Lathing question.....

[Firstgear]

If I have a 7/8” diameter, 36” long bar and I need to turn down about 10” or so to 3/4”, is the best thing to do is face one end and put a center drill into it and then use my live center to support it and machine it down? Or do I also need to line up the spider on the bar prior to facing off the one end? Operation steps?

 

[mmcmdl]

Face , center drill and turn . If you need to , turn it in 2 set-ups if you get chatter . ( turning 5" at at each set-up )

Edit . Not knowing what size lathe you have , you may need that spider for rear support . Watch your rpms and check out the " Bar whip thread " .

 

[Firstgear]

Face , center drill and turn . If you need to , turn it in 2 set-ups if you get chatter . ( turning 5" at at each set-up )

When do I cut it off the 36” length?

 

[mmcmdl]

Ah ..............you could cut it to length first and face and c drill both ends , then use a center in your 3 jaw and live center in the tailstock . Use a drive dog . Flip it and repeat .

Or turn the 10 inches to diameter and cut it off the bar .

 

[Firstgear]

26” overhanging the back side seems like a lot......

 

[Firstgear]

Ah ..............you could cut it to length first and face and c drill both ends , then use a center in your 3 jaw and live center in the tailstock . Use a drive dog .

Or turn the 10 inches to diameter and cut it off the bar .

Drive dog?

 

[mmcmdl]

6” overhanging the back side seems like a lot......

Look up at #2 post !

A lathe dog . Drive dog . Clamp it on your shaft and drive it with the chuck .

 

[Firstgear]

Ok....I have a PM1440GS......

 

[mmcmdl]

I don't know PM machines , 14 x 40 ?

Why can't you just cut the bar first to maybe 11"s , chuck it and turn it ? Then saw it or part it off to 10" .

 

[Firstgear]

Bar whip.....after watching the video in that posting, not be something I soon forget! I need to get that band saw sooner than later!