comparisson of temperature change to loss of power

[Tech_Marco]

[Funny though, I was reading around on Full Spectrum's site looking for water temp discussions. FS doesn't seem to think higher temps (higher than 25 degrees C) are a problem at all. Then again, they sell replacement tubes. lol ]

Toasty you're a bad boy ha..ha....

I agreed with Walt that 22~25'C is perfect for CO2 laser tube. Over than that the tube is still working but it will affect both performance and life span. As I said before, I'll monitor the 'out flow' temperature as well but not just the "in flow". I'll make sure that the "out flow" temp is kept below 30'C regardless the "in flow" water temp is 20'C or 25'C


Marco

[Tech_Marco]

By the way, I can suggest a very low cost solution to cool 40W laser tube, or may be 60W is likely possible.
Go get a small water depressor with compressor built-in from Walmart or Target The cost of a brand new is running about $130 ~ $150 for brand new. Or, get one used for half pride on Craigslist. Remember, you must get one with compressor but not the thermocouple (Peltier) in order to work. Even a small refrigerator will work. But some minor modification is required like adding a water pump and heat exchange coil.

For K40, I'm sure it should get you cool lower than needed. I have a used one and I'm going to give it a try. I was thinking to give it free to a friend but he didn't want it. Then, after seeing this post than I should give it a try.

Update: this is one I have: http://sacramento.craigslist.org/hsh/3952008961.html


Marco

[Toasty]

I agreed with Walt that 22~25'C is perfect for CO2 laser tube

Hmmm, a couple of months ago we discussed this and you told me up to 28 degrees was still within the perfect temperature range for a 40w tube. That's kind of why I was thinking everything was fine. Exact words were "25~28'c is great for co2 laser". That's why I've been a bit confused on the subject.

[waltfl]

Hi toasty
ok I did many tests with many parameter of the 40W tube.
if a tube is brand new the temperature could be as high as 30 C but this is only for about max 50hours like with a car or motor .
then the tube water temperature should never go over 28C. I have seen cases where only 5 minutes of 32 C did de-glue the front cooling chamber.
for cutting : the lower the temperature the more cutting temperature you get .
if you cut with 19C you could cut 6mm but if the temperature raises to 25C you probably can not even cut 4mm.
sure the manufacturer gives higher max temperature but they wana sell tubes and it is the max temperature without saying how long the tube would last. another point is there is many variables in manufacturing the tubes like what gas and how high is the concentration, what lens is with what glue used etc.
a friend of mine uses a 135W peltier element with a 120mm fan connected to a high performance heatsink and a 120mm radiator and it works perfect for him, but he is in Colorado meaning the outside temperature is way lower then at my place in florida. the room temperature need to be taken in consideration too. room temp of 28C needs more cooling then room temp 20C, that's what most people don't realize.
greetings
waltfl

I agreed with Walt that 22~25'C is perfect for CO2 laser tube

Hmmm, a couple of months ago we discussed this and you told me up to 28 degrees was still within the perfect temperature range for a 40w tube. That's kind of why I was thinking everything was fine. Exact words were "25~28'c is great for co2 laser". That's why I've been a bit confused on the subject.

[Tech_Marco]

I agreed with Walt that 22~25'C is perfect for CO2 laser tube

Hmmm, a couple of months ago we discussed this and you told me up to 28 degrees was still within the perfect temperature range for a 40w tube. That's kind of why I was thinking everything was fine. Exact words were "25~28'c is great for co2 laser". That's why I've been a bit confused on the subject.

