Keyless Drill Chuck

I have a very old 0-8mm Rohm Supra, (MT2) made in West Germany, so that was before the wall came down. Still very accurate, easy to use with self tightening mechanism.This has a JT0 taper so I don't think the JT2S will be a problem.

Keyless chucks can be of such variable quality, I have a keyless chuck with my Chester V20 mill that was supplied with it when new, it appears to be of very good quality it has performed faultlessly. I also have a Bosch Hammer Drill, not cordless, and the keyless chuck as fitted to that is awful, it is impossible to use the hammer facility the chuck just comes undone, so frustrating. Dave W

Dave

Keyless chucks for ordinary drills are very different animals to those used on proper workshop machines.

The proper type self tighten under load and loosen slightly, basically just enough to let you undo the thing, when the load is removed. Any attempt to use one like that on a hammer drill will cause it to undo instantly.

Ordinary drill style keyless chucks are just cheap hand tightened versions of the familiar keyed chuck slight geometrical differences that allegedly give a small degree of extra grip under load. Never seen any evidence for the self tightening myself.

If one of those is to stay tight when used with a hammer drill it must have locking facility otherwise the hammer action vibrates it undone very quickly. Some have an extra ring to engage the lock, some just go "click, I'm locked" when you securely hand tighten them. All the ones I've used are of the latter type, none have been very good. Makita cordless standard fare are good for about 4 holes when new but rapidly deteriorate. Mine are down to something between 1/2 and 1 1/2 holes in hammer. So I got a compact Makita battery cordless SDS drill, type DRH242Z, and never looked back. Affordable if you already have batteries.

Clive

Isn’t that why the SDS type of drilling machines were developed?

I bought last year the most expensive professional keyless chuck from Paulimot Germany because I didn;t want to wait long. I is the worst piece of shi..... I have in my shop. Has a +0.1 mm runout above 8 mm diameter, the holding force is terrible, the taper is terrible, and it can't be used for tapping because in reverse the tap get lose.

My best drill chuck is a 30+ years old abused chuck from Röhm. The 13 mm keyless Röhm metal drill chuck on a €55 Lidl cordless drill is better than most drill chucks I have.

What you should buy, depends on what you need. I bought a 16 mm MT3 drill chuck from Paulimot for €8,-- that was advertised as "runout out of tolerance" and I use it to hold my tapping holder, great buy.

Playing devils advocate~ have you considered a keyed chuck?

You don't say what machine it is intended to use this with but for your typical mini lathe/ mill i'd go with a keyed chuck any day~those keyless ones take up half the bed length on a small lathe!

Never owned a really good quality keyless but comparing like for like, a budget Rohm keyed tightens much better than a budget Rohm keyless IMHO.

Plus think of the endless amusement you'll miss out on not having to search for the chuck key.

That is why I use keyed chucks with cutters fitted (practically) permanently with my lathe. centre drill and small/large centre drills are in my “Quick change chuck” set. It is quicker to change the chuck than change the item secured within it.

These keyed chucks are old, reliable units and I can store the chuck keys where they won’t get lost! The keyless chuck is quickly and easily fitted for drilling.

As an aside, how much does run-out affect a chuck in the tailstock of a lathe? Rotating chucks, as in pillar drill or mill are a different consideration… but usually only result in larger holes than expected - which assumes perfect drilling machine and bits as well.

I agree with Vic on that thread. Why make a chuck with a JTS taper that you can't find an arbor for?

If there's source out there for a No.3 MT (M12) JTS arbor, please let me know. I haven't found one yet. Rotagrip don't have one.

Having failed to source an MT3/JTS Arbor for the Rotagrip Vertex 1 - 10mm KDC, I'm now looking at their "Porta" variants.

They offer the Porta 0 - 10mm KDC's with either B12 or B16 mounting. Although both are the same capacity, why the two different sizes?

Cost isn't the issue, but what do I gain with the B16, which is a larger chuck, but the same capacity?

The B12 is for people with an existing B12 arbor, the B16 for those with a B16 one?

The B16 chuck has a thicker shaft and is more rigid.

The B16 chuck has a longer clamping length and is more suitable for clamping end mills that have a Weldon shaft (flat area on the shaft)