Stronghold chuck question

[Trevor Mills]

I just bought a stronghold chuck and discovered that Oneway doesn't number their jaw sets. I have faith in Oneway products but I'm curious why other high end chuck manufacturers like Vicmarc number their jaws and Oneway doesn't. Can anyone offer an explanation?

[Brice Rogers]

In theory, the best machining of the jaws would require that they be ground on the chuck while in both an expansion or compression mode. But I kind of doubt that they do that. I base this on the following: I bought a chuck with numbered jaws and also an extra set of larger jaws (which came shipped separately) with numbers. There is a miniscule (or less) chance that the larger jaws ever saw the chuck before they delivered it to me.

On a metal lathe, often times the back of the jaws directly connect with the scroll. In that case, you need to know which jaw is which otherwise you can be off as much as 3/4 of the scoll pitch (maybe 0.150").

The only benefit of having numbered jaws on a wood lathe chuck - - as far as I can reasonably understand - - is that if you unscrew the jaws and re-attach them that you go back to the original position.

I suppose that if someone had a bit too much runout that they could try swapping jaws (even though the number matches would mean anything).

Just my own thoughts....

[Olaf Vogel]

I think that in theory, the numbering makes sense.

In practice, when you tighten the jaws, it will compress some of the wood fibres. The amount of compression likely is larger than any difference in the jaws diameter.

(That being said, I have had issues when clamping steel bars - trying to turn my own jackshafts, which might have been due to this issue, obviously steel doesn't compress as well as wood. But there were many other possible factors.)

My two sets of Strongholds and multiple jaws, both have had a ton of use / abuse and they have been great.
The occasional cleaning with compressed air and some spray silicone is all they need.

Enjoy them

[Peter Blair]

I too have just purchased my second Stronghold chuck and noted the jaws were not marked as well. I can understand that they are not marked because they are not machined on the chuck I bought as I bought a second set of jaws as well. I like to put them back in the same place so I always move them to the alternate side and test for runout and then mark them related to the slides at the best position. One must be careful because the jaw with the stop pin is usually installed in the shorter slot to ensure the slides remain within the body of the chuck for safety of turners but I usually place them where they are most aligned regardless of the extension. I just use a center punch and mark with dots. My beef is that the new chuck will not operate with my old key and vice versa. Just what I needed was a 4th key . . . . .

[Leo Van Der Loo]

I just bought a stronghold chuck and discovered that Oneway doesn't number their jaw sets. I have faith in Oneway products but I'm curious why other high end chuck manufacturers like Vicmarc number their jaws and Oneway doesn't. Can anyone offer an explanation?

Because with the precision that the Oneway chucks and jaws are machined, the jaws can be placed at any position, I have several Oneway chucks, both Talon and Stronghold, and my first one is at least 20 years old, they are all as good now as when I bought them, I have never taken them apart, just blow them clean, I never spray finishes on the lathe, and wipe on my finish with the pieces out of the chuck.

Keeping the chuck clean is important for it to keep running true, the way I work, I will pick a chuck up and the first thing I do is blowing it clean, blow the lathe spindle and install the chuck, stick the key into the chuck and rotate it, if it feels tight, like there is some shavings that got in-between the jaw and slides, I will blow and rotate the chuck open and close the jaws till it feels free again, and this does happen, especially if drilled or turned through a piece, where the fine pieces of wood are flung outward and then can get in between there.

Since I hardly ever have to change jaws now, it is still the habit to check and blow every jaw clean before installing, a habit I learned a long time ago, making sure parts are clean before installing them, as you can get into all kinds of trouble if you didn’t do that

[Bob Bergstrom]

We had Stuart Batty demoing at our club using a Hurricane chuck. He really like the chuck and especially the wrench handle. He did however tighten up the #2 jaws as small as the would go and used one of his straight edged scrapers to face off the surface. He stated the importance of a flat face for the bowl blank to set on. Two of the jaws surfaces were were proud of the other two. If that procedure is done, then I would reason that when the jaws are removed they should be placed back in the same positions. It would be interesting if some members would check the jaw surfaces on their chucks are all in the same plane?

[Peter Blair]

Bob, thanks for this. I have been focused on the grip part not the face. I'll check my chucks at the first opportunity and report back!!

[Trevor Mills]

Bob, thanks for this. I have been focused on the grip part not the face. I'll check my chucks at the first opportunity and report back!!

I'm away from the shop for a week but I'll definitely check my Nova chucks and the new Oneway for flatness of the face. I've only ever focused on the grip as well. Is there a video of Stuart Batty levelling off the face of those Hurricane jaws?

