Water chiller not chilling

[apriorius]

I'm setting up my 6090 and the digital water chiller that came with it seems to be keeping the water at ambient temps. Readout over the course of a couple hours yesterday showed around 20 degrees. I didn't see any way to adjust the temperature from the outside. Anyone know how to make this chill better?

[KTP]

Isn't that about what you would want? I know you don't want it to chill so much that you get condensation on the optics or whatever.

I think water from 20 to 30 degrees C woudl be ok.

[CNCadmin]

I run my laser at 15c.

[SkipW]

You don't have the in/out water connections backwards do you? Would that even matter? I probably have the same chiller that you do, the 3000 series, and with my shop at 60-65 degrees F (nw PA) , my temp readout shows about 14 C at startup and never goes above 18 C when running the laser. Not sure how accurate the digital readout is though.

I'm using distilled water with a little Sierra brand propylene glycol antifreeze added.

Skip

[apriorius]

Well I ran the laser a bit more today and temps were hitting 25-26 C. I don't think it's cooling at all, just circulating. Is there a switch, setting, dial or anything else you can use to control the temps?

[lamicron]

Check where you have it placed, air running, also check for the vent running..
I ahve seen some of this connections with the blue air hose, that rise the temp because the inner of the hose is too little, use silicon hoses.

[apriorius]

I'll check that. Are these things supposed to be able to chill the water below room temp or are they simply supposed to maintain room temp?

[avetek]

I have a machine the same as yours , after running it for 15 - 20 mins the temperature rises steadily. The "chiller" provided is no such thing - it is a water cooler/radiator. Anyway , the long and the short of it , I believe these are only suitable for the smaller lasers and do not have enough capacity for the 80W machines - in a manual I was looking through they specify 25 litres of cooling water for this sized laser - the "chillers" only have a capacity of 7-8 litres so there is not enough water in the system to keep the temperature rise down. I also took the cover off and looked at the air movement over the radiator - it has a 150 mm fan or there abouts and has no shrouding to direct the airflow over all the radiator face - the fan is only forcing air over a fraction of the available area - I made a simple cardboard caver to make the air flow over all the surface of the cooler and the temperature fell a couple of degrees. - I actually run mine without the cover and this helps as well.
You should also keep it away from the motor of the air extraction unit if possible.
The other heat source in the water pump and I just wonder if the amount of head the chiller has to pump is part of the issue - I have raised my chiller up so it is just under the laser tube to reduce the load and thus the heat from the pump
I am going to repipe the water system through a much bigger reserviour and see what effect this has.

Hope this helps

[apriorius]

Fantastic post, thank you very much! I have been playing around with the laser and also noticed the water temp rise to 28 degrees very quickly. After letting it sit for a while it went down to 25 or so. Worries me since it's not even summer yet and my shop gets pretty warm. I think I'll end up buying an actual cooling unit and set it to a couple degrees above ambient.

[avetek]

It is summer here (or just finished anyway) - I had my machine up to 31-32 degrees last month but I am not happy running it at that. I will probably look a a chiller unit at some point during our winter. I am going to move my machine into a new space soon so I will repipe it then.
I have been very lucky with my machine , It was imported into NZ by a distributer with a good tech support. I had a couple of issues with the arc speed in my dxf files which he helped me fix (would run correct speed on splines and go real slow on arcs).
I also had an issue with the inconsistant focus of the cut but I finally realised after much stuffing around that the problem was the mesh cutting bed - the bed is made from steel honeycomb and has an aluminium frame holding it together. When it is placed on the aluminium platens the whole thing sags about 1.5 mm so if you are cutting near the edges of the frame the focal length is 1.5 mm different. I packed up the middle and it fixed the issue.
This seems to be normal stuff with the machine as you learn how it operates. I also spent quite a bit of time getting the machine level and resetting up the mirrors after they loosened off when I did some practice engraving.
There are also some minimum speed settings you need to be aware of as well. If you try to send a file with the settings lower than the miminum speeds set in the base program it wont work (oddly enough)

Cheers

[coleong]

If you know where you can bypass the thermostat, you can try this.

1. bypass the thermostat (so you can run the compressor without stopping)
2. run your laser
3. note the tempreture rise if it rise or not, also note if the compressor runs full time without stopping.
4.If the indicated temp drops, make sure it does not goes too low (to prevent water freeze and damage to the tube)
5. If the temp keeps increasing, may be you can ask somebody to check the water chiller for refergerient leaks or if there is enough of it.

Note for this checking , you have to make sure the condenser fan is running and therefore cooling the condenser. The air coming out from the condenser should be warm to hot.

My 2cents of opinion

[MacGyver]

No need to go to all of that trouble. I would suggest running the water through a pail, not the laser. Let it run for a few hours, see if the water temp has changed. Pour in a few gallons of quite warm water (not boiling) and see how long it takes the "chiller" to cool it back to room temp.

My guess is it's not much of a chiller at all.