Jumbo jaws - Vicmarc or Stronghold?

[Leo Van Der Loo]

I agree Bob. I have two sets of jumbo jaws and then spent big bucks on a Longworth chuck. All worked as long as I was supported by the tail stock as long as possible.
Then with the purchase of a Holdfast vacuum system with two chucks, my jumbo jaws and Longworth have been gathering dust. I realize the vacuum system may not hold everything but so far it's been my go to for finishing bowl bottoms.
The vacuum system is so much quicker to set up and far more secure. My opinion only.

Of course a rough turned bowl isn’t nice and round, but warped and your vacuum chuck doesn’t just fit to that warped bowl.

Now later when you have re-turned the bowl and it is nice on round and smooth, yes then your vacuum chuck will hold it,

it is the steps needed before it is nice and round that the Jumbo jaws prove their value by being able to hold oval and warped bowls

[carl mesaros]

Of course a rough turned bowl isn’t nice and round, but warped and your vacuum chuck doesn’t just fit to that warped bowl.

Now later when you have re-turned the bowl and it is nice on round and smooth, yes then your vacuum chuck will hold it,

it is the steps needed before it is nice and round that the Jumbo jaws prove their value by being able to hold oval and warped bowls

Very true Leo, but I usually remount my rough turned bowls using the original tenon, return the bow,l and then use the vacuum chuck to finish the bottom.

[John Beaver]

The Vicmarc buttons have convex and concave sides so you can use them for outside or inside mounts. Of course there is a good chance they both use the same thread sizes so you could always buy the buttons separately.

One thing to keep in mind. If you get the big jaws, you need a long wrench to reach down to tighten the jaws. The geared wrench for the Oneway may not reach so you could not spin it freely. You would have to go one turn at a time. It would be easier to get a long wrench for the Vicmarc.

[Leo Van Der Loo]

The Vicmarc buttons have convex and concave sides so you can use them for outside or inside mounts. Of course there is a good chance they both use the same thread sizes so you could always buy the buttons separately.

One thing to keep in mind. If you get the big jaws, you need a long wrench to reach down to tighten the jaws. The geared wrench for the Oneway may not reach so you could not spin it freely. You would have to go one turn at a time. It would be easier to get a long wrench for the Vicmarc.

The wrench of the Oneway Stronghold chuck does reach, even with my Mega Jumbo jaws John, only when I mount the extensions do I have to slide the crossbar through the wrench to keep on turning, still do not need to take the wrench out of the chuck

[Clint Baxter]

I have both and use them both. If either were available, (not already holding something), I gravitate to the Stronghold because of its buttons. The round rubber buttons are much easier on you should you ever contact them while turning. I got bit by the Vicmark squares, and prefer to avoid a reoccurrence. I still will use the Vicmark, but usually only when my Stronghold is otherwise occupied.

IIRC, the Vicmark has a little additional reach, which sometimes then gets the call as well.

Clint

[John Beaver]

Good to know Leo.
The standard Vicmarc key can be a little short at full extension of the jaws.

The wrench of the Oneway Stronghold chuck does reach, even with my Mega Jumbo jaws John, only when I mount the extensions do I have to slide the crossbar through the wrench to keep on turning, still do not need to take the wrench out of the chuck