Not mine, but I'm helping a friend out with a poorly mini lathe. Its a bit of a rare beast, a melcer me3 with aluminium construction but steel inserts into all the slideway surfaces. What that means is its one person liftable which makes it really interesting for a trailer workshop...
Lathes.co.uk has it down as a single phase motor, with really unreliable speed controller. We're trying to work out how to replace it all with something off the shelf. I've got the manuals for it downloaded, but it has no wiring or electrical information in there.
http://www.lathes.co.uk/melcer/
Anyway, here it is getting prodded.
I've had a look at the circuitboard, and its covered in bad joints and rework, most of the chips are to drive the speed display which is 4 individual seven segment displays. But the L120AB is a diac trigger controller, and uber rare and NLA. I found one for a fiver because we think this is blown and its got lost in the post coming from japan.
I found this hanging loose inside, its a regular triac.
Drum switch for off/on + direction, I think this is bad too as it only makes contacts between what I think are the windings in one direction. It also appears to have 7 positions, even though the silk screen on the front only indicates 3.
So what we decided might be for the best given how unreliable they are, and that this looks like its been played around with a LOT, would be to fit a bridge rectifier feeding a chinese modular triac board + lcd rpm counter in place of everything. I am guessing that schafer transformer drops the mains voltage to whatever the motor needs to turn, which could be a problem finding out what voltage as it wont...
What is also confusing me is that the motor has 6 wires to it, I checked it out with the meter on ohms and I think its two pairs of windiings, but I haven't got a clue what the other wires are for and there's no manufacturer's name on the motor. I'm also trying not to look at those smaller wires just lopped off, there's random butchered wiring all through the machine like this...
Any pointers?
Lathes.co.uk has it down as a single phase motor, with really unreliable speed controller. We're trying to work out how to replace it all with something off the shelf. I've got the manuals for it downloaded, but it has no wiring or electrical information in there.
http://www.lathes.co.uk/melcer/
Anyway, here it is getting prodded.
I've had a look at the circuitboard, and its covered in bad joints and rework, most of the chips are to drive the speed display which is 4 individual seven segment displays. But the L120AB is a diac trigger controller, and uber rare and NLA. I found one for a fiver because we think this is blown and its got lost in the post coming from japan.
I found this hanging loose inside, its a regular triac.
Drum switch for off/on + direction, I think this is bad too as it only makes contacts between what I think are the windings in one direction. It also appears to have 7 positions, even though the silk screen on the front only indicates 3.
So what we decided might be for the best given how unreliable they are, and that this looks like its been played around with a LOT, would be to fit a bridge rectifier feeding a chinese modular triac board + lcd rpm counter in place of everything. I am guessing that schafer transformer drops the mains voltage to whatever the motor needs to turn, which could be a problem finding out what voltage as it wont...
What is also confusing me is that the motor has 6 wires to it, I checked it out with the meter on ohms and I think its two pairs of windiings, but I haven't got a clue what the other wires are for and there's no manufacturer's name on the motor. I'm also trying not to look at those smaller wires just lopped off, there's random butchered wiring all through the machine like this...
Any pointers?