I have been using the SmoothStepper since the start of the Beta testing days on my mill and also have the original Beta board on a coil winding machine. Both machines work great with the SS but they are really not a good benchmark for how good the SS can be. I have had one lying around for a couple of months now waiting for the spindle sync to be done so that I could fit it to the Lathe, I do a fair amount of threading so couldnt even contemplate using the SS on the lathe until the sync was done.
I got a test version of the PlugIn a few days ago, along with a few other of the original Beta testers. Today was the first day that I had time to test things out and to say I am very happy would be a vast understatement.
First off the threading, it is working perfect for me and produced a very clean well spaced thread as near to perfect as I can tell. I however have a large lathe and the spindle is around 20HP at the 1000RPM I cut the thread at so there is no chance of the spindle slowing even if I took the thread in one pass
So my results may not be the best test for the SS and threading but it does show that the SS is definitely not having a problem starting the thread at exactly the same point each pass.
Now the next bit, previously the max rapid speed I could get on my lathe was 3,300mm/min as the encoders are 2,000 line or 8,000count, this meant that at 45KHz kernel and 2:1 electronic gearing in the drive I was limited on the rapids.
Today I decided to crank things up a bit, I went from 3,300mm/min velocity and 200mm/sec/sec Accelleration to 6,600mm/min and 400mm/sec/sec. It ran very well so I decided to again double the Velocity to 13,200 but kept the Acell at 400, everything went well so I cranked up the Accell to 600 and again things went well. Then put the accell up to 800mm/sec/sec and initial tests seemed fine but testing further I found my Z axis would fault out occasionally. I turned it down to 700mm/s/s and all was well.
For my drive to fault the position has to be out by 20 counts so on my lathe that is 0.0125mm or 0.00049" so its not much
The saddle on my lathe weighs in at approx 400Kg and I just didnt have the courage to test any further on the velocity, in fact I will more than likely turn it down to 10,000mm/min and then maybe as I get used to it I will crank it up a bit further and see how things perform. I have attached a pic of the thread I did today with the SS, pic quality is not the best but it shows a 16mm dia thread with a 2mm pitch and the material was mild steel.
Hood