Spindle Speed Controller Question

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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.

[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.!