Re: How Would You Upgrade An Old Ox CNC Build Into A Serious Machine?
I'm with Jazz on this one - for most cutting you aren't pushing the spindle hard enough to generate much heat. I don't turn the pump on for short jobs either. I use a 12V caravan water pump that is supposed to feed a tap. I have run fairly narrow pipes from a shelf under the machine via three drag chains to the spindle. Far from worrying about flow rates, my pump switch is 2-way, centre-off, so I can use 12V for filling (occasionally) but for normal use I use 5V which gives more than enough flow. Don't over-think this one - there's more significant things to worry about!
On the subject of positioning - once the pipework is full, there is effectively no real head of pressure for the pump to work against. If you can come up with a way to fill the pipes (raise the bucket temporarily?) then a small pump will handle the circulation.
Re: How Would You Upgrade An Old Ox CNC Build Into A Serious Machine?
LOL Kiitwn. I’m the definition of a control freak. My hobby machine has cooling systems and thermometers and sensors that automatically trip the E-stop if they get dangerously hot. It’s confessions of an Electronics Test and Service Mechanic who has seen so many things that have gone wrong.
Basically it’s KISS... but verify.
And Jazz... your setup would set off my OCD for sure. I don’t mind rats nests behind the TV and such (because I alter it so often) but for a machine that is moving around so much I made sure to keep my runs as clean as possible. Hell, I was even planning adding dual drag chains to my new machine so that I can keep the water line separate from the other already full drag chain. But maybe my chain is too small. Dunno, not checked yet.
1 Attachment(s)
Re: How Would You Upgrade An Old Ox CNC Build Into A Serious Machine?
Quote:
Originally Posted by
NeoMorph
And Jazz... your setup would set off my OCD for sure. I don’t mind rats nests behind the TV and such (because I alter it so often) but for a machine that is moving around so much I made sure to keep my runs as clean as possible. Hell, I was even planning adding dual drag chains to my new machine so that I can keep the water line separate from the other already full drag chain. But maybe my chain is too small. Dunno, not checked yet.
Don't get me wrong I'm not advocating running a rats nest, far from it, and all the machines I build are wired and routed correctly neat and tidy. I am quite Anal about to be honest and drive my helper mad if things are not routed or wired just how I like them.
But My own personal machine is a testbed so I'm always pulling it apart and/or wiring something or other into it so how it looks is of no concern, thou it is safe. It's also why you'll never see a photograph of it.
However back to the cooling, like Neale says don't overthink this one as it doesn't need any fancy cooling system. Every machine I build uses a WC spindle and all of them bar 5 or 6 have had 20Ltr tubs of water located either under the machine or on the floor using a 24Vdc pump with head height of 7-8mtr.
If you are doing long jobs 2hr's + then it's a good idea to had a flow sensor just in case the pump goes down. But other than that KISS works.
Edit: If using bucket setup just add some antifreeze and try to use a bucket that blocks out light and you'll have no issues with water going bad.
Here's a setup that didn't use a bucket but instead used a small tank with pump inside bolted onto the rear of the machine. This also works perfectly and the tank only holds 3ltrs of water. Before the pump failed on my machine I was testing a PC rad with fan and one of those cheap nasty small pumps with 500ml reservoir integrated into it. This worked perfectly until the pump failed which was more to do with it being a cheap nasty pump.
Attachment 27269
Re: How Would You Upgrade An Old Ox CNC Build Into A Serious Machine?
Quote:
Originally Posted by
JAZZCNC
It's also why you'll never see a photograph of it.
Aww I was quite looking forward to that photo
Re: How Would You Upgrade An Old Ox CNC Build Into A Serious Machine?
Quote:
Originally Posted by
AndyUK
Aww I was quite looking forward to that photo
Andy, it's Frankenstein machine.!! . . It would scare all the children...:hysterical:
Re: How Would You Upgrade An Old Ox CNC Build Into A Serious Machine?
Quote:
Originally Posted by
JAZZCNC
However back to the cooling, like Neale says don't overthink this one as it doesn't need any fancy cooling system. Every machine I build uses a WC spindle and all of them bar 5 or 6 have had 20Ltr tubs of water located either under the machine or on the floor using a 24Vdc pump with head height of 7-8mtr.
For a second I thought you meant 7-8mtr tall CNC machine.
But going by your comments of your spindle not needing much cooling, isn’t your 20ltr tub of water overkill?
Re: How Would You Upgrade An Old Ox CNC Build Into A Serious Machine?
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.
Re: How Would You Upgrade An Old Ox CNC Build Into A Serious Machine?
Quote:
Originally Posted by
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.
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.
Re: How Would You Upgrade An Old Ox CNC Build Into A Serious Machine?
Quote:
Originally Posted by
NeoMorph
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.
Re: How Would You Upgrade An Old Ox CNC Build Into A Serious Machine?
Quote:
Originally Posted by
JAZZCNC
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.
Re: How Would You Upgrade An Old Ox CNC Build Into A Serious Machine?
I forgot to say, heat is also the reason why your hand drill can be awesome when new and yet limp as a dishrag when 10 years old. Replace the magnets though and the power goes back up.
A lot of diy repairers replace the windings of weak power tools and are confused when it is still just as weak. “I mean, it can’t be the magnets. They are ‘solid state’ parts after all”.
This is why you confuse me Jazz. You profess to knowing what you are doing and then are making noob errors like that. I’m not saying this to be an ass, I’m saying it to educate, like you educated me regarding water cooled spindles.
Take the info in the way it was meant, as I took yours and actually acted on it. Don’t know exactly when I will get my spindle though as all flights out of China appear to have be stopped at present.
Re: How Would You Upgrade An Old Ox CNC Build Into A Serious Machine?
Quote:
Originally Posted by
NeoMorph
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.!
Re: How Would You Upgrade An Old Ox CNC Build Into A Serious Machine?
Quote:
Originally Posted by
JAZZCNC
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.
Re: How Would You Upgrade An Old Ox CNC Build Into A Serious Machine?
Quote:
Originally Posted by
NeoMorph
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.!
Re: How Would You Upgrade An Old Ox CNC Build Into A Serious Machine?
Well it looks like this is the wrong year to upgrade my CNC with parts from China (or at least until the Coronavirus burns out). I ended up getting a refund for my spindle order. :concern:
Maybe once China starts their factories up we will be able to resume. I wouldn’t order anything of Aliexpress at the moment and I’m limiting my order on eBay to Europe only. Even that is affecting my orders for my Warthog cockpit project. A bunch of parts on Farnell are warning about long lead times. All because the 21st Century version of Spanish Flu hit the centre of Chinese manufacturing in Wuhan.
This just goes to show how the world is dependent on China for a bunch of things.
