Senior 3C Mill - head info reqd. pse.

Any info relating to Tom Senior mills and lathes

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DMIOM
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Senior 3C Mill - head info reqd. pse.

Post by DMIOM » Mon 24 Aug , 2009 23:40 pm

Senior 3C Mill (s/n 3C24037B, manufactured April 1987) - head info reqd. pse.

Appreciate if anyone can provide info on :

a) Z-drive motor. After repairing the intermittent Z servo tacho wiring, the quill has started "stuttering" and on inspection its at a regular interval which corresponds to one bout of stuttering per rotation of the Z servo motor. Now traced to what I believe is a shorted commutator or failed winding on the Z servo motor (with the motor just on low-voltage a DC supply it will turn through, say, 330 degrees and then jump the remaining 30 degrees). Am urgently trying to find a replacement or to get it rewound. No label on it. Appreciate if anyone could advise - anyone have a parts list? or just the motor specs? or even better, a user manual? or even just recognise the maker? (no label on the motor at all, castellated top may be distinctive? appears tacho is an integral fitting, appears to be remains of a Baldor label on one of the other larger bed servos ....). Base appears to be NEMA-34 footprint. Current motor (2 brushes) delivers app 30 RPM / volt (minimum start voltage is just under 3v); free-running/no-load current (i.e. motor off machine) is app. 0.2A. Tacho (4 brushes) gives out app 6.5v / 1000 RPM.

b) Quill - for a while have been concerned that the bottom of the quill feels warm after use. The Bijur system doesn't extend to the head, just a drip lube on the Z ballscrew, nothing for the quill or spindle itself. Is there supposed to be any way to lube the spindle bearings?

c) and just out of curiosity - has anyone ever fitted a power drawbar to a Senior 3C? ( I know some folk use the Coventry 'Easychange' but would like to have power drawbar which opens avenues for possible eventual ATC?)

thanks / Dave
1 Denford_3C_Z_Servo.jpg
1 - Senior 3C Z servo motor
1 Denford_3C_Z_Servo.jpg (148.16 KiB) Viewed 9978 times
2 Denford_3C_Z_Servo_tacho.jpg
2 - Senior 3C Z servo motor tacho
2 Denford_3C_Z_Servo_tacho.jpg (148.13 KiB) Viewed 9978 times
The attachment 3 Denford_3C_serial_plate.jpg is no longer available
Attachments
3 Denford_3C_serial_plate.jpg
3 - Senior 3C main data plate
3 Denford_3C_serial_plate.jpg (75.19 KiB) Viewed 9959 times

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bradders
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Re: Senior 3C Mill - head info reqd. pse.

Post by bradders » Fri 04 Sep , 2009 11:02 am

Unfortunately our records only go back to 1988, there were 2 built in that year and both had SEM 30H4.44 motors on all 3 axes

DMIOM
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Re: Senior 3C Mill - head info reqd. pse.

Post by DMIOM » Fri 04 Sep , 2009 11:04 am

Thanks very much for looking.

Is there anyone you would recommend to do servo rewinds?

thanks / Dave

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bradders
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Re: Senior 3C Mill - head info reqd. pse.

Post by bradders » Fri 04 Sep , 2009 11:15 am

I'd just Google "Servo Motor Rewinds" and look for one in your area

DMIOM
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Re: Senior 3C Mill - head info reqd. pse.

Post by DMIOM » Fri 04 Sep , 2009 11:26 am

Thanks - there isn't even an 'ordinary' motor rewind shop left here on the Isle of Man so I'll have to ship it to the UK - was only asking in case anyone had good or bad experiences.

Dave

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