1200*1800 XY stages. Huge!

[mixer911]

This is a great thread Marco... It answers alot of question about my new 1200*1800 Build.

[Tech_Marco]

Glad that help. I haven't had time to finish mine yet. Plus, my shop is very small and running out of space. But I'm going to fin a warehouse (4000~5000sqf) for future expansion

Marco

[drandolph]

I've been away on a business trip so I haven't had time to work on mine but I hope later this week to be home and get back to work on it.

[drandolph]

I've been busy with that darn thing called work and I haven't been able to work on the laser cutter much but I finally got some time. After all I can't let mixer911 finish before me

Everything is looking good and working good however I'm still having a focus problem. Everything is hitting square center but when I put the nozzle on the beam seems to hit the sides and lower the power.
However if I leave the nozzle off it cuts like a champ. Thoughts?

http://www.youtube.com/watch?v=Icbgm6F76BQ

[mixer911]

I've been busy with that darn thing called work and I haven't been able to work on the laser cutter much but I finally got some time. After all I can't let mixer911 finish before me

Everything is looking good and working good however I'm still having a focus problem. Everything is hitting square center but when I put the nozzle on the beam seems to hit the sides and lower the power.
However if I leave the nozzle off it cuts like a champ. Thoughts?

http://www.youtube.com/watch?v=Icbgm6F76BQ

I am chuggin away... inch by inch getting closer

I have been worried about this same thing happening. I have read where people's nozzles get hot from it as well. What Focal lenght focusing lens are you using?

Marco, any ideas why that is happening??

[Tech_Marco]

Usually it is caused by miss-alignment on the laser beam inside of the laser head. First of all, make sure light beam is entering through the center of the hole (top of the laser head). But I got to tell you that even the light beam is right on target (center), it make no guarantee that the beam may hit to the center of a focus lens (insider of the laser head) and reflection may happen and beam is hitting to the inner wall.

There are three adjusting knobs on the top of the laser head that used to change the beam alignment. Using these knows to fine tuning beam to make sure light beam is hitting to the center of the Focus Lens. It's very important that you have good alignment or the beam will be bounced away and will hit the barrel. If you see 'flashing' instead of a fine laser dot coming out from the laser tip, the chance is that you have the light beam hitting the inner wall of the laser head. If that happen, it generate a lot of heat on the laser head as you're not burning the tip.


Marco

[liaoh75]

I've had this problem before and here is how I solved it. Here are the steps.

1. get a piece plain old glass mirror (not the mirror for bounching the laser) that you can place under the laser head.
2. Prepare several pieces of clear 3mm acrylic that is in the neighborhood of 1.5 inch square.
3. Scribe a line from one corner to the other. This will find the center of the piece of acrylic.
4. Remove the lens from the assembly and the air assist nozzel as well.
5. Measure the diameter of the tube. For example, If you have a 20mm lens then the hole will be 23-24 mm in diameter.
6. Using a compass with a scribing pin mounted, scribe a circle of the diameter of the tube. You now have a reference for the hole and also the center of that hole.
7. Line up the scribe mark with the bottom of the lens holder tube and hold it up against the bottom of the tube. The mirror allows you to see what is going on as the laser is marking the acrylic. You don't have to worry about any of the beam escaping as a co2 laser cannot penetrate the acrylic for the short pulses you will need to fire the laser for allignment.
8. Using the cross hair scribed on the acrylic you can push the laser button until it makes a mark on the cross hairs. Change out the acrylic pieces as needed so you can clearly see where the laser is hitting. Adjust the head mirrors until the beam is hitting dead center. I remember going through about 10-15 of these cross hairs until my laser in the tube was alligned.
9. Put the lens back in the tube and screw on the air assist nozzel and presto! Your beam is alligned in the head assembly.

Good luck.

David

[felixlaser]

Normally speaking ,SS will be easier to cut than Al.
However I don't think a 130w can work on cutting metal.

[mixer911]

I've had this problem before and here is how I solved it. Here are the steps.

