PDA

View Full Version : 1/2" DOC on small lathe!



Elninio
08-13-2010, 01:38 PM
http://www.barrystarling.co.uk/id4.html (check out the picture)

Smart and Brown lathe 400
"
This was Smart and Browns most powerful Lathe it was built to celebrate 40 years, it was reported to take a 1" cut on dia without even a flicker from the amp meter.
The name 400 is in relation to the swing over the Bed (400mm)
It's power unit was a D.C SHUNT wound with thyristor, it's frame was a D160 foot mounted with Force vent cooling side mounted fan, giving with the controller a speed range of 50 to 4,700rpm at 50Hz Field weakening to give 10.7 Kw (14.3 hp) at 1000 rpm.
The 1000mm between centres model weighed in at 2.7 tons, the 1500mm at 2.9 tons "

Has anyone ever seen one running or have its manual/plans?

Carld
08-13-2010, 01:56 PM
Well, lathes at the turn of 1900 would take a 1/2" DOC with carbon steel cutters but they turned very slow.

What is so great about that lathe doing that unless it will do it at say, 1000 rpm? The other thing is it takes amps to produce hp to cut the metal so I have a hard time believing it didn't move the amp meter. Oh, you forgot to say the amp meter was a 5000 amp range meter perhaps.:rolleyes:

Is this superman lathe the first one at the link? The 10x24 perhaps?

Elninio
08-13-2010, 01:58 PM
Its the one under the "400" header, the one in green.

jkilroy
08-13-2010, 02:10 PM
My 1020, of similar size, will take cuts like that all day long.

Black_Moons
08-13-2010, 02:16 PM
Blah. also doesnt say what material. my 12x36 will take 0.25" deep on aluminum and 0.1" deep (DOC) on mild steel.. Can hear the motor groaning a little, but it grunts through and thats at highest feed rates and SFM (300+)... PS, my lathe is only 1000lbs.

Of course, the other question is at what RPM and feed rate and work diamiter.

Actual metal removed = RPM * work diamiter * Feed rate * DOC

Elninio
08-13-2010, 02:48 PM
My 1020, of similar size, will take cuts like that all day long.

I'm looking at buying one - do you have any pictures or can you give me a review of the cons of the machine?

Elninio
08-13-2010, 02:49 PM
Blah. also doesnt say what material. my 12x36 will take 0.25" deep on aluminum and 0.1" deep (DOC) on mild steel.. Can hear the motor groaning a little, but it grunts through and thats at highest feed rates and SFM (300+)... PS, my lathe is only 1000lbs.

Of course, the other question is at what RPM and feed rate and work diamiter.

Actual metal removed = RPM * work diamiter * Feed rate * DOC

0.1" DOC? They say five times as much as that!

camdigger
08-13-2010, 02:50 PM
Anyone who has seen Plastools demo their tool holders will have seen the old master take a 1/4" steel rod to a 0.050" pin with a single pass on a Sherline:rolleyes:

Let's make this perfectly clear, though... VERY fine cut (hand controlled - kudos due the old boy), Expert set up - tool on center, minimum overhang both on the work from the chuck and the tool holder, and a sharp (almost brand new insert)....

Dr Stan
08-13-2010, 03:21 PM
When I was on the USS Samuel Gompers we had some 18" American Pacemakers circa 1967 or so which made them 10years old. For those 10 years they had been bolted to a steel deck and I was still able to take 1/2" deep cuts in aluminum bronze with a 1" square chrome moly HSS cutting tool all day long.

I could then turn around and rough in and finish a pump shaft made of monel or kmonel approx 3' long and about 3" in diameter in the middle. The bearing diameters had a tolerance of + or - .0002" and a TIR of .001" max.

Carld
08-13-2010, 05:24 PM
Elninio, if your looking to buy that lathe it may work out ok for you but I don't think you should expect it to take a 1/2" DOC in steel. That is a considerable load on the machine and I do not believe it draws no current to do that. That is a lot of work and work takes horse power and very strong machine.

Now I am not saying it's not a good lathe, it may be very good. Another concern is 24" between centers is short and 36" or 48" is more useful. They are also calling it a Precision lathe and I don't think you would take those kind of cuts on a Precision Tool Room lathe like that because it won't be Precision for very long.

gnm109
08-13-2010, 06:17 PM
If you need a 1/2" DOC, may I suggest buying stock closer to the size you need? LOL.

macona
08-13-2010, 06:22 PM
Anyone who has seen Plastools demo their tool holders will have seen the old master take a 1/4" steel rod to a 0.050" pin with a single pass on a Sherline:rolleyes:

Let's make this perfectly clear, though... VERY fine cut (hand controlled - kudos due the old boy), Expert set up - tool on center, minimum overhang both on the work from the chuck and the tool holder, and a sharp (almost brand new insert)....

And 12L14 steel. I asked...

Mcgyver
08-13-2010, 06:23 PM
S&M are one of the best lathes made, you're talkning a 5000 lb lathe with 14hp; why would a .5 DOC surprise? Besides, its DOC + feedrate + surface speed that you'll give you a removal rate or how much work its doing


I'm looking at buying one - do you have any pictures or can you give me a review of the cons of the machine?

a 400 or 1024? the 1024 is a very high quality machine, reminds me of a 10ee, probably comparable even seems beefier if thats possible.....but you're probably looking at the 1024 that's advertised locally for the last year, walk away, its toast.

Elninio
08-14-2010, 12:19 PM
....but you're probably looking at the 1024 that's advertised locally for the last year, walk away, its toast.
What's wrong with it? If it's not cracked it might be worth fixing (scrap, change bearing, machine some gears for it?)

wierdscience
08-14-2010, 12:51 PM
"Almost no movement of the amp meter"-crappy Lucas amp meters:D