Is upgrading to a Röhm chuck worth it on a Chinese lathe?

[Choiliefan]

This may have already been mentioned but some of the better chucks have a "set-tru" feature which enables the chuck body to be fine-tuned to the diameter of the bar stock in its grip. My Rohm and older Yuasa chucks have this feature. The famous "Buck Chuck" may have been the first to offer this long time ago.

 

[ChazzC]

This may have already been mentioned but some of the better chucks have a "set-tru" feature which enables the chuck body to be fine-tuned to the diameter of the bar stock in its grip. My Rohm and older Yuasa chucks have this feature. The famous "Buck Chuck" may have been the first to offer this long time ago.

If you machine the boss on the backing plate slightly smaller than the register on the back of the chuck you can achieve the same effect by loosening the mounting bolts on the chuck, tapping the chuck until you have the desired concentricity and then tightening the bolts.

 

[RaisedByWolves]

Less runout, Repeatability and better holding power are all likely possibilities. Reducing vibration and chatter I would not think is likely to happen from a chuck switch unless what you have is really worn out. Rohm is good stuff.

Steve, the peas in your aviator are upside down.

 

[Cadillac STS]

Can you remove the chuck altogether and run it? May help figure out where your vibration is coming from. Gears, bearings, worn drive belt, loose motor mount?

 

[RickKr]

If you machine the boss on the backing plate slightly smaller than the register on the back of the chuck you can achieve the same effect by loosening the mounting bolts on the chuck, tapping the chuck until you have the desired concentricity and then tightening the bolts.

I did this with a Grizzly 7x12 minilathe I had over 20 yrs ago, but took it a big step further by machining and backplate that had the adjusting screws to turn a 4" Bison 3-jaw chuck into and adjustable chuck. Impetus was an article in Metalworking, The Best of Projects in Metal, Book One, titled "Greater Precision for Scroll Chucks" by Richard Torgersen. I wrote an article about it some years ago, which is attached. It could be adjusted to within .0001" TIR at the jaws.

Photos below are of another similar adjustable backplate that I made for an import 3-jaw chuck for a different lathe. The last photo shows it mounted in the chuck of a larger lathe, but it is the only shot I have of it from the front.

 

[coolidge]

Edit: Wrong chuck discussion obviously lol

 

[G-ManBart]

This may have already been mentioned but some of the better chucks have a "set-tru" feature which enables the chuck body to be fine-tuned to the diameter of the bar stock in its grip. My Rohm and older Yuasa chucks have this feature. The famous "Buck Chuck" may have been the first to offer this long time ago.

That feature has expanded to much less expensive chucks as well now. I've put several San Ou brand "adjustable structure" 3J chucks on several different lathes and they are every bit as accurate/repeatable as the expensive Buck, Bison and Pratt Burnerd adjustable/set-true style chucks I have for a fraction of the cost. The only real downside is they only offer them in a couple of sizes right now....210mm and 167mm so roughly 8-1/4" and 6-1/2" chucks. They run $229 and $169 before shipping from CME Tools which is the original importer...luckily they're local for me so I just pick them up there.

 

[seasicksteve]

Steve, the peas in your aviator are upside down.

Wow I didnt think anyone would notice Good eye

 

[Cadillac STS]

If you get a brand new chuck take the back cover off to see what it looks like inside. For mine there was just a squirt of grease (2 inch long 1/4 inch wide squirt) in there meaning most of the metal parts had no lubrication until time and use worked the grease through. What I did was take completely apart and clean all parts with brake cleaner. Then I got a little tub of Bison chuck grease to put it back together with.

Mine was a low price Asian made one. Came with an oversized cast iron backplate to be mounted on the spindle first then cut down with tools on that lathe until it had a perfect fit for the new chuck. It works great.