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View Full Version : Inconsistent cutting/engraving with a Universal M-300



Tim Warris
03-31-2005, 3:52 PM
I am new to this forum, and I must say it is a great source of information for all things laser!

I run a small company in Southern Ontario that produces track products for model railroaders and use a Universal M-300 laser for one of my product lines.

I have had this laser since last August and find it a great tool, amazing what can be done with one of these. Primarily I use it for cutting plywood, but occasionally do some engraving for myself.

The items I use the laser for are railroad ties, specifically for track switches.

http://www.handlaidtrack.com/images/QuickSticks-Standard-300.jpg

My core product line is aluminum assembly fixtures that allow modelers to construct their own trackwork as an alternative to purchasing expensive ready to run components. The laser cut ties are an additional item that can be used to complete the trackwork.

Since I purchased the laser I have had a nagging problem with its performance, and thought I would see if anyone else has had the same issues.

It seems that the power is fluctuating when cutting. I can cut one sheet of parts with no problems at all, very clean cut, and the next sheet, it will not cut completely though the material in several places, leaving material slightly attached where is should drop free. I don't believe this is an issue with inconsistencies in the wood, as I am frequently using material that was cut from a larger sheet.

When engraving in plastic, very noticeable lines appear in the engraved surface, horizontally. Again, I suspect that maybe the power levels are inconsistent.

A picture of a piece I made for my own railroad is below, I have painted it to look like a bronze plaque, but the horizontal lines are clearly visible

http://www.handlaidtrack.com/port-kelsey/pkimages/Control_panel_2.jpg

When I cut the wood parts the last step is to cut the part from the sheet, and using the exact same power settings it will not cut through, I have to slow this step down considerably to get a complete cut.

It is a very frustrating problem, and I have only had simple suggestions from the dealer about it, and Universals tech support so far has been very disappointing.

Has anyone experienced an issue like this before? Suggestions welcomed!

BTW, the material I am cutting is 2mm 3 ply Baltic birch plywood on a 35W machine.

Tim Warris

http://www.handlaidtrack.com/how-it-works.php

Mark Sipes
03-31-2005, 7:15 PM
The first question that must be asked is. Have you cleaned all the optics from the laser to the focus beam and all mirors in between? No obstructions that would cause the beam to be blocked? Verified that the focus lens is installed in the correct direction? Does the manual discuss tickle power or tickle delay settings. After that we are getting into $$. Electronics, Power Level Output, etc.


Hope others can add to this.

MArk

Mike Mackenzie
03-31-2005, 9:49 PM
Tim,

What power settings are you using? Check to see that the fan vents around the laser cartridge are clean and that you are getting good airflow.

What version of corel are you using. Or what program are you using to run the laser?

How old is the system?

Is the fluctuation in power in a particular area on the cutting table.

help me to answer these questions and we can figure it out for you.

Mike Mackenzie

Tim Warris
03-31-2005, 11:52 PM
The machine is only 6 months old. I am using CorelDraw 11 with a power setting of 100 % and a speed of between 3.0 and 4.0, depending on the mood the laser is in. Some times it will cut great at 4, and the next run it will not cut completely through.

I keep the optics as clean as possible, which seems to require cleaning after every sheet or two, about 2 hours of run time.

I am not using air assist, I had been using it but the noise of the compressor is becoming a problem. With the air I can cut a bit faster, and the lens will stay fairly clean.

The fans into the laser tube do get dirty, I clean them relatively frequently, but could do this more often.

Initially the inconsistent cutting was at random areas on the table, but lately it is definitely starting to fail at the lower right side, the side furthest from the laser tube, which I find suspicious.

An interesting note about the cutting, when it does fail, it fails in the same area of the part each time, its very consistent about this. The colors I use for cutting are black, red and green if that is relevant.

Tim Warris
04-01-2005, 12:35 AM
I thought I could explain what I am seeing better with an image....

As can be clearly seen on the part on the right the cutting has not gone completely through the material. The part on the left was cut from the same sheet of material shortly before the one on the right, using the same power settings and having the lens cleaned prior to cutting.

The first sheet of parts cut, which the part on the left was cut from, cut cleanly though with no parts left attached, the sheet of parts that the item on the right was cut from was unsuccessful. A typical sheet will have 6 to 8 parts on it.

What I have noticed happens every time the part fails to cut is that some areas will cut, and some will not, and it is always the same area on the part. The outside edges of the ties will cut through every time, while the inside pieces will not, this is very consistent regardless where the part is on the machine, and happens on every part of this type. I have a library of about 100 different designs, and every one will behave this way. The kicker is that it does not always fail, just occasionally, perhaps 20% of the time I will have this problem, the rest of the time it will work fine.

