Suitable tap for steel?

[sploo]

I've never used a tap and die set, but I'm facing the possibility of having to drill a hole in a chuck in order to remove it from an arbor (http://www.jacobschuck.com/drill-chuck-removal-guide).

I've seen advice that you can drill and tap a hole, and screw in a bolt in order to push out the arbor (instead of just drilling a hole and using a press). I'm assuming that the chuck will be made of steel (it's a Jacobs 34-06 (#06295)) and that I'd obviously need a tap suitable for the material.

There are loads of cheap HSS taps around (e.g. http://www.amazon.co.uk/Silverline-MS53 ... B000LFS22W) would that suffice, or do I need something a bit higher quality/harder material?

 

[paul-c]

hi sploo
personally i would say the set you are looking at will be fine if you are putting a thread in a block of cheese but a jacobs chuck will be a good quality steel. you would be better off deciding on the size you require and looking on ebay and buy a decent quality tap i.e. a dormer or skf tap set .
with a set you get
a first tap - this is tapered and only cuts a very shallow thread
a second tap - slightly deeper thread
and a final / bottom tap - the final thread with no taper (you can tap to the bottom of a blind hole)

remember to use cutting/threading compound and a set of quality taps will last you a lifetime.
best of luck paul-c

 

[CHJ]

• 
  1. What is the Jacobs chuck fitted to, is it the one on your pillar drill.
  2. Do you have a decent picture of the assembly.
  3. If not the pillar drill are you sure it is fitted to a taper and not screwed on.

If screwed on there could well be an internal locking screw (left hand thread)

For someone not familiar with using taps I might suggest that unless you are trying to repair an expensive power tool that has suffered an accident with the chuck, something like a standard Jacobs style chuck on a Morse taper shank would be cheaper to replace than buy a quality taps set with appropriate tapping drill.

 

[Hitch]

If you drill the chuck whilst its on the arbor, you would need to tap a very shallow blind hole, so would need a plug tap.

You cant have any thread in the arbor, or the screw begin to thread into that and hold it in place, rather than having the desired effect.

 

[porker]

I would have thought there was another (better) way of removing the chuck as suggested by CHJ.

Regarding taps, there aren't many cheap HSS taps about. Most are what are described as "High carbon steel" are not very good at making new threads. OK at cleaning up threads but in my experience that's about it. (There is nothing wrong with high carbon steel and there are plenty of good taps made with them, but unfortunately the cheap end of the market uses the term and 99% are poor). A Jacobs chuck is probably hardened steel and if so would be difficult to tap and drill.
If you do go this route buy a good make like Dormer or Presto. Places like Tracy tools sell them individually for about 4 quid each.

 

[woodpig]

You don't need to tap the hole, just support the chuck body and knock the arbour out with a drift and a hammer. That's what I did.

 

[dickm]

Be warned, if it's the JT taper on the end of the arbor into the chuck, they can be an absolute nightmare to remove. Not clear why they are so stubborn, but I've had to just give in on a couple of occasions when trying to do this. Looking round other forums, this seems to be recognised as quite a common phenomenon. In the OP's case, the advice to give in early and buy a new chuck plus arbor is probably the best, and might solve the runout problem on its own.

 

[xy mosian]

If it is the chuck you are trying to remove. Try a bolt fastened to the table with sufficient sticking up to grab with the chuck. Do the chuck grabbing bit with the table at a height which means the chuck is extended downwards before tightening. A couple of sharp taps of the vertical movement lever, upwards, might be sufficient shock to split the taper joint.
xy

 

[sploo]

Lots of great responses - many thanks.

To answer some of the questions - details (and a photo) are here: how-to-fix-the-wobble-on-my-drill-press-t89596.html

It's on a Jacobs A0206 2MT/6JT arbor.

Good point about the cost of a set of good taps vs the cost of a chuck/arbor. I think I'd be happy to fund a decent 6mm tap as I could see myself using it - other sizes not so much. I get the point about a bottom tap though.

Woodpig - there is a slot in the quill for a drift (got one on order) so I'm hoping I could take the chuck + arbor off the drill press; but actually I want to take the chuck off the arbor and see if the arbor itself is what's causing the runout problem I'm having.

