Single point threading with the LatheMaster.....not so good!March 29 2012 at 10:30 AM
Ed Canoles (Login nced1)
Response to Nice thing about my old Grizz...
I ground a 60 degree "threading bit", changed the gears for a 1.5mm pitch, set the compound to 29 degrees, squared the bit to the stock, zero'd out the cross slide with the point touching the stock, moved the saddle to clear the stock, advanced the compound 2 thou, engaged the half nut when the threading dial got to "5", then watched as the bit made a light and perfect 1.5mm cut. I was a bit disappointed when the half nut wouldn't engage the lead screw till the dial got a bit past the "5" but the first cut was nice. I backed out the cross slide to clear the stock, re-zero'd the cross slide, advanced the compound a couple more thou, engaged the half nut when the pointer got to "5", however this time the half nut engaged the lead screw thread a bit before "5". Well....as you guessed, the second pass didn't line up perfectly with the first pass but I figured that I'd correct the errant cut with successive passes. LOL....didn't happen since the half nut engagement wasn't consistent!
The funny thing is that the lathes in threading videos I watched always engaged the feed screw exactly as the appointed number rotated to the marker. I do have to mention that my LatheMaster has a 125rpm slowest rotation so perhaps the lead screw threads were rotating to fast for me to engage the half nuts at the exact same time.
Anywhoo......... I ended up disengaging the threading dial and decided to go back to using a threading DIE, ana I did order a new adjustable 10x1.5mm die for future work!
|This message has been edited by nced1 on Mar 29, 2012 10:32 AM|