I have noticed while watching it cut that the speed of the cutting changes quite dramatically, it will speed up about 50% in some areas, and slow down in others. I understand how ramping works, I have been a CNC machinist for many years, I don't think what I am seeing is a result of the ramping up and down as I have observed it cut the same size rectangle at two very different speeds.

The driver version is ULS 2004-06-25 WIN XP/2000 V1.07M

http://www.handlaidtrack.com/port-kelsey/pkimages/Laser-2-with-text.jpg

Mark Sipes
04-01-2005, 12:51 AM
Tried to e-mail you but you do not wish to be contacted in this manner.


Do you mind sending the file you have pictured for me to run on my machine to see it has any problems like yours. If so send it to:

sipesm@harbornet.com

Thanks Mark

George M. Perzel
04-01-2005, 7:38 AM
Hi Tim;
If I read you correctly it sounds as if you have two problems which do not appear to be related:
1. When engraving, you sometimes get banding or lines on the work.
2. When cutting, sometimes the cut will not go all the way through.

With regard to the cutting, you state that the material is 2 mm baltic birch. This is less than 1/10th inch thick and should cut easily providing the material remains flat and in focus. I suspect that some warping is occuring in combination with a change in the density of the material in spots-note that the poor cuts are all in the same direction. The inner core of baltic birch is not always the same homogeneous material. Normally, at a low cutting speed you can "blast" right through and do not notice any difference.
This, however, does not explain why the poor cut is showing up at the same place on different sheets of material. Try reversing your drawing 180 degrees and see where the poor cutting occurs.

With regard to the banding problem, I do not have a Universal laser so can not comment on specifics. However, the problem of banding on various lasers has been reported and discussed on this forum many times. I have yet to hear anyone say " I did this and the problem went away", although the consensus appears to indicate an change in power due to input power fluctuations. From reviewing the discussions, it appears that the problem occurs during jobs which take a long time to complete in a raster mode. I think the problem may be one of overheating -try directing a small fan at the air intake on the laser during the job or pausing the machine for a few minutes a couple of times during the job.

By the way, saw your website and must commend you on your engineering design and fabrication-excellent. Website design and functionality is also outstanding. Makes me want to get into model railroading but wife threatens severe punishment if I get any more hobbies!
Good luck
George

Mike Mackenzie
04-01-2005, 12:10 PM
Tim,

Sorry I forgot to ask What PPI/DPI settings are you using. Also you can check to see if the cutting table is at the same level from the right side to the left side.

Just focus onto the table as you would normally do then turn off the system and manually move the focus head to the four corners and see if the focus tool is the same in all areas of the table.

What version Driver are you using? Have you configured the Corel Properly?

My guess is either the alignment, or you have a tube that is not pulsing consistently.

Get back to me on the PPI/DPI settings and the driver version. Also where are you in Canada Vancouver side or east coast side.

The good and bad thing are that if it is the laser tube it is under warranty. the bad thing is we don't like to see these kind of problems with any of our customers.

All I can say is we will get it fixed. I would be curious to see the file itself just to make sure that it has nothing to do with it.

Could you send me an e-mail and I will reply with some instructions. (alignment, Corel set-up, Driver)

cemlasers@attglobal.net

Tim Warris
04-01-2005, 1:05 PM
Hi Mike,

Thanks for the feedback!

When cutting the 2 mm 3 ply I am using 200 PPI and 1000 DPI. If I increase the PPI any higher it turns the wood to charcoal. I have tried using air assist and it does improve performance somewhat, but causes a whole new problem. When cutting the small rectangles that make up the inner part of the trackwork, the air will blow the scrap piece partially into the honeycomb of the table top and cause the piece to stick up, the air nozzle will then run into these pieces and misalign the entire part, ruining it. So using the air seems to be out of the question unfortunately.

I have spent a great deal of time analyzing the flatness of the top of the downdraft table, measuring it carefully with a dial indicator (I'm a retired tool and die maker) and found the table to be VERY crooked, and the honeycomb very flat. Almost 1/8" out from one side to the other on the honeycomb supports. I informed Universal about this, and even included pictures of the misalignment, but got the impression they did not believe me, and was offered no solution. I disassembled the table and added several shims in the table to correct the problem, this solved the problem of it not cutting in the lower areas of the table, but the inconsistent cutting still persists.

The driver version I am using is ULS 2004-06-25 WIN XP/2000 V1.07M

I am in Kitchener Ontario, about 45 minutes West of Toronto, which is in the middle of Canada, about 3 hours East of Detroit.

