Lathe chucks - What (not) to get?

[reible]

So just to make this clear. All of shopsmith arbors and the like have this about 3 degree tilt. Ed

Is this 3 degree taper on the spindle unique to Shopsmith? Is it like the large hole in the saw blades, not a technical innovation but a sales tool?

So far as I know the reverse taper is unique to shopsmith. It provides some added protection in that it will not allow saw blades/sanding disk/lathe chucks/ drill chucks to simple slip off the shaft if the set screw is loose, well at least until the set screw is way loose. This is in contrast to the simple flat that you find on pulley arrangements.

I worked as an engineer for my career and one of the things that happens in any field are incremental "improvements". One of those was something called peer reviews where the other engineers and management would see a design before it was released. Evaluations as to most every aspect would be looked at and at some point a meeting of the "minds" would happen with either of three results. One being there were no issues and the design was done or two, it needed some changes and when they were done it was done. The worst was the third case where changes were extensive enough to have to go back through the whole process again.

If this design of the tapered spindle had come to me for review I would have signed off on it. So my opinion is as it is.

Now the large bore is one that I would have signed off on back then when it first started because of the steel blades of the time. If you didn't have to live through those days it is hard to explain but having a flat blade was a big deal. Now those days are gone, the blades they make are not only flat but with the tooth designs and damping designed in I think the need for that arbor size on a shopsmith are gone. My 12" miter saw has a large arbor and that is not uncommon with 12" blades but 10" blades.........

I don't buy the large arbor blades so there is my endorsement or lack of it.

Ed

[rudy49]

Thanks for the feedback. I checked the adapter and found I mis-stated the description. It is indeed as you describe.

[rudy49]

Not wishing to be contrary, but I recently purchased a Nova G3 chuck, with 3 accessory jaws from Woodcraft for $149. I purchased a 5/8 to 0 adapter for $30. The adapter works very well.

SS makes great equipment and materials at a good price but sometimes better deals are out there.

Larry

Add on the cost of the pin jaws that Shopsmith bundles before you compare the total price. I followed G3 prices on Amazon, eBay, etc. for quite a while. The best deal was the bundle from Shopsmith when they ran one of their periodic specials, and that's when I pulled the trigger. You need to sign up for their email specials, though, or the SS deals are easy to miss.

This set came with the pin jaws, jaws that grip the rim of bowl to finish the bottom of the bowl, a smaller set of jaws that I haven't tried yet.

Larry

[jsburger]

So just to make this clear. All of shopsmith arbors and the like have this about 3 degree tilt. You can and should see this even with your allen wrench each and every time you take thing on and off. I had noticed this many many moons ago and when I first address this some people here were not believers. The truth is out there and you can prove it to yourself.

Pull out the set screw and insert a bolt of the same thread size the is several inches long. Now look at it. Below is an example.

The attachment DSCF3496sc.jpg is no longer available

See I'm not crazy.

Ed

I hope you don't think I thought you were crazy because it is not true. Having owned SS for over 20 years I never noticed. However, I stand corrected! I did say in my original post that the angled set screw made perfect sense.

OK so when did the angled set screw show up? I don't believe is was a Magna design. If you look at the first picture all the Magna items have straight set screws. The chuck in the lower left is a Jacobs 3326 that came with the 10 E/ER. The second picture is a Jacobs 33B with an adapter that came with the first model 10 SS's. It too has a straight set screw. I have model 10 sanding disks in the garage 10 but did not check them. Does anyone with a 10ER have a problem with the set screws not being angled?

Now, here is the kicker. I checked all my MK V arbors (I think I have all that SS made/makes) and they all have the angled set screw except for the drill chuck. You can see that in the first picture. The drill chuck in the upper right is the chuck that came with my brand new MK V 510 in 1994 and is labeled SS.

I read the thread someone here linked to from 2012 about the Nova SS adapter and the non angled set screw. Two or three people including you Ed had problems with the set screw loosening but many others apparently did not.

Here is another thing. All the arbors I have with the angled set screw have a set screw with a rounded end. It appears to me that the amount of contact with the shaft will be the same regardless of weather the screw is 90* to the arbor or 3* tilted. Can someone explain why this would not be true?

[charlese]

THIS IS A CORRECTION FOR A POST EARLIER:
Had an opportunity to use my chuck today. It does have a slanted set screw!!! It is a TALON chuck made by ONE WAY and purchased from Shopsmith several years ago.

[BuckeyeDennis]

So just to make this clear. All of shopsmith arbors and the like have this about 3 degree tilt. You can and should see this even with your allen wrench each and every time you take thing on and off. I had noticed this many many moons ago and when I first address this some people here were not believers. The truth is out there and you can prove it to yourself.

Pull out the set screw and insert a bolt of the same thread size the is several inches long. Now look at it. Below is an example.

The attachment DSCF3496sc.jpg is no longer available

See I'm not crazy.

Ed

I hope you don't think I thought you were crazy because it is not true. Having owned SS for over 20 years I never noticed. However, I stand corrected! I did say in my original post that the angled set screw made perfect sense.

