New to Forum - New South Bend 9" setup

[jfk92]

Hi,

I have wired up a motor to a new to me south bend 9" metal lathe - I have belts on but haven't bolted down the motor frame yet. Is there a video or resource that someone might be able to provide guidance to a guy like me - I am super excited to learn about this tool and how to use it! Much appreciated - I can provide any details further needed -I have some original documentation - 1938! It is in tremendous shape!

Thank you,

John

 

[lectrician1]

you could look on youtube for a video. what are your questions?

 

[jfk92]

Thx lectrician1 - am looking at YouTube as well. Specifically - is there a distance from the mounting bolt hole of the motor/drive pully assembly to the base of the south bend lathe dimension - I have to drill the table I'm using to affix the motor/drive pulley housing. When I ran the motor the flat drive belt just spun over the lathe side pulley and di not turn the spindle. But nothing is bolted yet.... so I need to figure that out.

There is that arm that is pushed to tension the flat belt as well that I'm sure as it's threaded and adjustable needs consideration - so - with no immediate luck/videos found thought maybe there was a resource someone here might be able to point to.

Thank you,
John

 

[icewaterslim]

Don't have the answer to your question but these are nice little lathes. I'm assuming you don't have the gearbox on a 9" but if you did you could do little collet jobs on it. The flat belt drives actually are faster shifting that they look like they'd be. Can't say that for changing spur gears for the cutting feeds, in lieu of a gearbox, though. Only limit besides that is quick polishing as the old fashioned spindle bushings limit spindle RPM to 1200. Even without the gearbox I'd still rather have one than any of the little hobby lathes that are in the retail tool stores with their plastic feed change gears. I hope you got a pile of change gears with it.

 

[QuickChange]

Thx lectrician1 - am looking at YouTube as well. Specifically - is there a distance from the mounting bolt hole of the motor/drive pully assembly to the base of the south bend lathe dimension - I have to drill the table I'm using to affix the motor/drive pulley housing. When I ran the motor the flat drive belt just spun over the lathe side pulley and di not turn the spindle. But nothing is bolted yet.... so I need to figure that out.

There is that arm that is pushed to tension the flat belt as well that I'm sure as it's threaded and adjustable needs consideration - so - with no immediate luck/videos found thought maybe there was a resource someone here might be able to point to.

Thank you,
John

John, there is a SB factory "print" I saw somewhere on this site (I believe) that indicates all these dimensions (for locating the mounting holes of the horizontal drive unit relative to the lathe). I thought I had a copy of same, just went and looked for it, but no go. Someone here on PM probably has a copy they can post for you. Remember to measure TWICE, drill once

 

[CWC(4)]

John
I have a copy of that South Bend publication.
I may have posted it here before, don't remember.
I will try and get it scanned and posted for you later today.
CWC(4)

 

[jfk92]

John
I have a copy of that South Bend publication.
I may have posted it here before, don't remember.
I will try and get it scanned and posted for you later today.
CWC(4)

Quickchange/CWC - thanks so much.

I've bought this lathe weeks ago - finally was able to get assistance in wiring it up - very excited to learn how to use it and appreciate you getting me down the final mile of this beginning! Bought it from my neighbor - was his fathers who passed away this spring - he made some really - really cool things with it - miniature cannons and such - as such - I also have a TON of tooling and attachments including a 4-jaw chuck. an overwhelming about to be honest - all mixed in is tooling for a benchtop Atlas milling machine I also bought - also - tons of tooling - that I have to segregate and organize.

Needless to say I'm excited to start and appreciate anything that can be sent my way.

Best,
John

 

[jfk92]

Thx icewaterslim - I did get additional gears that go with it - I got a TON of things that "go with it" - I have quite a learning curve ahead and am quite excited about the adventure.

 

[johnoder]

Might be helpful from 1940. Says 19 5/8" front of lathe foot to back of drive foot. This is a catalog dedicated to 9" South Bends at that time. SB marked it as being Catalog 50-A

 

[CWC(4)]

John,
I did a quick search and found what you're looking for here:
WEWilliams - South Bend Lathe Library
Fifth from the bottom of the list is " 9 Inch Horizontal Adjustable Motor Drive Bench Lathe ", which has the layout dimensions.
Here is a copy of the layout, thanks to W. E. Williams. Hopefully, you can zoom in and see the dimensions.
I will look at mine later to see if it is the same.
CWC(4)

 

[CWC(4)]

John beat me to it while I was busily (slowly) typing.
That should be everything you need.
CWC(4)

 

[mcload]

Countershaft Mounting and Adjusting

John, welcome to the PM forum, and congrats on your lathe. I'm glad you are excited about it, and hopefully this means you'll maintain it as well as run it. Perhaps I can help and advise on your issue.

First of all, is your belt a seamless belt and still looped between the rear pulleys and headstock? Or does it have a pin that allows you to remove it?
Hopefully, it's the latter. I can only advise according to my set-up, shown below.

The distance between the countershaft (rear drive unit) and your lathe is not a distance written in stone. It can be as close or as far as you want, within reason, of course. Clearly, you don't want it too close to the lathe bed nor too far back where it requires a lot of room between your bench and the wall. On my lathes, I find that 9" is about right between the base of the lathe and the base of the countershaft. Note that I have the round portion of the base facing the rear...I don't think it matters one way or the other.

