Smaller-Dia 4-step Pulley for Rockwell 46-111 Lathe?

[Tom Overthere]

I'm considering buying my first lathe, a used "home shop" Rockwell 4-Speed, circa 1970s. It's kind of small and light, but seems to have a decent reputation online. It has an 11" swing over the bed and 14" over the gap.

Here's a link to an example being sold online (http://74.125.47.132/search?q=cache:lg9AHf3806UJ:www.stripersonline.com/surftalk/showthread.php%3Ft%3D629352+Rockwell+4-speed+Lathe+Model+%2346-111&cd=5&hl=en&ct=clnk&gl=us)

There's a 4-step pulley on the motor shaft, and another on the spindle. The seller tells me the speed range using the original 1/3 HP 110v motor is 3250/2220/1475/990 RPM.

That seems waaaay fast for this thing. I'd like to get the bottom speed down to around 300 RPM.

Does anybody know where I can find a replacement 4-step motor pulley that'll get me close to that? I'm thinking that might be hard to find...

Thanks

[Dennis Ford]

I agree that the step pulley will likely be hard to find and I believe you will have to put larger pulley on the spindle instead of / addition to the smaller pulley on the motor.

[Mark Norman]

Get some good hard maple and make a pair. Its worth a shot, I've seen many old wood pulleys and ya have a lathe.

[Bob Vallaster]

The upper pulley is limited by the casting, so there's no increasing that.
Although there are 4-step pulleys available, the target of achieving 70% speed reduction with just a bottom pulley change will approach the diameter of the motor shaft itself. Feel free to search brands like Browning, Chicago, Congress and others.
If the hunt is unrewarded, there are at least three alternatives: 1) Jackshaft (also called intermediate shaft), 2) DC motor & speed control, or 3) 3-phase motor & inverter (also gives speed control).

BobV

[Phillip Bogle]

I just bought a Rockwell 46-525. It probably has the same pulley. I can get replacement parts at acetoolrepair . You can get a variable speed clutch drive or a DC drive motor. You might even be able to buy the parts from an upgrade model and upgrade to the variable speed.

Good luck.

[Tom Overthere]

Thanks, fellows. All good answers. None are what I wanted to hear. :D

Dennis == That's what I thought, but Bob is right. The headstock housing is tight with the standard pulley in there.

Mark == I know! :D I can't wait to have that capability!

Bob == Point taken. I hadn't actually done the math/geometry, but was thinking that's a BIG reduction - from 990 down to 300 RPM. The "Jackshaft" idea is very interesting. I'll see what more I can find out about that.

Phillip == I checked Ace Tool Repair. I see the standard headstock pulley in their schematics. Good to know. Thanks.

I own this Griz 0463 bench mill (http://www.grizzly.com/products/Mill-Drill/G0463) and was thinking maybe I can find a similar DC variable-speed reversing motor to swap into this lathe (basically a treadmill motor, or so I've heard). But all told, that'll probably double the cost of the lathe...

The 46-111 is shorter than I want (38" bare spindle-to-spindle), has limited swing and is somewhat light in weight. I look it / talk it over on Friday. The seller is quite knowledgeable and teaches lathe classes. Hopefully he'll know some obscure workaround (yeah, maybe).

Might have to pass...

[Tom Overthere]

Found this jackshaft kit (http://cgi.ebay.com/New-Delta-Rockwell-16%22-Lathe-Jackshaft-Retrofit-Kit_W0QQitemZ120402451939QQcmdZViewItem) with just a 2-step pulley that appears to slide freely on a shaft. I guess for slowest possible speed: You run belt-1 from smallest motor pulley to large jackshaft pulley. Then run belt-2 from small jackshaft pulley to largest headstock pulley.

Also found this arrangement (http://home.comcast.net/~dpotts77/Machines/Lathes.htm), where a second bed was added for 76" length, and a jackshaft with opposed pulleys on either end is intermediate between motor and headstock spindle (16 speeds, but no fun changing 'em :D)

Very interesting, but not sure I'll have what I want/need in the end...

[Bill O'Conner]

PSI sells a replacement moter and hardware to replace the motors on the some of the mini lathes to make them VS for about 110 dollars http://www.pennstateind.com/store/TCLVSKIT.html

don't know if you could retro fit it to the one you're looking at

Bill

[Paul Atkins]

That was my first lathe and I made a platform with a jackshaft and the motor on it. Hinged at the back, the full weight weight of the motor was not on the lathe spindle and there's a shaft that I put a leather strop on. If I can get a picture of it I'll send it. The motor had a double pulley matched with the countershaft pulley and then went to the four speed setup. I then had 8 speeds. (4 plus Hi/lo) Following Del Stubbs setup with a rope and pulley to the floor step plate for a slip clutch effect. Yeah I know-pictures.

[Mark Norman]

Found this jackshaft kit (http://cgi.ebay.com/New-Delta-Rockwell-16%22-Lathe-Jackshaft-Retrofit-Kit_W0QQitemZ120402451939QQcmdZViewItem) with just a 2-step pulley that appears to slide freely on a shaft. I guess for slowest possible speed: You run belt-1 from smallest motor pulley to large jackshaft pulley. Then run belt-2 from small jackshaft pulley to largest headstock pulley.
...
Looks like just the ticket!

and looks like its made for your application. might work out for ya. keep us posted.

[Tom Overthere]

PSI sells a replacement moter and hardware to replace the motors on the some of the mini lathes to make them VS for about 110 dollars http://www.pennstateind.com/store/TCLVSKIT.html
Bill ==
That's a great idea. I found instructions on the page you linked, but am not sure I can retrofit... I wish I could find a picture of that kit actually mounted to a lathe.

There's no reversing switch either, so I'm going to Google my brains out and see if there are other VS conversion kits available. Thanks.

[claude callender]

I realize this is an old thread but maybe someone is still checking on it. I have a 46-111 lathe which I converted the motor to a 2 1/2 hp treadmill motor keeping the mc-60 speed controller to operate. Recently I began to have trouble with the vs switch. I ordered another one off eBay and hooked it up. Now I am having crazy happenings with speed. I can start out turning the dial up to about 500 and all of a sudden the motor will jump up to 800, 900, 1100 rpms. These are example #’s as they vary each time. Just saying it’s as though it is cursed and it go’s to a speed it wants. I can wiggle the switch and it might go down to 150 or so then wind back up into the 1000’s. Is it a bad switch or short or is the mc-60 going out? SUre would be nice to drive the demons out and have my old lathe back. Anybody ever heard of such? If so please help.
Thanks to all!

[Brice Rogers]

You mention a VS switch. In almost all cases, the component that controls the speed is a potentiometer not a switch. While the problem could be a lot of things, I'm wondering if you have a bad solder connection to the "pot" or a bad ("noisy") pot.

[Thomas L Carpenter]

I needed to slow my old step pulleyed lath down drastically to turn a large hunk of lumber. I replaced both step pulleys. Got the smallest pulley I could find for the motor and a large one for the lath. Got them both a Tractor Supply. Worked great. I don't now tee final RPMs but I was able to turn the large spindle without scaring myself to death. I replaced the step pulleys after I was done.