burr should stop the drill from wandering. Once a drill snaps in your metal it can be awkward to get out again. Dennis.

mizgeorge
07-12-2011, 12:32 AM
If you do snap a bit in metal, I've found a strong, warm solution of alum works well to dissolve the bit out. Alum is also one of my favourite pickles.

pearlescence
09-12-2011, 09:48 AM
I drill pearls all the time with a 0.7mm drill bit up to a 1mm bit, using a normal and quite old 'put up shelves' drill. It sounds to me as if the chuck is not closing properly. Try using a big drill (the drill bit will look silly and minute) This will give you the speed, torque and inherent weight you seem to be lacking. The suggestion of making a small punch mark where you want to drill is good too, to stop the drill slipping.
These small drills will snap if you look at them, so a steady hand is needed - I hardly ever drill my thumb these days