Spindle Speed Controller Question

[A_Camera]

Its a question of choice

Exactly. ...and one choice is not necessarily worse or better than the other. It seems that not everyone understands the meaning of this simple word called "choice".

Water cooled spindle :
1 Does not care about wood or metal dust , so will not clog, and dust there is , believe me on that. Even a vacuum shoe could not cover all typical scenarios.

I don't know if that clogging spindle is really such a problem in reality. Yes, dust is an issue, especially with wood, but even with water cooled, one should still have dust extraction. I can't for my life understand people milling wood on CNCs day in and day out and not installing any dust shoe, regardless if they use water cooled or air cooled spindles. If nothing else, they should think about their own health.

2. Will make negligible noise, which will not matter as usually cutter makes more noise. But not so with small cutters on plastic or metal. There its virtually silent

Like I said to the OP... compared to air cooled 400W DC motor, or any other air cooled spindles, like the pretty popular Kress, the brush less air cooled motors are pretty quiet and DEFINITELY not noisier that the those compared with at the same speed. I never said water cooled are not quieter that air cooled brush less motors. On the other hand, in my case I have used an air cooled 400W DC motor for one year, and the noise of the motor is definitely not a lot at maximum speed (12k RPM). I compared it with my air cooled brushless spindle and that is DEFINITELY even quieter. Once milling starts the motor noise is totally gone, overtaken by the cutting noise even though I basically only cut plastics. That cutter noise would be EXACTLY the same regardless if I used a water cooled spindle or air cooled one. Comparing the spindle at 24k RPM with the DC motor at 12k RPM is pointless, of course that the spindle is noisier in that case, just like if I drive at 100 kmh and then accelerate to 200kmh, engine noise will increase even in the best car. So the noise argument for my part is just nonsense. But, never the less, of course, I understand that by eliminating the fan and closing in the motor, like it is in a water cooled one, that motor generates less no load noise that one with a fan inside and holes right through. Also, as I said, if I'd run my CNC for many hours a day and 5-6 days a week I would not hesitate installing a water cooled spindle, but I don't, so for me life is easier with an air cooled one.

3. In fact there is no need for pump at all. Connect to water using garden hose connector and transparent cheap tubing and let it run. it will wast how much? 5 $ for one year

It is wasting water never the less. Very anti-environmental, considering the majority of earth does not even have access to potable water for their survival. Never the less, yes, that's an option if one is keen on saving a few bucks or have his CNC near enough to water. Again, I just described MY needs and MY choice. I know there are many other alternatives and many options to how water cooling can be done, but using air cooled spindle is one such option if there is no need for water cooled one.

4. A good proper spindle pump is 35$, an italian brand garden small pump is like 20 euro here. from a second hand market 1 euro and will run forever. yes even a 3$ one. The pump inside have no elements that could fail. Ceramic rotor and plastic fins. Water is the cooling and bearing.

Yes, I am aware of those prices and 35$ is more reasonable than the previously mentioned £3. I would not even touch a pump that cheap. Never the less, I don't know why people bring up costs as an issue. Why does everyone assume that cost savings was something I consider against water cooled spindles? On the other hand, if I'd go for a water cooled spindle I'd buy quality parts because it is indeed a critical part of the spindle. After all, if the pump fails your spindle will send smoke signals after a few minutes...

Actually, pumps can fail, they have indeed elements that can fail, but they don't rotate as fast as a fan in the spindle. Anyway, I have so far not heard of fan failure in these spindles. It can happen, I know that, but in really... anything can break, even a water cooled spindle or a pump.

When i bought my first spindle nobody had run it more than 5 months or disassembled it. Spindle bearings were a sacred subject. Water cooling was sth from science fiction. All were using Kress or Dewalt , etc. routers. Now all we know water cooled spindles are good for years to run. bearings are cheap. Most come with front ceramic bearings. So i don't see why the doubt.

I don't doubt at all that there are advantages of water cooled spindles. Where did you get such an idea? All I try to say that it is not needed, nor necessary for everyone and that not everyone wants one. You said it yourself, "Its a question of choice". It is not necessary to have one SINGLE choice for all, that's not choice...

[Boyan Silyavski]

Actually, pumps can fail, they have indeed elements that can fail, but they don't rotate as fast as a fan in the spindle. Anyway, I have so far not heard of fan failure in these spindles. It can happen, I know that, but in really... anything can break, even a water cooled spindle or a pump.

Even so if you are not milling steel and pushing it to its limits the spindle will NOT fail. It will heat up to ~60C, hot to the touch, but will continue to happily cut normally wood or light cuts in aluminum. It happened to me a couple of times when i was testing the new machines and the relay was not connected, so i had to manually turn on the pump. No smoke or whatsoever.

[JAZZCNC]

Even so if you are not milling steel and pushing it to its limits the spindle will NOT fail. It will heat up to ~60C, hot to the touch, but will continue to happily cut normally wood or light cuts in aluminum. It happened to me a couple of times when i was testing the new machines and the relay was not connected, so i had to manually turn on the pump. No smoke or whatsoever.