I suspect the tube is not firing consistently as well, but the head scratcher is that is will ALWAYS cut to outside of the ties, and fail on the inner rectangles as shown in the picture above, regardless of the file I am currently cutting. I have several hundred versions of a similar part and when it does fail, is always fails in this manner. I have evidenced this on 1mm, 1.5mm, 2mm and 2.5 mm material. Again, it only happens occasionally, but often enough to be an expensive problem for me as it takes 1 hour of laser time to cut a sheet. When engraving plastic, very noticeable lines appear in the surface of the engraved material, which appears to me to be fluctuating power levels while the engraving is being done.

The machine is still new, it was purchased in mid-August of '04, but has been used for about 6-8 hours a day since that time.

Thanks again Mike for the concern and interest in my troubles!

Jerry Allen
04-01-2005, 7:08 PM
It sure looks like the power was fluctuating on the set on the right. Either burning too much or not enough.

Have you tried a line conditioner?

I'm stumped by the great disparity in your PPI and DPI settings. What's wrong with 250/250?

The air assist is real useful and I don't know how you can work without it. Have you tried turning the air pressure down to 10-15 psi? Also, how about sorting the objects in Draw's Object Manager to prevent the head from pasing over an area that's alreay been cut and use tape to stabilize the sheet?

Tim Warris
04-02-2005, 11:41 AM
Hi,

Not sure what a "line conditioner" is, can you elaborate?

I have spent a great deal of time trying to make the air assist work for these parts. There is an improvement in cutting performance when using the air, but the trade off is that I have to constantly keep watch on the machine for pieces of scrap sticking up in the honeycomb table.

This happens with any air pressure setting, all the way down to 5 psi, of course it is less frequent at this pressure, but it still happens occasionally and the machine seems to find a way to run into the pieces. I considered tape of some sort, but the tape will be cut as well and in the end serves no purpose. Perhaps some sort of custom table where the parts can fall freely out, but again, I spent a fair amount of time exploring that option and found in the end it would not work. So the decision was made to eliminate the air assist for these parts, and for the most part it will cut fine, but occasionally it will give the inconsistent results shown earlier.

William Capman
04-02-2005, 7:16 PM
Hi Tim,

I am very interested to hear of your problem because it haunted me (and still does) until I have just learned to live with it. I make animal puzzles from 1/8" baltic birch and the problem occurs with some frequency. From your picture is appears that it's the same situation that I have. Believe it or not, the problem is NOT with your machine but with the birch.

I put a piece of a "no cut section" under a loop and found a different material between the plys in that area. I accused my supplier of have crushed rock in the plywood. Subsequently had egg on my face from that comment In his shop, we very carefully removed the top layer of wood and found it wasn’t rocks but pieces of very hard knots. The machine, for some reason, will not perpetrate those areas. (I have a 45 Watt Epilog) I didn’t believe it until he proved it to me by sanding it. It was in fact wood but extremely dence and very HARD. Blame those Russian trees.

The material that I’m buying is only sold by one supplier in this area so I’m living with the problem. By the way, I'm told that a no cut spot will also occur when there is a void between the ply as it tends to deflect the beam. I have not had this problem with the Baltic Birch but I'm told it happens.

Bill Capman
Wachusett Laser Crafts

Jerry Allen
04-02-2005, 7:30 PM
A line conditioner is usually a large ferromagnetic transformer that holds the line voltage at a stable 117V even when the input is about 80-150V. I think you could get away with a 10-12 amp unit. Probably around $100 or less if you search around. I would still use a surge suppressor at the output end and change it yearly as surge supressors degrade over time due to the way they work.

I use blue painters tape to hold down 1/8" Baltic birch ply when it is warped. I meant that you should use it at the corners and edges to keep the material from moving. I use a Harbor Freight air brush compressor at about 18PSI ($69 on sale--$89 when not) and I have never had a piece of ply blow out of its hole. Paper is about the only material I turn it off for. My cutting table is a plate with verticle roll pins on approx. 1" centers. If anything, stuff just falls through. Also, you said something about the noise of the compressor. Mine is inaudible compared to the laser and exhaust fan. What kind are you using? The thing is it's not just that air assist keeps the flame under control, and the cut cooler, but those mirrors and lenses are dreadfully expensive and the less you have to clean them the better.
I think you could improve the situation by getting your air assist back on line and making sure your line voltage is stable. Also sorting your cut could be useful. Past that point I'd suspect, alignment, the power supply board or the laser itself.

Ian Spence
04-05-2005, 10:17 AM
Hi Tim

I have a Universal M-200 and although we don't cut a lot of wood I have seen your problem on leather, but have put it down to the material not being flat therefore the laser being out of focus.

I am also in Kitchener (Bridgeport) and also a machinist.
If you like we could try your corel file and wood on our laser to see if we get the same problems.

