New Spindle Motor for the Boxford 125TCL CNC lathe.

by John

Reader Ben asked about the spindle motor replacement on the Boxford.   This is a small CNC lathe, and was often used for teaching in secondary schools in Australia.  Mine was made in 1985, and I replaced the electronics a few years back because they were obsolete and not functioning.  The mechanicals of the lathe were beautifully made and in excellent condition.  I did replace the ball screws, but in retrospect, that was probably unnecessary.   I also installed new and bigger axis stepper motors.

I was still getting some unreliable results, despite the the upgrades, and wondered whether the spindle motor was lacking power.  I was taking lighter cuts to try and cope but clearly a new spindle motor was required.

The space that the motor occupies is fairly tight, and initial searches for a suitable replacement were fruitless.  The new  ClearPath motors looked promising, but enquiries to the manufacturer indicated that the required power and rpm’s were not available.  Then my expert friend (or should that be “friend who is an expert”?), spotted the Ebay ad below, and bought and succesfully installed the servo motor in his 125TCL, so I did likewise.  I am afraid that the electronic aspects remain a mystery to me, so I cannot help with those.  It is a 0.75kW motor, substantially more powerful than the original, but very compact.

 

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Do an Ebay search on the code on the controller.  I paid $AUD339 but it is now plus postage and GST, so close to $AUD400

 

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The new spindle motor and servo controller

 

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A new motor pulley was required.  There is still a high and low belt ratio available, but with the extra power and torque I never use the low ratio.  RPM range is 300-3200.

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This has been a very successful modification.

Many thanks to Stuart Tankard for his generosity in time, expertise and advice in getting it going.