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Hard turning?

scott-ak

New member
271668219_10228009469528604_3175573053818775486_n.jpg

Truck transmission parts. I need to make the long one shorter. All I've got are average carbide inserts. Any guidance to keep from fubaring this part would be appreciated
 

partsproduction

New member
Ceramic inserts, up to 60 Rc, not happy with interrupted cuts. 2000 FPM so the chip rises red and loops over turning darker before it hit's the lathe, around .010" max DOC and a fine feed, watch your insert nose, but they last quite a while.

Also, regular negative carbide inserts run around 100 FPM, still can't take deep cuts but still works under 50 Rc OK, of course the speed shouldn't make the light grayish blue.
I don't claim to know it all but these things seem to work well for me.
 

EmanuelGoldstein

Active member
Truck transmission parts. I need to make the long one shorter.
Just the cylindrical part at the top ? Should be a picnic. Tranny gears are normally carburized, use any old carbide, take off .050 or so on a side, and the core should be about 35 Rc. I usually nail it in one pass with negative rake. After that anything works.
 

Orange Vise

Active member
Just use carbide. Chances are you'll get through the whole job on one edge. Worst case two or three.

Carbide is plenty capable of hard turning. It's just not ideal for production applications.
 

Cole2534

Active member
Just use carbide. Chances are you'll get through the whole job on one edge. Worst case two or three.

Carbide is plenty capable of hard turning. It's just not ideal for production applications.
What sort of feed/speed should one start with?

Programmed via Mazatrol
 

Milland

Active member
What machine and workholding? It's one thing on a good, rigid CNC lathe, another on a "hobby grade" tool.
 

michiganbuck

Active member
You are going to lose the center with turning, so why not just grind it shorter.

Turn the part between centers if it has centers, then grind off the stub
 

scott-ak

New member
Carbide cut it just fine, it wasn't nearly as hard as I thot it would/should be. Recutting a taper to the internal spline was a pita.

Thanx
 








 
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