Pillar drill chuck falls off - replace spindle?

[Chris Puttick]

Hi

I have a Scheppach DP19 Vario which keeps dropping the chuck. No reflection on the general quality of the machine, it seems accurate enough and the various features work well (if I was being picky I'd have to say the rack and pinion mechanism has too much play although that might (also) be me setting it up badly).

Full disclosure - when assembling the drill I was in a bit of hurry to start using it to complete a project, so I didn't clean the spindle/chuck well. The initial symptoms were the bit catching in a piece and the chuck stopping but the spindle continuing to turn, and then the chuck dropping off when it was raised. I have since used degreaser on the chuck and spindle, but the spindle has score marks; tried removing those with fine file and abrasive pad and then cleaning again, but the problem is getting worse - with a heavy bit (Starrett 18mm hole saw) it drops off more or less as soon as the drill starts.

I'm assuming the spindle (or chuck?) is no longer fit for purpose - but before I spring for a new spindle is there anything else I can try?

Thanks

Chris
T

 

[ChaiLatte]

Scribble over the male part of the taper with a marker pen. Install the chuck lightly (ideally a new one, but the existing one will suffice) and rotate it gently. Remove the chuck and look at the male taper. The ink will be removed from the high spots. Dress those down and repeat the process until you either get bored or you have full contact.

For what it costs, I would try loctiting the chuck onto the spindle. Warm the chuck before you install it as then it will shrink slightly when it cools and grip harder. Thump it a little with a rubber mallet when you install it.

If it still falls off after that, as you say, a new spindle and chuck might be in order.

 

[Sideways]

Torque and vibration are the enemies of the morse taper join between chuck and spindle.
Side loads creating vibration without a decent end load to keep the taper snug are also a recipe for morse taper shanks falling out of the spindle.
Forstners, saw tooth hole cutters and flat bits are all problematic because their diameters require higher torque and because of the vibration caused as they alternately cut with the grain and cross grain unless drilling end grain.
As @ChaiLatte advises above then make sure the morse taper is seated firmly not just lightly pressed home.

 

[Fergie 307]

Does it have a hollow spindle? If it does then you might be able to get a threaded chuck adaptor and use a draw bar. Or just weld a suitable piece of threaded rod to the end of the existing chuck arbour. An oilstone would be better than a file for dressing any high spots.

 

[ChaiLatte]

Torque and vibration are the enemies of the Morse taper join between chuck and spindle.

The drill press he has (Scheppach DP19) does not have a Morse taper. I took his post to mean the chuck is separating from the Jacobs (possibly not Jacobs, but instead B-taper because it is a European machine) which is integral with the spindle.

I would be hugely embarassed if someone used loctite on a Morse taper as a result of any misunderstanding.

 

[MorrisWoodman12]

Scribble over the male part of the taper ................

.........Warm the chuck before you install it as then it will shrink slightly when it cools and grip harder. Thump it a little with a rubber mallet when you install it.

Surely if it's a male taper you want to cool it so it shrinks. It will expand as it warms and then when fitted the taper grip will loosen when it's cooled. Perhaps it's better being cooled so it expands after it's fitted. Of course I know very little about these matters.................
Have fun
Martin

 

[Sideways]

I would be hugely embarassed if someone used loctite on a Morse taper as a result of any mimisunderstanding.

Erk !
Me too

 

[Phil Pascoe]

Surely if it's a male taper you want to cool it so it shrinks. It will expand as it warms and then when fitted the taper grip will loosen when it's cooled. Perhaps it's better being cooled so it expands after it's fitted. Of course I know very little about these matters.................
Have fun
Martin

Yes, that's why he said warm the chuck, not warm the taper.

 

[ChaiLatte]

Surely if it's a male taper you want to cool it so it shrinks.

I think the taper in the chuck itself is female. The Jacobs taper on the spindle is male.

It is a lot easier to take a chuck somewhere, warm it up and carry it quickly back to the machine than other options.

You are right. If you had some dry ice, you could put some in a plastic container and immerse the male taper end of the spindle in it.

 

[MorrisWoodman12]

Yes, that's why he said warm the chuck, not warm the taper.

Ah! My mistake. I assumed (i.e. made an ass of me!) the taper was rigidly fixed to the chuck and it was the taper-spindle interface not the taper-chuck one.

 

[robgul]

The chuck fell off my Scheppac drill the other day for no apparent reason - I just pushed I back on and gave it a tap with a soft-faced hammer to help it on its way up the taper - so far so good.

 

[Chris Puttick]

The chuck fell off my Scheppac drill the other day for no apparent reason - I just pushed I back on and gave it a tap with a soft-faced hammer to help it on its way up the taper - so far so good.

That's how it started for me, now it falls off under the weight of a heavy bit... I'll be trying the spindle fixes today, will add in the heat the chuck before fitment method. But if all else fails the part number is 5906820019 direct from Scheppach (I couldn't find a UK parts supplier).

 

[ChaiLatte]

But if all else fails the part number is 5906820019 direct from Scheppach

It would be prudent to spring for a new chuck if you are going to buy a new spindle.

Right now, both spindle and chuck are suspect and putting a (possibly malformed) chuck onto a new spindle might then damage the shiny new part.