Spindle Speed Controller Question

[thomashomer1986]

Hello all, another basic question here from myself!

I've managed to 'acquire' a spindle. very similar to this for nothing:
http://www.ebay.co.uk/itm/DC12-48V-Air-Cooled-0-4KW-Spindle-Motor-400W-ER11-for-Engraving-Milling-Machine-/252413006441hash=item3ac4fcd269:g:a6EAAOSwEgVWTYBS (http://www.ebay.co.uk/itm/DC12-48V-Air-Cooled-0-4KW-Spindle-Motor-400W-ER11-for-Engraving-Milling-Machine-/252413006441?hash=item3ac4fcd269:g:a6EAAOSwEgVWTYB S)

Now i know these are very underpowered and probably pretty useless for most work, but i currently don't have a spindle at all and my machine is just sitting there making nothing at the moment and i really want to start making chips! even if they are only small ones lol.

i'm only going to be cutting wood so i don't mind using a small spindle just for now until i can upgrade.

my question is though what kind of speed controller do i need? or do i need an inverter/vfd? if it is the latter am i just better off buying a new spindle/vfd together like this one?

http://www.ebay.co.uk/itm/1-5KW-AIR-COOLED-SPINDLE-MOTOR-1-5KW-VFD-DE-4-BEARING-MILL-GRIND-ENGRAVING-/200687114979?hash=item2eb9e25ae3:g:juYAAOSwAPlXhcv h

apologies for sounding dumb, but i'm rubbish with electronics lol.

i have the leadshine mx3660 breakout/driver board so if possible it would be nice to be able to switch the spindle on and control the speed through that. im using linuxcnc.

thanks in advance

[Lee Roberts]

Hi Thomas,

I think when all said and done these motors/spindles are just a typical DC motor, so you can just give them 12-48v and your away.

I would imagine then that you can just vary the voltage supplied, to control the speed, you may be able to do this with a controller depending on what you've got, however it may just be better to get/use a standard type potentiometer where you control the speed manually.

I say the above because to be honest I wouldn't bother to invest any time or energy in one of those spindles, they work yes (they hold a cutter and spin) but their not really up to much at all, not sure if you've noticed or not but they are fitted with an ER11 collet, that's going to limit you to very small cutters for a start.

If your looking to fit it to one of these £4-500 Chinese machines, then yeah pop it on the machine and crack on making dust as you've nothing to lose.

If it's going on a machine that is much more capable then that is when I would say don't bother, the machine will be capable of more than the spindle will like and you'll just kill it or be limiting yourself/machine, it will just end up being a false economy is what I mean to say.

If you consider what is involved with adding a spindle to a machine (properly), it would be a much better investment of everything to use a more worthy spindle to start with.

The best price I can find a 2.2k water cooled spindle and vfd for is £180, they've sold lots, comes with a 2 year warranty but more attractive is the quote of 4 quality bearings in the spindle:

http://www.ebay.co.uk/itm/170746857178

I haven't ordered from them yet but I will be soon and I'm pretty positive that's who I will buy from, they do have negative feedback but I couldn't find any that related to this item.

As I said these spindles do work, here is a video of one actually cutting something:

https://youtu.be/6v534cJNzrU

.Me

[Clive S]

Thomas If this is the build you are doing http://www.mycncuk.com/threads/6832-my-router-build-advice-needed/page2 I would go with a Water cooled spindle as they are very quiet. The air cooled are noisy. As Lee has said the 1.5KW has an ER11 collet the 2.2Kw has the ER20 which would be better if you want to make a bigger machine in the future. You won't be happy with the DC after a few minuets . Good luck with the build.

[Ger21]

Most of those little 400w "spindles" come with controllers that use a pot to control the speed. You should be able to use the PWM signal from Mach3 and convert it to a 0-5V signal to use in place of the pot.

But really, you're better off buying a real spindle.

[Boyan Silyavski]

1hp spindles also work very good for small machines and cutters up to 8mm. Plus a brand 0.75kw VFD like Toshiba are around 110 euro only. Actually for a small machine not meant for production, i don't see a reason for a bigger spindle.

