[fixtureman1]

check you step length for your y in the vender settings. on mine the settings for the length is the same for both X and Y

[shenhui laser]

yes, sounds like a step lenght problem to me also.
other possibility is belt tensioning.
But try the step lenght first
MAKE SURE to write down the original values before changing them.

Also, not sure what machine you have. on mine, there is a small box that you can click next to the step lenght, and it will calculate them for you.
meaning, make a square of 10 cm x 10 cm. engrave it and cut it (if that works)
measure the actual size, e.g. 10,2 cm x 10,1 cm
input these values in the calculation box for the step lenght
see if that works.

btw, vendor settings and user settings: I have a huge problem with these, please see my thread here, and let me know if anyone can help:
http://www.cnczone.com/forums/genera...reenshots.html

thanks

[QuickCutDieCut]

Hi Shenhui, I looked at your problem but don't know if I can help, I can't seem to access my vendor settings it is password protected. In my paper manual I can't find anything about the vendor settings and when I searched in the pdf version it just says add in the manufacturers password. I've also noticed that it suggests I check my system settings but my settings box only has two options "general settings" and "system info", their screen shot has 5 options including "laser export" "general settings" "machine para" "document" and "system info". The RDCAM software in the manual is V3.0 whereas mine is 6.0.25?

FYI it looks like I have a sh350 model also.
However my hardware and firmware is slightly different plus I have different stepper motors <- could this also be part of my problem?

Info on my machine:
Shenhui SH350
50 W laser
300 x 500 mm work area

Motherboard (white color enclosure): Don't know, how do I find out ? Do I need to open the cover?
Motherboard Software versions (as displayed on built in screen when booting): RDLC-V 5.00.30
Don't know this one ??HMI-V4.1.1??

Stepper Motor controllers (black boxes): 1 x 2M542-06 and 1 x 2M542-N

[shenhui laser]

Hi QuickCut
the Vendor password is RD8888
the manual is pretty useless, and for an older version, i guess the chinese don't update it regularly

if you look at the pictures in my thread, you will see the options in vendor settings and user settings.
the vendor settings have their own pop-up window.
the user settings are in the right hand side, where you normally put in the color and speed/power options. if you click on the tab "user", you get the user settings.

with all these, be very careful.
BEFORE changing anything, make screenshots, save them.
THEN click the "read" button. It will read the settings from your machine.
make screenshots again. save them
then make changes. write down what you change.
make sure you can reverse everything.

and if you hit the "read" button and make screenshots, please send me the pictures (here in the thread or as PM). I can then see if yours are different then mine and see if i need to change mine.

hope the explanation makes sense.
again, handle these things carefully. i didn't write down what i changed properly, and i think that mine are messed up now.

thanks

[shenhui laser]

oh, also, motherboard version:
if you open the side cover of the machine, where the white box and the power supplies / stepper motors are, on mine it has the version info printed right on the white box.

[QuickCutDieCut]

Hi QuickCut
the Vendor password is RD8888

Thanks Shenhui, couldn't check last night, it got to about midnight so I went to bed!
I run my laser cutting business in my spare time - I won't be able to get on to it until Wednesday evening as I'm out late tonight after work.
I'll be careful to keep note of all my settings. Fingers crossed we can help each other fix our problems!

Another thing I've remembered is that my laser focuses about 20mm from the head but the instructions suggest to use the measuring guide which is 10mm high. Do you think this could be part of the problem as to why it's not cutting as powerfully as it should? Took me a while to realise this as I was always setting up jobs at 10mm distance and was getting really bad edges and it sometimes was not cutting at all.

FYI don't know if you've read this before but I saw in another post that it is advisable to get a water chiller to regulate water temp for the tube and also get a higher capacity air-pump to keep the laser lens clean.

