Recomendations for a Keyless Chuck?

[SteviegtrParticipant @steviegtr]

Posted by Emgee on 31/12/2021 00:34:16:

In the picture posted by Steviegtr of the 1-16mm chuck if the arbor is fitted to the chuck then I would be concerned with the amount of clearance between the back of the chuck and the spindle.
Seems to me the diameter of the taper is too large at the big end.

Emgee

Emgee i will fit the chuck into the MT2 of the Tom senior & post a pic. You may be right. Never noticed that before.

Steve.

[Roger BestParticipant @rogerbest89007]

The arc chuck arrived Saturday, 13mm is a good compromise and they were in stock. I also got some bits and pieces to complement my improved drilling capability. Sunday was my birthday and the cheque from my Mum covered it, so I could say she bought me something specific and wanted even if she doesn't understand the attraction.

I will have a play when I can get into the workshop, it needs some serious tidying, and the house is worse!

The arc catalogue is terrific, it seems so much easier and impressive than their website, very helpful.

[Roger BestParticipant @rogerbest89007]

mmm I might have got something wrong. The tapers don't fit very well but it took me a while to work that out.

A quick video:

How do I get the chuck and arbour apart?

[EmgeeParticipant @emgee]

Posted by Roger Best on 15/01/2022 21:20:52:

mmm I might have got something wrong. The tapers don't fit very well but it took me a while to work that out.

A quick video:

How do I get the chuck and arbour apart?

A pair of split taper wedges to suit the arbor diameter at the back of the chuck.
ARC list them.

Emgee

[JasonBModerator @jasonb]

About what you could expect from a £150 Rohm chuck, these are all 0.05 runout.

Albright High Precision would  be 0.04mm runout and cost £275

So I would say save your money on the wedges

 

Edited By JasonB on 16/01/2022 08:00:27

[Tony Pratt 1Participant @tonypratt1]

The chuck does seem too far off the taper BUT as Jason B says the runout is about right for a drill chuck, less runout if you strike lucky at the price.

Tony

[JourneymanParticipant @journeyman]

Yes, looking at the video the chuck does seem to be a long way down the the taper (guessing B16) . I don't think a pair of chuck removal wedges will be much help as there is too much gap between the ridge in the arbor and the back of the chuck. You would have to make a 'thick pair'.

John

[EmgeeParticipant @emgee]

Posted by Journeyman on 16/01/2022 09:35:39:

Yes, looking at the video the chuck does seem to be a long way down the the taper (guessing B16) . I don't think a pair of chuck removal wedges will be much help as there is too much gap between the ridge in the arbor and the back of the chuck. You would have to make a 'thick pair'.

John

Or use a split packing piece of the required thickness to allow the wedges to enter.

Emgee

[Roger BestParticipant @rogerbest89007]

Thanks Emgee, I couldn't find those either on the website or catalogue.

I didn't jam it on tight it should pull off.

I will check dimensions against info here:

tools-n-gizmos

[JasonBModerator @jasonb]

From measurements of my own one it is the male taper that is a bit long beyond the gauge dia.

Gauge dia for B16 is 15.773mm

As best I can measure on mine against the back of the chuck it is 15.71mm

So that is a difference of 0.023mm

After a bit of trig if the gauge were spot on that would only allow the taper to go a further 0.4mm in. Which is far less than can be seen.

On no standards can I see a requirement for the length of taper beyond the gauge dia.

[Douglas JohnstonParticipant @douglasjohnston98463]

I have collected a few keyless ones over the years. Most are of the cheap type and all have worked well, but I did splash out and buy an Albrecht one with integral R8 arbor about ten years ago . The Albrecht one was on special offer at the time and cost about £100 but I have never regretted the purchase since it is so nice to use. There is something about quality tools that keep on giving joy long after you have forgotten the price.

Doug

[DiogenesIIParticipant @diogenesii]

..after talking about drills the other day, I think Rotagrip sells a B16 chuck wedge tool, but about £17

If your arbor has a drawbar hole, sometimes a loose weight on a drawbar used it like a slide hammer will jar the arbor out if it hasn't been on for long – drill a hole big enough for the arbor in a block of some solid wood to 'back' the chuck.. ..remember the chuck will fall somewhere once it comes off..

[Roger BestParticipant @rogerbest89007]

Thanks guys.

I only pushed the chuck on by hand and it hadn't been used so it came off easily with a tiny slide-hammer action. Bragging rights to DiogenesII.

I measured the arbour diameter and its oversize, 16.0 v 15.7, chuck seems OK size-wise, so I have sent an e-mail with pictures to the vendor and hopefully we can speak tomorrow and they can say what they want me to do with it.

Not being properly seated would account for much of the excess run-out over the fancy chucks, its a matter of leverage and we are talking microns. That's great.

Edited By Roger Best on 16/01/2022 20:24:14

[JasonBModerator @jasonb]

That sounds rather large, are you measuring it in the right place?

