Acceptable runout for a water cooled spindle.

[janapriya]

Hi Everyone,

I wanted to upgrade my DC spindle to a more powerful spindle. I went ahead and bought, following combo for US$209.
- 65mm ER11 1.5kW 220v water cooled spindle
- 1.5kW 220v drive inverter VFD
(WARNING: try to avoid this seller) http://www.ebay.com/itm/CNC-65MM-ER11-1 ... Sw~gRVyI8z

I've tested the runout of this spindle, using a 1/4 bit, just below the collect, using a dial indicator. It reads 0.001" runout (0.0254mm). Is this acceptable runout for cutting aluminum, using 1/8 bits?

[twforeman]

Well considering that he advertises the runout as less than 0.005mm...

0.001" runout just below the collet might be okay. Can you test the runout further away from the collet? Say 1.5" down? The runout will most likley increase the further you are from the collet.

[janapriya]

I'm getting same runout inside hollow collect taper.

see:

[janapriya]

Well considering that he advertises the runout as less than 0.005mm...

0.001" runout just below the collet might be okay. Can you test the runout further away from the collet? Say 1.5" down? The runout will most likley increase the further you are from the collet.

Would a drill bit straight enough for this purpose? , just wondering what I can use to measure at 1.5" down.

[Jimf]

I'm getting same runout inside hollow collect taper.

see:

That's where you have to test the runout since ER collets add there own error. Make sure the taper is very clean. Good Low runout ER collets are kinda expensive.

My 2.2kw was about .0005" but was 2 years ago and I haven't bothered to run a test on it since. You really need a good dial indicator to test. I use a brown sharpe bestest .00005" indicator.

Using a .001" indicator will give unacceptable error when trying to measure low runout.

[janapriya]

Thanks @jimf

[janapriya]

0.001" runout just below the collet might be okay.

thanks @twforeman