Recommend a lathe with 3” spindle hole?

[Leowren]

I’m looking for a lathe with a 3” spindle hole that will fit in a 12’ x 4’ footprint. Any suggestions on a good model lathe to look for that would fit my space?

 

[texasgeartrain]

I'd expect a 3" spindle hole would be a rather large swing lathe, and a slower turning spindle speed. Might be some turret lathes though that have some speed.

Any particular spindle speed you need to turn ? If the work is 3" or smaller, you probably want something that can spin a little quicker.

Not entirely sure what you have in mind for work pieces, but there may be other options if you give some more details.

 

[Leowren]

A typical job would be turning down the ends of a 5-8’ cold rolled steel shaft to fit bearings and a speed reducer on a conveyor. I probably don’t need more than 1000 rpm.

 

[Leowren]

Bearing sizes are usually 2-7/16 or 2-15/6

 

[ncjeeper]

I'd expect a 3" spindle hole would be a rather large swing lathe

Yeah I would think 24" swing or bigger would be a good starting point.

 

[texasgeartrain]

I don't have an exact lathe in mind, but you could have a few different approaches. Regardless which way, your going to need a couple/few steady rests, or steady rest type supports if you manage to get a through hole that large, and want work hanging out the left end of head stock. That should keep the work from whipping and killing someone.

To fit in that foot print, could be you use a lathe with a smaller ID spindle, let's say a 16" to 18" swing. Something with like a 78" spec between centers. But run the lathe without a tail stock to fit the 8' length, assuming 8'plus of bed with TS removed, you'll need a measure. Use steady rest as supports, but also a steady rest at tail stock end to hold work. And do all your cutting on the TS end of lathe.

Might need 96" between centers, but that'll cross your 12' foot print.

 

[Garwood]

Bearing sizes are usually 2-7/16 or 2-15/6

Have you ever done this before? have you ever stuffed a 3" bar 8' long through the headstock of a lathe and did machinisty stuff to the end?

I ask because this seems to be a common dream for folks who've never used a lathe before. They don't realize how difficult it is to get the material through the headstock and then how the hell they're going to support and dial it in on the outboard end.

There are lathes that are made for this. Most turret lathes have big holes because they were offered with barfeeders as options. The barfeed usually had a revolving combination scroll/independent 4 jaw chuck so you could sorta tweak in the outboard end when needed. The other lathes are made for oil field stuff, but usually had much larger holes than 3".

What would suit you better than a large headstock hole would be a long bed lathe with a steady rest. This way you can load the shaft easily, dial in both ends easily and do any work required efficiently.

Shops that do this work frequently like hydraulic cylinder shops often have lathes with revolving steady chucks instead of steady rests.

 

[Leowren]

Yeah I realize having a longer bed lathe would be the preferred way of doing this but I can’t fit it in my space. No I’ve not done this before as my current lathe only has a 1.5” through hole.

 

[Garwood]

Yeah I realize having a longer bed lathe would be the preferred way of doing this but I can’t fit it in my space. No I’ve not done this before as my current lathe only has a 1.5” through hole.

I see. You have a shop size problem, not a problem finding the right machine.

Very possible I could be wrong, but I do not believe the exists an engine lathe on the planet that can turn the ends of an 8'x3" bar and also fit inside a 12' x 4' footprint. The lathe you need is 15' long and 6 feet deep. You need a 16-20" actual swing lathe with 96+ center distance. Add about 6 feet to the center distance and that's how long you need.

The only 16"+ lathes I can think of under 4' deep are the very early flatbelt things. Anything with a gearhead, electric motor, contactor box, chip pan, etc is going to be 5' at a minimum and more like 6-7 deep.

 

[m-lud]

Quote from the Monarch forum:

Mostly for fitting bearings and reducers to shafts for conveyors. Shafts are typically 5-8 feet long and under 3” diameter so I thought it would be nice to have that size through hole. Any ideas on other makes of lathe that would fit the bill? I’ve found a couple Leblond lathes this size but have no experience with them.

Like Garwood said below even with the three inch through hole you cant work the ends of shafts that long with the long length into the headstock without supporting the end coming out the tail end.
I witnessed a guy trying to support a shaft coming out of the tail end with a adjustable stand. It ruined his chuck and his workpiece. You would need a second chuck at the drive end.
I may be misunderstanding your intentions here.

Read Garwood's post below.

Have you ever done this before? have you ever stuffed a 3" bar 8' long through the headstock of a lathe and did machinisty stuff to the end?

I ask because this seems to be a common dream for folks who've never used a lathe before. They don't realize how difficult it is to get the material through the headstock and then how the hell they're going to support and dial it in on the outboard end.

There are lathes that are made for this. Most turret lathes have big holes because they were offered with barfeeders as options. The barfeed usually had a revolving combination scroll/independent 4 jaw chuck so you could sorta tweak in the outboard end when needed. The other lathes are made for oil field stuff, but usually had much larger holes than 3".

What would suit you better than a large headstock hole would be a long bed lathe with a steady rest. This way you can load the shaft easily, dial in both ends easily and do any work required efficiently.

Shops that do this work frequently like hydraulic cylinder shops often have lathes with revolving steady chucks instead of steady rests.

 

[Leowren]

Sounds like I just need to find room for a bigger lathe- that’s what I needed to know- thanks for the help.

 

[m-lud]

Sounds like I just need to find room for a bigger lathe- that’s what I needed to know- thanks for the help.

As Garwood explains in post #9 you are pretty close to finding one that will handle an 8 foot shaft in your desired footprint. And now you wont need the large spindle through hole by chucking it up over the bed.
Although you may still want that large thru hole option.
Keep us posted on your progress.

 

[4GSR]

Here's you a lathe. 4.50" spindle bore, not too long center distance, plenty of swing, easily fit in a two-car garage, under $2k.

Broadbent Metal Lathe | eBay

 

[Garwood]

Here's you a lathe. 4.50" spindle bore, not too long center distance, plenty of swing, easily fit in a two-car garage, under $2k.
| eBay[/url]

That lathe will not fit inside of a 12' x4' footprint.

 

[ncjeeper]

Here's you a lathe. 4.50" spindle bore, not too long center distance, plenty of swing, easily fit in a two-car garage, under $2k.

Broadbent Metal Lathe | eBay

I saw that today and was going to mention it.

 

[Conrad Hoffman]

We used to have a big old lathe at a former job that might have fit your envelope and maybe had a bore big enough. Unfortunately I don't remember what it was. Maybe an old Warner Swasey or something that looked very much like it.

 

[4GSR]

That lathe will not fit inside of a 12' x4' footprint.

Correct. My wrong! BUT a little heave would push out one wall.....

 

[Garwood]

Correct. My wrong! BUT a little heave would push out one wall.....

That looks like a helluva deal though. Never heard of that MTB, but it looks OK enough and the price is right.

 

[gbent]

That Broadbent looks like a lot of lathe for the money. Its just across a little pond from the OP.

 

[4GSR]

If I recall, that is a English made lathe. I bet Limy knows something about them.