[twocik]

Might be a dumb idea, but was thinking about his today. Well I thought about how to keep tools as cold as possible to reduce wear, melting material to the cutter and maybe even a better finish.


Has anyone experimented with freezing the raw aluminum stock before use or maybe even dry icing it ?

Or maybe even hooking up dry ice coolant lines of some sort...


.

[Magnum164]

I am not sure, would need a materials person to verify. But depending on the material the process of freezing could make it harder and therefore would not be a big benefit. Think of the extreme of what happens when you freeze water...

Just like when you heat a material it softens up (while under heat).

Now hook a Peltier device up to the spindle and super cooling the cutter might be something interesting to try

[Don Clement]

Ditto what magnum said. Also materials change dimensions with temperature. BTW aluminum changes at twice the rate of steel and that change is inch/inch so larger diameter and longer parts will change more than smaller parts with a change in temperature. Although I have build a few projects using Peltier devices (one was a 4 stage Peltier device) I use a Vortec 610 cold air gun http://www.vortec.nl/fileadmin/Image...r_Guns_eur.pdf on my lathe, bandsaw and manual mill. The Vortec is not as efficient at removing heat as flood cooling though, but a lot less messy when used on manual machines without flood coolant shielding. The Vortec 610 can give up to a 40*C decrease in temperature. A 32*C change from ambient can be seen here as shown using T type thermocouple to measure the air gun output:
http://s72.photobucket.com/albums/i1...minus7degC.jpg
It does keep my 5hp 2-stage air compressor going continuously as it requires 15SCFM @ 100psi to run.

Don

[twocik]

Ahhh that's right magnum, I forgot when cooling/heating metal it changes size...

What about making some sort of water cooler we could stick into our tanks or at the end of the hoses ?

[Magnum164]

Ahhh that's right magnum, I forgot when cooling/heating metal it changes size...

What about making some sort of water cooler we could stick into our tanks or at the end of the hoses ?

Question is what is the operating temp range of the coolant being used? if you cool the coolant down too much the pumps may have a hard time pumping it.

I don't do that much machining at the moment to worry about heat. But if the coolant temp is a problem you can always run through a radiator like I do my PC.

[Pergamon]

twocik, interesting idea! A few thoughts of mine for your reference -

First off I get a little bit nervous when you say “keep tools as cold as possible”, hehe…the reason is that an extreme low temperature can reduce the material elasticity dramatically. Dry icing may not be a biggie as its only -70F, say, but If you pour liquid nitrogen to some cutter for instance, it can make the cutter surface brittle – something you don’t wanna see happening, lol. Also, as people mentioned above and I agree with, a high temperature gradient (assuming you are trying to cool the cutter down in some form while cutting) can cause deformation and thus worse stress concentration. So I can see that the cutter might wear even faster than its not cooled or simply coolant-cooled.

But speaking of dry-ice, I’m thinking there must be some better liquid that has a bigger capacity or lower temperature while it still maintains its liquidity so it pours or drains more easily than solid…something to ponder. Hope this helps a little

[307startup]

Dry ice is already a medium for cooling machine tooling. Google it. The issue becomes evacuating the fumes, as it displaces oxygen. Not helpful to the operator at all

Several materials machine better when cooled...delrin, polyethylene, UHMW HDPE, nylon, teflon, etc. The issue becomes machining to size before the material warms up due to friction.

As an interesting side note...proper cryo-treatment of HSS endmills, cobalt endmills, even carbide and ceramic inserts show a 2-5x increase in life.

[300sniper]

As an interesting side note...proper cryo-treatment of HSS endmills, cobalt endmills, even carbide and ceramic inserts show a 2-5x increase in life.

i am pretty sure a local cryo guy found that it does the same to disposable razors.

[Don Clement]

Wouldn't it be better to use a closed loop with cooling fluid so that machining could be kept at a constant temperature such as ambient? That way there would be no dimension change in the material when machining. Same goes for spindle cooling, a closed loop system that would keep the spindle temperature constant. Different types of fluid (water is very effecient at removing large amount of heat) could be used. Also air could be used. I have worked some with a closed loop air driven systems for testing semiconductors such as this system http://www.bridgetec.com/kinetics.html Seems like for machining such a closed loop system with air might just work with out the mess of flood coolant. BTW I used a sort of manual feedback closed loop temperature to set the bearing preload on my Sherline 10K rpm spindle with a self-adhering T type thermocouple probe on the spindle body http://www.omega.com/ppt/pptsc.asp?ref=sa1xl I measured the spindle temperature and adjusted the bearing preload until a prespecified temperature was reached for 10K rpm. This sort of manual feedback closed loop appraoch might also be used for machining cooling and spindle preload on the Tormach.

