[myrko]

No look.
The problem is on all the design not only at the begin and the end of the border design (so not only when acelerate and decelerate) but also when the speed is constant in the middle of the design..
problem come when the laser switch ON and OFF eatch time the design is white (don't need to beam on material ) during the engraving process.

[Tweakie]

Myrko,

OK, just scrolled your picture and realize now that it is not the beginning and end of the line. Please disregard my post.

Tweakie.

[myrko]

Tweakies
What do you think about the stability of the laser power supply ?

[Tweakie]

Myrko,

I really can't say because I have never had this problem.
Is it the psu that is taking time to stabilize or is it the tube ?.
Perhaps Zax will have some knowledge of this problem.

Tweakie.

[zax15uk]

That is very unusual, but I don't think it is the laser PSU because the problem is on the off side as well as the on side.

If the problem were only on the leading edge where the laser is switched on I could understand a brief instability from the laser PSU causing it.

So, what could be the cause - well I thought it could be from anti-aliasing on the imported image, but now I am not so sure. It may be from the driver or even firmware if this is a continuous issue.

Zax.

[Tweakie]

Zax,

Just a thought but it could always be when the laser is switching on and we are looking at the next line (return path) at the other side of the image.

Tweakie.

[myrko]

AND trying to wire the laser from TTL analog to PWM ?

does anybody try tochange the original chinese wiring from analog to PWM ?

[Tweakie]

Myrko,

AND trying to wire the laser from TTL analog to PWM ?

I think you had better explain this a bit more because you have just moved the goalposts, so to speak.

Tweakie.

[myrko]

The problem is the same at any speed. (between 200 to 500 mm/s.) other speed I have not tested.


My idea is that the DC power of the laser is not stable and that perhaps by controlling the power by a PWM signal instead of analog variation might be more accurate.

or
second idea is from the backlash value I put in the settings of the controller to have perfect shaped charters when engraving.

It is dificult to find a solution in this case.

Sorry for my writing in english , I need to use translate web tools to to correct some wording of sentences.

[zax15uk]

It is really difficult to tell from the picture, but it appears to be on both ends of every line - in which case I still don't think it is the laser PSU or mode.

Are these vector designs you are engraving or do you import as an image?

Zax.

[myrko]

this is BMP file ( vector design and a jpg and text exported from coreldraw x4 as bmp file)..
but with a vector square the problem is the same.

[grwx]

Just a Thought,
I remember reading some where that these Engravers will only work with Corel 12 not the X versions.
Can someone confirm this.
May be the problem?????????

GR

[luckydoglele]

Just a Thought,
I remember reading some where that these Engravers will only work with Corel 12 not the X versions.
Can someone confirm this.
May be the problem?????????

GR

it can work with Corel X3

[grwx]

Well we can disregard that then ?
Excellent because I have X3 at home.

GR

[myrko]

corel X4 work fine

This problem don^t come from the design software it come from the machine hardware or from the backlach...

[grwx]

Myrko,
How are you checking the backlash
And is there options in the controller to adjust it?

I would'nt Of thought there's a lot of backlash in timing belts and pulleys
and a light weight head with mirrors and a lens. ( BUT ,I am very new to this Laser stuff, so I am probably ,very wrong)

I am operating a Cnc Mill/Drill and a Cnc Router ( 1300 X 2700 ) ,
all from China and the Backlash is very minimal,

I would check first mecanical ,then electronically .
just a thought.

regards

GR

[zax15uk]

If it is bi-direction engraving (likely) then backlash would only make sense if each line were staggered - which doesn't appear to be the case.

It also wouldn't explain the change in power at the beginning and end of each line.

I think it has to be due to the controller / software but agree it is always wise to rule out mechanical issues.

Zax.

[myrko]

Hello all I wanted once again to warn consumers before you buy produce that manufacturers promise us the moon.

See the last surprise happened to me last week.
Here's the email I sent to the company JQLaser.

Hello,
I bought a laser machine from laser JQ (Laser engraving machine?Laser cutting machine from China JQLASER.) in August 2010.
This machine has a laser tube RECI A8 200w.
After 50 hours of use the tube comes out more power (can not cut a sheet of paper).
After consulting with F: A: Q on the RECI website, I gather JQLaser did not limit the output current to 28 mA which has spent the tube prematurely.

I expect today the JQLaser company to a refund or sending a new 200W laser tube.

I also expect the RECI company to send me a documentation or procedure on how to limit the output current to 28mA.

_________

I will follow the vendors' responses as they answered.

It is important for us to denounce all the screws manufacturing our valued suppliers do. You can follow the evolution of a case of after sales service and judge for yourself whether the warranty offered is real or not.


I have some picture but i don't know where to post it.

[Tweakie]

Myrko,

I am extremely sorry to hear about the problem with your new laser.

Please don't take this the wrong way, I mean no disrespect but I do think that your use of the machine is beyond the control of JQ Laser and that you should perhaps not consider that they are in any way responsible for your actions.
It's a bit like buying a new car and then complaining to the manufacturer that the tires have all worn out prematurely because they did not fit a speed limiter to stop you driving faster than 200 kph.

Sorry but this is just my observation.

Tweakie.

[myrko]

I do have to agree with you. To make an analogy with the car. it's like driving at 100km / h on your speedometer and in reality you are at 150 km / h. because the speedometer is set incorrectly by the manufacturer.

for my 200w tube, I mesured the curent.

RECI (the tube manufacturer) recomand:
Beijing Reci Laser - the largest manufacter of high-tech CO2 laser tube in the world

"
The working current: test current is 32mA. Maximum working current is 32mA. The running current must be kept below 30mA. The life span can reach 10 thousand hours if the current is kept below 28mA. The ammeter indicating current must be connected to the negative electrode.
"

The mesured curent was 38-40 mA !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

And for limit the curent RECI recomand:

"
IV. Current limitation

The potentiometer of current limitation lies in the operation hole underside the power supply (please refer to the schematic diagram). Control the maximum output current according to the maximum current requirement of its laser. The working current should be limited before delivery.
"



And
..For my second tube (60W) It is the same problem....

the set curent is 29mA ant it should be max 24 mA !!!!!!!!!

...

à qui la faute alors ????