OK so when did the angled set screw show up? I don't believe is was a Magna design. If you look at the first picture all the Magna items have straight set screws. The chuck in the lower left is a Jacobs 3326 that came with the 10 E/ER. The second picture is a Jacobs 33B with an adapter that came with the first model 10 SS's. It too has a straight set screw. I have model 10 sanding disks in the garage 10 but did not check them. Does anyone with a 10ER have a problem with the set screws not being angled?

Now, here is the kicker. I checked all my MK V arbors (I think I have all that SS made/makes) and they all have the angled set screw except for the drill chuck. You can see that in the first picture. The drill chuck in the upper right is the chuck that came with my brand new MK V 510 in 1994 and is labeled SS.

I read the thread someone here linked to from 2012 about the Nova SS adapter and the non angled set screw. Two or three people including you Ed had problems with the set screw loosening but many others apparently did not.

Here is another thing. All the arbors I have with the angled set screw have a set screw with a rounded end. It appears to me that the amount of contact with the shaft will be the same regardless of weather the screw is 90* to the arbor or 3* tilted. Can someone explain why this would not be true?

I believe that the advantage of the angled set screw is that the contact patch against the tapered flat is symmetrical about the axis of the set screw. With a non-tilted set-screw, the set screw will engage off-axis on the flat, toward the front of the taper. So as you tighten it, the set screw will tend to rotate the arbor on the spindle, and the set screw may "walk" the arbor off the center of the flat. I could see this reducing the holding power, if the arbor sees torque applied in the opposite direction.

Now that I think about it, the torque applied if on the main spindle would be in the no-problem direction. But on a Mark V Aux spindle, the usual torque would want to loosen it. Since 10E/R's don't have an Aux spindle, it may have never been an issue with them.

BTW, I lucked into a Starret #359 Universal Bevel Protractor in a goody box that came with my 10ER. It's just like the one in the photo below, except an earlier vintage. These are accurate to 1/12 degree. After cleaning it and carefully calibrating it against a precision straight edge, and then testing it at 90 degrees against machinist squares, I used it to measure the angle of the flats on three of my SS spindles. Mark V 520, Power Station, and 10ER. All three were dead-on at 2.5 degrees.

image.jpeg (73.17 KiB) Viewed 5917 times

[JPG]

. . .

Here is another thing. All the arbors I have with the angled set screw have a set screw with a rounded end. It appears to me that the amount of contact with the shaft will be the same regardless of weather the screw is 90* to the arbor or 3* tilted. Can someone explain why this would not be true?

It is indeed true and the REASON for the oval end rather than a flat end.

A flat end and 2.5° taper would NOT be as stable as the oval end. The flat screw and the flat shaft has greater contact area, but no safety margin re walking off the shaft.

[jsburger]

. . .

Here is another thing. All the arbors I have with the angled set screw have a set screw with a rounded end. It appears to me that the amount of contact with the shaft will be the same regardless of weather the screw is 90* to the arbor or 3* tilted. Can someone explain why this would not be true?

It is indeed true and the REASON for the oval end rather than a flat end.

A flat end and 2.5° taper would NOT be as stable as the oval end. The flat screw and the flat shaft has greater contact area, but no safety margin re walking off the shaft.

This is my thinking exactly. However, it still brings me to another question. If we agree (and I think you did) that a round end set screw has the same amount of contact with the tapered shaft regardless of weather it's hole is tilted or square then why go to the trouble of tilting it? If the set screw being used was flat on the end then the tilted hole makes perfect sense.

The 10ER arbors I looked at all have straight holes and cup (square) end set screws. The set screws all have the rim of the cup deformed only over bnout 45* or so of the diameter of the rim. That is exactly as it should be given a tapered flat and a 90* hole.

[reible]

"Here is another thing. All the arbors I have with the angled set screw have a set screw with a rounded end."

Or do they?

IMG_0840sc.jpg (47.64 KiB) Viewed 5867 times

Now I have no knowledge of when the angle was added. If you say the 10 series did not have it fine, but at some point it was changed. Did it have anything to do with a problem they found and corrected? Well you don't normally make things more complicated because it is a Tuesday. Anything to do with the law suit? More to the point the people at shopsmith decided to make this the law of the land for shopsmith product at some point in time and which ever company it was at the time.

Now for the record my problem was never with the Nova product. The chuck I got back in 10 or so years ago had the set screw at an angle and has never come loose. There was a time when shopsmith/nova were shipping the wrong adapter and for what ever reason that was we don't know. We do know that both nova and shopsmith corrected the issue and replaced the adapters so it was important enough to do so.

For me I feel that if I want to stake my life and limb on a project with a 5 pound hunk of wood spinning around at 1500 rpm anything that can be done to make is safer is a good thing. So I think we have over stayed our welcome on this thread with set-screw talk.

Ed

[tomsalwasser]

So far as I know the reverse taper is unique to shopsmith. It provides some added protection in that it will not allow saw blades/sanding disk/lathe chucks/ drill chucks to simple slip off the shaft if the set screw is loose, well at least until the set screw is way loose. This is in contrast to the simple flat that you find on pulley arrangements.

Now the large bore is one that I would have signed off on back then when it first started because of the steel blades of the time. If you didn't have to live through those days it is hard to explain but having a flat blade was a big deal. Ed

Thanks Ed. I learned something new here in both cases.