Ian

Tim Warris
04-11-2005, 12:15 PM
Update

I have been contacted by Universal and my dealer about this issue and they have both agreed that there may be a problem with the tube. Although a rare occurrence, they have seen this issue in the past. They have agreed to send me a replacement tube, which was quickly dispatched and I am expecting it today. Hopefully this will eliminate the problem. I'll keep the forum updated with the results.

The Universal team redeemed themselves nicely.....

Tim

Mike Chance in Iowa
04-28-2005, 9:42 PM
Tim,

Did the new laser tube solve your problem?

Michel

Tim Warris
06-10-2005, 2:04 PM
Did the new laser tube solve your problem?

Unfortunately no.

Its been a while since I responded to this thread as I have been quite busy with demand....

I have come to the conclusion that this is an issue with the software driving the laser. I have brought this up several times with Universal, but for some reason they do no acknowledge this possibility.

When watching the laser work, very obvious changes in speed can be observed while cutting the same part with the same power and speed settings.

This can be very easily illustrated in the picture below....

http://www.handlaidtrack.com/port-kelsey/pkimages/Laser-ties-1.jpg

The area with the smaller rectangles all cut completely through, and the larger rectangles did not. Watching this cut, very noticeable changes in cutting speeds can be observed. This makes sense as the motors have to ramp up to and down from the maximum speed settings, and when cutting a smaller area will appear to cut slower. I thought the software was supposed to take this into consideration while cutting and adjust the power settings appropriately, but I think there is an issue here.

What is very odd about this is the piece of material I am using to cut is left over from another run on very similar parts, and I have no issues what so ever cutting these. This fact will eliminate inconsistencies if wood density as the culprit.

Any feedback I have got back from Universal on this issue seems to always be pointing to inconsistent wood, but I can prove that this is not the case.

Has anyone else noticed this phenomenon?

George M. Perzel
06-10-2005, 8:27 PM
Hi Tim;
I'm also thinking it may be a software issue.
Have you ever done an identical piece which came out perfect- all pieces cut?
As I recall you are using Corel 11. Your image contains a very large number of nodes and the Corel softwar may not be able to handle them all at once. Try taking about 1/4 of your image and cutting it as a separate file- also send me the 1/4 image and I'll try it on my Laserpro and let you know the results.
Good Luck
George

Mike Mackenzie
06-10-2005, 10:37 PM
Tim,

Please let me know what firmware, Windows, Corel Version and Driver version you are using.

If you want to send me the file and I will test it on our M300. I am curious what configuration the system is set up as.

Dave Rawn
06-17-2005, 9:51 AM
Hi Tim

Have you got the problem with your laser fixed? I recreated a section of the railroad ties and cut them out on my laser and they all come out fine the dropout parts stayed on the grid and it looked really good. I cut out thousands of small parts for the craft industry out of 1/8 inch baltic birch each week and I would be willing to cut out your parts untill you get your problem solved with your laser. Let me know if I can be of any help. If you would like I can send you a sample of the railroad ties if you would like to see it.

Tim Warris
06-17-2005, 10:53 AM
I will attempt to attach the CorelDraw 11 file for these parts here....

This is a single section of this part, when cutting, I have as many of these grouped on the page as possible.

Hopefully this file will work....

Dave Rawn
06-17-2005, 11:29 AM
Hi Tim

The attached file did not work. You can E-mail me with the attachment if you like cvstss@frontiernet.net

Dave Rawn
06-17-2005, 11:31 AM
I forgot I need your shipping address to send the sample

Mike Mackenzie
06-17-2005, 12:46 PM
Tim,

I really believe that this problem may be coming from your optics getting dirty. In an earlier post you mentioned you had to clean your Len's 4 to 5 times a day. If your Len's is getting dirty in the middle of a run this would cause inconsistent cutting. Try running the air without the cone just to see if it helps to keep the lens cleaner during the run.

George M. Perzel
07-22-2006, 9:56 AM
Hi Tim;
Did you ever figure out what the problem was with the inconsistent cutting? Another guy has a very similar problem and is pulling his hair out as you did.
Thanks
george

Bruce Volden
07-22-2006, 3:29 PM
I too have had some "weird" engraving/cutting problems in the past which had me pulling my hair out (both of 'em)!!! I fought and fought and it WAS a software problem at my end. I have a web accelerator program which runs in the background, I like it as it blocks all types of pop ups, hijacks, etc... When it is running however, I cannot get a "correct" file sent to my 2nd laser???? It strecthes the file vertically and places it ~2" down vertically???YES!! I can duplicate it anytime I have my accelerator running. I thought it was a Corel issue all along. My suggestion would be to start turning things off until all is well---Hopefully! Good luck.Bruce