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View Full Version : New Universal M360 - Need some Suggestions



Bob & Elaine Robinson
11-23-2007, 9:56 PM
I have finally taken delivery of my Universal 50w m360 w/down draft table and 1.5 lens. In talking with people cutting what I am ( 1/16" basswood and .035 chipboard) I have encountered a radically different recommendation for settings to vector cut with each person I have talked too. These recommendations are alleged favor either speed or both. Without going into detail (unless someone wants to know) I tried all these suggestions. Making the same part (vector cutting) across the whole 12" x 24" table, I did not have much luck getting good, consistent through cuts with a constant line width,

I eventually made some progress and managed to do a couple jobs with both wood and chipboard. I tried power/speed settings of 25/5 and 35/7 and both worked reasonably well. However, like the "extreme" settings I first tried, I am still getting a noticeable amount of variation in the quality and character off the cut/kerf from one end of the table to the other. I called Universal and suggested the downdraft table was not level, based on my observations of line width growing as one goes from right to left. They said I was right, it wasn't level and suggested I shim the table. Per their instructions, I focused the lens at the upper right (where I get a very nice cut) and then shimmed the left until it matched the somewhat crude focusing instrument universal supplies. I ended up shimming the left side up .045. Things improved somewhat, with the line widths shrinking some on the left side, but I think it could be better (?)

When I look at the bottom of the sheets of the materials I have cut, the exit lines from left to right are all very fine, about .002 (I'm guessing) The entry cuts, however, look to be about .003 on the right and about .07 on the left. Any radical change in settings and these differences get exaggerated.

I have seen more consistent (width of cuts across the table) results with these materials on this machine in other shops. So when I think about all the possible speed/power, etc. combinations, convergence/divergence implications, etc. and my beginning status, I'm not sure what I should try next here. I'm also wondering if I should accept this downdraft cutting table which seems so far out of whack.

I know I'm just beginning and have just started to probe, so any suggestions/opinions are appreciated.

Bob

Mike Mackenzie
11-23-2007, 10:04 PM
Bob,

First check the level of the solid table. Focus in the upper left corner and then turn off the system and move the X axis head to the other corners of the table. If this table is not flat the cutting table won't be either.

Did someone come and do the installation? Did they check the alignment?

If you PM me your e-mail address I have some PDF's with instructions on how to check these items that I will gladly send to you. I would get your rep over there to help you check these things this should have been done during installation.

Tim Warris
11-24-2007, 10:53 AM
Hi Bob,

We suffered through this at the beginning as well. I had two issues that kept coming up, one, as you described the material would not cut through on the edges of the material, and two, inconsistent cutting depending on the length of the cut being made. We have since solved both these issues.

The first issue of the down draft table not being level was solved by adding shims along the edges where necessary to get the top of the mesh within .010". Its good to see that Universal is admitting that this is happening, when I contacted them about it they didn't seem to believe this was possible. I sent them images showing the lip that supports the mesh top was off almost 1/8" from one side to the other, and still not much feedback about it from them.. This solved the level issue, but there was also another issue with the table. We cut plywood almost exclusively, 2mm being the most popular size. New plywood sheets have a tendency of being a bit warped and would not sit flat onto the table, and the down draft feature didn't exactly down draft much. There seems to be a huge flaw in the design of the laser in that the entire back of the laser is open above the plenum of the down draft table, and this would prevent the material from being drawn down onto the table. We covered over the hole in the back of the laser constricting all the venting through the table only. After that a sheet of plywood would literally slam down onto the table and be held very tight, regardless of warpage. With these two fixes, plus some trial and error to get the right settings and we are now getting great results.

Quite a bit of trial and error was done to get the right feed and power settings for the different sizes of plywood we cut. We always use 100% power and adjust the speed settings, this way we are certain to be cutting as fast as possible. I can't think of any of our settings that use less than 100% power, at least on the wood. Also we always set the PPI to 1000. This is the "pulse per inch" setting and controls how often the laser will fire. A higher setting here will fire the laser more often and will result in a smoother cut quicker.

I was surprised how slow it was necessary to get a cut in ply, usually around 4-5 on the speed. Any faster and inconsistencies in cutting start to show up. Eventually we opted to import our own plywood sheets directly from a mill in Finland designed to be "laser friendly". This allowed us to cut material a bit faster (we were using 2 on the speed) and without and charring on the edges of the wood.

Currently we run the laser 10-12 hours a day, non stop to keep up and after 3 years of this we have had no issues with performance.

Hope some of this is helpful!

Cheers!

Tim Warris
Fast Tracks

Mark Winlund
11-24-2007, 2:54 PM
[quote=Tim Warris;701650]Hi Bob,

.... There seems to be a huge flaw in the design of the laser in that the entire back of the laser is open above the plenum of the down draft table, and this would prevent the material from being drawn down onto the table. We covered over the hole in the back of the laser constricting all the venting through the table only. After that a sheet of plywood would literally slam down onto the table and be held very tight, regardless of warpage. With these two fixes, plus some trial and error to get the right settings and we are now getting great results.



A good way to do this is to use magnetic sign material. Cut it with a pair of scissors to just fit over the slots. By using this material, you can adjust the air flow by sliding the magnetic sign material around.

Mark

Mike Mackenzie
11-24-2007, 6:20 PM
Tim,

It is not a design flaw because not everybody gets the downdraft cutting table. It should have been taught to you the best way to use the cutting table for your application.

Peter Meacham
11-25-2007, 9:23 AM
Tim

I (and I am sure others) need a good supply of quality thin plywood - is your source in Finland something you can share please. Also, what are your products?
Thanks, Pete

Mike Hood
11-25-2007, 11:53 AM
Tim

I (and I am sure others) need a good supply of quality thin plywood - is your source in Finland something you can share please. Also, what are your products?
Thanks, Pete

I stumbled across an estate sale a year or so back and bought 176 half sheets (48"x48") of 1/32" and 1/64" aircraft ply ($80 for the whole pile).

I'm set for life when it comes to ply myself, but this all came from Aircraft Spruce. They've got decent prices and ship worldwide.

Bob & Elaine Robinson
11-26-2007, 11:28 PM
I've been getting a lot of help and suggestions. My rep had me do the diagnostic/alignment. We aligned the beam with the red dot pointing at a piece of masking tape covering the hole leading to the mirror lens in the x-carriage. After alignment (it was off quite a bit), I did a burn through the masking tape covering the hole. The beam stayed in alignment, but I also noticed the laser beam made an elliptical hole, which I am told is often not a good sign. Talks with ULS tech during this procedure indicated they will send a new tube as soon as I ask for it - after doing cutting tests/post alignment. Anyway, the tests I did after the alignment shows that the problems still exists, so I may be getting a new tube.

Bob

Bob & Elaine Robinson
12-03-2007, 10:58 PM
Got a new tube today and I now have a machine that cuts like it should. The cutting across the table is consistent at various power/speed settings and the cut is now vertical/perpendicular - something that I wasn't getting before.

I got help on on-line and a coordinated phone effort from my rep and the factory. Thanks to all. I'm now in production.

Bob

Mike Null
12-04-2007, 7:38 AM
Bob
Glad to hear all is well.

Thanks for reporting the good news.