UC of Santa Cruz

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Joined: Mon Jun 15, 2009 3:00 pm

UC of Santa Cruz

Postby Tech_Marco » Wed Aug 30, 2017 6:28 pm

Aug 18, 2017


Machine: 1200x900
Location: Santa Cruz, Ca
Manufacturer: MornTech-USA (closed business)
Laser: 100W
Controller: Ruda 6442 or older
Problem(s): Cutting speed slow (6mm/s on 6mm MFD), Noise

I reserved 3 days for a 2.5 stars hotel in San Jose. I tell you what, I would never use this motel forever. I'll tell you later why
My booking was 9:00Am at Santa Cruz and folks in California should know that it would take 3.5hrs driving without traffic. But if whoever lived closed to Berkeley or San Francisco, the traffic I won't say that it was horrible but annoying enough. I used to drive 2.5hrs to work from China Hills to Long beach daily. I had to take 3 different highway and driving bumper to bumper everyday started 6:30am and 4pm. That's why I decided to move up to Sacramento. Anyway, back to trip! Because I didn't want to be late, I decided to take a day early to start the journey. Why chosen San Jose but not closer? Well, would you pay $300 or $180 for just taking 8hrs sleeping time and just need to take 1hrs drive to the job site. I chosen the latter one because I'm cheap :lol:

Ok, I woke up at 7:00am and carried my tool box and laser tube to my truck. Oh, I forgot to mention that I brought two Reci tube;100W & 130W and the 130W tube was too long to fit into my truck. So, I have to bring it with me to the motel. The box is quite big: 16"x16"x68" and my room was way far to the elevator! It took me two trips to moved it in and out.

The UC Santa Cruz has huge campus and too me a while to find the Engineering building in the middle of the hill. While I was unloading my stuff, I felt something staring at me. Oh, a nice 'wooden' craft deer was standing under pine trees. I looked at it and though that it was a real one but it didn't move at all. Hmm...why would someone put a craft deer in engineering building I though it should be seeing that in art center. Ok, I moved my tool box and the long Reci 130W out from my truck. By the time I turned toward to the building and I found that the wood deer was walking away. OMG, it was a real deer! LoL.

Ok, back to the subject. I met Professor Russ and Max who taught robotics in the school. They were very nice to show me the machine and explained what was the substitution of that the machine. The main problem was that i cut very slow by running at 5~6mm/s for 6mm MDF. Plus, the movement was very rough and noisy. I powered it up and ran a few tests and got some idea what was happening. Surgery began!

First of all, I took out the old tube which was a 100W generic tube. When I took out the Reci 130W, all of us worried that it won't fit into the machine and need to settle with Reci 100W tube instead. I made some measurement and decided to go for it. There about 1" space in between the first mirror and the laser tip which was totally acceptable. The machine was built non-professional way with so many sensor wires runs closed to the HV power line in parallel way. Plus, there was no protection jacket (silicon) cover the HV wire. After I swapped the tubes and found that HV cable was too short! No choice that I have to opened the machine cabinet and re-wired the setup. Luck that I could spare out another 9". Another problem popped up after the HV cable issue. Now the water tubing was short either! Too bad I didn't bring spare water tubing. Ouh~!
Well, Professor Russ and Max were nice enough to search for a coupling for me because they have some short water tube around. Ok, got the issue fixed and moved on next

After tube setup and we're ready to fire it up. The first thing to do was: check the max current.
It seems that no one show them how to configure the machine nor did they learn how important of max current being set. When fired up I saw the current meter swing hard enough to the max which was 50mA! In fact it could be 40mA because of swing movement from the analog meter with a needle type indicator. Of, I locked into the controller with the password I used for our controller and it worked! That surprised Russ and Max because they didn't know that at all :lol: OMG, it was set to 98%! So, I set it down to 80% and give it a fire test. Bomp! The need still swing hard to roughly 35mA. Ok, I tuned it down to 75% and the reading was 30mA. So finally I set it to 72% and it stayed at 29mA roughly. Note that we tested laser tubes we shipped and marked down the current it need to output the rated power. For this Reci 130W, it reached 130W at 26mA and it could delivery 138W at 28mA.

After tube setup properly and I ran a small cut for testing. It worked good so far. Then, the next step I did calibration on stepping because the square box didn't show 'square' and ratio wasn't right either. I showed two gentleman how to do it and it came out perfect square after the calibration. Then let's do a real cut. I draw a box of 50mm x 50mm (must use bigger size than 25mm to give time to speed up) and it cut out at 25~26mm/s!
They were happy to see the result. Well, not yet. I found that the cut out wasn't in perfect shape. The cutting edge was kind of slide or called slop. It means that the laser beam from the laser head was not straight down but in angle. Ok, no problem. I know where to correct it and took me roughly 20min test & try to get the beam straight enough. I ran another test and showed to Max and he seem the improvement. Ok, laser is good now but was it done yet? Not that far! The machine show squish sound. It happened on the X rail and it always happened when move from Left to Right but not the other way. The Y rails sounds a little under stress and not smooth but no squish sound though.

Ok, cleaning is necessary for all machine. So, I use WD-40 to clean the machine entirely. I have used towels to clean the rails times and reply another lubricant. Technically speaking, I have to soak the rail cartridge and the bearing. After spending almost entire hour for cleaning, the machine sounds much better and runs very smooth. All strange squish sound disappeared or to certain level not as obvious as before. The machine is happy now. When doing a job it sounds like it was singing a song. Before, it sounds like crying or screaming. "Help me~~~" LoL

After spending 7hrs there, mission completed. I have seem a happy machine and happy customers. Time to wrapped up and heading back to the 'low grade' Motel. The next journey was Monterrey Bay


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