Don

[R.DesJardin]

Ok, this sounds like someone doesn't want to use coolant which is a proven way to do what is needed.
So is your machine in a basement or a ultra clean garage where coolant would make a mess?
I use coolant, it can be messy, it's in my shop, it gets messy, I manufacture stuff, it's in a shop. Coolant works.
I would think that using air would take quite a good compressor to keep up if you are doing any length of cut time.

[Magnum164]

Ok, this sounds like someone doesn't want to use coolant which is a proven way to do what is needed.
So is your machine in a basement or a ultra clean garage where coolant would make a mess?
I use coolant, it can be messy, it's in my shop, it gets messy, I manufacture stuff, it's in a shop. Coolant works.
I would think that using air would take quite a good compressor to keep up if you are doing any length of cut time.

I think the discussion was about alternative solutions. Nothing was said about coolants being messy.

For the record, yes my machine is in a finished basement. My coolant is CONTAINED within my enclosure. So no mess.

But doesn't mean we can't discuss alternative solutions. That's how innovation is kept alive

[Magnum164]

Wouldn't it be better to use a closed loop with cooling fluid so that machining could be kept at a constant temperature such as ambient? That way there would be no dimension change in the material when machining. Same goes for spindle cooling, a closed loop system that would keep the spindle temperature constant. Different types of fluid (water is very effecient at removing large amount of heat) could be used. Also air could be used. I have worked some with a closed loop air driven systems for testing semiconductors such as this system http://www.bridgetec.com/kinetics.html Seems like for machining such a closed loop system with air might just work with out the mess of flood coolant. BTW I used a sort of manual feedback closed loop temperature to set the bearing preload on my Sherline 10K rpm spindle with a self-adhering T type thermocouple probe on the spindle body http://www.omega.com/ppt/pptsc.asp?ref=sa1xl I measured the spindle temperature and adjusted the bearing preload until a prespecified temperature was reached for 10K rpm. This sort of manual feedback closed loop appraoch might also be used for machining cooling and spindle preload on the Tormach.

Don

I think closed loop would be fine. When I was talking a radiator and cooling I was thinking more of cooling the coolant back to ambient. I think cooling beyond that would introduce just more complications. Granted with a closed loop you are going to need a really good filter system to keep the swarf out completely. So as you build in one area, it complicates another

Even if you use something like a peltier, the opposite side is heated, so you have to move the heat out of the area or you increase the room temperature as well.

Then again. You could always set a little portable fridge beside the machine, plumb the coolant tank and pump inside and you have can adjust the cooling effect on your coolant by simply adjusting the fridge temp or the time the coolant spends in the fridge Would be interested in knowing the temp change in coolant when doing a lot of machining.. I am not at that point, just made a few simple parts for my lathe.

[Don Clement]

Ok, this sounds like someone doesn't want to use coolant which is a proven way to do what is needed.
So is your machine in a basement or a ultra clean garage where coolant would make a mess?
I use coolant, it can be messy, it's in my shop, it gets messy, I manufacture stuff, it's in a shop. Coolant works.
I would think that using air would take quite a good compressor to keep up if you are doing any length of cut time.

I agree. Flood coolant works. It is what I use everyday on my Tormach. Parsimony is always best. KISS

Don

[twocik]

"Ok, this sounds like someone doesn't want to use coolant which is a proven way to do what is needed.
So is your machine in a basement or a ultra clean garage where coolant would make a mess?
I use coolant, it can be messy, it's in my shop, it gets messy, I manufacture stuff, it's in a shop. Coolant works.
I would think that using air would take quite a good compressor to keep up if you are doing any length of cut time."



Read the title I'm not trying to reinvent the wheel here, just thinking out loud and thought I'd ask if anyone has every messed around with it. Who knows someone might come up with something else, isn't that why we bought machines to invent things.. Yes, the machine is at my house, so ?

The coolant containment, my shop and I make things comments/questions are irrelevant to thread.... Don't post things like this, keep it professional please. yes, I agree coolant does work but how much do we spend on it.... Next I'm more annoyed with it evaporating so fast and having to keep filling it up. I recently added a portable AC unit to my setup and so far its cooled things down by 10° or so.


Another idea I wanted to bounce off you guys was what if I hooked up an AC line right over the machines head or maybe even some sort of extra enclosure with an AC line directly to CNC Guard Kit. Thinking if the cold air from the AC unit hits the coolant as it's sprayed out of the line, it would be at least twice as cool before hitting the work piece.... Any thoughts ?

