[skippy]

What did you end up doing for the cooling system? Did you end up going with the 650gph pump you were talking about? You mention above the "heat exchanger". What did you use, water to water? (as opposed to liquid (water) to air like a radiator in a car or an oil cooler) Like everyone else I'm looking forward to seeing more pics and good luck with the project.
Skippy

[cncadmin]

Yes I did, and I used a oil cooler used for transmission cooling.

[skippy]

Paul, I don't want to be a wet blanket BUT if the trans cooler came from a car it would be lucky to flow 100 - 150gph and you'll probably find that the 650gph pump will attempt to run at too higher pressure (not that centrifugal pumps are capable of all that much pressure) due to the restriction caused by the small orifices of the cooler OR it will develop cavitation within the cooler or pump. You will probably need to run a bleed off tap (as first suggested by Ynneb) just after the pump but before the laser. Crack open the bleed off tap sufficiently to dump as much excess flow straight back to reservoir but still keeping the return water (that which passes by laser tube) and at a manageable temp level (that's the unscientific method without resorting to pressure guages and pressure meters). You may have already done this or you may have decided on something else. Your machine = your decisions. I'm enjoying watching your progress.
Skippy

[cncadmin]

The pump will not cavitate when being pushed through a 1/4" hole, ( I tested it) but I do plan on using a bypass to keep the presuser low. This is the same pump that is used for medical lasers.

This is where I got my info from-
http://repairfaq.ece.drexel.edu/sam/lasercc2.htm
"The 25 to 50 W Sharplan lasers use a 22 litre per minute plastic pump made in Germany by a company called Eheim (model 1060). It's got a nonconductive case and rotor but is not self priming. They have a 1 liter reservoir above the pump to keep a constant level in the system. The radiator used is a 6" by 8" unit with 3 layers of fins, 1/4" tubing in the core, and a 200 cfm fan."

[skippy]

(A) As we hadn’t heard any more re your cooling system in the earlier thread I therefore didn’t know where you were at with it. The major problem with that earlier discussion was that no one had any base figures (ideal requirements) to work with BUT I see you now have that. Certainly, using the Sharplan example as model to work from, your cooling system set up including the “bleed off” should be fine. What’s more it didn’t/won’t cost you much in terms of money/floor space/set up time.

(B) I notice that quite a few people are hanging on the results of this project. You’ve voluntarily made yourself the test “Guinea pig” for this area (low cost laser projects) of cnc development so once again, good luck with it. (Hopefully you use that same expression in the US)

Paul, do you get the feeling that we, as a group are putting you under pressure here? I hope so. What's this about no time? Day job + home life + 10 hobby projects on the go + 5 cnc/workshop projects on the go + website to run. Piece of cake! hehe! Hang in there!
Skippy

[cncadmin]

This weekend, I hope to have it 95% done, I'll take lots of pictures and a summary of what I have done. I'm pretty sure that the cooling in a non issue any more. I wish I had more time to work on it, and fill all you guys in.

[da21]

can't wait for the big Hurrah! it works , then it's off to the bank for a Loan

for balsa parts etc what size laser is resonable or do you need to get into the 100w range etc , or will 5 or 10w fit the bill , also look forward to more details on parts and construction too .

Dave

[owhite]

in case anyone's interested I bought a neslab hx100 cooler and installed recently. Its about the size of a dishwashing machine, and sounds like a compressor for a standard walk-in fridge. Its sits in the basement between the washer and the dryer. I hooked it up to 220, and ran 3/4 pvc pipe between it and the laser that is in another room. The system works great. I bought a very inexpensive outdoor thermometer from home depot. These have a small pill shaped unit with adhesive on them that are meant to be stuck on windows to get a temperature measurement of the outside. I placed the pill on brass tubing leading into the laser to monitor the temperature, and there is basically no variation once the laser stabilizes with the system. Runs at a cool 20 degrees C. The neslab cost $500 on ebay.


owen

[cncadmin]

Very cool, I checked themn out on ebay, might be a great way to go if I step-up to a 100 watt laser.

[cncadmin]

Here is some long awaited pictures of my progress

[cncadmin]

Here is the laser PSU and the stepper controller case and my radiator-

[cncadmin]

Here is my beam aligning device, this is sold as you see if from emission technology for 500.00 it cost me 40.00 to make myself.

[ynneb]

I reconize that beam aligning laser diode. Out of a toy gun hey?
Tell us how you use it. Do you have to shoot the beam back into itself to find alignment?

I just cant wait for you to show us some cutting pics or even a video.

[cncadmin]

The red (650nm) beam hit that piece of special mirror that lets IR (10.6nm) pass but reflects the visible into the path of the IR.

[cncadmin]

This week I will get the beam locator thingy glued on the end of the laser tube and begin aligning all the mirrors. Once that's done, it's just a few more wires to hook up away, and we fire the laser!

[cncadmin]

Here is the busy end of the laser-

[cncadmin]

This weekend I should have the laser tube installed and the plumbing hooked up, and next week I should be cutting. I'll post more pictures this weekend of my progress.

[anoel]

Just out of curiosity.... And the fact that I have "NO IDEA". How does the beam get to the (you know the cutting thing... culminator? ) I know the Laser doesn't sit on the gantry and get moved around. So what's the trick?

[cncadmin]

Gold mirrors.

[owhite]

This weekend I should have the laser tube installed and the plumbing hooked up, and next week I should be cutting. I'll post more pictures this weekend of my progress.

how is alignment going? You reckon it will be pretty straightforward?

I have some suggestions if you need them.

owen