BT30 or BT40 ?

[kimhan]

Hi all,

I am considering buying chevalier VMC 1418
They have BT30 and BT 40 models

My work mostly 6061,7075 and stainless steel , small run prototyping works

Which model suitable : 15k rpm BT 30 or 10k BT40 ?

I appreciate any comment / suggestion

Thanks
Jon

[DareBee]

If you are working the aluminum with small dia endmills you will REALLY want the 15K spindle. If not using too many small cutters go with the 40 taper. 30 taper is not rigid enough for heavier work and the tooling is less common.

[kimhan]

Thanks for your info, I think 3mm endmill is the smallest , should I go with 40 taper?

[Zumba]

No question, go with the 40.

[DareBee]

For me - I agree with Zumba

BUT

I have done some large aluminum parts with small diameter cutters. For instance a 3mm cutter carbide with AT coating should run at 38,000 RPM. I have a 10,000 RPM spindle. My machine cutting time was somewhere around 70 hours on this part. If I could have met SFM I would have saved 50 hours on that part. At 15,000 RPM I would have saved 17.5 hours.

You need to consider how much aluminum and how often small cutters.
I will only buy 40 taper or bigger and my next machine will have a 15K spindle.

[kimhan]

I am thinking about spindle heat developed by 15k spindle.
running it more than 8 hours, will be there any problem because this model has no spindle chiller

Jon

[HIRAH]

don't forget to balance holders running that high of an rpm.
recommended balancing is over 15,000 rpm, but definately over 20,000 or you are going to have spindle issues.
and don't just buy balanced holders and put tools in, they need to be balanced together at those rpms. it's amazing how much the force on the spindle increases with an unbalanced holder as the rpms go over 15,000.

[eorourke]

No doubt, you should get the biggest diameter spindle available or you are going to run into chatter problems. Even with 15K spindles, they are not fast enough to do justice to the small diameter tooling today. You also mentioned SS. You certainly don't want to machine SS with a 30 taper. BTW, any time one runs over 8K rpms, you should balance the toolholders. You will get better spindle performance, better tool life since you have minimized the potential for tool runout and better surface finishes. With small diameter tooling, with a balanced toolholder at 2.5 g, and indicated in, it should work very well for you.

[silverfoxx03]

If you could get HSK taper it would be wayyy better. HSK63A would be sweet--

[eorourke]

You ain't gonna get no HSK from Chevalier!