Pillar Drill Chuck Keeps Dropping Off ?

[ukracer]

Done, I used a block of wood on the table and lowered the chuck onto it a few times, the jaws were withdrawn inside the chuck body.

I am undecided if I should just "go for it" and try the 11mm hole without 4mm pilot or go back to the 4mm pilot scaling up to 11mm now that I have cleaned up the taper and chuck. The 540rpm lowest speed restrictance with the drill is leaning me towards the 4mm pilot then the 11mm. I think if I "go for it" at 540rpm for the 11mm hole without 4mm pilot hole I have a high chance of blunting the bit?

Rgds

I would use a 4mm pilot as an 11mm drill will find it hard to make a start and start rubbing. Thereby blunting the drill. I am guessing you are pecking rather than holding constant pressure. A drill should be cutting or it will be blunting itself.

 

[rikrobson]

is this a different chuck to the one that was supplied with the drill? It could be its got the incorrect taper on if its a replacement.

 

[ukracer]

How the he'll are you multitasking.

As for the OP if you can get a morse reamer you could gently clean it up inside.

Looks like it was only me reading it wrong...lol

 

[hotrodder]

I'm lost through not knowing what a morse fitting is. The taper is in my eyes male and the chuck just slides onto it. In the manual it says the spindle type is JT6. The tapered part that the chuck slides onto is approximately 2 inches long.

JT6 is a Jacobs taper, one of several tapers used on chucks. Morse tapers are a different shape, larger drill presses usually have a female morse taper in the spindle and chucks are mounted on an arbor which look like



Because of the way morse tapers work* it's quick and simple to swap chucks or put the chuck aside and fit MT drills directly into the machine. Smaller machines like yours have a solid spindle with a male taper on the end to accept the chuck

* In theory once a JT is assembled you need chuck+removal+wedges to get the thing apart, morse tapers however are designed with quick removal in mind and use a larger drift that's more difficult to lose (or they can even be self ejecting on posher machines)

 

[brightspark]

do what I did 20 years ago. clean the taper with fine emery cloth put some Loctite in and tap it on with a copper hammer . leave for a day and its going nowhere

 

[rikrobson]

still could be the wrong taper on the chuck.
http://littlemachineshop.com/reference/tapers.php

 

[penfold]

I don't see how, there are no overlaps in the jacobs taper series.

 

[Kent]

To big a pilot drill Imo. At 11mm I should just cut the grind in and go straight in on the centre pop unless it was high precision in which case a smaller pilot.
I should certainly run faster especially on 5mm Ms.
Cleaning the tapers is good, whacking with a mallet is bad! . Block of wood on the table and a few firm draw downs onto a tightly closed chuck.

 

[The Coal Man]

Update:

All seems to be working OK now after cleaning the taper and seating the chuck by descending it onto a block of wood on the table. I drilled 8 x 11mm holes using the De Walt Extreme2 HSS-G drill bit without drilling a 4mm pilot hole. I had no chuck slippage or stalling and no instances of it falling off. I kept backing up the drill bit to apply a squirt of coolant and eveything proceeded OK.

Many thanks to you all for your help, most appreciated.

Rgds