Vendor promised the new controller in couple of days..
In the meantime, I tried the circuit discussed earlier (it is basically dimmer, 20Acapacity).. and it works OK, as expected. Probably not any worse than original controller (apart from overload protection and whatever else non-obvious features are implemented).
So - lathe is operational as of now
That's great news Seeing your lathe, has renewed my enthusiasm and I have been tinkering with mine making a hand mandrel for it, at the moment to help with threading.
Simon
That's great news Seeing your lathe, has renewed my enthusiasm and I have been tinkering with mine making a hand mandrel for it, at the moment to help with threading.
Simon
My next project with lathe will be adding steppers... turning manual into CNC.. but not now
Now, this situation is becoming ridiculous...
The new controller arrived today, I installed it in the machine... and nothing, no "m" of motor moving... but this time indicator LED (at one of processor's output) was ON..
All connections seems to be OK....
I applied external 12V to board and there is PWM on FET's gate.. so this time I have board with faulty FET.
Plan now is to transfer (probably) good FET from old board to new one and see what happens...
Yes..
The original problem was in faulty wire-wound potentiometer, the wire was broken on one place and when I was turning the knob the wire touched the metal enclosure of the potentiometer, so the processor input was put directly to 340V and consequently destroyed..
After replacing the pot with new one, the second board works as intended.
Electronics is still not sorted out 100%, I discovered the minimum head speed is ~ 180rpm, too fast for threads..
I am sure they send me the wrong controller, it is probably suitable for US (110V AC).
I tried with variac, and yes, min speed is correct at 110VAC, but then the safety switch doesn't work.
So I asked for another one, it is on its way now...
In the meantime I had a look at mechanics.. and found one thrust bearing broken.. already replaced.
The cross slide lead screw doesn't have any bearings, 10mm shaft sits on edge of Ø9mm bore in aluminium bracket !!!!.
So I widened the bore (using step drill on the same lathe, mounted in tailstock) so I can insert the ball bearing (8x16x5mm, the only one that fits into available space). It is radial type, not ideal for the purpose but it should be way better than original "design". I will also insert the front bearing, but not right now, for this I need access to another lathe.
I can't say I am bored as SIS .
Well, not missing really... only crashed, I found half of it.
what was it made out of? Takes serious pressure to crash a bearing ball. Usually the track or cage are the first to go. You might want to go around the whole lathe and replace them with equivalent timken or other.
... You might want to go around the whole lathe and replace them ...
That's what I am doing...
I think this bearing was installed like this in first place... because the feed spindle was turning OK when I first inspect the machine. I realized it was faulty only when I went to investigate the reason why the nut self-unscrewed and fell on the floor.
New compound bearing plate (aluminium flat bar, 60x12mm)...
I will cut off the excess later (with circular saw).. the current size is larger to fit the part into 3-jaw head, properly centered for bearing seat.
The seats will wait for thrust bearings to arrive (in couple of days).
Electronics is still not sorted out 100%, I discovered the minimum head speed is ~ 180rpm, too fast for threads..
It sounds like youre getting there, and by what you are doing will be way better than stock lathe. Imagine the person that cant problem solve and fix things would be getting sick of sending things back
My lathe has geared speeds and 160 is the slowest, no brake, so it just winds down when turned off. I thread away from the chuck. Same set up except tool is upside down and you run the lathe in reverse. Start from the run out for the thread. Make a carriage stop so you start in the same place each time. This way you can thread right up to big shoulders, or in bores you you can thread a blind hole up to the end. Much simpler and you dont have to worry about quick winding out or crashing the tool. (On bores thread off back face with an opposite hand bar and thread is always visable). Speed is then not an issue and most things cut better with a bit of speed.
Al