1. get a piece plain old glass mirror (not the mirror for bounching the laser) that you can place under the laser head.
2. Prepare several pieces of clear 3mm acrylic that is in the neighborhood of 1.5 inch square.
3. Scribe a line from one corner to the other. This will find the center of the piece of acrylic.
4. Remove the lens from the assembly and the air assist nozzel as well.
5. Measure the diameter of the tube. For example, If you have a 20mm lens then the hole will be 23-24 mm in diameter.
6. Using a compass with a scribing pin mounted, scribe a circle of the diameter of the tube. You now have a reference for the hole and also the center of that hole.
7. Line up the scribe mark with the bottom of the lens holder tube and hold it up against the bottom of the tube. The mirror allows you to see what is going on as the laser is marking the acrylic. You don't have to worry about any of the beam escaping as a co2 laser cannot penetrate the acrylic for the short pulses you will need to fire the laser for allignment.
8. Using the cross hair scribed on the acrylic you can push the laser button until it makes a mark on the cross hairs. Change out the acrylic pieces as needed so you can clearly see where the laser is hitting. Adjust the head mirrors until the beam is hitting dead center. I remember going through about 10-15 of these cross hairs until my laser in the tube was alligned.
9. Put the lens back in the tube and screw on the air assist nozzel and presto! Your beam is alligned in the head assembly.

Good luck.

David

Thanks for the info David. I think this will help out a lot.

Also dont forget about aligning the head itself. After removing the four screws last night to attach my cable chain bracket, I realized how easy it would be to have that out of alignment as well. Then the mirrors would never be able to be aligned in the center if the head was off axis even just a hair.

[drandolph]

I see the end (of this phase
I got my nozzle focused and it's humming away.
http://www.youtube.com/watch?v=iW3Ytancm48


Al thats left for me now is to build out an electronics enclosure to give me all my e-stops and etc.

[liaoh75]

Hi Drandolph or Mixer911 or Tech Marco,

Can you do me a huge favor? I've been tracking down a problem in my build for a long time. I'm running servos on all axis and am having great difficulty with engravings and cutting lining up and I've also be plagued with low speed (80 mm/second envraving speed for no ghost images running x-swing). For example I engrave something and then cut out the engraving, the engraved image will always be off center. I am considering getting the same x-y stage you have if the engraving speed can be 800 mm/second or higher running x-swing (not unilatteralism). Would you be willing to do a test for me if I sent you the *.ud5 file and post a video of it? I'd be willing to pay you for your troubles. I'm just looking for a solution to my problems. I'm in a production environment and CNC has always been a hobby for me. A lot of people ask me why I don't just buy a manufactured machine, but then where's the fun and joy?

If you can help me out, I'll post the file. Sorry about the bother.

Thank you,

David

[drandolph]

...

[Tech_Marco]

Hi Drandolph or Mixer911 or Tech Marco,

Can you do me a huge favor? I've been tracking down a problem in my build for a long time. I'm running servos on all axis and am having great difficulty with engravings and cutting lining up and I've also be plagued with low speed (80 mm/second envraving speed for no ghost images running x-swing). For example I engrave something and then cut out the engraving, the engraved image will always be off center. I am considering getting the same x-y stage you have if the engraving speed can be 800 mm/second or higher running x-swing (not unilatteralism). Would you be willing to do a test for me if I sent you the *.ud5 file and post a video of it? I'd be willing to pay you for your troubles. I'm just looking for a solution to my problems. I'm in a production environment and CNC has always been a hobby for me. A lot of people ask me why I don't just buy a manufactured machine, but then where's the fun and joy?

If you can help me out, I'll post the file. Sorry about the bother.

Thank you,

David

Hello David:

Sorry I missed your post. Sure you can send me the file and I'll give it a try. I've been busy recently as I'm preparing to move to a warehouse in Sacramento. It is 15,000 sqf and there are plenty of work need to do before we move in. We're going to do moving on next Sat & Sunday. But I do have two machine for testing. So, if the graphic is not over 600X400, then I can handle it.

Again, my apology of not replying you on time.

Marco