Lathe steady rest roller fingers?

[wonderwolf]

I ended up getting the 10 pack of bearings I linked above shipped for $7.50, that's 3 complete change overs with a spare. I'll update my progress when I go on vacation here in 2 weeks....planning on doing a lot of turning in that time

[John Taylor]

I bought my bearings from Enco before they went to MSC. Now the price seems a bit high. To reduce chatter, don't have any radius on the cutting tool. I use carbide inserts and grind the end to get rid of the radius, ( diamond wheel ). With carbide you can run 5 times faster. If I'm doing more than one barrel at a time I will thread and chamber all barrels before doing the contour. Once the machine is set up for the taper I want, each barrel will get one end turned before changing the setup for turning the other end. I have had as many as 25 barrels all the same at one time. First step is to turn all the barrel down to about .050" over what the finish size will be at the chamber end. Most barrels I get will be 1.2" ( GM) or 1.25" in diameter but Douglas barrels are usually 1.315".

[Chill Wills]

Have you made any progress on this?
I am getting closer to do something too.
I could likely make these or close and have $50 in change but that is just one more project in the way of doing what I really want to do.... chamber some barrels.

[Stockcarver]

Think way out of the box. I made this one over 30 years ago. Shazamm: Works like a 4 jaw chuck.

[Chill Wills]

Nice!
I would have no Idea where to start.

[wonderwolf]

I have the bearings in hand and materials are inbound from my metal place.....Vacation starts for me tomorrow when I get off work so hopefully I can have the finger bearings done by the end of the weekend and get caught up on my backlog of projects that need them to go forward.

[john.k]

Stockcravers idea of an auxilliary bearing requires two opposed bearings with adjustment,ball bearings are best because accuracy is much better than tapered rollers.A single bearing has internal clearance and causes chatter.Unless you spend hundreds/thousands on hi spec bearings.Lots of people say only three screws are needed to centre a barrel,but the next time they always go for four.

[Stockcarver]

Stockcravers idea of an auxilliary bearing requires two opposed bearings with adjustment,ball bearings are best because accuracy is much better than tapered rollers.A single bearing has internal clearance and causes chatter.Unless you spend hundreds/thousands on hi spec bearings.Lots of people say only three screws are needed to centre a barrel,but the next time they always go for four.

Look close. The housing is an old Babbitt pillow block that has been bored out. There is a precision angular contact ball bearing in each side of the housing. The hollow spindle goes through both. Note the SKF bearing adjust nut and tabbed lock washer. This thing is tighter and with less run out than most metal lathes. Yep, the bearings are opposed.

4 set screws are real easy when dialing in the barrel true to the bore. Just like a 4 jaw chuck.

Note the brass shims used in aligning the spindle to the lathe centerline. Alignment was a bit of a chore, you have to be good with dial indicators and precision alignment.



T handle used to adjust the setscrews. The top and bottom of the ship channel are machined true.

[Stockcarver]

Nice!
I would have no Idea where to start.

I started with an idea, then a few pencil sketches. Checked the junk boxes in the machine shop for parts. After a few revisions to suit the material found, it was just simple machining.

[john.k]

When you are a beginner ,you have too little stuff.After 50 years in engineering,you have too much stuff.Unfortunately all my super accurate machines were also super big,so they are now all sitting in a field or in shipping containers.Im left behind by 24/7 shops and robots.

[Chill Wills]

I started with an idea, then a few pencil sketches. Checked the junk boxes in the machine shop for parts. After a few revisions to suit the material found, it was just simple machining.

Yup. I'll get right on it.

[nekshot]

awesome! Now I have a way to get around my unimats tighter bore than I like. I often thought of doing something like this now I know it will work. This site sure is good to me!! Stockcarver, thanks for the pictures along with your project.

[Chill Wills]

I have the bearings in hand and materials are inbound from my metal place.....Vacation starts for me tomorrow when I get off work so hopefully I can have the finger bearings done by the end of the weekend and get caught up on my backlog of projects that need them to go forward.

Okay. If you want to post a picture and how building it worked out, I would be interested.

[country gent]

We had one similar to the bearing set up shown above. It used 2 big tapered roller bearings with adjustable end caps so the bearing play could be adjusted to set end play and bearing clearance. The tube had a shoulder the bearings were pressed against setting distance/spacing. The caps were a fine thread with a lock and end play could be set fairly quickly. Set cap snug and back off 1/4 turn then repeat on other side. This one ran with 90 weight gear lube lubricating the bearings in a resivoir. Final settings could be made to it running. A lot of your better load carrying live centers use tapered roller bearings and a needle roller in between. On rollers watch for heat build up when running as this will destroy lube and then the bearings.

[john.k]

I have found that ordinary" good quality" taper roller bearings have a repeating runout corresponding to the rotation of the cage.This runout is typically 1/2 thou.If this is acceptable,then OK.Ball bearings of good quality have much less runout,and in a selection of 10 SKF ,you can usually find one or two with a tenth.But any bearings must be paired with adjustment.,grease is good enough lube unless high rotational speeds or heavy loads are required.

[wonderwolf]

All done, here is where I ended up at

https://wonderwolfs.blogspot.com/201...ollers-or.html

[EDG]

Ball bearings are built with many different standards of precision. (ABEC PRECISION GRADES) You can get a review at W bergs web site or PIC or Stock Drive Products.
Ihave about 10,000 hours running engine lathes. We never messed with rollers. On delicate work we wrapped a strip of nylon around the work piece and clamped the ends under the gap in the steady rest frame. We applied way lube to the work piece and nylon interface. The fingers of the rest had the nylon strap between them and the work piece. The fingers were adjusted as normal. Easier to do than descfibe. That was 50 years ago.