I have a couple here and the measure 16mm at the largest part of the taper but that is NOT where you measure. The dimension is at the gauge length which in the case of B16 is 24mm up from the end.

What runout are you expecting? I've already linked to the fact the £25 chuck is showing to be within the spec of a £175 Rohm top of their range or only just outside a £250 Albright.

[Ketan SwaliParticipant @ketanswali79440]

Hi Roger,

Ian will review your email when he comes in, and he will get back to you.

Just reading this thread (without site of your email), I would suggest that both the chuck and arbor are fine, regardless of expectation for the price in comparison with expensive Rohm or Albrecht chucks.

We sell both products on a daily basis… mainly to industrial users, as well as certain blue chip trade re-sellers, without complaint. We know the factory from where we have purchased the chucks from, and we know the factory from where we have purchased the arbors from. Apart from the odd Friday afternoon product, we are comfortable with the consistency of our supply. However, I will let Ian review your email and get back to you.

With regard to getting into detailed discussion on the subject on here, this is all I will say:

About ten years ago, my team, John Stevenson (who passed away in 2017) and I spent over a year checking keyless chucks from 5 different factories. There are three grades of Chinese keyless chucks. There is high precision – used for CNC (P), Heavy Duty (H), and General (G).

Our findings were as follows:

• Some factories sampling fialed to reach any of the specifications they specified.
• Some factories only offered us G grade.
• Two factories offered us all three grades, and we chose to test the P and H grades only.
• P grade failed all around on the SIEG machines on which we tested them, and we found that the run-out was worse that the H grade.
• We even had a batch of P grade which we returned to the factory as they failed on run-out.
• Tests on our machines included using silvers steel, known turned reference stock, reference stock supplied by the keyless factory for testing, 6mm and 10mm. These were checked at 15mm and 25mm away from where they were held in the chuck. These were checked by hand rotation, as well as at low speed. The chucks were loosened, the stock was moved by hand inside the chuck, so that the jaws could be tightened in a different position. Then the chucks were checked again for run-out. These checks were done on three different machines.
• Results were different on every machine. Variable factors taken into consideration… spindle run-out, distance from end of spindle to the point at which the round stock was checked, arbor fit to the spindle, JT/B taper fit to the keyless chuck, and one or two other elements which I may have forgotten.
• Results on the keyless chuck factories test rigs were also different to the results we were finding when fitted to the SIEG, as well as Johns and certain other peoples machines.
• An average was taken, and we finally settled on the factory we use use, with the H grade. It happens to be the most expensive, but at the same time the smallest factory (in terms of production run), from the five factories we tested.
• It would still be wrong for me to set a reference for comparison against Rohm chuck because:
  • there are too many variables involved as mentioned above
  • we do not buy the arbor with chuck pre-assembled at the factory
  • our results differ from rests on the keyless chuck factories test rig

We are not prepared to purchase and supply chucks pre-assembled with arbors from ANY factory. Reasons are:

a. non of the factories we tested, including the keyless chuck factory we use make their own arbor.

b. the quality/grade of the material used for the arbor in the pre-assembled units can be variable.

c. the accuracy of the material used for the arbor in the pre-assembled units can be variable.

d. the cost of the arbor from the factory where we buy the arbor is more expensive than the cost of the arbor supplied by the keyless chuck factory, and we cannot be certain of the source.

d. we do not want to keep pre-assembled stock of products…. as this would mean we would have to keep more stock.

We have purchased and supplied the same consistent quality of arbors from one specified factory for over 20 years. The return rate is next to zero.

Chuck removal wedges: For jacob style chucks – they are slim wedges. Albrecht wedges are very thick.. I am guessing because some of their chucks may fit with a bigger gap… but I cannot say for sure.

If the tapers have been mated correctly – i.e. male and female cleaned out to remove the transit oil, and press fit correctly/hard enough (and not by hand only), the resulting run-out is considered to be reasonable for the chucks and arbors we sell. Again, it would be wrong for me to get into results of the tests, as well as any detailed discussion on this over this forum, due to all the assembly variables involved.

Also a note: depending on type of use, the keyless chucks can also tighten and jam.. including Rohm/Albrecht or any other keyless chucks. If mail/female tapers were not cleaned before assembly, they will mark the mating tapers and change accuracy. Using hammers to dismount chucks from tapers can also result in the same problem.

This is a matter for Roger to discuss with Ian and conclude.

Ketan at ARC.

[Ketan SwaliParticipant @ketanswali79440]

Here are some rough and ready pictures:

This picture is same as the keyless chuck you purchased, hand assembled:

Rough measurement of the gap:

Measurement of the gap after hitting (shocking) the arbor into the chuck with blow hammer… not ideal method, but just done for the purpose of these pictures:

Overall picture of an Albrecht chuck removal wedge:

Close-up:

Albrecht chuck removal wedge in gap. The assemble is usually held in the mill, and a sharp blow with a blow hammer is used to separate the mating tapers. Picture just taken to show it in the gap (not usually used at an angle for removal). Usually held at 90 degrees… but good possibility of marking the arbor or the chuck, depending on how long the assembly has been in place…. more difficult to take off after longer period of time..

