Spindle Speed Controller Question

[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

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-...AAAOxypthRtpaL

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-DC...gAAOSwOVpXcqnO

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-...YAAOSwAPlXhcvh

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/18192...ype=pla&crdt=0

water cooled
http://www.ebay.co.uk/itm/like/18175...ype=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/18192...ype=pla&crdt=0

water cooled
http://www.ebay.co.uk/itm/like/18175...ype=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.

[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.!!

[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 cooled

I 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.

[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.

Fine. So you mean that the only one who can have a valid opinion is you? You must be joking...

[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?