Less than that i would not go.

[thomashomer1986]

Yes Clive that is the machine it is for, it's been a long build but it will get finished one day lol! Family life takes over and it keeps having to be put on hold.

I'll leave the 400w spindle then, I was expecting that answer tbh!

I'll save up and get the water cooled spindle then, I will have to get some new brackets made to mount it tho so may take me a bit longer. I used to be a machinist in a heavy engineering workshop so had access to making pretty much anything I wanted back then, but now I'm in an office job I'm limited to asking my old work mates to make bits for me!

Do you have a link to one of those spindles Boyan?

Thanks for the advice everyone!

[Boyan Silyavski]

Do you have a link to one of those spindles Boyan?



0.8kw spindle (http://www.ebay.co.uk/sch/i.html?_from=R40&_trksid=p2047675.m570.l1313.TR0.TRC0.H0.X0.8kw+spi ndle.TRS0&_nkw=0.8kw+spindle&_sacat=0), its ok to buy it together with the chinese VFD drive, which many people use. I use one for my 3kw spindle , price wise. But for smaller motors i personally use and prefer the Toshiba VFD (http://www.ebay.co.uk/itm/INVERTER-VETTORIALE-TOSHIBA-0-75-kW-230-Volt-MONOFASE-USCITA-MOTORE-TRIFASE-1-HP-/262497473532?hash=item3d1e1193fc:m:maMd849Pw6kmG87 cmq8J1bw)


With the correct cutter 0.8kw spindle does not have problem to go up to 1/4 deep in aluminum with 1/4 carbide bit, provided mist cooling

[Clive S]

The 0.8Kw spindle are only 65mm Dia. Think first if you are going to build a bigger machine in the future as the 1.5Kw or 2.2Kw are not much more money and they have a bigger collet

[thomashomer1986]

I did make a mistake when building my machine to not account for a bigger spindle, but who doesn't make mistakes on there first build lol?

The idea of this build was just to get me going and learn from it so that when i wanted to make a bigger and better machine i would have a better understanding of machine building. However since my circumstances have now changed considerably (ie 2 kids and changing jobs) the likely-hood of me building a second machine is pretty slim.

with regards to spindles, are the air cooled ones really much worse than the water cooled? because i'm under the impression that the water cooled system requires a separate water tank and pump? which would just put the price up further.

[njhussey]

What are you looking to cut with your machine? Have you thought of making a brushless DC spindle like in this thread? (http://www.mycncuk.com/threads/3793-Diy-brushless-spindle?highlight=brushless+spindle) I've made one and although not used it yet Jonathan and Mark have used theirs with good effect. They are controlled with cheap servo testers and a brushless Radio Controlled ESC.

[thomashomer1986]

I only plan on cutting wood and maybe some plastics.

I have already read that thread from start to finish which is why my original plan was to make one of those brushless spindles, thats why i made my motor mounts to suit 52mm dia spindle body. However making a spindle now is out of the question as I no longer have access to a workshop. I really do miss the working on the tools sometimes!

[Clive S]

are the air cooled ones really much worse than the water cooled? because i'm under the impression that the water cooled system requires a separate water tank and pump? which would just put the price up further.
The air cooled are very noisy not necessary worse. The water cooled only require a very small fish tank pump £3 http://www.ebay.co.uk/itm/Ultra-Quiet-DC-12V-3m-240L-H-Brushless-Motor-Submersible-Pool-Water-Pump-Solar-/201590630064?hash=item2eefbce6b0:g:muYAAOSwR5dXREE ~
and a 2 ltr Tupperware container for the water.

[njhussey]

I only plan on cutting wood and maybe some plastics.

I have already read that thread from start to finish which is why my original plan was to make one of those brushless spindles, thats why i made my motor mounts to suit 52mm dia spindle body. However making a spindle now is out of the question as I no longer have access to a workshop. I really do miss the working on the tools sometimes!
I have this one just hanging around gathering dust.....[emoji6]

http://uploads.tapatalk-cdn.com/20160726/637bf4044e3d87d62aabe4b963eec755.jpg

[thomashomer1986]

How much would you be willing to sell it for Neil? Because something like that would be perfect for my machine and I still have the option upgrade to a water cooled spindle later on when I have more money.