To Toasty

That's what I though 28'C was great for tube as I asked many machine manufacturers about it. May be a small tube is less tolerance than a bigger tube like a 80W or 100W tube. I will do some test once my machine setup. As you mentioned that before, 25'C is hard to achieve for folks without water chiller at room temperature because the room temperature is 26~27'C. And, I could get good cutting with room temperature water when I tested a customer K40 when I helped him for modification. If you ever ask Reci sales Rep, they willl tell that you that the max temp is 40'C. So, that's what I came up my theory, the 40'C they mentioned means the "out flow" temperature. Or, as I said, different tube (size & power) may have different spec. Inside of the laser tube, it is not only CO2 gas but a mix with other other type gas per different manufacturer. I think unless we line up a few tube for testing, it is hard to make a final conclusion

FYI, small tube are using small mirror/lens but large tube are using bigger mirror/lens. That will make a lot of difference as well. When I talked to machine manufactures in China, they told me that below 30'C should be fine but 25'C~28'C is great for laser. By the way for YAG the requirement is even higher; 24'C +/- 1'C

My apologize if I gave you wrong information and caused trouble for you. I'm learning everyday. I hope my "water cooler" is a solution for you to fix the problem


Maro

[waltfl]

Hi guys
no reason to apologize there is always two totally different things between theory and practice and it also always depend on the all circumstances.
the manufacturer use always a perfect setup like room temperature max 20 C, water flow no real requirements given should be 5LPM,
normal engraving, most K40 machines are not for real cutting max 2min.
what the most guys are doing is cutting up to hours like they describe in the forums.
I have and quite a few others who I tutor too, paid for not paying attention to the requirements, which are essential for long tube live at least 1,000 hour.
My data are from practical work with cutting up to 4 hours with just a minute to change the material.
I can tell from most described problems that the people did not watch it and not did the exact measurements just mostly some eye balling what is mostly deadly.
if marco says something it is what the manufacturer told him and nobody should hold him accountable.
I have written on pretty much every group and forum what should be watched and discover every time they did not and then try to find somebody to blame.
I just wana say this to be fair.
greetings
waltfl

I agreed with Walt that 22~25'C is perfect for CO2 laser tube

Hmmm, a couple of months ago we discussed this and you told me up to 28 degrees was still within the perfect temperature range for a 40w tube. That's kind of why I was thinking everything was fine. Exact words were "25~28'c is great for co2 laser". That's why I've been a bit confused on the subject.

To Toasty

That's what I though 28'C was great for tube as I asked many machine manufacturers about it. May be a small tube is less tolerance than a bigger tube like a 80W or 100W tube. I will do some test once my machine setup. As you mentioned that before, 25'C is hard to achieve for folks without water chiller at room temperature because the room temperature is 26~27'C. And, I could get good cutting with room temperature water when I tested a customer K40 when I helped him for modification. If you ever ask Reci sales Rep, they willl tell that you that the max temp is 40'C. So, that's what I came up my theory, the 40'C they mentioned means the "out flow" temperature. Or, as I said, different tube (size & power) may have different spec. Inside of the laser tube, it is not only CO2 gas but a mix with other other type gas per different manufacturer. I think unless we line up a few tube for testing, it is hard to make a final conclusion

FYI, small tube are using small mirror/lens but large tube are using bigger mirror/lens. That will make a lot of difference as well. When I talked to machine manufactures in China, they told me that below 30'C should be fine but 25'C~28'C is great for laser. By the way for YAG the requirement is even higher; 24'C +/- 1'C

My apologize if I gave you wrong information and caused trouble for you. I'm learning everyday. I hope my "water cooler" is a solution for you to fix the problem


Maro

[Toasty]

Don't get me wrong. I'm not blaming Marco. In fact, I wouldn't hold him to anything because I didn't buy my machine from him (just the dsp kit and table) so it's not really his problem. He was nice enough to give me his opinion. I'm sure he wants to know the correct range too since he does sell his own version of the k40.

I'm also not trying to find anyone to blame as I've had zero problems with my machine so far (again, knock on wood, gonna keep doing that. lol). I use mine for real work, every day, usually for around 4 hours at a time. Again, mostly engraving at around 13% power.

I'm really trying to get a definitive answer because I'm a bit ocd about doing things the right way and the numbers people throw out are all over the place. Obviously there's no exact answer to the question anyway.

I do think that it's good we are talking about it like this though, it's always kinda just skimmed over when people talk about the k40. Heck, the instructions that come with the machine show a bowl of water and have no mention of temps. It's no wonder everyone thinks these machines are junk. If you purchased a k40 and you had zero knowledge about laser engravers you're doomed to have something go wrong. With a little bit of care (and a dsp kit ) you can have a very nice little machine.

