My Lathe with the SmoothStepper

[budman68]

Those look like hell, is that the best you can do? 

Dave

[Hood]

Those look like hell, is that the best you can do? 

Dave

Afraid so, maybe if I had used better steel rather than crappy mild steel they would have come out better Actually I ran out of mild steel and had to use a bit of EN24T, its the second bottom one, bit more shiny
 The losest one shows that at 45KHz the withdrawal is not perfect for me for some reason, the last few threads are grouped together, the 35KHz kernel and the two SmoothStepper ones have a nice clean withdrawal though.
Hood

[Overloaded]

Hood,
The bottom sample in your pic.
What did you use for the "L" word in your G76 and what RPM did you run ?
RC

[Hood]

Russ
 L0 in all of them, in fact they all used exactly the same code with the exception of the 35KHz test in which I had to drop the speed as the axis couldnt do 2mm/rev due to the reduced velocity possible at that kernel.
 Top 2 on SS  and the lower one on PP @45KHz were 1000RPM and the third down was 35KHz kernel on PP at 710RPM

Hood

[Overloaded]

Hmmmm...interesting.
I remember when Graham and Brian changed the L to Angle of rotation instead of angle to the X axis.
Maybe L360 would work better for you ? Maybe not.
360-720 works best here.
RC

[Hood]

Thanks Russ, seem to remember discussions about that now you mention it, thing is though the retract is perfect on the SmoothStepper threads and also on the one done at 35KHz on the PP. Previous to the last couple of versions of Mach my retract was also perfect at 45K so for some reason its something new thats just crept in for me.
 I am not particularily bothered about it as I dont think I will be using the PP for much anymore, the SS is just too good It would be nice to know what is causing it just in case others get the problem.
Hood

[Overloaded]

Here's the topic where I asked Graham about the angle: http://www.machsupport.com/forum/index.php/topic,5250.0.html

Also, if you enter L0, then theoretically the tool would retract instantly leaving no transition from the full depth of the thread to the OD of the stock. A "Step" if you will. Of course this is not possible but can you tell approximately what degree of rotation the retraction takes place with the SS ? Just curious as I hope to set mine up soon.
Thanks,
RC

[Hood]

Not really sure Russ, have turned the threads off now but next one I do I will take a note for you.
That thread was interesting and makes me wonder if previously I had been using the old macro and now with the new one its acting differently. Will set up my L to a few different numbers and see.

Hood