My 1957 DSG 13" has 48 pitches 2tpi up to 112tpi, not that I think you would ever use anywhere near that fine, metric or other pitch types required altering change gears. The 1972 1307 machine I have just bought has 45 pitches 4tpi to 112tpi but also metric 26 pitches 0.5mm to 7mm selectable from a lever on the gearbox, the headstock has provision to provide a 4 to 1 coarse threading drive when in the back gear, or if in high belt speeds a 2/7 reduction on the feeds, meaning the usual 0.04mm per rev minimum feed (just shy of 2 thou) becomes 0.011mm (about a half thou), which should be really useful. Max feed is 1.12mm per rev or about 44 thou. It is a metric machine with a 6mm pitch (by 35mm dia) leadscrew
Yes, there is all the backlash in the gearing too so there is about 1/2" of iffy threads right at the start. This was a little harder to deal with on the small diameter making it really tight at the tail center so I just let it do that because reducing the diameter any more for at the start of the thread would weaken the part too much. On my Southbend, I used a shaped wood handle that hooked to the rear way, came under the chuck to brake the machine to a stop, it had a rubber pad on it. Does the same thing.
well last night on the South Bend I tried this threading technique.... muscle memory kicked in and I kept disengaging the half nut......Duh.... and then I decided to not pull the cross slide back on one pass and you can imagine how that went, that carbide tool never knew what hit it ...kaboom But !!! I did get my taper attachment going and proceed to make a taper at the maximum angle....so now I have a very pointy thingy to impress my buddies.... thank you so much Don......Paul, over and out....@@deedeeindustrialsuperprecision
Dee Dee, you can never have too many machines......cheers from Orlando.....Paul
If I can keep the quantity low and the quality high I am doing good.
I haven’t cut a thread that fine as of yet. Thanks for sharing, have a great day.
Thanks, you too!
It's Gold, Jerry....Gold! ✌
Thanks for tuning in
My 1957 DSG 13" has 48 pitches 2tpi up to 112tpi, not that I think you would ever use anywhere near that fine, metric or other pitch types required altering change gears.
The 1972 1307 machine I have just bought has 45 pitches 4tpi to 112tpi but also metric 26 pitches 0.5mm to 7mm selectable from a lever on the gearbox, the headstock has provision to provide a 4 to 1 coarse threading drive when in the back gear, or if in high belt speeds a 2/7 reduction on the feeds, meaning the usual 0.04mm per rev minimum feed (just shy of 2 thou) becomes 0.011mm (about a half thou), which should be really useful. Max feed is 1.12mm per rev or about 44 thou.
It is a metric machine with a 6mm pitch (by 35mm dia) leadscrew
The DSG lathes are really interesting, I have been watching what videos I can find!
🦘🦘🦘🦘🦘 Cheers D, Davo
Hi Davo! Thanks for tuning in!
Don, 16:50...is the drunken thread at beginning caused by backlash in lead screw ?
Yes, there is all the backlash in the gearing too so there is about 1/2" of iffy threads right at the start. This was a little harder to deal with on the small diameter making it really tight at the tail center so I just let it do that because reducing the diameter any more for at the start of the thread would weaken the part too much. On my Southbend, I used a shaped wood handle that hooked to the rear way, came under the chuck to brake the machine to a stop, it had a rubber pad on it. Does the same thing.
well last night on the South Bend I tried this threading technique....
muscle memory kicked in and I kept disengaging the half nut......Duh....
and then I decided to not pull the cross slide back on one pass
and you can imagine how that went, that carbide tool never knew what hit it ...kaboom
But !!!
I did get my taper attachment going and proceed to make a taper at the
maximum angle....so now I have a very pointy thingy to impress my buddies....
thank you so much Don......Paul, over and out....@@deedeeindustrialsuperprecision