What are the sizes/specs?

[njhussey]

How much would you be willing to sell it for Neil? Because something like that would be perfect for my machine and I still have the option upgrade to a water cooled spindle later on when I have more money.

What are the sizes/specs?
Good question on both counts....the motor specs are in the spindle thread I think, 1.7kW @ 60A max springs to mind and a max speed of approx 6500 rpm @ 24v....pm me with an offer and I'll have a think if what I want for it...

[thomashomer1986]

Thanks Neil I'll have a look through the thread then and let you know.

Is 6500rpm fast enough though? I thought much faster spindle speeds were needed for wood carving?

[thomashomer1986]

Thanks for the offer Neil but i think i'm going to go with the water cooled spindle. I think the 0.8kw spindle would be fine for my machine but as the 1.5kw is only about £5 more through the same supplier on ebay i might just go for that one.

Thanks again for everyones help, i will more than likely be posting soon with questions on how to wire it up lol.

[njhussey]

Thanks for the offer Neil but i think i'm going to go with the water cooled spindle. I think the 0.8kw spindle would be fine for my machine but as the 1.5kw is only about £5 more through the same supplier on ebay i might just go for that one.

Thanks again for everyones help, i will more than likely be posting soon with questions on how to wire it up lol.

No problems, the water cooled spindle is by far and away the best bet!

[A_Camera]

Hello all, another basic question here from myself!

I've managed to 'acquire' a spindle. very similar to this for nothing:
http://www.ebay.co.uk/itm/DC12-48V-Air-Cooled-0-4KW-Spindle-Motor-400W-ER11-for-Engraving-Milling-Machine-/252413006441hash=item3ac4fcd269:g:a6EAAOSwEgVWTYBS (http://www.ebay.co.uk/itm/DC12-48V-Air-Cooled-0-4KW-Spindle-Motor-400W-ER11-for-Engraving-Milling-Machine-/252413006441?hash=item3ac4fcd269:g:a6EAAOSwEgVWTYB S)

Now i know these are very underpowered and probably pretty useless for most work, but i currently don't have a spindle at all and my machine is just sitting there making nothing at the moment and i really want to start making chips! even if they are only small ones lol.

i'm only going to be cutting wood so i don't mind using a small spindle just for now until i can upgrade.

my question is though what kind of speed controller do i need?

That spindle is just a simple DC motor, so almost any PWM controller can be used. If you want to control it from the CNC software then you need something similar to this:

http://www.ebay.com/itm/12V-24V-48V-110V-5V-110V-Max-10A-DC-Motor-Speed-Control-PWM-MACH3-Speed-Control-/261177721706?hash=item3ccf67c36a:g:ImAAAOxypthRtpa L

But if you just want manual speed control then you can also get a much simpler and cheaper one, like this:

http://www.ebay.com/itm/Universal-DC10-60V-PWM-HHO-RC-Motor-Speed-Regulator-Controller-Switch-20A-/172256692888?hash=item281b4c8a98:g:8SgAAOSwOVpXcqn O

On the other hand... I have a similar spindle and have speed control as well, but I almost always run the motor at full speed. The motor is pretty weak and by reducing the speed it gets even weaker. So, it depends what you want to do with your CNC, perhaps speed control is not necessary at all.


or do i need an inverter/vfd? if it is the latter am i just better off buying a new spindle/vfd together like this one?

http://www.ebay.co.uk/itm/1-5KW-AIR-COOLED-SPINDLE-MOTOR-1-5KW-VFD-DE-4-BEARING-MILL-GRIND-ENGRAVING-/200687114979?hash=item2eb9e25ae3:g:juYAAOSwAPlXhcv h

apologies for sounding dumb, but i'm rubbish with electronics lol.

