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View Full Version : Laser won't cut a perfect circle



Robert Rosensteel
05-19-2009, 10:56 PM
Looking for any one who might have had this problem.I have emailed and talked with tech support about this problem. And now they have run-out of things for me to try. The problem is when I try to vector cut a circle it is lower on one side by about 1/16 of an inch.I was told first time that this was because I was using Corel that it would not cut a perfect circle.Than was told to rotate the circle at 90 degrees.Than I tried to adjust the x motor belt tenion and check the x motor shaft and the coupler.And on and on.The cutting will start at 12 o:clock and end at almost 12:0 clock but a 1/16 higher.I have measured the bridge from the back of the machine to make sure its no uneven. I have two choices I can ship the machine back or have a tech come for $500 a day. The last time I had to ship my tube and rf and power pack for repairs it cost me $200 service charge for them to adjust some thing to keep the beam from burning all the time.Some thing with the tickle.And my laser is still under warrany till June. Thanks any help.

Mike Null
05-19-2009, 11:04 PM
Have you noticed anything out of line when you are rastering side to side, such as the right side being quite a bit higher or lower than the left side?

I am inclined to think it is a y axis issue rather than the x axis.

Bill Cunningham
05-19-2009, 11:38 PM
Looking for any one who might have had this problem.I have emailed and talked with tech support about this problem. And now they have run-out of things for me to try. The problem is when I try to vector cut a circle it is lower on one side by about 1/16 of an inch.I was told first time that this was because I was using Corel that it would not cut a perfect circle.Than was told to rotate the circle at 90 degrees.Than I tried to adjust the x motor belt tenion and check the x motor shaft and the coupler.And on and on.The cutting will start at 12 o:clock and end at almost 12:0 clock but a 1/16 higher.I have measured the bridge from the back of the machine to make sure its no uneven. I have two choices I can ship the machine back or have a tech come for $500 a day. The last time I had to ship my tube and rf and power pack for repairs it cost me $200 service charge for them to adjust some thing to keep the beam from burning all the time.Some thing with the tickle.And my laser is still under warrany till June. Thanks any help.

That sure sounds like a problem with the machine, not Corel.. It's under warranty and they still charge you for a service call from your Rep? Thats enough to turn anyone into a Xenephobe.

Gary Hair
05-20-2009, 12:22 AM
I was told first time that this was because I was using Corel that it would not cut a perfect circle.

All I can say to that is bull&*)%^

Corel is the most widely used program for laser engraving and this is the first I have ever heard that you can't cut a circle with it. In three years I have cut thousands of circles and not one didn't meet at the end. But then again, mine is a GCC/Pinnacle...

If your laser uses stepper motors instead of servos, I would guess that it was losing steps. If it uses servos then there is something wrong with the encoder or something mechanical going on.

Does a rectangle or square have the same problem? If not, then it could be that your laser has a problem with a circle from Corel, but certainly not a problem that is due to Corel. I would be willing to bet that you either have a mechanical problem or there is a bug in their driver.

Either way, I would be on them like stink on a sh$%wagon until they fixed your laser - before the warranty runs out. If they can't fix it then they should replace it with one that runs on industry standard software.

Gary

Mike Null
05-20-2009, 6:28 AM
I should have mentioned earlier that if your machine is in warranty and you've paid that much money (or any money) then either your distributor or Xenetech or both should be held accountable.

Have you attempted to contact the president of Xenetech?

Carl Sewell
05-20-2009, 7:32 AM
Robert,

What material are you cutting? Are you cutting on a vector table? If you haven't already, try double-side tape under the circle. I have had occasions where that same thing has happened to me (just yesterday with a 3" acrylic circle). It wasn't a 1/16" but it was very noticeable.