I'll Confirm and Back up this. For Jobs less than 30-45 I don't bother connecting the hose pipe and I exclusively cut Aluminium. Also like Boyan unknowingly due to my error I've cut jobs lasting 2hrs+ without water being on and not had any issues. Take the Fan off your air cooled spindle and watch it melt down in 10mins.!!

[Ger21]

I've used high quality air cooled spindles for years with no issues, running 8-10 hours a day, 6 days a week. HSD spindles with electric fans for over 10 years at a previous job.
At my current job, we have a 10HP spindle that's cooled by the dust collection airflow. It's been running full time for over 8 years now.

I own a couple air cooled chinese spindles, but haven't used them yet to see how long they'll last.

[JAZZCNC]

I've used high quality air cooled spindles for years with no issues, running 8-10 hours a day, 6 days a week. HSD spindles with electric fans for over 10 years at a previous job.
At my current job, we have a 10HP spindle that's cooled by the dust collection airflow. It's been running full time for over 8 years now.

I own a couple air cooled chinese spindles, but haven't used them yet to see how long they'll last.

Yes Gerry but that's not comparing Apples with apples. High quality Air cooled HSD spindle is different Animal to the cheap Air cooled what's been talked about here.
In my experience at the price level of the WC spindle NOTHING comes close to comparing and only fool would buy Air cooled at or very close to same money has WC.

[Rye]

I have a shonky Chinese 6040(any luck i'll be upgrading soon) that's falling to bits at the seems, but the 1.5kw WC ER11 spindle works a charm. Often have it running for 8 hrs solid and it only just gets warm to touch. Very quiet too - although the same can't be said for my pump(gets hot and sounds like a foghorn; anyone recommend a relatively cheap and "silent" one from ebay UK, would be grateful.) Would definitely recommend a WC over an AC - but get one with a larger collet than ER11.

[Neale]

I use a Whale submersible pump, designed as a pressure pump for fresh water for caravans, etc. Says max run time 15 mins at 12V, but I use 12V to purge the air at the start of a session then switch to 5V and it runs silently and happily for hours on end. Sits in a bucket of water and connects via cheap pvc tubing. Cost about a tenner, about 4 years ago, and still running fine.

[A_Camera]

Yes Gerry but that's not comparing Apples with apples. High quality Air cooled HSD spindle is different Animal to the cheap Air cooled what's been talked about here.
In my experience at the price level of the WC spindle NOTHING comes close to comparing and only fool would buy Air cooled at or very close to same money has WC.

Only a narrow minded fool does not understand that different people have different needs. Money is not an issue in my case, has NOTHING to do with why I prefer air cooled.

[A_Camera]

I've used high quality air cooled spindles for years with no issues, running 8-10 hours a day, 6 days a week. HSD spindles with electric fans for over 10 years at a previous job.
At my current job, we have a 10HP spindle that's cooled by the dust collection airflow. It's been running full time for over 8 years now.

I own a couple air cooled chinese spindles, but haven't used them yet to see how long they'll last.

Air cooling in itself is not negative, except in the narrow minds of some people. Water cooled is a buzz word among hobby CNC machinists today, everybody wants it regardless if they really need it, and some preachers are chanting about it like if it was best thing after sliced bread. As far as I understand, the only real advantage of water cooled spindle is the possibility to run the spindle at very low speeds, and/or for very long periods non-stop. On the other hand, if that is necessary then these cheap Chinese 24k RPM spindles are the wrong choice anyway. Many people use spindle noise as an argument, but that is only valid for those who are always milling air. Blowing around of dust may be an issue for those milling MDF or wood, but that's only an issue for those who don't have any dust extraction, which in my opinion is just as important with water cooled as it is with air cooled spindles, at least if you are milling wood or any other dusty material. Yes, the fan inside can break, but so can even the cheap bearings (which is more likely to break at high speeds) or the water pump, or the water sealing gaskets inside the spindle or the joints or whatever else.

BTW, I checked at the HSD spindles and interestingly, most smaller power air cooled have the same kind of built in fan as the cheap Chinese spindles we are talking about. Only a very few have active cooling with electric fans. Also interestingly, most of their motors have a large gap between rated and maximum speed, so calling these cheap Chinese motors 24k RPM motors is a bit wrong, even here, regardless if we talk about the water or air cooled ones. I think my assumption earlier that these cheap motors should not be run at speeds higher than 18-20k RPM, at lest not for long, was about right if even the more expensive ones have 18k rated RPM. Yes, they may work at 24k as well, but they are not designed for that. So, while water cooled has it's advantages, I don't think it is necessary for everyone, and definitely not for me. I have used my air cooled DC motor for about a year now, and never once I thought "...oh, I only wish I had a water cooled spindle" so I should know and understand my needs by now. Never the less, if my current cheap air cooled spindle would die, I'll have a closer look at HSD, or some other quality air cooled spindles, so thank you for the information. I know the price is about the same as my CNC costs, at least for some of them, but hey, this is my hobby and we live only once...

[Clive S]

I see that you are still trashing this post by Thomas just like you did with the another one.

It is not good manners to take a thread so far off course why don't you start a thread of your own.