A VFD controlled brushless "real" spindle is of course much better than a DC motor, but probably not going to make life easier for you, unless you really need it. Maybe you could start with the simple DC motor and buy a VFD and a three phase motor at a later stage when you know what you really need or want or can afford. I bought a similar, 1.5kW air cooled spindle motor but I bought a better VFD, a Bosch Rexroth, because I wanted good service, support and documentation, as well as proper electrical design and safety. Buying a real brand makes it a bit more expensive though not a lot more, but the benefits are in my opinion many, so the extra cost is money well spent. I have not yet had time to install my spindle, still have the DC motor on the CNC, but have run it for test and all I can say is that for my needs and my environment it was the right decision to buy an air cooled spindle.

Many people say that brushless air cooled spindles are noisy, and maybe they are noisier than water cooled ones, but definitely not noisier at the same speed as the DC motors, or brushed motors like the Kress. Air cooled motors are easier to handle as well, since you don't need to install water pipes, cooling fluid, pump and pump control. Never the less, of course, if you are going to use your CNC 8-10 hours a day 5-6 days a week then water cooled is worth the trouble, but again, even if you buy air cooled to start with, upgrading to water cooled once you realize you need it is pretty simple.


i have the leadshine mx3660 breakout/driver board so if possible it would be nice to be able to switch the spindle on and control the speed through that. im using linuxcnc.

thanks in advance

Sorry, I can't help you with LinuxCNC or the mx3660.

[Clive S]

even if you buy air cooled to start with, upgrading to water cooled once you realize you need it is pretty simple.

What is the point in buying an air cooled THEN upgrading to water cooled when they can be had for the same price
air cooled
http://www.ebay.co.uk/itm/like/181927153256?lpid=122&chn=ps&googleloc=1007118&poi=&campaignid=628859225&device=c&adgroupid=28306099746&rlsatarget=pla-184492168626&adtype=pla&crdt=0

water cooled
http://www.ebay.co.uk/itm/like/181751969561?lpid=122&chn=ps&googleloc=1007118&poi=&campaignid=620865095&device=c&adgroupid=27378760866&rlsatarget=pla-181484358786&adtype=pla&crdt=0

For the water cooled you will need a small pump £3 from eBay and a 2lr Tupperware container for the water. No contest.

Be aware that both of the above only have ER11 collets

[A_Camera]

What is the point in buying an air cooled THEN upgrading to water cooled when they can be had for the same price
air cooled
http://www.ebay.co.uk/itm/like/181927153256?lpid=122&chn=ps&googleloc=1007118&poi=&campaignid=628859225&device=c&adgroupid=28306099746&rlsatarget=pla-184492168626&adtype=pla&crdt=0

water cooled
http://www.ebay.co.uk/itm/like/181751969561?lpid=122&chn=ps&googleloc=1007118&poi=&campaignid=620865095&device=c&adgroupid=27378760866&rlsatarget=pla-181484358786&adtype=pla&crdt=0

For the water cooled you will need a small pump £3 from eBay and a 2lr Tupperware container for the water. No contest.

Be aware that both of the above only have ER11 collets

Air cooled = less installation work, simpler machine, less possible problems, less space, zero risk for leakage causing problems, no chemicals to handle, simpler motor, less risk for electrical problems...

Yes, I know that the price difference is marginal. I did NOT mention saving money since it is not a lot you can save, even though I doubt you can install a water cooling system for £3, and in fact I would not even bother buying a pump that cheap.

Remember that this is my opinion, if you have a different opinion that's fine, but personally I prefer air cooled. YMMV

[Boyan Silyavski]

Air cooled = less installation work, simpler machine, less possible problems, less space, zero risk for leakage causing problems, no chemicals to handle, simpler motor, less risk for electrical problems...

Yes, I know that the price difference is marginal. I did NOT mention saving money since it is not a lot you can save, even though I doubt you can install a water cooling system for £3, and in fact I would not even bother buying a pump that cheap.

Remember that this is my opinion, if you have a different opinion that's fine, but personally I prefer air cooled. YMMV

Its a question of 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.
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
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
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.

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.

[Clive S]

What is the point in buying an air cooled THEN upgrading to water cooled when they can be had for the same price
air cooled
I see you did not answer this point.