I've got some Jacobs wedges on order. If they fail I'll try drilling the chuck (and pushing a bolt to remove the arbor), if that doesn't work I'll look into tapping the hole.

 

[xy mosian]

When you have the chuck arbor split from the quill. Trying dropping the arbor through a hole, progress being stopped by the back of the chuck. The shock might just do it.
xy

 

[Robbo3]

If you are anywhere near West Oxon, I have a drift & a 2MT reamer if you need to borrow them.

 

[sploo]

If you are anywhere near West Oxon, I have a drift & a 2MT reamer if you need to borrow them.

Thanks Robbo - I saw you'd sent that as an email titled "Drill Chuck" on Sunday, but there didn't seem to be any mechanism by which I could reply (it's not on the messages on my USER TOOLS on the forum).

I'm a bit further south east of you (Didcot area) but not far. Hopefully the bits I've ordered will do the job, but I've ordered a cheap drift, so if that fails I'll probably be asking for help :wink:

 

[sploo]

All, updates on the original thread: post971650.html#p971650

xy mosian - I did try the, err, "drop test" with no luck.

 

[Tortion-Stephen]

I am restoring a lovely old Meddings, the amount of arbour sticking out of the quill made folding wedges impractical, I drilled the centre (started at 2mm and then went up to 5mm and used a pin drift with the shoulder of the chuck 'cradled' in my engineering vice was able to punch the arbour our the back of the chuck quite easily onto a folded soft blanket.

As stated you'd probably need a blind/flat bottom tap, plus knowing the right depth to drill would be pretty hard.

Interesting side note, there is <0.1mm run out on the arbour when rotated in the quill (i.e. sometimes it registers 0, sometimes it bounces to 0.1mm on the gauge)- chuffed to bits at this!

Hope this helps.

 

[Eric The Viking]

Surely it's easier to drill through the flat (narrowest) end of the Morse taper than the chuck - would be a shame to damage it unnecessarily. once you've done that you can put some chunky fence wire through it, hang something heavy on the bottom under the bench, and repeat the drop/shock "test".

Personally I'd do that for starters, but also try to get PlusGas to penetrate on the Jacobs taper beforehand. It's the only properly effective releasing fluid I know (and plain liquid is much better and less messy than the silly aerosols). If that works, you'll need to clean the PG off the JT taper thoroughly before using it again - meths or carb cleaner. Otherwise it will keep coming undone!

E.

PS: It looks from the picture as though somebody/something clobbered the chuck sideways at some point, probably bending the Morse/JT adaptor at it's thinnest point. I'd separate chuck and taper, then try a new adaptor.

I didn't quite get your comment about a bit of the drill coming off - do you mean it's got a bigger Morse taper and an adaptor? They're usually M2, so is this M1-->M2 or even M2--M3? If there's an adaptor sleeve, that's not going to help the run-out!

In any case, MT2 to JT adaptors are cheap, as are even Rohm chucks from people like Chronos. It'd be well worth buying a new set, e.g. a good chuck for small drills, and testing that, in case it's the chuck+Morse taper that are at fault (which would be a great relief, I'd say!).

 

[woodpig]

Surely it's easier to drill through the flat (narrowest) end of the Morse taper than the chuck.

Not really, the tang on the arbour is normally pretty hard.

Drilling the back of the Chuck is also the method recommended by Jacobs, they should know! :wink:

 

[Tortion-Stephen]

Surely it's easier to drill through the flat (narrowest) end of the Morse taper than the chuck.

Not really, the tang on the arbour is normally pretty hard.

Drilling the back of the Chuck is also the method recommended by Jacobs, they should know! :wink:

On the Jacobs chuck on my drill it actually went quite easily.

 

[woodpig]

A guy I used to work with had a very nice Jacobs chuck with a damaged arbour. He tried everything (so he said!) to get the arbour out so he gave it to me. If you can get it out you can keep the chuck he said. I looked at the Jacobs site and it said to drill out the back of the chuck and drift it out, easy, and it was. My old drill has had a very nice chuck on it ever since! :lol:

 

[xy mosian]

All, updates on the original thread: post971650.html#p971650

xy mosian - I did try the, err, "drop test" with no luck.

Oh heck. Still no damage, no cost, and little effort.
xy