On 2 August 2024 at 11:42 Hollowpoint Said:

Searching around the web for known brand ones has proved surprisingly difficult (R8 type).

What do you mean by or who do you include in ‘known brand’?

The Trump Organisation has a well-known brand identity but would be unlikely to sell R8 Jacobs taper arbors. And even if it did, do you value it as a brand?

As above, it is the seller reputation that matters more than the typeface and logo on the product.

On 2 August 2024 at 11:42 Hollowpoint Said:

…
So I have a few questions

Has anyone ever tested a bunch of cheap ones against branded ones?

Not as far as I know!

In you guys experience what would you consider good/acceptable runout? (No one advertises max runout!)

The run-out should be of the same order as the machine it’s plugged into.  Measure the run-out on your VMC spindle.   But, but, but remember twist drilling isn’t a precision operation.  Run-out may be the least of the problems!

Are branded ones worth the extra cost?

Probably not unless a unbranded one can’t be found to match the run-out of the mill.

More generally, have a think about what value is provided by a branded product.   Might just be a warm feeling it must be better.   Or bragging rights.  Or have features not needed in your workshop, such as being balanced to run at high-rpm, or toughened and hardened to take more horse-power than your mill can provide.    Good brand tools are likely to work out of the box, which is important in a “time-is-money” workshop, but much less so to “man-in-shed” who can send the odd dud back.   Extra reliability may not matter once we’ve reached three score and ten, at that age it seems daft to waste money on tools to last a lifetime!

I reiterate the point others have made about buying from reputable suppliers: brand names are often counterfeited.   Think twice before buying a £5,000 Rolex in a pub car-park!

Hollowpoint said “Naturally I have been trying to get the best I can afford.”   Sacking offence where I worked because engineers should never waste money.  Required to ditch lazy notions of ‘best’ and ‘quality’, and instead decide what ‘value for money’ and ‘good enough’ meant to the application.    There’s an escape clause for hobbyists and collectors, because buying ‘the best I can afford’, could be a valid part of the hobby’s fun and interest.   Just don’t confuse fun and interest with engineering!

Dave

If you want to put a number on it I just clocked the R8 one from ARC and at the top of the drill taper it is a whisker over 0.01mm runout but that is about the same as the R8 socket.

Don’t know what you get upto in your workshop and what your needs are but I have 3 drill chucks that regularly get used on ARC arbors (also ARC Chucks), MT3 in the lathe and another MT3 that is used on the X3. The R8 one flits between the SX2.7 and the CNC. Together they have been quite adequate for my needs and used to build over 50 model engines and in the case of the CNC seem happy spinning round at 5000rpm. Although the steam engines may be a bit more forgiving the, IC and Sterling engines need a bit more precision and all run OK.

I have used a fair number of drill chuck arbours, they have come from Arc, Zoro (Kennedy) and ones direct from China. They all perform well and there are no run out problems.

I strongly suspect they all come from the same factory. There are more important things to look out for when drilling, the arbours would be bottom of my list.

Andrew.

I would have thought that the obvious choice is an Accupro arbor to maintain the accuracy and quality of the item. Fitting a crappy arbor to such a quality chuck is rather like fitting a set of re-mould tyres to a F1 car.

As said, the same items are quite often made in the same facility.

(EXAMPLE

Sieg lathes are imported into UK by at least three different companies. The warranty or after sales back up may be the deternining factor for a major purchase such as this. There are variations!)

I have witnessed oil filters being manufactured, and then branded for a number of machine and engine manufacturers. So one brand name might be no different from another, just “What the traffic well bear” in terms of price.

Howard

On the “same” part coming out of the same factory and sold by different dealers it is important that the Chinese and Indian factories wil build to the quality that the dealer asks and adjust the price to suit. IT’s similar to MichaelG’s comment. The other thing that most subcontract manufacturers will do is if the customer asks for X items they price for X + Y or even X x Y This allows for wastage production failures etc. SOME wil then sell the extra items on the black market. This is not specific to the low cost far eastern companies.I have seen some do it with large excess to make additional profit.

My experience is mostly with small batch electronics but even then it happens.
I would typically tell a printed circuit board manufacturer  / assembler the minimum quantity I required but state that I’ll if they cost for a larger amount (may be to suit manufacturing batch size e.g. number of boards that will fit on a standard “panel” size as well) I will buy any excess that pass inspection. Gives my spares and saves waste.

Robert.

You didn’t say, but is that a keyed or key less chuck Hollowpoint?

