Emco compact 5 cnc lathe motor

[kilartanParticipant @kilartan]

Hi all, I’m new to here so apologise in advance if this is in the wrong place. The spindle motor on my emco compact 5 cnc mk4 lathe has died and I’m after a replacement. The machine is completely standard. I can’t find any information on a direct replacement. Does anyone know of a suitable replacement? I’d like to keep the machine as standard as possible. thank you.

[simondavies3Participant @simondavies3]

Hi Kilartin,

I did something similar on my 5PC a few years back so I should have the details somewhere – I also added a speed controller under manual control (the intention was to integrate it with the Mach3 software, but life got in the way!)

 

details ‘will’ follow.

Simon

[John HaineParticipant @johnhaine32865]

According to lathes.co.uk the motor…

“The spindle was driven by a 440W motor (though the exact power did vary from year to year) and had a speed range from 50 to 3200 rpm”

So like most of these small CNC machines (e.g. Boxford / Denford) it was almost certainly a DC commutator motor, either PM (most likely) or wound-field.  Apart from the brushes these motors are pretty bombproof, and replacing the brushes should be easy.  However the controller may be a different matter, as it probably used a thyristor or SCR to control the speed and this might have blown.  There would also be electrolytic capacitors in it which could be degraded especially if the machine was standing idle for long periods.

So before you rush to replace the motor, have a good look at it – are the brushes OK?  If you disconnect it from the speed controller and connect to a low voltage (e.g. 12V) does it run though slowly?  Disconnect the controller from the mains and have a look inside, is there evidence of it getting very hot / components browning?  Or a “loud brown smell”?

There are a lot of suitable speed controllers around on eBay etc though may not be compatible with the machine controller if that matters to you.  Also many of them do not have a speed control input that is mains isolated.

[EmgeeParticipant @emgee]

Did you see my reply to your earlier Message ?

For information the original motor on the Compact 5 cnc lathes was a 400W PMDC motor with a no load speed of 4000rpm.

The spindle speed range of 50 to 3200 rpm was achieved by belt changing between 3 settings.

 

Emgee

[DrDaveParticipant @drdave]

I took a different approach when the motor on my Emco 5 cnc died: I have replaced it with a 3 phase motor.  The controller for the motor is fitted inside the cabinet (I replaced the old Emco boards with a newer controller, which created a lot of room for this).  The new cnc board (Acorn) has a voltage output that allows the motor speed to be controlled.

I suspect that the maximum speed of the new motor is less than the original DC unit, but I weighed the lower speed against having no motor!  I hope that this helps.

Dave

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