Lathe Question

[Aaron]

Hey everyone,

I know there are a lot of machining wizards here!

I have a steel tube that is 10 inches long and 6.5 inches
diameter. The steel is 1/4 " thick so the ID is 6".

When I see lathes listed as 7" x 12", 14" x 20", etc...
what does that mean?

What spec of lathe is necessary to be able to hold this
6.5" pipe steady so that it can be turned down so that
the middle 80% can be shaved down to 1/8" thick to
lighten it up. Does 7" x 12" mean it can do something
up to 7" diameter and 12" long?

Thanks!

[PwrTrp]

Aaron
Those numbers refer to the swing, measured from the center of the chuck to the ways, and the length. 7 x 20 You can turn a part not more than that dia, and length.

[ANTIQUER]

Lathe diagram

Hi Aaron;

This will help you to understand terminology;

Lathe Diagram with explanantion of components

Also a good place to call for info.
I am assuming you have a piece of water pipe. Unless you have a lot of these to turn I'd suggest a machine shop. Lots cheaper, no safety issues, no ruined pipe.

Al

[1NRG24Seven]

Hey everyone,

I know there are a lot of machining wizards here!

I have a steel tube that is 10 inches long and 6.5 inches
diameter. The steel is 1/4 " thick so the ID is 6".

When I see lathes listed as 7" x 12", 14" x 20", etc...
what does that mean?

What spec of lathe is necessary to be able to hold this
6.5" pipe steady so that it can be turned down so that
the middle 80% can be shaved down to 1/8" thick to
lighten it up. Does 7" x 12" mean it can do something
up to 7" diameter and 12" long?

Thanks!

Aaron....I have a 9 x 20 ...I could turn that pipe with the right chuck set up, and that would leave aprox. 1.5 inches between the pipe and ways. A pipe that big and with that length tho would weigh more then I would like to turn because of motor HP rating. Also tail stock reduces workpiece max length (when on the machine) significantly.

hope this helps...24

[dragon]

Aaron, In order to do any machining to that size you would need to make sure the "swing over table" is large enough to handle it. They rate them for the largest piece you can swing over the way's but with long sections like that you'll need to be able to have the table move under the part to machine the outer diameter.
________

[Aaron]

Lathe & Mill

Thanks everyone!

That answers my question.

This is the lathe I was thinking of:
- Harbor Freight Tools - Quality Tools at the Lowest Prices
It is 3/4 HP so maybe not strong enough for this.

It isn't crucial to lighten this 6x10 piece but I do need to
shave down a 4X10 piece of same thickness.

Would that lathe be strong enough for the 4x10 piece? I'd like to shave
it from 1/4 inch thick to 1/8 inch thick.

Also, I need to drill some angled holes in the 4x10 piece along the
length at 45 degrees.

Would this one work for this size?
- Harbor Freight Tools - Quality Tools at the Lowest Prices
If this smaller one works, that would be fine too:
- Harbor Freight Tools - Quality Tools at the Lowest Prices
If the smaller works, that is better since it is 1/2 the price.

I have some 1/4" to 3/8" thick flat pieces of steel and I want to cut them
into shapes, circles and then a circle in a circle to make rings. A 6.5"
round solid piece is needed and some 4.5" ID rings are needed to be made.
Can the lathe do any of that or do I need some kind of metal saw to get
the general shape first then turn it down on the lathe to make it round?
Also, how would I cut out the middle of a circle to make a ring?

I can actually have this work done free locally for me, but I'm at the
mercy of other people's schedules.

I've actually wanted my own equipment to learn with for a long time but
just never really looked into it so I don't mind spending the money for
the tools. It has been one of the greatest stumbling blocks for me not
doing as many experiments as I want because of not having the equipment.
That 6x10 piece of pipe is probably one of the biggest single pieces I'd
need to machine so if I get a lathe for this, I'd at least like to know I'll have
the biggest that I'll need for 95% of anything I'll ever do.

Plus the above mill and lathe are 110v so I can just run wiring from my
present breaker box without changes, which would be nice.

Thanks for any suggestions or comments!

[Aaron]

combo machine

What do you all think about combo machines? Lathe + Mill?

G0516 Combo Lathe w/ Milling Attachment

So the lathe is 9 3/4" diameter and 21" is "distance between centers" is that
the same as length it can do?

And the mill can do something 8" thick if I'm reading that right?

What are some reasons dedicated/separate machines are better? More
than one person can do something. But what else?

[1NRG24Seven]

Thanks everyone!

That answers my question.

This is the lathe I was thinking of:
- Harbor Freight Tools - Quality Tools at the Lowest Prices
It is 3/4 HP so maybe not strong enough for this.

It isn't crucial to lighten this 6x10 piece but I do need to
shave down a 4X10 piece of same thickness.

Would that lathe be strong enough for the 4x10 piece? I'd like to shave
it from 1/4 inch thick to 1/8 inch thick.

Also, I need to drill some angled holes in the 4x10 piece along the
length at 45 degrees.

Would this one work for this size?
- Harbor Freight Tools - Quality Tools at the Lowest Prices
If this smaller one works, that would be fine too:
- Harbor Freight Tools - Quality Tools at the Lowest Prices
If the smaller works, that is better since it is 1/2 the price.

I have some 1/4" to 3/8" thick flat pieces of steel and I want to cut them
into shapes, circles and then a circle in a circle to make rings. A 6.5"
round solid piece is needed and some 4.5" ID rings are needed to be made.
Can the lathe do any of that or do I need some kind of metal saw to get
the general shape first then turn it down on the lathe to make it round?
Also, how would I cut out the middle of a circle to make a ring?

I can actually have this work done free locally for me, but I'm at the
mercy of other people's schedules.