Robert Rosensteel
05-20-2009, 7:40 AM
The laser rasters fine just can't cut anything out that has around shape to it. I did talk to the President of the company about the laser leaking,and he told me that he would talk with the tech who worked on the laser parts.I got a email from the Tech. saying that they had spent alot of time working on my laser and it should have been more than $200.But before TALKING TO THE PRESIDENT I was told that I would have to send the tube,rf and power supply to them .Which was $243 to ship the parts.I got a call and talked to the Tech. and he told me they had one of the techs.who made some adjustments and it seemed to work better with less leakage. But said that I should send the tube to synrad in Washing State and have them test it. There would be a $500 dollars up front fee plus shipping for them to look at the tube. And the most I would have to pay would be $3500 for repairs or replacement for the tube.I aked about the $500 charge was that taken in account for repairs ,no was the answer. So I told them ship my parts back, and that was another $144 dollars shipping. I had my parts back in three days. It took me about 3 days to get around to putting the machine back together. I fired the laser up and it worked fine no buring it worked great. In case I was not clear the problem was when I turn the machine on, not the laser if you would set anything like wooden rose or leather under the red dot pointer,it wood start burning a mark on it. So I emailed back saying that what ever they adusted the machine is working fine. Thats when I got a $200 servive bill...But my problem now is to cut a circle, I have loss some nice jobs (coins and clan crest badges) that I would engrave on both sides and can't flip them to fit in the same cut out space,because it not true cut. I have had this since I bought the machine,and called the local people that sold me the machine.And they told me to call the company. I did and I have talked to 3 different techs and tried all different types of adjustment and software changes. And the techs are nice and try to help. I guess I never thought that I would be doing all the repairs or adjustment after paying more than $30 thousand dollars for this laser. Sorry for the long story. I guess I will just have to live with the machine the way it is till I can find a less costly way to fix it.Can't afford $500 a day with the way thing have been, Thanks Robert

Belinda Williamson
05-20-2009, 8:02 AM
Robert, I don't have a Xenetech laser, but I had a very similar problem not long ago with my LaserPro Explorer. Tech support recommended I increase the pulses per inch and this corrected the problem. Sorry, I don't recall the setting that finally worked.

Richard Rumancik
05-20-2009, 10:00 AM
. . . The problem is when I try to vector cut a circle it is lower on one side by about 1/16 of an inch. . . .

From what I understand of the situation, it would seem to me that there is some kind of mechanical backlash in the system. Since the circle is not closing at the 12:00 o'clock position, I would check for backlash in the y axis. You have already tightened the belt . . .check that all the pulleys are tight on their shafts. If there is a loose setscrew, it will require the pulley to "wind up" a few degrees before motion occurs and when rotation of the shaft reverses the opposite happens. This can cause the shape to not close properly.

Richard Rumancik
05-20-2009, 10:53 AM
Another thought . . .I don't know the mechanics of this machine but my LaserPro has a small belt coupling the y-motor to a shaft that runs across the machine (left to right). (That shaft in turn moves the y axis carriage).

If your machine uses a similar construction, make sure that the small belt coming off the y-motor is tensioned properly and that pulley is tight on the motor, and on both ends of the long shaft. I assume there is one long drive belt on the left and one on the right? Make sure the tension is similar in each.

Like Mike, I don't know why they asked you to look at the x-axis (left to right axis) when the problem seems to be in the y-axis.

What happened when you rotated the circle 90 degrees? I don't think you said. As a temporary work-around, if the circle starts and stops at 3 o'clock or 9 o'clock instead of 12 o'clock it might hide the problem enough to get through this job. Rotating the circle 90 degrees should do that if I'm not mistaken. Otherwise, convert the circle to curves and break it at one node to force a start-stop where you want.

I'd also be interested if there is a difference in the discontinuity if you cut CW vs CCW with 12 o'clock closing. It might shed some light on the problem.

Rastering can hide a backlash problem because once the slop is taken up the travel is always the same direction and the y-motor is not reversing at all. You could have a lot of y-backlash and a raster image would still look okay (although it may be inacurately positioned.)

Doug Griffith
05-20-2009, 11:18 AM
First off, I would be pretty darn mad that my hard earned money was going down the drain on a machine that is still under warranty. It would get ugly.

To check if its a circle issue or axis issue, take the same circle and rotate it 90 degress (start at the 3:00 position) and cut again. If it does the same thing, it is most likely electronic or the driver. if there is a gap or overlap between start and end, it is most likely a mechanical axis issue. Then rotate it another 90 degrees to the 6:00 position and see if it shifts the same as the 12:00 position (1/16 towards inside). If it does, it is most likely an electronic or driver issue. If it is the opposite (1/16 towards outside), it is most likely a mechanical axis issue.

My guess is its an issue with your electronic hardware. If it is the driver, every other user with that driver will have the same problem.

Cheers,
Doug

Rob Bosworth
05-20-2009, 11:44 AM
Robert, check to see if your Y axis belt is tensioned evenly front to back and back to front. With the machine turned off, grab hold of the X axis arm and pull the assy. towards you. Watch the Y axis belts to see if they appear to be "tight". Then watching the belts again, push the assy. towards the back of the machine. I am not sure of how that machine is assembled, but sometimes drive belts can be installed and tensioned, leaving a bit of slack on the underside of the belt.