[Bob Bergstrom]

I'm away from the shop for a week but I'll definitely check my Nova chucks and the new Oneway for flatness of the face. I've only ever focused on the grip as well. Is there a video of Stuart Batty levelling off the face of those Hurricane jaws?

It was a simple process. Close the jaws all the way. Set the tool rest perpendicular to the chuck face and the the scraper at center height. Use a scraper with a straight ground edge. Light move it back and forth across the face of the jaws. I suggest numbering the jaws if you ever remove them from the chuck or face them off again.

[Brice Rogers]

How badly was the scraper chewed up by cutting the steel?

It was a simple process. Close the jaws all the way. Set the tool rest perpendicular to the chuck face and the the scraper at center height. Use a scraper with a straight ground edge. Light move it back and forth across the face of the jaws. I suggest numbering the jaws if you ever remove them from the chuck or face them off again.

[Bob Bergstrom]

How badly was the scraper chewed up by cutting the steel?

I would think any high quality high speed steel one would work. The steel in the jaws is not hardened.

[Peter Blair]

I was in the shop yesterday and checked three chucks. Two Stronghold and a Nova. My test was far from scientific. For one thing I couldn't decide if I should check them with the jaws closed, jaws open, with a wood spigot in the jaws or about 20 other options. Not being a scientist or an engineer I decided I would want them to be set the best when they had a wood spigot installed. I should note that all have a small amount of fore and aft movement when not gripping anything and as a result I expect they would 'tip' a little when gripping something. The results were the same with all three. I found a 1 - 2.5 th difference in each set. Some varied across the face of the individual jaw. Because of my skill level and the different types of wood I use I am of the opinion that this much play will make very little difference to me.

[Bob Bergstrom]

I was in the shop yesterday and checked three chucks. Two Stronghold and a Nova. My test was far from scientific. For one thing I couldn't decide if I should check them with the jaws closed, jaws open, with a wood spigot in the jaws or about 20 other options. Not being a scientist or an engineer I decided I would want them to be set the best when they had a wood spigot installed. I should note that all have a small amount of fore and aft movement when not gripping anything and as a result I expect they would 'tip' a little when gripping something. The results were the same with all three. I found a 1 - 2.5 th difference in each set. Some varied across the face of the individual jaw. Because of my skill level and the different types of wood I use I am of the opinion that this much play will make very little difference to me.

Yes, I wouldn't think the majority of turners would notice the few thousands difference. He also discuss the advantage of dovetail jaws. He was making a heavey cut and pulled the blank out of the chuck? The tenon stayed in tact. He stated that if the jaws were serrated it would have snapped off the tenon. I have three Oneways with serrated jaws and have achieved both results. Just his thoughts.

[Alan Trout]

Yes, I wouldn't think the majority of turners would notice the few thousands difference. He also discuss the advantage of dovetail jaws. He was making a heavey cut and pulled the blank out of the chuck? The tenon stayed in tact. He stated that if the jaws were serrated it would have snapped off the tenon. I have three Oneways with serrated jaws and have achieved both results. Just his thoughts.

I started using the serrated jaws from Oneway for exactly the same reason he feels the dovetail is superior. I have even discussed it among many other things with Stu sitting at a bar drinking. With my mixed resin pieces using a dovetail as you tighten the jaws it pulls the dovetail at the shoulder/face and dovetail junction. With resin this will cause the dovetail to fracture at this junction and it will pull off. That is really scary when you have 75 or so hours in a piece before it hits the lathe. It does not do that with the serrated jaws. I have now come to where I prefer the serrated jaws for many reasons and have turned many large heavy pieces without issue over the years. I have used every major chuck available and they all work pretty well. If I had to I could live with any of them. Its just for what I turn the serrated jaws work best.

Alan

[Bob Bergstrom]

I started using the serrated jaws from Oneway for exactly the same reason he feels the dovetail is superior. I have even discussed it among many other things with Stu sitting at a bar drinking. With my mixed resin pieces using a dovetail as you tighten the jaws it pulls the dovetail at the shoulder/face and dovetail junction. With resin this will cause the dovetail to fracture at this junction and it will pull off. That is really scary when you have 75 or so hours in a piece before it hits the lathe. It does not do that with the serrated jaws. I have now come to where I prefer the serrated jaws for many reasons and have turned many large heavy pieces without issue over the years. I have used every major chuck available and they all work pretty well. If I had to I could live with any of them. Its just for what I turn the serrated jaws work best.

Alan

Well stated. Weather it's chucks, tools or technique, we all use what works for us.