Think about it logically (although it appears you already have) and how the tooling forms a chain between the fixed reference surface such as the spindle taper run out that you can’t do much about, and the cutting tip on any drill. There would be little point adding a much higher priced and more accurately ground arbor if the drill chuck itself might have .010″ / .025 mm or more of run out. You might reduce that by a small percent with a much better and very accurate arbor, but it would be almost meaningless. The reverse is also true, buying something like a very good Albrecht chuck and then adding the cheapest possible arbor probably isn’t going to work out very well. The exact same applies to the cutting tools themselves. Good enough for the task is good sense as someone else mentioned, but with that arbor, you can’t add or get any better accuracy later without regrinding or replacement. If your chuck does match it’s .04 mm claimed accuracy, that’s more than impressive. I wouldn’t settle for much less than the most accurate and precision ground arbor I could find. However I was under the impression that the Accupro brand was a MSC Industrial owned trademark, but I might be mistaken. In the U.S. MSC does show Accupro R8 drill chuck arbors. That still may not be worthwhile for you since they have our usual 7/16ths X 20 draw bar thread, and almost for sure your mill would use metric.

But chuck arbors are simple, and due to how the tapers would in most cases be completely ground in the same machine and during a single set up. A good brand name arbor should be fairly easy to grind to a very high degree of accuracy. I personally wouldn’t accept even .001″ / .025 mm run out for use with any decent chuck. A few .0001″ or thousandth’s of a mm would be more like it. But the amount of measurable run out is still only one item on that arbor, those taper angles and the close to exact match between the spindle, chuck and the arbor are just as important. The metal quality, heat treating, accuracy of grinding, surface finish and costs of manufacturing in different locations are why there’s large differences in price. And I can pretty much guarantee there certainly not all being produced in a few off shore factories. Given some of today’s country of origin laws, those more reputable companies would be risking serious legal prosecution in some cases even trying that.

And it might be worth adding, how you initially seat that arbor into the chuck is also critical. Both need to be spotless and oil free. Install the arbor in the spindle, then retract the chuck jaws and place the end of the chuck against a piece of wood on either your mill vises bed or the table. Then use the spindle down feed handle on the mill head to start the arbor into the chucks taper. Retract the spindle and rotate it a bit while again using the down feed to slowly add more seating pressure during each partial rotation. I’d estimate I use at least 50 pounds or more of pressure on that quill feed handle before I consider the arbor is fully seated into the chuck. Tool tapers grip by both a slight wedging action as the mating parts very slightly expand or try to compress, and the frictional grip between both surfaces. The closer those surfaces match and the better the surface finish, then the better that grip will be. A chuck coming off or spinning on its arbor while under power usually results in non repairable damage for most of us. And as I mentioned, that chuck also needs to be pressed onto the arbor as squarely as possible. Yes both have those tapers, in theory they should automatically go together and be directly in line with each other. Except everything is built to a + – tolerance. Even a partial degree of misalignment and given the multiplication of the chuck length and the additional drill length used in it, any misalignment between the arbor and chuck tapers greatly increases the final amount of run out at the drill tip. So in my opinion, it seems worthwhile to use a bit of care when seating any chuck onto it’s arbor.

This would seem to suggest Accupro are made in South Korea

Note: __ I think this exhausts my interest in the matter, but someone else may wish to dig deeper:

https://www.prnewswire.com/news-releases/msc-expands-accupro-metalworking-portfolio-300072013.html

My reading of that ^^^ is that MSC uses Accupro as  ‘brand name’ for some of its higher-end products.

So our faith in the quality of the product relies upon MSC

… in much the same way as it does when we trust ARC

MichaelG.

Some places do know what the runout average is for their drill chucks. Just because its expensive does not always mean it is going to be concentric.

For home I went with a local supplier and bought the cnc version of the Vertex keyless chuck. Its a -13mm series. I also have a 3-16mm Jacobs chuck with a key, that I use for power tapping holes. Both are less than 0.03mm runout on the NT30 spindle. The cnc version comes with a pair of C spanners to tighten or loosen the chuck. It is also a more heavy duty style compared to the cheaper model that is a light duty one.

I also did get a cheapy from the Express place, that is for the smaller drills, it is a 0-6mm on a NT30 arbour, supplied by the same company. It is surprisingly good at less than 0.05mm on the range, and at 4mm is near 0. Reamer size for my pistons and conrods.

The expensive one that work got recently R8 for a Kondia mill is terrible.  You can see the wobble of the drill in it without needing an indicator on it. It still drills ok, but no one uses it for dowels or reaming. Only for clearance holes which is most of the drilling is anyway. The 40 year old Albrecht chucks are still the best at work .

With a lot of hobby mill spindles, they are often not as true as one might expect them to be. Mine at the nose is about 0.01mm runout at the front/bottom of the taper, but the other end inside, over the 50mm distance is out by 0.04mm to 0.05mm. It required to be corrected, which I was able to do at work on one of the bigger lathes and a steady rest.

Without the correction, no drill was ever going to be running true. I got my mill 2nd hand so was not in a position to get it replaced.

Some places, even allow you to buy a chuck and set it up and see what the runout is like. If not happy and all still looks new, will happily take it back or offer something different. Where it is made often is not the issue, it’s the quality of materials used and the quality of the manufactured parts. The better products also have replacement jaws available for instance and a manual showing how to open the chuck to replace the jaws.