The first thing you want to do is go ahead and bolt down your lathe, keeping in mind to allow swing of the gear cover on the left. Just center it up on the bench where you feel comfortable. You don't want it far away to where you have to lean way over to watch it. The ideal height is about chest high, again just to avoid having to bend over. No sweat...you can always change this later on once you get it up, running, and cutting. (You can do an image search of "South Bend 9" Lathe" and you'll see tons of photos for reference).

Once your machine is bolted down straight, you can now measure off about 9"-10" from the lathe base to where the base of the countershaft (CS)
should start. (This is more than likely the minimum distance between the two). It is VERY important that you FIRST align the pulleys, otherwise your belt will want to "travel" one direction or the the other. If/when your belt keeps sliding off, this is usually the reason. Find yourself a good straightedge and lay it across both middle pulleys up against the shoulders. Be certain there is NO angle whatsoever between the two. Now mark the 3 holes in your base plate. Be sure to drill in the middle of the "ovals" to allow a bit of final right/left tweaking if necessary. Also know that the two
allen bolts on the base will allow a bit of fine LATERAL ONLY adjustment, but not very much. Ideally, the belt will run without running against a pulley shoulder nor will it drift off. Pretty easy to figure out the geometry here.

Adjust the tensioner to keep the belt taut, but not too tight. Just enough to keep it from slipping. By the way, make sure the pulleys and the inside surface of the belt are VERY clean and free of oil. Use alcohol or acetone to clean the belt. You might disengage the fwd/reverse idler gears on the side (just under the spindle) so that you aren't running all the gears during all of this. (Loosen a bolt and put them in neutral so that neither touch).

Since you are mounting the machine to a new/different bench, you might have to purchase another belt, and I would recommend a pinned belt for now just to get up and running. These are very cheap and probably good to have one around. To measure for a new belt, first set the tensioning rod coupler somewhere in the middle of the threaded ends. Then move the tensioner to "cocked" position. Take a flex steel rule tape and thread all the way around the center pulley to find out the length you need. It should be about 58" or so, but your measurement will be more or less depending on where you mount the CS base. Plenty of people sell belts, but I'd use Albino:
Lathe belt pricing | Your choice of metal-laced belt with pin or complete glue kit

Since I/we have yet to see a photo of your machine, I don't know if you are using a seamless belt, or if you even have flat pulleys or V-pulleys. It is always helpful to show us photos of your issue(s) in the future, so please learn how to post photos (there's a sticky thread up above on how to do this). If I can do it, so can you. It's easy once you learn how.

Now, IF you are running a seamless belt and it is still on your machine, then you will have to modify this procedure a bit in pre-guessing how much tensioning you'll need. See if you can somehow clamp the base first before committing to drilling the bolt holes.

-------------

I'll spare you the lecture, but has your 1938 machine EVER been taken apart and the felts replaced? If not or if you don't know, I sure would do that before getting hot and heavy in using your machine!! You need to oil the hell outta it!
Good luck.

BTW, it would probably be good idea to go on Ebay and buy the South Bend book "How To Run A Lathe". You can get an original, a reprint, or a CD. Someone here will probably send you a link to a free download. But it will answer a lot of your questions and provide very useful information.

PMc

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[jfk92]

CWC(4), johnoder, mcload,

So many thanks for your replies - very helpful. I will be sure to move some things around and test hopefully clamp - prior to drilling.

Took some pics - my flat belt is glued not pinned.

 

[mjr6550]

I'm not sure if your setup is the same as mine. With my SB 9" the motor/countershaft mounting bolts are approximately 18" from the rear bolt of the lathe bed. I got a belt with mine, so the dimension was based on the existing belt length.

 

[mcload]

CWC(4), johnoder, mcload,
So many thanks for your replies - very helpful. I will be sure to move some things around and test hopefully clamp - prior to drilling.
Took some pics - my flat belt is glued not pinned.

Thanks for the pics; looks like a nice little survivor. If you plan on using that oval table, I personally would bolt a solid-core door or perhaps a couple of thick ¾" plywood boards on top of it. Lathes really need to be level and bolted to a very sturdy bench. As opposed to what you might think, they are very flexible from one end to the other, and can contain a lot of twist, which will affect the accuracy of your work. That one seems a bit sketchy, not to mention very little room to mount the countershaft. Sometimes a good old metal desk works good too.

I can tell that the old belt is leather, and probably way past its useful life. Personally, I would cut it off and get a new pinned one (synthetic). This will make your life so much easier and allow you to position the CS wherever you like.
BTW, you are missing a couple of oiler caps on the top yoke of your countershaft. Replacements are cheap and available, but you might
find something to plug the holes with in the meantime.

PMc

 

[mcload]

I'm not sure if your setup is the same as mine. With my SB 9" the motor/countershaft mounting bolts are approximately 18" from the rear bolt of the lathe bed. I got a belt with mine, so the dimension was based on the existing belt length.

Interesting rig, MJR. I've never seen a motor mounted quite like that. I assume it has a 90-degree plate bolted to the CS frame to lift up
when you tension the belt? I mean, it has to!!
Metal drafting table is a good platform for a 9" lathe....love that old light too! (That would be a good alternate bench for JFK).
What Model is it?

PMc

 

[mjr6550]

Mine is a 415 Y (Catalog No. 6, unsure what that means). It is a Model C with change gears and has a 3 foot bed.

I like the high table. Its better for my back II also already had the table when I got the lathe). I put an oil drip pan under it to contain oil and most chips (not an original idea).