Water cooled / air cooled 2.2kw spindle

**EddyCurrent** · 24-02-2015

Originally Posted by suesi34e

. . . but from what I have been reading they need to be run for so long at such a speed and then such a speed and so on.

I think you are referring to the bearings here. The Elte spindle I use has a start up sequence like that but it doesn't last for long and only has to be run at the start of each day. I have a small piece of gcode that runs it through the speed changes at the required intervals so I run it while getting the stove fired up. It's air cooled but I've had it running for hours at a time and it stays pretty cool, it helps that it's industrial quality. It also matters what speed you intend to run the spindle, if it's just slow rpm then you probably don't need the startup sequence but if you intend to run at 20k rpm or higher then I think it's a good thing and cheaper than changing bearings.

**suesi34e** · 24-02-2015

Hi Eddy,

Many thanks for your reply.
Yes, I read about your routine I understand what you are doing. What you say is a help to me I will probably go for the water cooled one as due to the lesser noise. I will have to see if I can get a good deal on one I may check with you guys before I go off and make a purchase. I expect to get a good finish running at 16000 rpm so it sounds like it may not be much of a demand on a spindle.
Many thanks
Suesi

**mitchejc** · 24-02-2015

I complete agree with Eddy, go water cooled. I've got both, a high quality air cooled spindle on a commercial router I got +- 5 years back and a chinese water cooled spindle for the machine I'm building at the moment, so I don't have any practical experience on the water cooled one yet but I've run it several times for testing and its whisper quite in comparison. To me noise is the biggest issue with air cooled, above 16-18k rpm cutting nothing mine sounds like a fighter jet taking off, really the kind of noise that one gets allergic to over time. I think the warm up sequence is similar for both and not a big issue. Run it for a few minutes in the morning increasing rpms gradually and that's it. A little like a car in the morning, if its cold don't start it an blast away at full rpms but not an exact science either so none of the let it idle for 43.5 seconds and then slowly put it in drive and don't exceed 2643rpms for the first 4.432 minutes BS.. :-)

The only pro I can think of for air cooled is that on mine the air exits at the bottom so depending on the kind of cut sometimes I don't switch on the compressed air nozzle to clear chips as the wind from the spindle is enough to clear it. I think the extra effort to add a tank and water pump is a small price to pay for a quieter work environment + other benefits as Eddy outlined.

**suesi34e** · 24-02-2015

Hi mitchejc,

Thanks very much for your msg, what you say makes a lot of sense. I think it is a water cooled all the way! I hope I can easily change the speed as need by via a control as it will not be on a CNC so there will be no code or macro to do that.

Many thanks

Suesi

**EddyCurrent** · 25-02-2015

I've just had a quick look at a Chinese vdf manual and it looks like you can use a digital input to select different acceleration ramp speeds. So in theory you could have a switch somewhere that would select a slow ramp so that the vfd would slowly increase it's speed over time. Then you just switch it back to normal operation.

**suesi34e** · 25-02-2015

Hi EddyCurrenet,

Very good of you to look into that for me mate I appreciate it. I think it is the way I will go perhaps something like this would do the job. http://www.ebay.co.uk/itm/2606245274...%3AMEBIDX%3AIT

I shall do my homework on them now to try and learn about them prior to buying one.

Many thanks

Suesi

**JAZZCNC** · 25-02-2015

Originally Posted by EddyCurrent

I've just had a quick look at a Chinese vdf manual and it looks like you can use a digital input to select different acceleration ramp speeds. So in theory you could have a switch somewhere that would select a slow ramp so that the vfd would slowly increase it's speed over time. Then you just switch it back to normal operation.

There is No need to warm up these spindles they don't use high precision bearings and there's enough tolerence for it not to be a problem.
I've never warmed my spindle up and it's been cutting aluminium for the last 3+yrs for 10+ hrs most days and bearings are still fine with no signs of wear.

**suesi34e** · 25-02-2015

Hi Jazz, thanks very much for the msg mate. What I am learning about these spindles seems to make me more and more keen on one. I don't know if the one in the link I provided is any good seems quite cheap to me so I am unsure!
http://www.ebay.co.uk/itm/2606245274...%3AMEBIDX%3AIT
Many thanks Suesi

**EddyCurrent** · 25-02-2015

Originally Posted by JAZZCNC

There is No need to warm up these spindles they don't use high precision bearings and there's enough tolerence for it not to be a problem.

That sounds right, from what I've read many times, the bearings in these are so shite, why waste your time looking after them.

**JAZZCNC** · 25-02-2015

Originally Posted by EddyCurrent

That sounds right, from what I've read many times, the bearings in these are so shite, why waste your time looking after them.

They do the job and do it well so thats all that matters at end of day.!!. . How much did you pay extra for your spindle/vfd with Not so shite bearings.? Bet I could buy 3 or 4 WC spindles with VFD's for same or less money.!
Even in light/med industrial use I wouldn't buy your spindle and just buy 2 x WC so keeping a spare and still save money.!

Suesi That spindle is fine and they all come from same place and often same person trading under many names.