Threading upside down

[Jim F]

I can't thread this way, yet. My chuck is threaded on the spindle and running it in reverse could cause it to come unloosened. I have plans to add a spindle collet adapter which will let me thread some things this way, but using a collet, but anything that requires a chuck is a risk.

I have not , or found evidence of a chuck un-threading. if installed properly.

 

[jwmay]

I guess I’ll have to study what you guys are explaining. If I flip the tool holder upside down, place it back on the far side of the compound, and run the spindle in reverse, then the insert will be broken off the holder as soon as it touches metal.

 

[LEEQ]

If you are cutting on the back side of the material, the tool is right side up not upside down

 

[LEEQ]

The machine is running reverse and feed is set to thread away from the chuck while the spindle is turning in reverse

 

[LEEQ]

One of the guys just posted a video on that method in this thread. Check it out

 

[MyLilMule]

I have not , or found evidence of a chuck un-threading. if installed properly.

"SAFETY WARNING.......Please exercise caution and use good judgement when running a machine with a true screw on chuck in reverse. Excessive spindle load with the machine in reverse could potentially unscrew your chuck causing damage and personal injury."

Maybe you just haven't seen as much as you think.

 

[Just for fun]

I use my internal threading bar upside down 16IR insert. Run the spindle in reverse, it works great.

 

[Parlo]

I use my internal threading bar upside down 16IR insert. Run the spindle in reverse, it works great.

And the insert automatically stays on centre.

 

[Just for fun]

I needed to center it just like any other cutter. I can get some better photos tomorrow if you like.

 

[Ischgl99]

I guess I’ll have to study what you guys are explaining. If I flip the tool holder upside down, place it back on the far side of the compound, and run the spindle in reverse, then the insert will be broken off the holder as soon as it touches metal.

You’re combining a couple different techniques in that sentence. When threading away from the chuck, you can either place the toolholder upside down and in the front of the work piece with the spindle in reverse. Or, place the toolholder behind the work piece and right side up with the spindle in reverse. If you get those mixed up, then yes you will break an insert.