Also, make sure your X axis arm is square to the machine. Again, I am not familiar with how your machine is constructed, but other systems manufactures have hard stops that X axis arm has to hit on both ends of it. If the machine has two hard stops towards the front of the machine, pull the X axis arm all the way forward until it hits the stops, or one end hits the stop. IF the stops are at the rear fo the machine, push the X axis arm all the way back to the stops. If both ends of the X axis arm do not hit the stops at the same time, you are going to have to make an adjustement. Again, I do not know your machines configuration, but many machines have collar clamps on the drive gears for each side of the X axis rail. IF the drive gear collar clamps just use a set screw onto the round drive shaft, loosen up one of the collars and pull/ push the arm up against the hard stops. IF the drive shaft has flats on it where the set screws are supposed to hit, you might have to make the drive belt jump a cog to even it out.

If non of the above applies, sorry. If you start digging into it and think there might be something to what was written above, but you do not quite get it, feel free to call or PM me at any time. If you need a little extra help, and you think we might be onto something, send me a couple of photos of the machine's inner workings, and we will see if we can't solve your problem, without having to ship it out.

Good luck.

Mike Null
05-20-2009, 12:37 PM
Rob

Your suggestion is what I was alluding to as I had a similar problem with my ULS. It was an easy and painless fix.

For those of you who don't know Rob, he is probably the premier seller of used laser equipment and pretty savvy on most machines.

Mitchell Andrus
05-20-2009, 1:12 PM
Sounds like the head is rocking causing the laser beam to find a new resting place.

...like pointing the sun in your friend's face with your watch.

Adjust the rollers on the cross-beam to hold a bit tighter.

To test, make a circle with a tiny gap and move the gap to different spots on the circumference. The laser should start/stop on the gap.

Mike Mackenzie
05-20-2009, 1:58 PM
Robert,

What happens if you were to slow it down? Did you try different areas of the table does it do the same thing all over the cutting area?

See if it is related to speed. My guess would be like the others in that one of the Y axis belts, Drive gears, or clamps is the problem.

John Noell
05-20-2009, 2:43 PM
After listening to this saga I am very glad I did not go with a Xenetech.

Michael Wintermute
05-20-2009, 8:43 PM
Robert,
Starting with the Z position focused on the table.
Remove the focusing lens(red holder)
Tape a piece of paper in the middle of the table.
Move the beam in the middle of the page(do not move X or Y again until finished)
Press the Service soft key.
Press the Beam Alignment
Set the Power just high enough to burn a small hole(start low).
Press run(running man).
Move the Z axes down to 8-10 inches & run again, adjust power if needed to just scorch the paper.
The two burns should be centered to each other( if not do a realignment).
If /When that is aligned, repeat only leaving in the focuing lens.
The realign procedure is in the manual(or can be downloaded from the Xenetech site)
It is my bet that the two burns are a miss in the direction of the out of size direction(X or Y)
I keep my system updated as soon as I see an update.
I also recheck this whenever I think something is wrong.
I can hold circles to .003" round in .25" and .375" and .005 in .5" plexi.(can't explain the .005)

Hope this helps,
Mike

Robert Rosensteel
05-21-2009, 10:43 AM
Thanks To everyone for you help. I was contacted by Xenetech yesterday and the tech spent a good hour with me and said there is some real problems with my laser.He is taking it to the President and said they will make thing right for me.TheTech said he will call me before lunch today and let me know what they have decided.Will keep you informed. Thanks Robert

Robert Rosensteel
05-26-2009, 11:14 AM
Hello Everyone Good news Xenetech called back and I was told they will have a repair person contact me for directions;). They will make repairs to my Laser at my location.Will let you know how it goes. Thanks Robert

Bill Cunningham
05-28-2009, 8:36 PM
That was a pretty quick about face! Sounds like they have someone in their higher echelon that reads this forum?

Robert Rosensteel
06-02-2009, 9:25 AM
Hi Bill Not really that fast of a turn around. I was told that I would be contacted by Repair Tech to set a date to repair my machine, and a week has going by with no contact.So I called AGAIN last week and was told he would contact me shortly that they just got a email from him as we were talking. That was last Wenesday, I am sure they are busy with other customer and shows.But where I come from I don't forget a customer surely after he has called twice. Thanks Robert

Phil Thien
06-02-2009, 8:48 PM
At least it sounds like you're all set for making spirals. :D