Sherline Lathe Power Feed

[Forty Niner]

I built a new power feed setup from my Sherline lathe that works great. The finishes that I have obtained are incredible. On steel, brass, or aluminum I have achieved finishes that look a lot like "ground and polished", using HSS tool bits. The idea of using a gearmotor is credited to Mikey. I found that the super duper gearmotor that Mikey uses was out of my price range, so went looking for a cheaper solution.
The gearmotor is DC 24V with max speed of 50 rpm. (The same physical size gearmotor is available in other orientations, voltages and speeds.) I have to confess that I first bought a 160rpm version. That was a mistake. Then I bought the 50rpm that I am very pleased with.
To see more details about the gearmotor try searching "jcf63l dc24v 80w 50rpm speed reducing high torque electric gear box motor"

It easily dials down to speeds as low as 6 rpm (about 0.3 inches per minute feed). The Sherline standard power feed (no longer sold) is 20rpm / 1" per minute for comparison.

From the picture you can see I mounted the gearmotor some distance away from the headstock. The clearance allows the headstock to be turned for cutting tapers.
The gearmotor is controlled and powered with easily sourced parts. A 24v power supply and a PWM motor controller. I mounted them in a steel box.

 

[Steve-F]

I like that !! Going to try that on my Emco I'm putting together

 

[Karl A]

Nice to see.

I want a power feed on my Sherline lathe. Toward that end, I bought an Arduino beginner kit to learn about electronics, microcontrollers, and motors; I am going through the lessons. I look forward to trying pulse width modulation on the little DC motor that came with the kit.

Do you set the limit of travel of the power feed by using the hard stop kit that is shown installed on the headstock?

 

[Forty Niner]

Do you set the limit of travel of the power feed by using the hard stop kit that is shown installed on the headstock?

No. My setup requires me to stay awake. I am interested to hear more about your project.

 

[Karl A]

I have thought for a couple years that being able to control things digitally is a useful skill to have -- both for my job and my hobbies. My desire to add power feed to my lathe is providing sufficient incentive to learn.

Currently, I am controlling the feed rate on my lathe manually, using an metronome application on my smartphone to set the RPM of the feed rate. Usually, I set the metronome to produce four beats per revolution. I count 1 to 4 as I rotate the hand wheel one revolution. The metronome helps, but turning the hand wheel at a consistent RPM requires focus. The approach of the end point distracts me. I will try counting out the number of revolutions times four, instead (1, 2, 3, 4, 5, 7, 8, 9, 10, 11, 12 ...)

My goal is to control a stepper motor through a smartphone, with inputs of feed distance per spindle revolution and travel distance. I don't know whether I will achieve it. At this point, I envision it consisting of a smartphone application providing a g-code interface, an Arduino microcontroller board, GRBL firmware installed in the Arduino, an Arduino CNC shield. a stepper motor, and a Sherline tachometer encoder & cable assembly (81500).

Here is an example of a tutorial.
https://howtomechatronics.com/tutorials/how-to-setup-grbl-control-cnc-machine-with-arduino/

Karl

 

[Aaron_W]

Interesting set up. Are you still able to turn the lead screw manually or is it now completely dedicated to use with the power feed?

 

[Forty Niner]

The feed is engaged or disengaged with the lever on the head stock. When it is disengaged, the lathe is operated in the standard manual way.
The engagement lever is the same lever that is used to engage the screw threading attachment and the original power feed setup. The engagement parts are all available from Sherline, and come with their threading attachment mentioned above.

 

[mikey]

Infinitely variable speed and feed allow you to dial in a cut on the fly - what's not to like? If you think about it, the only other thing to control is depth of cut. Once you set that then you can adjust the other two cutting conditions to optimize the cut for that depth.

For those of you who are contemplating a power feed, it is NOT necessary. You can manual feed and get the job done. What power feed allows you to do is to completely control the cut in real time; this is practical and really useful. Power feed is also nice when you have a long work piece and don't want to crank the handwheel for the entire piece; the fact that this greatly enhances finishes goes without saying.

Your cutting conditions (speed, feed, depth of cut) are interwoven in an intricate ballet. Each affects the other two and it wasn't until I adapted my lathe to power feed that I really learned, at a visceral level, just how this all works. That lesson enhanced my basic understanding of how turning tool geometry impacts on lathe performance so for me, power feed was a great learning tool.

Most lathes have power feed. Some lathes have variable speed. Few lathes have both. @Forty Niner and I have a distinct advantage!

 

[Steve Bergeron]

Is there any drawback with using a Sherline Stepper motor for the drive?
It seems to be about the same price for the motor. I have no idea how to connect it up (electrically), but I am trying to learn and research.

I want the variable speed, forward and back "rheostat" type drive for my lathe. As you guys have created.

Long time Lurker, First time poster.

Steve

 

[Karl A]

Is there any drawback with using a Sherline Stepper motor for the drive?

I think that a drawback is that the electronics are more complicated. You would need a power supply, a driver, and a controller.

For power feed on a Sherline lathe using a stepper motor, see posts by Nick Clarke on June 19, 2021 and August 26, 2021 on Sherline Lathe and Mill Group (Facebook) https://www.facebook.com/groups/975235319239533/user/1579402533 Nick Clarke also posted a wiring diagram named single-axis-frequency-generator.pdf. Look for it in Files. https://www.facebook.com/groups/975235319239533/files