Lathe power feed options

[Randy]

The gear train on my Jet 1024 is horribly noisy. So noisy that I don't use it at spindle speeds over about 500 rpm. I'm sure that excessive clearance is mostly responsible for for the noise. Someday I'll probably buy some new gears and make a new tumbler bracket that's more precisely fitted, that should reduce much of the noise. But I recently found Bob Engelhardt's account of his variable speed DC servo motor drive for his feed rod. Which got me thinking, perhaps a common power feed unit for a Bridgeport mill would work well to drive a lathe feed rod as well. Powerful enough, for sure, and just watching my machines tells me that the speed range is suitable as well. There's also James Clough's electronic lead screw, but I don't need that much sophistication. My QG gearbox covers my threading needs. Have any of you adapted a mill table feed to a lathe?

[The Artful Bodger]

IIRC Sir John once showed us a conversion using tooth belts? Quiet running and easy to install gears for threading when needed.

[JRouche]

IIRC Sir John once showed us a conversion using tooth belts? Quiet running and easy to install gears for threading when needed.

Hey now! Sr John, and I both had the same mill, and drive system,

Yep. I was a regular. Thats all. JR

[SVS]

It’s work-able. Been done before.

A buddy used industrial surplus DC gear motor and drive on a big old antique with a half missing loose change gear system. He really liked the effortless variable feed.

[The Metal Butcher]

Having the vary the feed to keep a consistent chipload is one of the worst things about mill power feeds. I know what feed numbers I like, and I can set them and change RPM on a whim. YMMV.

[RMinMN]

Start by lubricating everything. Bearings and gears work quieter if well lubed. Then check the engagement of the gears. Loose engagement makes noise.

[Ian B]

It's common to have one of the gears made of a more resilient material than iron / steel; here's one: https://www.ebay.co.uk/itm/262821060...sAAOSwEE9dOGmg

Put it in the train so that it meshes with the spindle gear (usually the highest speed gear), and it'll take a lot of the noise away. It also acts as a sacrificial link in case something jams up solid.

When setting the gears on the banjo, trap a sheet of paper between them to give a small amount of clearance. And yes, lubricate the gears.

Ian

[olf20]

I'm currently adding a stepper ELS to my little Smithy.
I already have the motor and stepper mounted. Working
on the software using a arduino, keypad, and lcd display.
Very simple mechanically, and lots of trail and error on
the software end, which I enjoy.
olf20 / Bob

[Stu]

I have a windshield wiper motor powering the leadscrew on my Craftsman 12" lathe. It has plenty of power and works very well, and is very quiet.

[john b]

I also use a windshield wiper motor. Two speeds forward and reverse. It's amazing how you can change the finish by just changing the RPM and not the feed rate.

[BCRider]

Randy, I'm in the same boat as you. Change gears are so noisy that I seldom use them other than threading. And then they are fine since the whole machine is running slow.

The proper lube sure does help. I use a spray on open gear and chain lube that does help a lot to cut down the noise. It's very sticky and doesn't fly off like oil or even lithium style greases. And it greatly aids with cushioning the rattle that is what is making the noise. But even so it's still a hell of a racket. As a result I've gotten pretty good at hand feeding even for final passes rather than listen to the noise.

More than once though it's occurred to me that if I used the gearing more often that over time they would burnish themselves to a more quiet running fit. As it is now I've used them so little even over the 25'ish years of ownership that the teeth still show a good amount of their original factory finish. The issue being that unless loaded down they won't really burnish into a nice quiet fit. I tried for a few days some years ago. But it was just too much to listen to in the end.

Using a secondary motor and belt sounds like an interesting idea. Especially if it were fitted on the geared end so the QCGB was still part of the options.

[JCByrd24]

Here is mine. Loved it.

[Randy]

No amount of grease is going to quiet those gears. Each gear pair has from .015 to .030 of tooth clearance, and there's no adjusting them. They're barely engaged. The only fix is a new tumbler bracket with correct clearances. I need to make that in any case. But then, I've needed to do that for 40 years now. It looks like a fun project anyway.

Ian, I'd never considered anything but steel gears, but non-metal tumbler gears may be a very good choice. Tufnol looks like what we call phenolic on this side of the Atlantic. Not cheap, so I hope the aluminum shear pin I use to couple the feed rod to the gearbox will still be act as a fuse. It's saved me a couple of times already.

Stu and John, a windsheild wiper motor is a promising idea.

JCByrd, thanks for the link. No surprise that this topic has been discussed before. Helpful info.

I won't ditch the idea of a mill table drive yet. It comes with everything needed, power supply, fwd-rev switching, variable speed. It does the same job on either machine, it's just a matter modifying the mount and shaft coupling. One nice addition would be tying it in electrically to the lathe motor so that it's running only when the spindle is turning. I use a VFD so I can't just wire it parallel to the spindle motor, but tapping into one of the VFD outputs to trigger a relay at some threshold voltage should be straightforward. That could be done after using the drive for a while. I might decide it's fine as-is. Money could be saved with a junkyard motor and inexpensive power modules, but a mill drive for less that $200 is still pretty affordable to me, would work well enough and be less bother.

But keep the conversation going. Thanks, guys.

[J Tiers]

No amount of grease is going to quiet those gears. Each gear pair has from .015 to .030 of tooth clearance, and there's no adjusting them. They're barely engaged. ............................

Does it not have a normal sort of "banjo" setup with slots? Those are pretty universally adjustable, and it looks like it has one that the two change gears are on.

Maybe you mean the slop is in the tumbler gears? Usually those are the ones that are good, but I cannot really see them in the picture, could be clearance, or a shadow.

[Randy]

Maybe you mean the slop is in the tumbler gears?

.
Yes. Poorly fitted, no adjustments possible. I plan to make a new tumbler bracket, and index plate for the selection lever.