Hopefully Marco will come up with a low cost cooling kit for these.

Like most people, I'm just trying to make my tube last as long as I can. One great thing about these small machines is that the replacement tubes really are not THAT expensive either.

My former boss (who owns a shop that does the same things I do) called me and we were talking about him just replacing the tube on his LaserPro machine that I used to run. It was around $3000 for the Synrad tube and he flew someone in to install it. He didn't tell me how much the labor cost was. I could have easily purchased two of my machines for the total repair cost I'm sure. Of course his tubes last for several years and that is a VERY nice machine (big too) but I'm starting to ramble... lol

[waltfl]

hi toasty
you will not get real numbers because not many even measure or test the tube like I do. I got two thermometer on the tube one in and one out going water and one room temperature, the next is the current meter, one hour meter.
this would be a request for the DSP update to integrate the cumulative laser run time, maybe marco can ask for, then everybody would know how many hours he got already on the tube, most don't even recognize how many hours they running the laser, that's whats happen to me too in the beginning .
even if the K40 is a so called ( primitive version) of a laser it still is a sophisticated technology what should be handled like this.
I agree that the manual what comes with it is for a newcomer nothing where to find the answer to the most questions on the other hand if there would be all questions in there it would be a couple phone books thick.
like with so many things many especially young people believe they know better , can do it easier and better only to find out this can destroy this little machines.
I run my machines all converted K40 for more then 6 hours 6 days a week and the tubes have between 500 ( the newer one) and 1,250hr the old one. most of my work is engraving and heavy cutting of 5mm bamboo solid.
just to say
greetings
waltfl

Don't get me wrong. I'm not blaming Marco. In fact, I wouldn't hold him to anything because I didn't buy my machine from him (just the dsp kit and table) so it's not really his problem. He was nice enough to give me his opinion. I'm sure he wants to know the correct range too since he does sell his own version of the k40.

I'm also not trying to find anyone to blame as I've had zero problems with my machine so far (again, knock on wood, gonna keep doing that. lol). I use mine for real work, every day, usually for around 4 hours at a time. Again, mostly engraving at around 13% power.

I'm really trying to get a definitive answer because I'm a bit ocd about doing things the right way and the numbers people throw out are all over the place. Obviously there's no exact answer to the question anyway.

I do think that it's good we are talking about it like this though, it's always kinda just skimmed over when people talk about the k40. Heck, the instructions that come with the machine show a bowl of water and have no mention of temps. It's no wonder everyone thinks these machines are junk. If you purchased a k40 and you had zero knowledge about laser engravers you're doomed to have something go wrong. With a little bit of care (and a dsp kit ) you can have a very nice little machine.

Hopefully Marco will come up with a low cost cooling kit for these.

Like most people, I'm just trying to make my tube last as long as I can. One great thing about these small machines is that the replacement tubes really are not THAT expensive either.

My former boss (who owns a shop that does the same things I do) called me and we were talking about him just replacing the tube on his LaserPro machine that I used to run. It was around $3000 for the Synrad tube and he flew someone in to install it. He didn't tell me how much the labor cost was. I could have easily purchased two of my machines for the total repair cost I'm sure. Of course his tubes last for several years and that is a VERY nice machine (big too) but I'm starting to ramble... lol

[Seeker]

My plan was to get a Iceprobe aquarium chiller like this: http://www.saltcorner.com/Reviews/showr ... reviewID=2

I have seen then as low as $112.00

I live in Florida, and the room I am in gets hot. Up till now I have been taking a couple of 1 liter bottles and filling them with tap water and freezing them. I put them into my water reservoir to cool it. Since it is such a small amount of water to cool, this seems to work well and keeps the water clean. But the Iceprobe looks like a more hi-tech solution that wouldn't require any prep work. I think they claim it can cool 10 gallons 6 degrees, 20 gallons 3 degrees, 40 gallons 1.5 degrees. So on the two gallon tank I use it should cool more than enough.

Has anyone tried one of these units?