I doubt you can install a water cooling system for £3, and in fact I would not even bother buying a pump that cheap.
Remember that this is my opinion, if you have a different opinion that's fine, but personally I prefer air cooledI did not say you could install a cooling system for £3. Yes it is your opinion and having reread all your other posts with opinions I will not be replying again to this one.:hopelessness:

[A_Camera]

I see you did not answer this point.

I did answer indeed...

"Air cooled = less installation work, simpler machine, less possible problems, less space, zero risk for leakage causing problems, no chemicals to handle, simpler motor, less risk for electrical problems..."

Now, the point is if you realize you need a water cooled you can pretty easily upgrade, but if not than you get the above advantages. OK, this way you may get a spindle over, but so what? You can always use it as spare or just simply sell it on to the next one. The important thing in my opinion is to get the right VFD and the right power. A new motor is no big deal.

Similar to buying anything else, camera, car, house or whatever else. You may buy something you think is going to work well for you, get experience and realize that you need some other feature, or more space or power so you simply buy or upgrade to a new one.


I did not say you could install a cooling system for £3.

No you did not. But why quote such a price, like if it was the major part of the cooling system? I mean, I didn't even brought up saving or costs as argument, you did that, because you assumed that my reason for air cooled was money saving, which is not.


Yes it is your opinion and having reread all your other posts with opinions I will not be replying again to this one.:hopelessness:
Fine. So you mean that the only one who can have a valid opinion is you? You must be joking... :tickled_pink: :tickled_pink: :tickled_pink:

[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...

[njhussey]

Similar to buying anything else, camera, car, house or whatever else. You may buy something you think is going to work well for you, get experience and realize that you need some other feature, or more space or power so you simply buy or upgrade to a new one.

I think Clive's point is that normally as you state above you learn by experience....however the whole point of coming on a forum is to use the experience of others to shorten the learning curve...therefore why buy something that others are saying (yourself included) you'll replace later?

[A_Camera]

I think Clive's point is that normally as you state above you learn by experience....however the whole point of coming on a forum is to use the experience of others to shorten the learning curve...therefore why buy something that others are saying (yourself included) you'll replace later? I am NOT saying that an air cooled spindle must be replaced. It can be the case, but not necessarily and in my case not likely that I will need to replace it.

There is no "one size fit all" solution, regardless who claims that. Points and experiences valid for one person are not necessarily valid for everyone else. I don't claim that everyone should use air cooled spindles, just that it works FOR ME, as well as for many others, and most arguments for using water cooled spindles are pretty lame. Considering most of us are amateur CNC users and DIY builders, using our machines very irregularly and for short periods every time I regard water cooled systems overkill. This may change in the future, nobody knows, not even I. If I'd start using my CNC more professionally and much more often than I am ready to pay the price of upgrade. This is one of the fun points of DIY engineering. Just like my first CNC had unsupported curtain rods and a pretty weak design as well as a 400W DC motor (which I am still using) even though I knew about the weak points, I decided to build it that way to start with, KNOWING that if I continue with the hobby I'll upgrade it, some parts will be thrown away or become unused. My version one was successful enough, used it for a year and made me more money than I expected initially and motivated an upgrade. So I did the work, which meant new, redesigned frame, supported rails, proper ball nuts and ball screws, new power supply... and so on, as well as VFD (Bosch, not cheapo Chinese) and a motor. I read a lot about other peoples experiences and opinions because I wanted to know, but I am an adult, so I made my own choice because only I know what my needs are. Not everyone needs water cooled systems, both systems have advantages and disadvantages and we learn mostly by our own experience. Asking about others experience is valuable, listening to what others have to say is also valuable, but that does not mean we have to follow every word of it. We have SEVERAL choices and reasons why we decide to go one way or the other, but just because somebody is going a different route or recommends a different solution or an alternative he/she is not stupid or ignorant and must not be flogged alive for having a different opinion.

No, I am not saying that an air cooled spindle must be replaced by a water cooled one, what I am saying is that it has many advantages over a water cooled one and that not everyone needs water cooling. What I am also saying is that water cooling MAY be necessary if you run a professional work shop and use the machine practically 24/7, but that's a totally different subject.