Again these are just ideas

[Magnum164]

"Ok, this sounds like someone doesn't want to use coolant which is a proven way to do what is needed.
So is your machine in a basement or a ultra clean garage where coolant would make a mess?
I use coolant, it can be messy, it's in my shop, it gets messy, I manufacture stuff, it's in a shop. Coolant works.
I would think that using air would take quite a good compressor to keep up if you are doing any length of cut time."



Read the title I'm not trying to reinvent the wheel here, just thinking out loud and thought I'd ask if anyone has every messed around with it. Who knows someone might come up with something else, isn't that why we bought machines to invent things.. Yes, the machine is at my house, so ?

The coolant containment, my shop and I make things comments/questions are irrelevant to thread.... Don't post things like this, keep it professional please. yes, I agree coolant does work but how much do we spend on it.... Next I'm more annoyed with it evaporating so fast and having to keep filling it up. I recently added a portable AC unit to my setup and so far its cooled things down by 10° or so.


Another idea I wanted to bounce off you guys was what if I hooked up an AC line right over the machines head or maybe even some sort of extra enclosure with an AC line directly to CNC Guard Kit. Thinking if the cold air from the AC unit hits the coolant as it's sprayed out of the line, it would be at least twice as cool before hitting the work piece.... Any thoughts ?

Again these are just ideas

have you considered a different brand?

[300sniper]

i'd say coolant is pretty cheap in the long run. i am still on my original 5 gallon bucket of hangsterfer's s-500 and have about a third left. sure i have to add water to it every so often in the summer due to evaporation. i guess about $100 spread over 4-5 years is not that expensive to me.

[twocik]

I absolute love the coolant I'm using now (hangsterfer's 777), it's just the bottom of Florida sucks for evaporation I guess. It's extremely hot during this time of the year and the humidity doesn't help. Mine was about $160 if I remember correctly, yes that's pretty cheap but not if it's going to move this quick. I've had it in my tank for almost 3 weeks and i'd say it's about halfway.

My new house is definitely going to have a AC unit hook up for sure, but for now the portable AC is doing pretty good. I'm going to check the level again in a week from my last marking. However this isn't the point of this thread, just curious on other ideas for cooling that might help, but like yo say sniper maybe it's just because it's summer.

[Magnum164]

ok ok back on topic

I am just up from you, very hot hear. Not as much evaporation, but I do have a concern that is making me rethink the coolant.

That is the designation of hazardous material for the coolant. Probably talked to death on the forums, but for a home shop I have tried to stay away from those issues and the reason I don't do any anodizing.

So might have to re-consider Don's cold air setup.

[twocik]

"That is the designation of hazardous material for the coolant. Probably talked to death on the forums, but for a home shop I have tried to stay away from those issues and the reason I don't do any anodizing."



Woo woo I'm not sure I follow what you're saying here... Are you saying it would be twice as hazardous with the evaporation here in FL with anodizing or that my/your coolant could be harmful ? I know all of the stuff says environment friendly, but you never know. I was just about to start with a diy anodizing kit and understand the dangers in it, but haven't fully looked into everything just yet.


You know it's funny you bring this up, I recently had this nose infection that just won't go. Well back again and not near as bad as last but it's starting again. I wasn't sure if it was from the coolant splashing me or maybe just a normal cold.





Mag where are you located ?

[Magnum164]

"That is the designation of hazardous material for the coolant. Probably talked to death on the forums, but for a home shop I have tried to stay away from those issues and the reason I don't do any anodizing."



Woo woo I'm not sure I follow what you're saying here... Are you saying it would be twice as hazardous with the evaporation here in FL with anodizing or that my/your coolant could be harmful ? I know all of the stuff says environment friendly, but you never know. I was just about to start with a diy anodizing kit and understand the dangers in it, but haven't fully looked into everything just yet.


You know it's funny you bring this up, I recently had this nose infection that just won't go. Well back again and not near as bad as last but it's starting again. I wasn't sure if it was from the coolant splashing me or maybe just a normal cold.





Mag where are you located ?

my concern was mainly disposing of the material, I eould have to check if if classifies as hazardous material and when I do decide to start a business could affect being able to do work out of my house. i want to stay a design shop, not a mfg shop.Plus depending on what you cut and the oil/cutting fluid used the bt product may require a hazardous material fee for disposal. Minor fee if you are actually mfg parts, but for prototypes could be expsensive. Anodizing I am sure the city would give me trouble.

When i hooked up my coolant originally I was sick as well with sinus, but once I got everything setupwith a refractometer(sp) I have not had any trouble. I have no sense of smell so I can;t tell if it stinks in the house


I am in Huntsville, Al about 20-30 minutes from the Tenn line and about 5 hours from Fl line (I drive fast). So not far from you, unless you are down in the Keys.