[waltfl]

Hi seeker
just keep in mind before you buy that during cutting the temperature raises about 8 to 14F by a water flow of recommended 5LPM.
greetings
waltfl

My plan was to get a Iceprobe aquarium chiller like this: http://www.saltcorner.com/Reviews/showr ... reviewID=2

I have seen then as low as $112.00

I live in Florida, and the room I am in gets hot. Up till now I have been taking a couple of 1 liter bottles and filling them with tap water and freezing them. I put them into my water reservoir to cool it. Since it is such a small amount of water to cool, this seems to work well and keeps the water clean. But the Iceprobe looks like a more hi-tech solution that wouldn't require any prep work. I think they claim it can cool 10 gallons 6 degrees, 20 gallons 3 degrees, 40 gallons 1.5 degrees. So on the two gallon tank I use it should cool more than enough.

Has anyone tried one of these units?

[Poltergeistas]

Hello,
At this moment I'm upgrading mine k40. Waiting now for new tube 45w(50w), also ordered new water pump 10lpm.
Just now I found this thread and it looks that haven't been updated for long time. Maybe someone found cheap and efective solution for cooling down water to the right temp?
Chiller is a little bit to expensive as I already invested into machine about 1700$. I hope to get great machine when I will finish all upgrades. The only thing left to buy components for water cooling.
I would be very grateful for any suggestions

[jjpumphrey]

Hello everyone! New guy on the block and just finished upgrading my K40 to a AWC608 control along with all new electronics.

An idea on using the radiator with large ice cubes. Let the distilled water flow through the inner part of the radiator and use regular water based ice on the outside of the radiator. I use a muffin tin to make large ice cubes for my beer brewing hobby. The cubes last a long time and is very cheap to make and is done in a 24 hr period. My thought is to lay the radiator flat and place ice cubes on top and let the cubes melt and trickle through the fins of the radiator. This should remove heat better than a fan. To make the ice colder you can put a little salt on the ice. This trick works great for a cooler full of beer.

Any thoughts, anyone?

[NickWL]

I very quickly got fed up with messing around with miniature (120mm) radiators, ice cubes, evaporative cooling and so on.
Kept an eye on eBay until a decent deal came up on an aquarium cooler - got it for £100 (c. $150?) and a drive of an hour or two.
I NEVER LOOKED BACK|!!! I can set the temp to ½ degree accuracy according to whatever the latest view is on this forum
I have a 20 litre tub of water which is circulated through the cooler and the tube pump just takes water from and returns it to this pool. A digital thermometer in the tube outlet hose lets me know if anything's going wildly wrong.
It hurt buying it but it's been totally worth the investment.
All this on a fairly busy K40 which, at last, more or less does what it should!
Nick

[waltfl]

hi nick
what size did you buy?
greetings
waltfl

I very quickly got fed up with messing around with miniature (120mm) radiators, ice cubes, evaporative cooling and so on.
Kept an eye on eBay until a decent deal came up on an aquarium cooler - got it for £100 (c. $150?) and a drive of an hour or two.
I NEVER LOOKED BACK|!!! I can set the temp to ½ degree accuracy according to whatever the latest view is on this forum
I have a 20 litre tub of water which is circulated through the cooler and the tube pump just takes water from and returns it to this pool. A digital thermometer in the tube outlet hose lets me know if anything's going wildly wrong.
It hurt buying it but it's been totally worth the investment.
All this on a fairly busy K40 which, at last, more or less does what it should!
Nick

[brian257]

Wow, I would have never guessed that temperature changes in that range would make a noticeable difference in cutting power at all. I figured that it would affect the tube life, but not cutting power. Many thanks for the good information. So what happens if the temperature gets below your ideal temp? Does the cut power go down?

I had been playing around with different speeds and power and writing down what works best. Now that I know it is so affected by temperature (and since I have my machine in an un-air conditioned space in Florida, my database I have been building up does not mean much. Looks like I need to get my temperature controlled at a steady state just so that my preset speeds and powers work all the time and I don't need to make adjustments all the time.

I am thinking that modifying a small fridge would work OK. I have seen some small ones that are made to cool just a six pack for pretty cheap. just put a quickie temp sensor and controller on it and should be quick and cheap.