The Shop > Tools

Warco 180M DOA

<< < (3/3)

lesterhawksby:
I really doubt that turning the speed down to zero before starting makes all that much difference, on any control board that has ramp-up. The Warco board definitely doesn't "jolt" into action when turned on with the speed not at its lowest. I have played with some of the old generic minilathes and the WM180 is definitely better all round than those (that's why I got one back then) but the modern improved Siegs' brushless drive is better electrically. I wouldn't entirely trust Warco to know the details of the electronics, judging by Gopherit's report of what they said about swing to start... My experience with them was never bad, though they can be confused, but I think it really depends who you get on the phone.

WeldingRod:
Swing to start works when you have a 3 phase motor running with a lost phase ;-)

Very rough running, of course!

Sent from my SM-G892A using Tapatalk

Gazz292:
i think what was said is that that lathe needed it's spindle spinning by hand just once or twice, then after that it starts up on it's own?    as to why it needed that at first... wonder what motor it is, standard permanent magnet DC motor then maybe a dirty commutator?

i'm kinda thinking of generators where if they have been standing for a while they lose their residual magnetism, so you apply DC to the field winding to get them to start producing output,   but a motor should always start as you are putting power to it in the first place, and that's not relevent to a permanent magnet type motor.

maybe a brushless motor without a position / direction sensor... commonly used in radio control models, they sort of vibrate forwards and backwards very fast before figuring out which way to turn using feedback from the motors coils.. that's the weird ttzzzziinggg noise you hear a model plane make when the  brushless motor starts.



As for the way to start the lathe,  my reel bull lathe had an interlock board in it that required you to turn the speed knob to zero...where a switch opened,  then you pressed the no volt release switch (green button)  and only then turned the speed knob up and it'd start up, it simply would not start any other way.

if you lifted the chuck guard (or even just caught it) it'd cut out and you had to do that annoying start up procedure again, same if you operated the forward - off - reverse switch, but that's a good thing as applying reverse polarity to a motor spinning at speed wont do it much good at all.

The board also braked the motor when you cut power... the only feature i liked about it, but alas it was unreliable and died shortly after i got my lathe (second hand), i asked amadeal (place the lathe originally came from) about the cost of a replacement board, or a circuit diagram so i could try and repair it, and was told i'd be better off bypassing it, as a new one will likely do the same in a few months time!!

So for the past 10 years or so i've just left the speed control knob where i want it, and start and stop the lathe with the no volt release switch.. the red and green buttons.


BUT my lathes speed controller board has an acceleration feature, it dosent just apply what ever voltage to the motor the speed control is set at, it ramps it up over about 2 seconds, i've been told by John Rudd who knows these boards well.

If the warco speed controller does not have that feature, then they really should have an interlock board that makes you start up with the speed knob on zero, sounds like they don't :(

lesterhawksby:
Following up on this: now I've taken my wm180 apart, I can report that mine definitely has the kind of motor drive that has acceleration (and a little "accel" trim pot to tweak it). This probably explains why I always got away with turning it on at whatever the last RPM was and not bothering to wind it up from low speed. I suspect the other kind are only on the smaller "mini" machine.

I am in the process of swapping in a Sieg brushless motor in the hope of more low speed torque... fingers crossed.

Hope Gopherit's machine is now behaving itself!

vtsteam:
The surprisingly inexpensive Samgold brand AC to DC speed controller that I originally bought as a stopgap for my new lathe before buying a higher capacity DC converter/controller seems to have a similar feature as well.

I was at first confused by the fact that when I turned the speed up it wouldn't start right away, but now I realize it's a quite sensitive surge limiting control. I thought it couldn't start at a very low setting. But actually there's simply a delay in starting, so you can set it quite low from the off state, and in a second or two it will start.

Though I always intend to start slowly and ramp up from a stop, once or twice it happened that the control was set well above off when I switched the motor on. The delay and ramp up prevented the over current circuit from shutting it down completely or a circuit breaker from cutting out. Instead it just ran after the delay.

Navigation

[0] Message Index

[*] Previous page