View Full Version : Chinese laser owners with coolers

pete hagan
03-26-2009, 12:20 PM
I had issues with the cooler on my Chinese Rabbit laser so I decided to do a little upgrading of the hoses, add a filter etc. Well after some investigation and many leaky connections on the hose nipples and a sudden low pressure on the output I thought “Let’s take this apart and see how well it’s made”. If you own one of these machines with the cooler it is worth your time to replace a few items inside the tank before you end up with the BROWN CRUD flowing through your tube.

It turns out these inventive Chinese builders used metal hose clamps INSIDE the water cooler tank to hold a hose onto the outlet nipple which had completely corroded with rust. Likewise when I replaced the brass nipples on the outside of the tank with nylon I had twisted the internal hose cutting off the flow of water.

If you have this cooler it would be wise to take it apart and do some corrective maintenance.

BTW it does work well even with its construction methods!

Skip Weiser
03-26-2009, 5:30 PM
Pete, what's the model name/number of your cooler?

pete hagan
03-26-2009, 11:06 PM
Cooler is: YONGXING Model P0015 Water Chiller

The unit works rather well but I was tired of changing the distilled water because of the brown crud I was getting in the tube.

So here's what I would recommend doing if you'd like to improve the cooler.

Supplies needed (Home Depot numbers)
(2) 1/2" PVC threaded couplers (to extend the in/out connections a little further than what the current brass nipples do now) Model 430-005HC
http://www.homedepot.com/catalog/productImages/300/dc/dca952a8-7e10-4a89-a715-c19da6d7f515_300.jpg (http://javascript<b></b>:openLayer('popup-enlarge-image');)

(2) 1/2" MIP to 3/8" Nylon connectors like this 90 degree one (if your cooler is on the floor) or simply straight connectors.

Appropriate hoses. I'm using 5/8 reinforced clear hose which is stiff enough to not get kinked but you can see fluid flow.
I would highly suggest using Teflon tape AND I used silicon around the tank and the 1/2" couplers just in case.

1) Begin to take the top cover off by removing the top 2 silver allen head screws in the front panel and rear panel.
2) Remove the three silver allen head screws in the side panels along the bottom. The top cover should come off at that time.
3) Remove the four screws holding the top on the water container...Gasp at the crude Chinese construction.
4) Remove the cheap flex hose from the pump (take the rusted hose clamps off) and replace with either a small section of clear vinyl or use 5/8" heater hose for autos. (65 cents or so) This should be VERY snug on the pump and output connector so no hose clamp is needed.
5) Make sure you thoroughly wash out any crud / rust from the tank and it would be good to remove the pump and clean it as well. It's held down by four small suction cups on the bottom. It looks to be a decent little pump much like the Little Giant pumps we use in commercial coolant tanks.
6) Remove the brass nipples on the output and input, you'll need a deep socket wrench.
7) Thread the 1/2" couplers on the in/out to extend the connection past the cabinet panel. Here I used silicon to seal the 1/2" coupler to the tank. It may be overkill but I hate leaks.
8) Thread the 1/2" MIP to 3/8" hose barbs onto the in/out and make sure you wrap the threads with Teflon plumbing tape to avoid leaks.
9) Let the silicon dry overnight if you used it and come back to test the cooler before reassembly.
10) With the tank top OFF fill with enough water to cover the pump and use a small piece of tubing to connect the output to the input and plug in.
11) You should have very strong flow and the flow switch will actuate lighting the front panel light. The flow switch is inside the tank on the input connection. Mine was blue and had a right angle connector which shot the fluid towards the bottom of the tank.
12) If all is OK reassemble the tank, put the cover on and connect the hoses to the laser.

For what it’s worth I added a simple GE home water filter (1/2” in – ½” out 10 micron filter $25.00) on the output of the cooler to filter out any remaining crud and filled my unit with 50/50 water / antifreeze. I’ll inspect everything in a month to make sure the antifreeze is doing no harm but the laser is running a couple of degrees cooler now and much better coolant flow.

Picture of my cooler and the airpump is below

Skip Weiser
03-27-2009, 7:49 AM
Thanks Pete. I have a different make and model. It's a CW-3000 made by S&A Electromechanical Co.

Brian Robison
03-27-2009, 8:09 AM
We used to add chemicals to a chiller for the injection molding machine where I used to work. I should remember what they were (since I was in charge of it) but alas.....
Do some research for chillers and I'm sure you could find out what the chemicals are for chiller use.

Dave Johnson29
03-27-2009, 8:57 AM
We used to add chemicals to a chiller for the injection molding machine where I used to work.

Hi Brian,

That may have been because of the metals in the system, the die-plates etc. Often copper tubing is used in connecting plates and the additives would be to minimize electrolytic interactions and rusting.

In my 8+ years experience with glass laser tubes, I dropped back to using just plain deionized water providing there were no metal fittings involved, including inside the pump. It seems to work as well as without additives and is easier to maintain and clean up spills when servicing.

Just one man's opinion. :)

Eric Fuller
03-29-2009, 11:33 PM
My chinese cooler is still sitting around like a $300 doorstop. Didn't work for beans. I made my own out of a 10 gallon beer cooler, a fountain pump, a desktop fan, some MDF and a small race car radiator. Temps go up maybe 2 degrees C after 8 hours of cutting at 90%.

Bob Davis
03-30-2009, 3:04 AM
So if that is a sample of the design of the cooling system outside of the laser box, what's it like inside?
I don't much like the idea that an interior fitting under pressure could spring a leak. My understanding is that electricity and water are a bad combination... Do the water-cooled lasers have failsafe protection?

pete hagan
03-30-2009, 9:58 AM
To quote my favorite animated actor Private in Madagascar

"Kaboom kaboom!"

If the water is not flowing then a limit switch turns the laser firing off but other than that there really is no issue.

Dave Johnson29
03-30-2009, 1:54 PM
Do the water-cooled lasers have failsafe protection?

Not sure about the Chinese lasers but my glass tube ones always have a flow switch at the return point to the reservoir. No flow, no power, no lasing.

The last thing you want to hear from a glass tube laser is "click." Nothing spectacular, just a quiet little "click" and it's a deadn in about 1/4 second.