Author Topic: Learned something new about drill chucks today  (Read 230 times)

savarin

Learned something new about drill chucks today
« on: April 15, 2019, 04:00:40 AM »
I needed to transfer some holes in two pieces of stainless sheet so I placed the two disks together then to align the holes I used a length of 8mm stainless rod held in the drill chuck and set it in the top hole then clamped it all to the drill press table.
 Upon rotating the drill the rod prescribed a circle, I thought there must be bend in the rod so I quickly cut another, same problem.
 Argh, my reasonable new drill press is wearing already???. Possible 0.5mm out???
 Nope!
 I tightened the chuck with the key in one hole only as I always do then for some reason I  tried using all three holes and gradually tightened the chuck.
 Bingo, the rod is now perfectly centeredI have never noticed this with the drills before but I guess this is how I will tighten drills in the chuck from now on.

Carpenter84

Re: Learned something new about drill chucks today
« Reply #1 on: April 15, 2019, 06:24:56 AM »
Same has always gone for 3 jaw scroll chucks too. I have no idea why, but even some major precision guys (Stefan gotteswinter) has said the same.
Shawn

First 9x42 column mill,
Enterprise 10x28 lathe,
Ko Lee 6x12 surface grinder,
Airco dip/stick 160 welder,
Fully stocked wood shop.

f350ca

Re: Learned something new about drill chucks today
« Reply #2 on: April 15, 2019, 09:18:52 AM »
A good 3 yaw scroll chuck will have one pinion marked as the master. Apparently thats the one used at the factory when they grind the jaws, using it usually gives the best runout.

Greg

chips and more

Re: Learned something new about drill chucks today
« Reply #3 on: April 15, 2019, 11:48:31 AM »
Perhaps you have a bad and or worn chuck? What kind of chuck is it? Who made it?

Carpenter84

Re: Learned something new about drill chucks today
« Reply #4 on: April 15, 2019, 12:25:02 PM »
Could also have been some crud in the jaws too.

I suppose it does make sense.. if you use one key hole to tighten, it could cause the scroll or sleeve to canter over, pulling one or two jaws out of align. And when we're talking about thousands or even tenths run-out, it obviously doesn't take much movement to cause that. Tightening with all three holes maybe evens out the scroll or sleeve, or at takes up any play?

That works in my head, anyways...
Shawn

First 9x42 column mill,
Enterprise 10x28 lathe,
Ko Lee 6x12 surface grinder,
Airco dip/stick 160 welder,
Fully stocked wood shop.

4GSR

Re: Learned something new about drill chucks today
« Reply #5 on: April 15, 2019, 03:07:41 PM »
I've caught myself several times chucking up the drill bit on the sides of the jaw.  That'll throw you for loop!
Ken

Carpenter84

Re: Learned something new about drill chucks today
« Reply #6 on: April 15, 2019, 05:57:07 PM »
I do that ALL the time with my keyless chuck when going to a much smaller bit.
Shawn

First 9x42 column mill,
Enterprise 10x28 lathe,
Ko Lee 6x12 surface grinder,
Airco dip/stick 160 welder,
Fully stocked wood shop.

savarin

Re: Learned something new about drill chucks today
« Reply #7 on: April 16, 2019, 11:16:58 AM »
Its a good quality drill press and the chuck is spot on, its only around a year old at max (forgot when I purchased it)No crud, I experimented again and if only using one hole it can tighten very slightly out of centre but by using all three it tightens with no measurable runout.

chips and more

Re: Learned something new about drill chucks today
« Reply #8 on: April 16, 2019, 01:59:19 PM »
Sounds to me like your chuck guts have too much slop. If the drill chuck is all nice fitting inside, it should not do that and one hole to tighten will be adequate. Or, maybe is dirty inside and needs to be taken apart and cleaned?

Carpenter84

Re: Learned something new about drill chucks today
« Reply #9 on: April 16, 2019, 04:31:16 PM »
Would pressing the sleeve on a bit tighter potentially take out some of the play?

Or, if tightening the 3 holes gives you no measurable run out, I'm not sure I'd play with it at all! Having no run out on a drill chuck I think is quite an achievement. Small amount of effort, in my opinion.
Shawn

First 9x42 column mill,
Enterprise 10x28 lathe,
Ko Lee 6x12 surface grinder,
Airco dip/stick 160 welder,
Fully stocked wood shop.