[packrat]

No one mentioned this, so maybe it's not a factor here. What is going to happen to the tram of the machine as the aluminum heats up and grows in length?

The thermal linear expansion of aluminum is •aluminum : 0.000023 (m/m oC)
From; Thermal Expansion - Linear

It might cause problems or not.

[lgalla]

Would there be a possibility of condensation?TOO COOL?spindle bearings need some heat.Anyone know how hot the bearings should be?BTW I like the idea.
Larry

[CarveOne]

No one mentioned this, so maybe it's not a factor here. What is going to happen to the tram of the machine as the aluminum heats up and grows in length?

The thermal linear expansion of aluminum is •aluminum : 0.000023 (m/m oC)
From; Thermal Expansion - Linear

It might cause problems or not.

It could, as it only takes a very small change in length to cause binding in a preloaded mechanical system. I had been assuming that the idea is to keep the water temperature close to moderate room temperatures.

CarveOne

[Zuni]

Um...

I don't have any experience with these Chinese spindles yet, but I get the impression that folks are overestimating just how heated the bearings (and therefore the coolant) get during spindle use.

From what I read about these spindles, I have a hunch that the heat rise of the coolant during spindle operation will be just about unmeasurable. I'm just trying to keep things simple.

It's easy to make things complicated, but difficult to keep things simple.

[RomanLini]

Plumb the cavities in parallel then. Feed all four from one end and collect them back to one hose at the output end.

"General Overkill" would prefer to use an array of Peltier devices ...
...

You made me chuckle.

But seriously a couple of small fans will work well for extracting the heat not only from the water, but extracting that heat AWAY from the assembly as a whole. So that reduces the thermal expansion.

As for the amount of heat energy, if you know the spindle type and operating watts, and can guesstimate its operating efficiency you can get a ball park figure for how much heat will be extracted in the water.

As an optimal system you could just run the water through a finned air cooled heat tube (like a small radiator or oil cooler) with a decent extractor fan on it. And you can do that away from the machine so all the heat is extracted well away.

But there is a cool factor using the machine to cool itself.

[CarveOne]

You made me chuckle.

But seriously a couple of small fans will work well for extracting the heat not only from the water, but extracting that heat AWAY from the assembly as a whole. So that reduces the thermal expansion.

As for the amount of heat energy, if you know the spindle type and operating watts, and can guesstimate its operating efficiency you can get a ball park figure for how much heat will be extracted in the water.

As an optimal system you could just run the water through a finned air cooled heat tube (like a small radiator or oil cooler) with a decent extractor fan on it. And you can do that away from the machine so all the heat is extracted well away.

But there is a cool factor using the machine to cool itself.

Using the extrusion for cooling is an attractive idea, if the expansion isn't a problem. I have no idea how warm the water gets after 3 or 4 hours of running. It deserves to be tested to see if it is a viable solution.

I was getting carried away with it though, and the General Overkill solution came from a Peltier cooler for a laser diode I worked with in the early 90's. It was a little over an inch square, had 25 or more Peltier devices sandwiched between two thin ceramic plates, and worked the way I described it. It could heat or cool like a small heat pump. Very inefficient because of the power required to operate it but it was able to control the temperature to close tolerance in a very small space. I was picking at you again, and figured that you know what they are.

CarveOne

[Zuni]

No one mentioned this, so maybe it's not a factor here. What is going to happen to the tram of the machine as the aluminum heats up and grows in length?

The thermal linear expansion of aluminum is •aluminum : 0.000023 (m/m oC)
From; Thermal Expansion - Linear

It might cause problems or not.

Interesting little calculator. I worked it in inches--Thinking that any heating of the coolant will be very minimal, I used a 1-degree Farenheit rise in gantry temperature, which caused a nine-tenthousandths of an inch (0.0009) increase in the length of the gantry.

I don't plan on storing/using my machine in a climate-controlled workspace, so I imagine this will be no different than when the air temperature in my garage changes during the normal daily and seasonal temperature cycles.

[diyengineer]

Interesting little calculator. I worked it in inches--Thinking that any heating of the coolant will be very minimal, I used a 1-degree Farenheit rise in gantry temperature, which caused a nine-tenthousandths of an inch (0.0009) increase in the length of the gantry.

I don't plan on storing/using my machine in a climate-controlled workspace, so I imagine this will be no different than when the air temperature in my garage changes during the normal daily and seasonal temperature cycles.

The heat from these spindles is a joke. Your setup will be more then enough.