Easy way to motorize a lead or feed screw.

[olderdan]

My old SB lathe has a feed apron but uses a keyway on the leadscrew to drive it, this means changing the gear train from threading to feed speeds which is a real pain for making multiple parts (the lathe does not have a QC gearbox). A separate drive from the tailstock end seemed the most practical as the gear train for screw cutting could then be left set up. The only alteration to the lathe is to drill and tap the end of the leadscrew for a hub for the Poly V pulley. I used a 12 volt DC Bentley golf trolley motor which has an integral gearbox and a PWM controller, power source is an old battery charger giving 6 or 12v (the newer intelligent chargers are no good for this). The drive is mounted on a friction pivot to disengage so after turning a part I just have to pull the motor forward, engage the tumbler and screw-cut etc a matter of a few seconds. It has also been a boon to adjust the feed rates on the fly Hardinge style for optimum removal and finishes, it will slow down enough for me to use the graduations on the hand wheel. Of the many mods I have done to this lathe this has been the most useful and has given a more modern feel to using it. As there is no interlock between the two drives the belt drive will pull the motor forward and slip if the sequence is forgotten and acts like a mechanical fuse.

[DIYer]

Thanks olderdan! We've added your Lathe Leadscrew Motorization to our Lathe Accessories category,
as well as to your builder page: olderdan's Homemade Tools. Your receipt:

Lathe Leadscrew Motorization by olderdan

tags: lathe, power feed

[Paul Jones]

Very useful description and photos.

[tonyfoale]

Alan,

good one as usual.
what is the ratio of that gearbox and are they readily available?

[DIYSwede]

Alan,

good one as usual.
what is the ratio of that gearbox and are they readily available?

Ball park figure (but unfortunately not about its GB ratio, Tony):
Facts stated elsewhere about the golf trolley unit: 12V, 200W in, max 5mph (and a wheel dia of 26,5 cm) would give 160-ish rpm out at full throttle.
No figure given for its duty factor, but there's a remote control unit that can be used up to 100 m (in open terrain)...

Cheers
Johan

PS: Readily available, but certainly with a hefty price tag given its origin, Tony.
A car/ lorry wiper motor from a scrap yard would get you the same performance with a 100% DF at a discount,
and they're also originally designed for minimum noise. D

[olderdan]

Thanks Tony, I have been unable to find the original supplier of the motor as so many sites have shut down recently. The motor has no info at all (Chinese) but I measure the output speed of the gearbox on full speed at 200 RPM, my reducing pulleys put the leadscrew at 90 RPM, plenty fast enough for most tasks. Sorry not to be of more help.
DIYSwede has some good advise in his reply.
Regards
Alan

[dan91640]

Hello, can you fixed, handwhell on the end of leadscrew; please?
do you have a section?