Cross Slide Power Feed

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Cross Slide Power Feed

Post by William » Wed Apr 25, 2018 6:19 am

Lathe Cross Feed Electric Power Drive

This is an improvement to a small Chinese lathe. It motorises the cross slide. This photo shows the back end of the cross slide. The aluminium bracket and armoured cable are for X-Y axis encoders.
Some existing designs add a belt drive to the front of the lathe. This is a back end drive coupled directly to the lead screw. The drive motor has an integrated epicyclic gear box coupled to an electromagnetic clutch driving a spur gear. Two additional spur gears drop the mechanism out of the trajectory of the cross slide.
The 3-D CAD design is shown below. The Perspex cover keeps chips out of the gears.

The feed rate can be adjusted from zero mm per minute to about 10 mm per minute by varying the voltage to the motor which can run both backwards and forwards. Watching the rotation of the cross slide handle gives a feeling for the right speed and it can be measured using the x-axis DRO if necessary. When the clutch is disengaged the handle is used to crank the slide manually. When voltage is applied to the clutch it engages and the motor drives the lead screw. The essential parts of the gear train are shown below.
Gear Train.jpg
This photo shows the gearbox, without the chip guard mounted on the lathe.
The mechanical parts cost around £20 with an additional £20 for the electronics. The power feed makes the common tasks of facing and parting so much more satisfying than hand cranking. There is some machining skill required to build this gearbox and it probably took more than 50 hours to complete. The parts are commonly available on the Internet. It might be a good idea to add micro switch interlocks to stop the slide accidentally running too far forwards or backwards under power. There are drawings available for this design which could be scaled to suit any particular lathe.

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Re: Cross Slide Power Feed

Post by binnaway » Sat Apr 28, 2018 3:19 am

You have mentioned that drawings are available is there a website or any contact details looks like a great project

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Re: Cross Slide Power Feed

Post by EOsteam » Sat Apr 28, 2018 8:50 am

I’m very much interested in the drawings. There is a Myford Super 7 in the shop in the shop that is just begging for that modification.



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Re: Cross Slide Power Feed

Post by chucketn » Sat Apr 28, 2018 10:23 am

Me too! I would also be interested in the plans. I have a salvaged drill motor and pwm controller looking for a purpose...

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Bill Shields
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Re: Cross Slide Power Feed

Post by Bill Shields » Wed May 09, 2018 4:53 pm

looking at the castings for the apron...I suspect that we have sister / clones of the same machine.

It is a slick idea..but the question begs to be asked...

Doesn't the lathe have a mechanical power feed through the apron...using the same lead screw used for long axis feed / threading?

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