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Dave Johnson29
11-08-2008, 7:19 PM
Hi all,

I am sick of the noise my air cooled laser makes and would like to convert it to water cooled.

My laser casing has the grooves for the cooling tubes but I would like a couple of close up pictures of how the tubes sit in the grooves and how they are attached to the casing.

Could someone point me at some big pics of a Synrad please?

Thanks in advance.

Richard Rumancik
11-08-2008, 10:45 PM
Dave, I thought I had a few pics but can't find them. (My own Synrad is air cooled). Not sure why the noise is so objectionable though - maybe one option would be to put on newer DC fans. (Also, more fans with lower rpm = quieter.)

However if you want to convert there are a few pics on eBay right now. Search on Synad and look at the eBay Stores. As of today there are 2 Synrads with tubes for water cooling. It might give you an idea of how they are plumbed.

Synrad might be able to supply the parts unless you wanted to try and rig something yourself. I don't know what they use to get good thermal contact between the water tube and aluminum extrusion. Thermal grease? The Synrad technical guys are usually very helpful and could give you some tips. It may be even possible to use a coil of soft copper tube and make a continuous loop - so as to avoid the fiittings on the ends.

If at all possible, I'd leave the fans in place as a backup. You might also consider adding some kind of indicator that shows pump activity and laser housing temperature. You can get indoor/outdoor digital thermometers very inexpensively - maybe you could attach a probe to the laser surface to show tube temperature. (If you run it for some time with the fans only you will get an idea of normal operating temperature.)

Dave Johnson29
11-09-2008, 10:45 AM
maybe one option would be to put on newer DC fans.


Hi Richard,

Thanks for the reply, I had actually looked at both ebay and Synrad's site but the pics were not too forthcoming with detail. I had emailed their tech support and will see what transpires tomorrow or so. I also emailed their Service department to see if I can buy just the tubes that go with the metal case. I have more than enough lab-tubing fittings to plumb it all together.

The DC fans may be a better idea for noise, but more expensive as I would also need a DC power supply for them. My AC ones howl at about 98db. I have fitted a switch so I can shut them off when not cutting and burning but it is still pretty noisy when it is working. Maybe I am just old and grumpy around loud noise.



consider adding some kind of indicator that shows pump activity and laser housing temperature.


Thanks for the suggestion but I have been messing with lasers (just not engravers) for a long time and I have some water cooling systems I use on the glass lasers I have. I have flow switches in the line so if the pump goes out the laser output goes to zero. I also have temp sensors on the lasers themselves and they too can shut down the laser.

Just FYI, copper and aluminum are a no-no together when , moisture (humidity) is involved. Galvanic action will eat away the aluminum.

Thanks for taking the time to offer suggestions.

Richard Rumancik
11-09-2008, 12:54 PM
Dave - don't you already have a DC supply in the laser? The Synrads usually run on around 30VDC. The way mine is wired the 24VDC fans use the same supply. There might be a dropping resistor but I'm not sure. If you can find surplus fans they are not that expensive and some have a wide input range. There are 28VDC fans out there as well ued for server racks and telecom products. Of course you would need to ensure you have reserve capacity on the supply if you did this.

Newer fans have better blade designs than many of the old AC fans and so are less noisy. If you used common 12VDC fans you can pick up a DC supply for very little money. Or use a computer supply which you can get at no cost.

Yes, it's true you would not want to put bare copper against bare aluminum. But your laser housing is black anodized, isn't it? In such a case I would not expect galvanic corrosion as there is no alum-copper contact. I would probably use thermal grease as well (even if Synrad doesn't) to improve heat transfer, and this would also reduce corrosion risk. Of course, aluminum tubing is available too in coils or straight sections. Straight manufactured tubes would probably lie in the slot better. I think that the Synrad tubes use straight tubes clamped into grooves in the extrusion. But it sounds like you know what you want to do.

The Synrad all-metal tube lasers are not as sensitive as glass lasers. A glass laser tube will fail within seconds/minutes of no cooling. The Synrad tube will not fail catastrophically upon the loss of cooling; it will just start to overheat. So you don't necessarily have to interrupt the job in process if the pump fails, but that is your choice.

Dave Johnson29
11-09-2008, 1:18 PM
don't you already have a DC supply in the laser? The Synrads usually run on around 30VDC.

Hi Richard,

Yup I do, well actually 24v at but from memory only about 1.4Amps at the power supply. The AC fans are rated at 250CFM and there are 4 of them. A 250CFM DC fan would draw about 2A each so it is a pretty big PS needed.

Admittedly I have plenty of room to mount a couple of old computer supplies, but I think I will push forward with the water cooling. The ones I have on glass lasers here are silent and keep glass ones cool just fine.

I know what you mean about glass lasers. It is the faintest of "clicks" when one goes. Don't ask! :eek: A most uneventful but costly happening, no sparks, no loud bangs or shattering glass. That's why I include a flow switch in the cooling systems now.:):)

Rodne Gold
11-10-2008, 12:13 AM
Be careful the fans dont cool the power supplys and the main board or other components , getting rid of them might just make for other problems.

Dave Johnson29
11-10-2008, 9:25 AM
Be careful the fans dont cool the power supplys and the main board or other components , getting rid of them might just make for other problems.

Hi Rodne,

Thanks for the tip but the power supplies will be fine. The laser is outside the main box and has it's own cooling box so those fans are just for the Synrad, but thanks for the heads up just in case.