BTW, aren't you one of those who built spindles from scratch? Did you regret it? Why build one when you can buy a ready made? I am joking, don't answer those questions, because I really understand even those who build motors or rewind existing motors to improve or modify them. However, I would never do such thing but I understand it is an interesting experience and very cool in my opinion. I mean, you of all people should understand my points.

[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]

No, I am not saying that an air cooled spindle must be replaced by a water cooled one, what I am saying is that it has many advantages over a water cooled one and that not everyone needs water cooling. What I am also saying is that water cooling MAY be necessary if you run a professional work shop and use the machine practically 24/7, but that's a totally different subject.

Why do assume because It's hobby most machines are run for short periods at time.? Just because you may doesn't mean others do.! . . Infact I can tell you thru my experience of building machines for Hobby people which are used in vastly different walks of life it's actually very common for machines to be run for extended periods in Hobby use. Single Jobs that take 8-10hrs cutting 3D models in very abrasive model board or MDF moulds etc. On large 3D Jobs this can 24hr+
Yes they may not do this every day or every week but at least they can if they wish to and not worry about killing there spindle. Which isn't the case with Air cooled spindle. Run it for 24hrs none stop at 24000rpm and it will Die.!!

Try that with Air cooled Spindle and see how long it lasts.? The duty cycle alone eliminates Air cooled Spindle. The dust just Kills the bearings Fans etc in short period of time. Which in practice on long jobs often doesn't happens because the heat Kills them first.!
(Stopping the spindle for cool down period isn't an option either because it leaves tool marks on the work piece.!)

Now we come to the Simpler Part.? . . . Really 2 hoses connected to pump in bucket isn't exactly Complex or rocket science. Or Like Boyan says and what is actualy happening on my machine at moment due to robbing the pump for another Job is straight thru the hose pipe and out again.
Other than this there is no difference. The advantages of WC spindle with VFD greatly out weigh any slight None complexity of the cooling system. And for No or very little extra cost.

For anyone building there first CNC Machine then buying a Air cooled spindle costing same or few £$ or euros cheaper than WC is Dumber than Dumby recommending to do so.!

[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]

Why do assume because It's hobby most machines are run for short periods at time.? Just because you may doesn't mean others do.! . . Infact I can tell you thru my experience of building machines for Hobby people which are used in vastly different walks of life it's actually very common for machines to be run for extended periods in Hobby use. Single Jobs that take 8-10hrs cutting 3D models in very abrasive model board or MDF moulds etc. On large 3D Jobs this can 24hr+
Yes they may not do this every day or every week but at least they can if they wish to and not worry about killing there spindle. Which isn't the case with Air cooled spindle. Run it for 24hrs none stop at 24000rpm and it will Die.!!

Try that with Air cooled Spindle and see how long it lasts.? The duty cycle alone eliminates Air cooled Spindle. The dust just Kills the bearings Fans etc in short period of time. Which in practice on long jobs often doesn't happens because the heat Kills them first.!
(Stopping the spindle for cool down period isn't an option either because it leaves tool marks on the work piece.!)

Now we come to the Simpler Part.? . . . Really 2 hoses connected to pump in bucket isn't exactly Complex or rocket science. Or Like Boyan says and what is actualy happening on my machine at moment due to robbing the pump for another Job is straight thru the hose pipe and out again.
Other than this there is no difference. The advantages of WC spindle with VFD greatly out weigh any slight None complexity of the cooling system. And for No or very little extra cost.

For anyone building there first CNC Machine then buying a Air cooled spindle costing same or few £$ or euros cheaper than WC is Dumber than Dumby recommending to do so.! ha... ha... ha... Why assume that EVERYONE uses his CNC in dusty environment for jobs which definitely classed as industrial work? Even if it is called "hobby" it is just as industrial manufacturing as any other professional work if you do such long runs. It's not me making assumptions, it is you and all the other people who lack imagination and can't understand that what suits your needs may not suit everyone else and what you may need may not be necessary or needed for others, and the environment you have around you may not be the same as everyone else have. That seems to be very difficult for some of you to understand.

