How much RPM for small parts

[JohnJW]

Originally Posted by Geof Would I get the 3600 rpm spindle??? I don't know. I am not very good at hypothetical questions. The extra rpm can be useful as pit202 mentioned, for some steels but it is possible to compensate by using high rake cutters to get a good surface finish. Are you getting the enclosed TL2-P or the open one? To be honest the idea of a chuck doing 3600 rpm just in front of my nose makes me nervous. Not a totally rational response I agree.

Oh no, I've been basing quite a bit of my purchase decision base on some of your posts, ie the enclosure. Looking at it from a dollar point of view I think I'm too cheap to pay for something like the enclosure. I'll look at it and think it's just something to satisfy the EU bureaucrats. However, I saw that Geof has it and a few other people also chime in on it, I figure I should probably get it as well

Anyway since I am getting the full enclosure and initially I'll be turning in the smaller size of the TL-2 envelop maybe the 3600rpm spindle is not a bad idea. It has the same size spindle bore and hp as the regular spindle but I think the 3600rpm spindle is even less popular than the enclosure. How come? Does the 3600rpm spindle have less torque than the 2000 rpm spindle?

[Geof]

Originally Posted by Donkey Hotey ....I don't know of any 10", manual scroll chucks that want to be spun harder than 1500-1800 RPM, right?....

Wrong.

I just checked; the 8" is rated for 3100 rpm max and the 10" for 2700 rpm.

[Geof]

Originally Posted by JohnJW ..... the enclosure. I'll look at it and think it's just something to satisfy the EU bureaucrats..... ...It has the same size spindle bore and hp as the regular spindle but I think the 3600rpm spindle is even less popular than the enclosure. How come? Does the 3600rpm spindle have less torque than the 2000 rpm spindle?

You have a point about EU bureaucrats.

The enclosure does keep you cleaner and dryer and you don't get a face full of chips.

One possibility for the 3600 rpm not being popular is that I think (could be wrong on this) that it needs 3 phase power for the larger motor. This does limit installation flexibility.

[pit202]

Higher RPM`s are great but not so sweet how it seems , on our SL-20 (10" chunk ) we had always trouble to turn small parts above 2800 RPM because the parts were always pushed by the tool into spindle , Higher RPM`s are loosing the pressure on the part , therefore we changed into collets , now we can turn at maximum speed without worry ( up to 65mm bar ).

[Geof]

I cannot resist the temptaion to indulge is some alliteration and say the Polish person's point is very pertinent. (pit202 I apologise if you have to find a dictionary for pertinent.)

My experience with manual chucks is that they do not lose grip as much at high rpm and I always figured this is because they tighten up mechanically.

Hydraulic chucks are really bad and I find it funny how a chuck can be rated for several thousand rpm but it is not useable because the grip is lost.

[Vern Smith]

alliteration - lord, some spell checkers don't carry that one. Must have something to do with endless iterations : < )

[Geof]

Vern;

I am sure you are expecting this so I will not dissappoint:

Alliteration is a literary or rhetorical stylistic device that consists in repeating the same consonant sound at the beginning of several words in close succession. An example is the Mother Goose tongue-twister, "Peter Piper picked a peck of pickled peppers …".

[Vern Smith]

You do bring a pleasant prospective to a discipline dominated by mind numbing geometry, trigonometry, and Boolean mathematics.

[JohnJW]

I got Milton's email Haas_Apps and Milton's reply to my questions is as follows,

The 3500 RPM spindle is only a disadvantage if your work is mostly large and heavy. You have a wide range of work and therefore the wise choice to make is the 3500 RPM spindle mainly because you need the speed for all your small work and still some descent power for large work. The figures below will give you an idea of what I mean.

With the 1800 RPM spindle:
@ 300 rpm you get 110 Ft/lbs of torque and 9 Hp output.
@ 1800 rpm you get 28 Ft/lbs of torque and 9 Hp output.

With the 3500 RPM spindle:
@ 300 rpm you get 83 Ft/lbs of torque and 5 Hp output.
@ 1800 rpm you get 37 Ft/lbs of torque and 12 Hp output.
@ 3500 rpm you get 14 Ft/lbs of torque and 9 Hp output.

The figures above are directly from our Torque/Horsepower charts. It is clear that you would benefit the most from the high RPM spindle due to your variety of work. You will have less power when doing large work. It is a decision you will need to make depending on what type of work you will have the most of and where you want to be most productive. Small work or large?

Please feel to contact me in the future for any more questions regarding your Haas product purchase. If you have any programming or set up questions you can contact the Applications department at (805)278-8500 Selection 2. Also, if you would like to post this in CNC zone, Please feel free. This information and assistance is available to everyone in the machining industry and I would be glad to share my expertise.

Kind regards,

Milton Ramirez
Product Technical Specialist
Turning
Haas Automation, Inc.
mramirez@haascnc.com <mailto:mramirez@haascnc.com>
www.HaasCNC.com <http://www.HaasCNC.com>
Tel: (805)278-1800 X7127
Fax: (805)278-1803

Anyway, thanks again for everyone's input.