Question for Milgunsmith

Zebra13

Member
Milgunsmith,

In the "Anyone know what this is" thread, which the author deleted, you stated you would "line bore" the opening on the lathe if you were making a bearing type steady rest. Can you explain how you would do this? I can't figger it out...

Thanks,
Justin
 
Line Boring

First you need to make a line boreing tool, this is a large diameter bar that is held in the lathe chuck and supported by the tailstock center. There is an adjustable cutter perpendicular to the bar that will cut the final dimensions. The Bearing support has to be fitted to the ways and the hole roughly machined out. Then the bar is put thru the hole and the lathe carriage set up to push the bearing support on the ways past the spinning cutter for each pass. There is a good series ov videos on YouTube showing the basic idea, just adapt. http://www.youtube.com/watch?v=cUH6VJHFi5w
The boring bar is shorter since you only need to machine an inch or so. You could also use a standard mill boring head in the lathe headstock and just push the bearing support along the ways.
 
Line Boring

First you need to make a line boreing tool, this is a large diameter bar that is held in the lathe chuck and supported by the tailstock center. There is an adjustable cutter perpendicular to the bar that will cut the final dimensions. The Bearing support has to be fitted to the ways and the hole roughly machined out. Then the bar is put thru the hole and the lathe carriage set up to push the bearing support on the ways past the spinning cutter for each pass. There is a good series ov videos on YouTube showing the basic idea, just adapt. http://www.youtube.com/watch?v=cUH6VJHFi5w
The boring bar is shorter since you only need to machine an inch or so. You could also use a standard mill boring head in the lathe headstock and just push the bearing support along the ways.

Why would you have to line bore...????.....Isn`t the thing adjustable..???? ...Like a tailstock spider...
 
First you need to make a line boreing tool, this is a large diameter bar that is held in the lathe chuck and supported by the tailstock center. There is an adjustable cutter perpendicular to the bar that will cut the final dimensions. The Bearing support has to be fitted to the ways and the hole roughly machined out. Then the bar is put thru the hole and the lathe carriage set up to push the bearing support on the ways past the spinning cutter for each pass. There is a good series ov videos on YouTube showing the basic idea, just adapt. http://www.youtube.com/watch?v=cUH6VJHFi5w
The boring bar is shorter since you only need to machine an inch or so. You could also use a standard mill boring head in the lathe headstock and just push the bearing support along the ways.

Milgunsmith,

Thanks. I had thought of using a boring head in the chuck, but was unaware of the line boring tool. I couldn't figger' out how you moved the work into the cutting tool. When you push the bearing support forward with the carriage, how do you keep it dead-nuts vertical so as to get a straight hole?

Justin
 
You can rig up a angle plate from the compound to help hold it. As every lathe is different, there is no set of plans for that.

The reason for boring it is that the bearing has to be dead nuts on line with the spindle, then use the adjustment bolts to dial the barrel's bore in.
 
Another consideration if you are going to turn faster than 200 RPMs

You might want to take your center bearing/cathead and have them balanced in a motor balancing shop. You don't need any unnecessary vibration.
Some companies will come to your shop and balance your equipment on site.
Nat Lambeth
 
putting ball bearing on the steady rest fingers.

Not exactly the same, but I was thinking of modifying my conventional steady rest to run on the small ball bearings that are used on wood router bits. My thought is these bearings are commonly available & run at a gazillion rpm on the router bits, so they must be pretty good on runout. Has anyone else done this?

Regards,
Ron
 
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