Clarke CL251mh Milling Attachment Wiring Help

I have just aquired a Clarke CL 251mh Milling Attachment that would have been the milling attachment for the Clarke CL250m Micro-Lathe,. I would like to make the Milling Attachment CL251mh into a Stand-Alone Milling Machine,.The Milling Attachment would normally be connected to the back of the Lathe via the cast-iron Foot at the base of the 45mm Dia Column, then a Jack-Plug (Kettle type plug) connects directly to a matching (kettle type plug) also on the back of the lathe bed,. All the Power ie Variable Speed/ Forward/Reverse/ Powerdrive Control Knob, and the Lathe / Mill-Drill Head Selector On / Off Switch comes from the Lathe,.I don,t need most of these, All I would require would be a 13amp power supply to a NVR Switch then through a Variable Speed control to the Motor,. The Motor is Single-phase 230v AC 50Hz 1 Ph. Power Rating 150Watt. Currant Rating 5 Amp. The motor is Small 3" Dia x 4.5Lg Spindle Speed 10-1300,. This Motor is the supplied motor and fitted as standard,. As this is a Stand Alone project there is no Start Capacitor or any method of variable speeds etc attached, I have bought a NVR Switch the basic type Without the Emergency Stop also bought the Variable Speed Control 2000w AC SCR Electic Voltage Regulator/Speed Controller,. I also notice the outer casing on the motor is a strong magnetic using a screwdriver ( just thinking is this a different type of motor). I have tried to run this connecting up direct to a matching plug with a circuit breaker ahead first, the Motor is trying to Run but only very slowly and is Stuttering,. It Does NOT trip the Circuit breaker,. I confess to having very little electrical knowledge with Motors,. Any Help or Advise would be Gratefully Received,. Pete Retired Fitter/Turner 75yrs.

Peter,

I have just sold a Clark milling attachment and lathe bed ideal to set up as a stand alone Miller, the motor on it was a DC motor not sure if they fitted an AC motor as standard.

I am no help to you in your quest for a suitable controler but please double check if its an AC motor.

From your description of the external magnetic field from the motor it is a permanent magnet motor. These are DC motors. DO NOT connect it to an AC supply as doing so is likely to demagnetise the permanent magnet and burn out the winding.

Les.

In support of Les, the circuit diagram in the CL250 Manual identifies the output of the lathe's control board as 220VDC.

The output of the reversing switch under the legend OUT DC 220V on terminals 10 & 11 connect invisibly to terminals 10 & 11 on the motor select switch bottom right above Motor M1. The manual also refers to the motor brushes, which are also characteristic of DC motors.

The easiest way to power the milling head would be to buy a spare controller board for the lathe from Clarke's Service Department and box it up.

So far from best practice I hesitate to mention it, but you could rectify the output of the SCR controller with a diode or bridge rectifier and apply that to the motor. Apart from serious safety concerns it would put too many volts on the motor. Some solutions are too simple!

Dave

I have one of these. I can tell you with 100% confidence it is a DC Motor. I know because it confused me too. The problem is the little sticker on the milling head describes input voltage to the lathe and not the milling head motor. 😒

You will need a DC speed controller to get it running.

These are far less common than the Cl250M lathes they fit on and may sell quite well - I suspect parting with it and putting the money towards a small mill (I have a SX1L from Arc Euro £387 at present)  will work out far easier and cheaper than converting this accessory with a compound table, motor controller, case etc

Edited By Nick Clarke 3 on 18/08/2019 13:45:40