How Would You Upgrade An Old Ox CNC Build Into A Serious Machine?

[AndyUK]

The tub provides a thermal reservoir; any heat from the returning water is spread out across all the water in the tub. The greater the mass of water, the lower the overall temperature rise for a given heat input. The larger the surface area of the water in the reservoir, the quicker it'll lose heat to its surroundings.

So, in a nutshell, big reservoirs hold off the need for a cooling radiator.

[NeoMorph]

The tub provides a thermal reservoir; any heat from the returning water is spread out across all the water in the tub. The greater the mass of water, the lower the overall temperature rise for a given heat input. The larger the surface area of the water in the reservoir, the quicker it'll lose heat to its surroundings.

So, in a nutshell, big reservoirs hold off the need for a cooling radiator.

I understand that... I was pointing out the comments Jazz made about the fact that he ran his spindle WITHOUT pumping water and said it was okay.

What I was pointing out was that if it was “okay” then you wouldn’t need a large tank of water. The fact that many CNC machines do indeed use large tanks of water to sink the thermal energy into point to the need for good cooling of the spindle to ensure longevity and reduce thermal damage to the permanent magnets.

[JAZZCNC]

I understand that... I was pointing out the comments Jazz made about the fact that he ran his spindle WITHOUT pumping water and said it was okay.

What I was pointing out was that if it was “okay” then you wouldn’t need a large tank of water. The fact that many CNC machines do indeed use large tanks of water to sink the thermal energy into point to the need for good cooling of the spindle to ensure longevity and reduce thermal damage to the permanent magnets.

You didn't read what I said about my machine carefully enough.! . . . .My PERSONAL machine doesn't even have a water pump it's feed straight from the tap and out into the drain. Wasteful YES but I don't cut long jobs on it often so rarely turn on the water. It runs fine for 30-40 mins without water.
It's been this way for over 2yrs and the spindle is over 6yrs old so it's not doing any significant harm to it. I've got woodworking machines out in the field that are 10yrs + old used 8-10hrs daily and still using the same spindle. They are robust spindles for woodworking.

My comments regards 20Ltr containers are for the machines I build. These need to be capable of long periods of use which are unknown to me so that's why I use 20ltrs of water. Also the containers are simple and easy to empty or find if need replacing.

However, if don't believe what I'm telling you then crack on and build an overly complex system so you can sleep easy.!! . . . . I don't give a Stuff.

[NeoMorph]

You didn't read what I said about my machine carefully enough.! . . . .My PERSONAL machine doesn't even have a water pump it's feed straight from the tap and out into the drain. Wasteful YES but I don't cut long jobs on it often so rarely turn on the water. It runs fine for 30-40 mins without water.
It's been this way for over 2yrs and the spindle is over 6yrs old so it's not doing any significant harm to it. I've got woodworking machines out in the field that are 10yrs + old used 8-10hrs daily and still using the same spindle. They are robust spindles for woodworking.

My comments regards 20Ltr containers are for the machines I build. These need to be capable of long periods of use which are unknown to me so that's why I use 20ltrs of water. Also the containers are simple and easy to empty or find if need replacing.

However, if don't believe what I'm telling you then crack on and build an overly complex system so you can sleep easy.!! . . . . I don't give a Stuff.

LOL. Don’t take it to heart son.

I take it you don’t know thermal effects on magnets. Heat breaks down the magnetic properties meaning that the motor is having to work harder to produce the same number of rpms. Outwardly it may appear to be unaffected by the heat but I can assure you, motors that exceed their thermal capacity are going to get damaged.

The Electronics course I was on actually showed this in a practical demonstration. They tested the motor, showing the amps needed to drive the motor at a specific RPM. Then they disassembled the motor and shoved the magnets into an oven. I can’t remember how hot or how long it was because this was back in 1985.

Anyhoo, they air cooled the magnets (because artificially cooling magnets actually strengthens them) and put them back in the motor and then run the motor back up to the same RPM.

The motor did it but it struggled. It was drawing a higher voltage and amperage to run at the same speed. It was pointed out that this would eventually cause a domino effect downstream by stressing the power supply and control circuits... and ironically at that point the smoothing capacitor on the demo blew the top off and left a hole through the ceiling, scaring the crap out of us because we were sitting bunched up around the desk.

You may be an expert at CNC stuff but I’ve been playing and working with electronics and electro mechanical stuff since the 70’s. Just because it doesn’t seem damaged doesn’t mean damage isn’t occurring.

[JAZZCNC]

LOL. Don’t take it to heart son.

I take it you don’t know thermal effects on magnets.

You may be an expert at CNC stuff but I’ve been playing and working with electronics and electro mechanical stuff since the 70’s. Just because it doesn’t seem damaged doesn’t mean damage isn’t occurring.

Yes, I do know the effects but I also know that these effects are not taking anything away from the motor in terms of performance or longevity that is of any concern. I know this through the experience of using them not through doing the maths.! . . I'm 99% of the time hogging aluminum which would quickly show any power loss and it's been doing this for a long time now so I'm not concerned about longevity because if it died tomorrow it's paid for it's self many times over.

But like I say Crack on and build something overly complex if it makes you feel better.!

[NeoMorph]

Yes, I do know the effects but I also know that these effects are not taking anything away from the motor in terms of performance or longevity that is of any concern. I know this through the experience of using them not through doing the maths.! . . I'm 99% of the time hogging aluminum which would quickly show any power loss and it's been doing this for a long time now so I'm not concerned about longevity because if it died tomorrow it's paid for it's self many times over.

But like I say Crack on and build something overly complex if it makes you feel better.!

Some time, just get your abused motor (that you said you forget to cool at times or not bother to cool) and measure the power draw... then get an identical new spindle and check the power draw on that.

I was TRYING to help YOU in this case, by warning you of what you are doing to the long term condition of your spindle.

But you obviously know better. Next thing you know, everyone will be calling you Trump.

[JAZZCNC]

But you obviously know better. Next thing you know, everyone will be calling you Trump.

I'm not saying I know better. I know exactly what you are saying and the consequences of heat.!
What I'm saying is what I know to be true from my quit extensive experience of these spindles over a long period of time.

Also just for the record and I've said it many times on here so you can check if you don't believe me. I run my VFD so it shows current not RPM so I can monitor tool wear.
So I know exactly how much it's dropped over the years and yes I agree with you it as dropped from when it was new, but not to any degree that it's a problem.
Because I only ever cut aluminum and pretty much the same grade which is Cast aluminum and same cutters then I've been able to monitor the drop better than most can. So In six years it now pulls roughly 5.6A instead of 5A. It's an 8A spindle so the losses are more than acceptable to me.

Now I've said enough so crack on.!