Have you ever tried this?

GunsOfNavarone said:
If I could figure out a way to mount a cut off tool from backside of my g0602, I'd be all over that.
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When I made my 6 bolt compound clamp for the 602, I also modified the cross slide by adding 6 more holes to the rear, along with the central bore for the compound. I had to set the the three oilers so they were below the surface of the cross slide as well. I can move my compound 4.5" to the rear which gives me more than enough travel for operations from the back side of the lathe.
 
The t-slots are a HUGE perk, and yes, I have been aware of the upside down backwards technique as long as I have owned a lathe. I can say, since I installed an ELS on my lathe, I can thread away from the chuck, I guess I’m so used to doing it the other way, I’m a bit apprehensive to change. Yes, that’s dumb…
 
I totally respect Joe Pieczynski and value his videos. He did make two misstatements in the video though. First, at 2:20, he said that running an even pitch thread, you can use any mark on the thread dial and for an odd pitch thread you can only engage on the numbered marks. Second,at 5:10, he said that if the lead screw is turning in the same direction as the spindle, you will cut a right hand thread and if it is turning in the opposite direction, you will cut a left hand thread.

My Grizzly G0602 has a 12 tpi lead screw and a left hand thread so my lead screw turns opposite to the spindle for cutting a right hand thread and turning in the same direction will cut a left hand thread.

My thread dial has 12 marks on it so I have different rules of engagement. I can cut any thread pitch divisible by three using any any mark on the dial. For whole integer threads, I engage on every third mark (1,4,7,10 or 2,5,8,11 or 3,6,9,12). For half integer threads like 11-1/2 tpi, I engage on every sixth mark.

The point is that there are multiple configurations which can be used and the user should always refer back to the operator's manual rather than accepting sweeping generic statements. I learned quite early in life the adding "always" or "never" to a statement is a red flag. (Oops, I used always in the sentence above!)
 

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RJSakowski said:
My thread dial has 12 marks on it so I have different rules of engagement. I can cut any thread pitch divisible by three using any any mark on the dial. For whole integer threads, I engage on every third mark (1,4,7,10 or 2,5,8,11 or 3,6,9,12). For half integer threads like 11-1/2 tpi, I engage on every sixth mark.
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I have a hard time remembering these rules and it's different again when cutting metric threads so I just leave the half nuts engaged the whole time when cutting threads. Of course, that means I have to stop the spindle, back out the cross slide, reverse to the beginning, cross slide in, advance the compound and repeat until the thread is done. Like others, I'm still not convinced it's a good idea to invert the tool and have the forces trying to lift the carriage.
 
Inverting the tool also puts all the cutting forces on the clamping screws rather than the floor of the tool holder. You could of course, remove the adjustment nuts and mount the tool holder upside down. Cutting from the backside presents different concerns. For my 602, it means moving the compound assembly to the rear of the cross slide which is a lot of fussing if only cutting a single thread. The compound also has to orient in its conventional position as the backsplash prevents rotating 180º. This can be an issue if using the tailstock for support of the work. I tried both and decided to just use traditional methods. So far, my reflexes are still up to the task.
 
I really hadn't taken into account the internal structure of the compound/cross slide. I can see upside down cutting for threading, very little load, and cut off, again light load, but for heavy stock removal, normal procedures should be observed/used.

I was day-dreaming, I guess, Back to daily life. And yes, and ELS (electronic lead screw) would be perfect on these gear-change-required lathes.

One last note, Yes, I can cut .100 deep at .007 feed in normal mode. I wouldn't have thought the lathe would do it.

Thanks for straightening me out.
 
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