Set-tru chuck?

[Chris Mackey]

I have a Set-tru chuck on my Jet 13x40, it was on it when I got it. Really nice piece but occasionally drives me crazy. Curious what chuck people are using when doing their barrels?

Thanks
Chris

 

[LVLAaron]

Usually a 4 jaw. In the gunsmith forum you'll find a dozen interesting ideas to use an inboard spider.

 

[SKWERLZ]

I made spiders for both end of the headstock.

 

[Walt Krafft]

Set-true

 

[swd]

Buck Set Tru.

 

[Chris Mackey]

Here is my setup, not perfect, but all I know. This set-tru drives me crazy sometimes.

 

[WSnyder]

Here is my setup, not perfect, but all I know. This set-tru drives me crazy sometimes.

If those blocks are as flat (not radiused) as they appear they are not doing you any favors.

 

[Walt Krafft]

I don't see the adjustment screws on the chuck. Another picture of the chuck and its mounting to the spindle is needed. Your lathe is too small for a tbas imo. Those little blocks are not helping you.

 

[LVLAaron]

If you're going to gimbal the barrel around, you need to hold it differently in the chuck. Here are the "inserts" I use when I use a 4-jaw. It allows the outboard end to move. Looks like you're just bending things.

 

[Chris Mackey]

Thanks guys,

I’m headed out to Denver for few days, I’ll get couple pics of the adjustment screws, there is four but not 90 degrees apart, more like two and two.

So I’m bending the barrel with those little 1/2” blocks, hmmm. I had to remove the jaws to do my little ppc barrels, used to use copper wire between the first notches in the jaws, but that wouldn’t work with the jaws removed. Guess I gotta figure something better out.

thanks
Chris

 

[LVLAaron]

That chuck sounds weird... you can always put new adjustment screws in it 90 degrees apart.

 

[ridgeway]

It's the way Bison chucks are. No problems dialing in. My 2 cents...make yourself a spider with brass tipped 3/8 set screws or cap heads.

 

[LVLAaron]

With swivel tips!

(I sure wish these were available in fine thread)

McMaster-Carr

McMaster-Carr is the complete source for your plant with over 595,000 products. 98% of products ordered ship from stock and deliver same or next day.

www.mcmaster.com

 

[Tim Singleton]

Inboard spider for me

 

[Chris Mackey]

Couldn’t resist, woke up early and ran down shop to get pics before heading to airport.

 

[Walt Krafft]

The first thing I would do is a detail teardown and cleaning of the chuck. Check the face the chuck "slides on" to be sure it is perfectly square with the axis. Re-assemble with a light coat of grease on this surface. I snug the bolts that clamp the chuck to this plate so I can adjust it with the 4 screws. Having them at 90 degrees would be nice but yours will work. Stamp numbers on them to help you keep track when adjusting. I usually tighten the clamp bolts after I have it indicated in. Recheck after tightening. The narrow clamping area of just the master jaws, should be enough of a pivot imo.

 

[WSnyder]

I have a couple Bison set-tru’s and no problems dialing in with the non 90° adjustments. I also have a larger Yuasa set-tru for the big lathe with only three adjustment screws.

 

[LVLAaron]

.... but.... why are the set-true bolts like that?

 

[WSnyder]

^^^ with the Bison design in order to fit all the adjustable bits that’s the only place they’ll fit. Mby not ideal but seems to work just fine. I have a D1-5 Buck on the Nardini that’s 90° but in practice I don’t care one way or another, they both adjust just fine.

Edit: Got to thinking and it hit me so I went and took a look. The Buck design only has one scroll adjustment where the Bison has three (at least my two do). That’s the difference as to why the Bison are not 90°.

 

[LVLAaron]

Interesting. I do like that the adjustment hardware is big. I have a Buck 6 inch and the screws are kinda small...