fitting chuck to back plate, help needed

Investigator

H-M Supporter - Gold Member
H-M Supporter Gold Member
Joined
Jun 8, 2016
Messages
640
I recently purchased a Shars 4-jaw independent chuck (6 inch), and a 6" back plate to mount it on. I have a Logan 12" lathe with the 2-1/4 -8 threaded spindle. I ordered the back plate for a South Bend with the same threads. As you probably know it wont mount all the way onto the Logan, the unthreaded portionof the spindle is just a bit larger on the Logan compared to the South Bend. So, i need to bore that a little larger. I know I can mount it on the spindle backwards to do that. I also need to face the step for the chuck to mount.

My question is what type of metal is this? What SFM/RPM to turn it at and what speed to feed?
 
I recently purchased a Shars 4-jaw independent chuck (6 inch), and a 6" back plate to mount it on. I have a Logan 12" lathe with the 2-1/4 -8 threaded spindle. I ordered the back plate for a South Bend with the same threads. As you probably know it wont mount all the way onto the Logan, the unthreaded portionof the spindle is just a bit larger on the Logan compared to the South Bend. So, i need to bore that a little larger. I know I can mount it on the spindle backwards to do that. I also need to face the step for the chuck to mount.

My question is what type of metal is this? What SFM/RPM to turn it at and what speed to feed?
it's probably cast iron
 
All Shars backing plates are cast iron. They have a great techie who can help you. Just call and ask for technical info.
 
Most chucks plates like that are made of what the industry calls "semi-steel" which is really gray cast iron. The SFM is 60-80. You can use HSS or carbide. No oil during the cut. Some people use spray to keep the dust down. It's loaded with graphite and you will get filthy from it. I kinda hate working with it for that reason.


Ray
 
One way to deal with the dust from cast iron is to cover your ways: I have used aluminum foil which is cheap, conforms to the lathe bed
and won't hurt you if it gets caught in your chuck. Another possibility is to set up a shop vac to suck the chips away from the tool
as you're working. Makes cleanup easy.
 
If you use some galvanizerd steel from ducting, you can attache a couple of strong magnets to it. You'd be surprised at how much of the airborn dust it attracts!!! I place them on the ways with several magnets on the ends. about 16" by 8" with the magnets on the short ends, so I don;t magnetize my vee ways.
 
It's cast, and if you use a vacuum check to be sure the filter is in it. When I did one for myself, I noticed that mine had fallen off too late and the dust was EVERYWHERE.
 
It's cast, and if you use a vacuum check to be sure the filter is in it. When I did one for myself, I noticed that mine had fallen off too late and the dust was EVERYWHERE.

My wife would kill me!
 
Back
Top