Turning Aluminum at 1400??

M

MWCurl

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Hi Guys

I am considering buying a new 1236 lathe that turns at a maximum of 1400 RPM. When I use the formula for calculating recommended RPM’s for turning aluminum with a 1/2” diameter, I get a recommended speed of 2000 RPM. Does anyone have experience turning aluminum with that diameter or small at 1400 RPM? If so, what is the result?

Mike
 
It will work fine. I'm constantly turning small diameter pieces of aluminum at less speed than that just for the fact that I don't want to go to the hassle of changing speeds for such a short operation.
 
It's fine. Think of it as a maximum speed rather than a minimum. I rarely go higher than 400 because I'm lazy and don't want to change the belts around. I mostly use HSS though, which likes lower speeds.

The higher speeds are nice in that things happen faster with the power feed etc.. But it's often only a minute or two with the smaller parts I make, so I don't mind.

If it's 3 phase you could use a VFD to speed up the motor if you want faster, but then you have bearings and gears to consider.
 
I have a 12-36 G4003G, I typically use 1/3rd the recommended speeds. Most of my 1" turning (inside and out) is done at 360 RPMs.

But I am NOT doing production work, nor is my time valuable. {It is to me, but that is a different story.}
 
The spindle speed is dependent on the cutting speed required.
For .5" aluminum, say common 6061 rounds I would consider 2000 RPMs slow.
There is no reason that such a part can not be run at 5000 RPMs using carbide tooling or 2000 RPMs with HSS tooling in general turning operations.

I use 600 FPM as a starting point with this material, this would be 4600 RPMs to start with a .5 diameter round.
 
Speeds are specified for those who need to spend as little time as possible, (production).
Those of us who play in the shop are not required to use the fastest speed. There is no penalty or reason not to go slower than the max. Finish will not suffer.

Edit: Speeds, not feeds. CSR kicking in. Mia Culpa.
 
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I fully understand this, do not however confuse cutting speed and feed rate.
Cutting speed is one parameter, feed is a completely different thing.
 
T Bredehoft said:
Feeds are specified for those who need to spend as little time as possible, (production).
Those of us who play in the shop are not required to use the fastest speed. There is no penalty or reason not to go slower than the max. Finish will not suffer.
Click to expand...
 
I find that if you take your time, you get really good surface finishes in aluminum, if you keep your tooling sharp - no really sharp, and you feed your cutter very, very slowly...

I never use carbide in aluminum so I defer to thos with more experience. I use HSS for aluminum.
 
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