Are slant bed machines superior to flat bed machines?

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08-17-2007, 01:28 AM
Quickers

Are slant bed machines superior to flat bed machines?

Companies that sell machines with slant beds constantly rave about the improvement in quality compared to flat bed design. Is this school of thought really justified?

I am looking to buy my first CNC lathe and have narrowed it down to a Daewoo Lynx 220 (30deg slant bed) or a Haas SL20 (flat bed) all I keep hearing about from the Daewoo dealer is how superior his machine is because of the slant bed. Does it really matter or is it just sales talk?

My company only machines plastic anyway so will it really make a difference?
08-17-2007, 03:05 AM
HuFlungDung

You might not think it was a big deal, but getting the chips to fall (reliably) out of harms way is the biggest plus I can see for a slant bed. A conventional bed seems to have more places to snag and pile chips up.

Also, I guess that it is easier to see what is happening in the cut zone on a slant bed, and when doing tool setting, without having to lean way over, and so on.
08-17-2007, 04:12 AM
.xXACEXx.

ive been runing lathes for a few years now...i ran a slant bed for about 3 years...and flat bed for about 4-5 years...for production huflungdung is right..it is very important for the chips to fall to the chip pan...slant beds do this better...plus most take up less space,every thing is rotated about the centerline away from the operator which can put the spindle closer to get parts in and out ,dont get mw wrong i love flat beds (feel more comfortable with them) but for production a slant bed prolly is better...only my 2 cents
08-17-2007, 05:22 AM
Geof

Quote:

Originally Posted by Quickers

....I am looking to buy my first CNC lathe and have narrowed it down to a Daewoo Lynx 220 (30deg slant bed) or a Haas SL20 (flat bed) .....

This confuses me. The Haas SL series, like the HL before them, are what I thought were slant bed machines. The X axis comes in from the back and is inclined upwards at an angle of about 30 degrees.
08-17-2007, 05:28 AM
toastydeath

Just a little bit of history for anyone interested, the switch to slant beds came after thermal effects in machining were better understood. Hot chips falling on the ways conveyed a lot of heat, adding an element of unpredictability. This became a big issue after the speed of CNC equipment began to pick up, which in turn produced a hotter, but smaller, chip. It was this point that the switch to slant bed machines began, and ways with huge temperature differentials in them became less of a problem.
08-17-2007, 10:06 AM
Quickers

Just to clarify what I ment.
The Daewoo machine is a true slant bed because the Z and x axis slides both run on an angle, whilst with the Haas lathe the Z axis slides run on a horizontal plane and the X axis runs on the angled plane.
08-19-2007, 12:56 PM
star-turn

In past experience i have found that flat bed lathes hold tighter limits for longer ie. harhinge and Nakamura. these lathes also tend to be small and built for high precision.

BUT, my personal preference is slant beds, much easier to work with, ( space wise ) and of course a lot less conjestion with swarf.

just remember, you get what you pay for....

While both the Haas and Daewoo ( Puma, Lynx ) are good machines, they are fabricated m/c beds rather than the more soild cast beds of top quality machines.

overall i would go for Daewoo, usually they have more for the money - but over the long haul ( 5 to 10 years ) both makes will show wear and tear that would leave little between them.

Another factor, with all machines is how hard you treat them and if you prang them!

I run a Nakamura 35 ( 12 yr. old ) that held 0.02mm limits all day with great finishes ) yet the sister m/c, which had an animal running it for 5 years and crashed several times ran like a pig.

All the Best

ST
08-19-2007, 01:59 PM
Geof

Quote:

Originally Posted by star-turn

..While both the Haas and Daewoo ( Puma, Lynx ) are good machines, they are fabricated m/c beds rather than the more soild cast beds of top quality machines....ST

Haas is cast.
08-19-2007, 02:26 PM
star-turn

really ? then i happily stand corrected.

but i'm sure that the sl10 i worked on was made up of several parts.
08-19-2007, 02:41 PM
Geof

Quote:

Originally Posted by star-turn

really ? then i happily stand corrected.

but i'm sure that the sl10 i worked on was made up of several parts.

Well, yes, most machines are made up of several parts; a base, a head stock, Z axis carriage, X axis cross-slide and a few other bits and pieces bolted on here and there :D .

But to be serious, the SL10 bed is a casting, one piece from end to end top to bottom.

Haas does make one range of machines that are fabricated, the Gantry machines; rather immense fabrications too.

The MiniMill/Super MiniMill machines confuse some people. The base of the machine is a fabrication which also forms the coolant tank but there is a casting bolted on top of the base and the column is a casting.
08-19-2007, 03:27 PM
star-turn

So i'm betting that you are a Haas Fan then ??

(not that i'm saying Haas are rubbish!...... just that there are many better machines out there )

ST
08-19-2007, 04:10 PM
Geof

Quote:

Originally Posted by star-turn

So i'm betting that you are a Haas Fan then ??

(not that i'm saying Haas are rubbish!...... just that there are many better machines out there )

ST

Better value for the price?

I wouldn't identify myself as a Haas fan but my business uses all Haas machines simply because the first machine I bought at a very good price was Haas and I was too lazy to learn a different control when I bought sixteen more. I suppose I could have spent two or three times as much money buying other machines but then I would not be able to afford the price of a Contache every year because it would be eaten up in machine payments :) .
08-19-2007, 06:02 PM
star-turn

WOW! what can i say Geof, such a great business empire, plus finding th time to do all those posts in this forum as well!! - i bet you never get time to sleep!!

still that information will be invaluable to the OP who asked about slant beds vs flatbeds !!!
08-19-2007, 07:10 PM
Geof

Quote:

Originally Posted by star-turn

WOW! what can i say Geof, such a great business empire, plus finding th time to do all those posts in this forum as well!!....

That is because I have Haas machines, and good employees, the machines just run and run so I am not needed 90% of the time. :D :D
03-27-2009, 04:49 AM
1Adam12

SLANT BED

Slant bed can move faster with less resistance because of gravity.
03-28-2009, 06:41 PM
Glacern

Quote:

Originally Posted by 1Adam12

...less resistance because of gravity.

That's only true with the X-axis (and Y-axis if you have one) in the minus direction. Gravity creates more resistance in the X and Y axes when holding position or moving in the plus direction, and it doesn't affect the Z-axis.
06-01-2019, 09:11 PM
Bluey312

Quote:

Originally Posted by star-turn

WOW! what can i say Geof, such a great business empire, plus finding th time to do all those posts in this forum as well!! - i bet you never get time to sleep!!

still that information will be invaluable to the OP who asked about slant beds vs flatbeds !!!

Got put in your place.... Buthurt looser!