I've actually wanted my own equipment to learn with for a long time but
just never really looked into it so I don't mind spending the money for
the tools. It has been one of the greatest stumbling blocks for me not
doing as many experiments as I want because of not having the equipment.
That 6x10 piece of pipe is probably one of the biggest single pieces I'd
need to machine so if I get a lathe for this, I'd at least like to know I'll have
the biggest that I'll need for 95% of anything I'll ever do.

Plus the above mill and lathe are 110v so I can just run wiring from my
present breaker box without changes, which would be nice.

Thanks for any suggestions or comments!

Hi Aaron....that is my lathe, except mine has the grizzly label, they are sold under many different tool brands but same exact lathe, and yes you could do a 4" x 10" quite nicely on that unit....hope this helps...24

[ren]

What do you all think about combo machines? Lathe + Mill?

G0516 Combo Lathe w/ Milling Attachment

So the lathe is 9 3/4" diameter and 21" is "distance between centers" is that
the same as length it can do?

And the mill can do something 8" thick if I'm reading that right?

What are some reasons dedicated/separate machines are better? More
than one person can do something. But what else?

Hi Aaron,

Im in the same boat as you right now, Im looking at purchasing a simple lathe to learn and have the ability to work on pieces in my spare time.

One of the pre-requisites I had was the ability to turn pieces with a diameter of 300mm (12 inch) or so. Most of the bench top models in my price range were just too small, usually in the 200 - 250mm range. But then I stumbled on this one. Its a lathe/mill combo, so I guess you get two for one. Im not sure how good the mill is, but the lathe was the only one I found that could do a larger diameter piece in my price range. It has limited length, but that wasnt as much of a concern for me. 400mm diameter x 409mm length.

https://www.machineryhouse.com.au/Pr...stockCode=L159

Regards

[Aaron]

lathes and mills

Thanks 24!

My friend has this mill:


The geometry of that vertical shaft is that rectangle kind. He says when
the bit comes down and puts pressure on something that the vertical bar moves
up to 1/1000's of an inch and throws off the accuracy. Have you or
anyone ever experienced something like that on your lathe/mill combo?

So because of that, I'm thinking about this one:

It is twice the price but I have 20% off coupons for harbor
freight, but the thing is over 600 pounds!!

Are all of these able to be fitted with some aftermarket cnc setup?
I'd like the option if I ever get that involved with it.

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

I don't know who else is a beginner interested in buying some
machining equipment, but there are some yahoo groups I found:

9x20Lathe : 9x20Lathe
X_Series_Mills : X Series Mills

Anyone interested can search those groups for lathe or mills
and a bunch will come up.

That is a really good one with a ton of docs on modifications, etc...
Seems the Harbor Freight and other similar ones are ok out of the box,
but there are a handful of "must have" mods, etc... some machinists are
turning these cheap Chinese lathes into Lamborghinis. Pretty blown away
by what some of them are doing.

There are other yahoo groups - check out the files section. In the one
above, there are a lot of great guides for beginners, etc...

[Shamus]

This may be of use to some. I'm tempted to try it after looking at Gingery's 'Machine Shop From Scrap Metal' book series.

[stonewater]

lathe tailstock

Hi Aaron,

I also have a jet 9x20. there is another thing to consider here and that is the fact that if you have a pipe that is that long you will need to support the end not clamped in the lathe chuck. if your piece is hollow you will have to either get a very large live center, or fabricate a plug that will fit into the end of the pipe that you can use your live center on too support. I will also tell you buy as BIG as you can afford to, both mill and lathe. their is nothing as nice a s a big mill with a 6 or 8 inch rotary table. another thing to think about is the "throat" or arbor size of the chuck mounting. some times you want to machine the end of a piece that is longer, but you cannot because you cannot slide it into the chuck. there is a lot I want to do but cannot because that is a limiting factor for me.

[HiggsBoson]

Aaron, In order to do any machining to that size you would need to make sure the "swing over table" is large enough to handle it. They rate them for the largest piece you can swing over the way's but with long sections like that you'll need to be able to have the table move under the part to machine the outer diameter.

This pretty much sums it up for me, the swing over the ways or bed means nothing if you want to do something near the chuck with a 10 " long pipe.
By the way a pipe is measured by the I.D. and the wall thickness is usually stated later. A 1/2 inch steam pipe looks enormous. 1/2 inch water pipe is much smaller.
Second hand lathes are cheap and a quick tweak of the gibs can give you a larger more versatile machine, But very heavy and hard to move.
Also the the initial inrush of current on startup can draw many amps and overload a circuit that is not standalone ie. household circuit (if mum has the hairdryer going and a heater is on lookout).This needs to be taken into account as a serious lathe normally requires 3 phase power.
Sometimes a separate circuit is advantageous.
Another hint - when you are close to finished diameter the same cut can be run more than once without turning the handle on the cross-slide
By the way I have turned many square and rectangular things on a standard lathe

[Aaron]

mill column - round vs rectangle

I'm looking at mills right now and from different machining forums I've
read, many people knock the round columns versus the rectangle columns.

Why is that? It seem all the ones with round columns would be a lot more
rigid and would have a lot less "flex".

Anyone have any input on this?

[Schpankme]

This is the lathe I was thinking of: 9" x 20" Geared Head, Belt Driven Bench Lathe (3/4 HP).

Optional Suggestion

The CQ9325 is a relatively new 10" bench lathe which directly competes with the popular 9x20 models on price and features.

CQ9325 10x18" (250x450mm) Chinese bench lathe
YouTube - xynudu's Channel

Schpankme

"Measure it to the thousandth, mark it with a felt tip pen and cut it with a chain saw." - LA Capps