Like I said before, if you use your CNC as an industrial machine, even if you have it as hobby, of course water cooled is to be preferred. If you run the spindle for 24hr+ jobs that in my vocabulary is called industrial use, and in fact, demands high quality parts, even for hobby and even if you have a water cooled spindle. If I would be planning for that kind of activity I wouldn't even look at cheap Chinese spindles at all, water cooled or otherwise.

As for 24h test run you propose, no, I am not going to test run my spindle for 24 hours non-stop at 24k RPM because such test is totally pointless, regardless of the outcome of it. Other than that, I think what most likely would fail is the bearings, and those bearings are the same in both water cooled and air cooled spindles if they come from the same factory. What I hear is that these spindles are NOT made for spinning at that speed, even if they can do that, because of the low bearing quality. I have no idea if that is true or not and not going to pull apart mine just to have a look. Also there are huge individual variations, some spindles die faster than others because of generally low QC. So, your proposed test of my spindle is totally pointless, but if you want you can send me one at your own cost and I can test run that one for 24+ hours and report about the results. In parallel, you could send me a water cooled one from the same factory with the same power so that I can run the two in parallel and see what happens. I can set up the water cooling necessary, have a pump I can use and all the necessary other parts for the cooling, so don't bother about that.

Other than that, I will use my spindle just the same way I want or need to. The longest run with my DC spindle was 1.5 hours work. It worked just fine and is still working. I expect the spindle I have now to last even longer and for at least the same length of jobs. I will not likely need to run my spindle at 24k RPM since I am currently pretty happy with 9-10k RPM, so even here, if I can double that to 18-20k RPM that's more than I need. Regarding the heat... well, don't worry about that, I am supervising the heat of not only the spindle, but also all my steppers, power supply and drivers. So far I have not seen heat as a problem the way I am using my CNC. BUT... if my air cooled spindle would die I would evaluate the reasons and if the reason is poor quality I will buy a new air cooled spindle of much higher quality and price and don't bother with the cheapo Chinese ones. But again, that's just me looking at my own use, need, environment and so on. Not necessarily the same or similar to yours and it may not suit you at all, but definitely suits me very well.

[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...

:beer:

[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.

[Slixxor]

Hi Thomas,

I think when all said and done these motors/spindles are just a typical DC motor, so you can just give them 12-48v and your away.

I would imagine then that you can just vary the voltage supplied, to control the speed, you may be able to do this with a controller depending on what you've got, however it may just be better to get/use a standard type potentiometer where you control the speed manually.

I say the above because to be honest I wouldn't bother to invest any time or energy in one of those spindles, they work yes (they hold a cutter and spin) but their not really up to much at all, not sure if you've noticed or not but they are fitted with an ER11 collet, that's going to limit you to very small cutters for a start.

If your looking to fit it to one of these £4-500 Chinese machines, then yeah pop it on the machine and crack on making dust as you've nothing to lose.

If it's going on a machine that is much more capable then that is when I would say don't bother, the machine will be capable of more than the spindle will like and you'll just kill it or be limiting yourself/machine, it will just end up being a false economy is what I mean to say.

If you consider what is involved with adding a spindle to a machine (properly), it would be a much better investment of everything to use a more worthy spindle to start with.

The best price I can find a 2.2k water cooled spindle and vfd for is £180, they've sold lots, comes with a 2 year warranty but more attractive is the quote of 4 quality bearings in the spindle:

http://www.ebay.co.uk/itm/170746857178

I haven't ordered from them yet but I will be soon and I'm pretty positive that's who I will buy from, they do have negative feedback but I couldn't find any that related to this item.

As I said these spindles do work, here is a video of one actually cutting something:

https://youtu.be/6v534cJNzrU

.Me

A PWM speed controller would be much better for a DC motor. You will struggle to find a resistor that is rated high enough wattage wise to limit the current. Also, reducing the voltageis not a good idea as it will shorten the life of the motor. You're on the right track though.