Forgot to add… thickness of Albrecht wedge:

Ketan at ARC.

Edited By Ketan Swali on 17/01/2022 10:29:51

[Tony Pratt 1Participant @tonypratt1]

Ketan, Interesting & informative read as I like all things engineering.

Tony

[JourneymanParticipant @journeyman]

Interesting, I always thought that chuck removal wedges were used as a pair so that they remain parallel to both the arbor shoulder and the back of the chuck and avoid bending forces.

I had a look at my collection of chucks and on many of these the back of the chuck is quite a way from shoulder in the arbor probably not such a large gap as the OP's but wouldn't work with standard (thin) chuck removal wedges without packing but would brobably be OK with the Albrecht ones.

John

[egaParticipant @ega]

One advantage of the standard keyed chuck is that the body can be drilled and tapped for a jack-off screw; the same hole can then be used for a (smaller) retaining screw.

[Tony Pratt 1Participant @tonypratt1]

Posted by Journeyman on 17/01/2022 11:42:38:

Interesting, I always thought that chuck removal wedges were used as a pair so that they remain parallel to both the arbor shoulder and the back of the chuck and avoid bending forces.

I had a look at my collection of chucks and on many of these the back of the chuck is quite a way from shoulder in the arbor probably not such a large gap as the OP's but wouldn't work with standard (thin) chuck removal wedges without packing but would brobably be OK with the Albrecht ones.

John

They are used as pairs, much better engineering.

Tony

[Ketan SwaliParticipant @ketanswali79440]

Posted by Tony Pratt 1 on 17/01/2022 12:36:23:

Posted by Journeyman on 17/01/2022 11:42:38:

Interesting, I always thought that chuck removal wedges were used as a pair so that they remain parallel to both the arbor shoulder and the back of the chuck and avoid bending forces.

I had a look at my collection of chucks and on many of these the back of the chuck is quite a way from shoulder in the arbor probably not such a large gap as the OP's but wouldn't work with standard (thin) chuck removal wedges without packing but would brobably be OK with the Albrecht ones.

John

They are used as pairs, much better engineering.

Tony

The Jacobs style 'thin wedges' are sold and used in pairs.

I have observed the thick Albrecht ones being used as singles as well as pairs. Although it feels better for the Albrecht ones (or any other) to be used as pairs, sometimes these wedges are too thick at the slimmest part to fit into the gap in between the chuck and the arbor. I guess it depends on the application.

Many moons ago we purchased the Albrecht ones for use in our own workshop (now mothballed) in singles rather than pairs. We also used pairs of the jacobs slim style, and we made a few of our own… all depending on application.

We stopped selling the slim wedges a couple of years ago after the maker closed down.

Ketan at ARC

[Ketan SwaliParticipant @ketanswali79440]

The reason why we had different wedges in our workshop was for the purpose checking different chucks on arbors.

Question for those who may know: In normal use environment, why would people need these wedge/s?, unless the JT/B taper is a permanent part of the spindle, or the wedge/s are being used in a muti-tool type assembly… such as the one used in a multi-purpose live centre set.

I mean, once the chuck and arbor are assembled correctly, why should there be a need to take the assembly apart?. If the chuck becomes faulty over time, it should be cheap enough nowadays to buy both the chuck and arbor NEW, doing away with any damage when taking the assembly apart.

Ketan at ARC

[JasonBModerator @jasonb]

Posted by Ketan Swali on 17/01/2022 15:41:42:

it should be cheap enough nowadays to buy both the chuck and arbor NEW, doing away with any damage when taking the assembly apart.

You should know by now how deep the pockets of many model engineers are compared to the length of their arms, they would rather spend £5 on a pair of wedges than £6 on a new arbor Either that or spend 3months contemplating and finally making a pair of wedges.

I see in an Albrecht catalogue they show their tool (not described as a wedge) being used as you show with a lever action.

[Rod RenshawParticipant @rodrenshaw28584]

Ketan

Sometimes the male taper is formed directly on the end of a machine spindle, eg drilling machine spindle, and if the chuck becomes faulty the wedges are used to remove the chuck ready to replace it with a new one.

Rod

[Ketan SwaliParticipant @ketanswali79440]

Posted by Rod Renshaw on 17/01/2022 15:48:49:

Ketan

Sometimes the male taper is formed directly on the end of a machine spindle, eg drilling machine spindle, and if the chuck becomes faulty the wedges are used to remove the chuck ready to replace it with a new one.

Rod

Ahh I see. I am familiar with the JT/B taper being a part of the spindle, where the wedges become essential… as is the case in a SIEG X0 mill.

As I am not too familiar with drilling machine spindles, I failed to take that thought into consideration.

Thank you Rod… learned something new (to me) today.

Ketan at ARC

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