[fixtureman1]

when you get to your vender settings you should read them then save them before you make any changes

[shenhui laser]

@fixtureman: yes, he should save them, forgot to mention that. but I am not sure if that actually works, the screenshots are a double-backup. the software is not really 100% perfect, as we know
@quickcut: Wednesday is fine, no problem.
My focus is about 22mm from the head, so thats not a problem. you could change the height of the head, if you want, by unscrewing the big tensioning screw on the head, and then move it up & down. but it only means there is 10 cm less of travel in the unfocused laserbeam before it hits the focus length, so no worries.
A water chiller is definitely a good idea. I have a CW3000 from china, around 250 Euro on ebay. It also makes the water circuit a closed loop, so no dust etc. gets in the water. some people add some coolant liquid (for car radiators), mainly to prevent bacteria growth. something i want to do once i get my machine to work properly.
the lens-cleaner pump with mine works just fine, and doesn't get hot. it is the loudest thing in the whole setup, but does a good job, even on high power settings, so i don't see a need to spend money on it.

in the vendor settings, you can also check if the min and max power for the laser are set to 2% and 98%. maybe the max power there is set wrong, which could be the reason for your weak power. but i doubt it.
your mirrors are alligned properly? the beam hits the center of the last mirror hole in all four corners (top left to bottom right) and is overlapping in all positions?

also, did you check if all mirrors and the lens are clean? when doing the alignement with the tape method, there can easily be some smoke residue on the mirrors, happened to me when i set the power too high.
if you have a red-dot laser, you can visually check if the light comes out of the laser head when you shine the laser in the mirror at the laser tube side.

another option could be that your lens is put in the wrong way around. the outwards curved side needs to point down. you have to remove the air-assist hose first before you can unscrew the pointed headcone, if yours is like mine.

to sum up your power problems: mirrors & lens alignement & check. water check. settings check. test file check. double check again. If all this is correct, then it could be that your laser tube is a dud. i don't know how to check on that, sorry, but someone else might.
i know there is a laser power measurement tool. looks like a thermometer like for the meat temp in the oven. this is being placed right at the laser tube end, and that should tell you the actual output power. but i dont know where to get that.
good luck

[fixtureman1]

[QUOTE=shenhui laser;1483046]@fixtureman:
another option could be that your lens is put in the wrong way around. the outwards curved side needs to point down. you have to remove the air-assist hose first before you can unscrew the pointed headcone, if yours is like mine.

On my laser the curved side is up and that is how I was told to do it.

[QuickCutDieCut]

my step lengths were different but I can see they are different on your settings too. Fixturemans are the same. I cut 100mm square and inputted the expected versus actual dimensions into the box as you suggested and it has worked.
I thank you both for this suggestion of checking step length. There is still discrepancy in doing a circle though. Not quite right but a lot better. My belts are definitely tight.


here are screenshots of my vendor settings after hitting read and changing y step length, my software version is obviously different to yours as you can see from the gui. I couldn't make the box any bigger so had to do 2 screen shots for x and 2 for y

Attachment 235230 Attachment 235232
Attachment 235234 Attachment 235236
Attachment 235238



I have also saved the file if you want me to send to you?
I have also pulled out the lens and cleaned it. Can't remember which way it was facing for sure but think it was pointing down because the outer curve was the hardest to clean.

There doesn't seem to be any motherboard info on my white box.

[shenhui laser]

@fixtureman: interesting, thanks for the tip. I read up about the convex side facing up, toward the laser, and now have to check which way mine is actually in. But kinda makes sense.

@quickcut: thanks for the pics. can you also post your "user" settings? in my software version, they are a tab on the same spot where you normally input your power/speed settings for the cut colors. see pictures in my other post.

glad that the tip about step lenght helped.
on cutting circles: I spent about 3 hours yesterday with the belts to get this (more or less) right. a LOT of trial and error. all 3 belts have to be just right, it seems. also, they should be not TOO tight, as this will damage / stretch the belts over time, and the motors have to work too much against the tight belts.
Also, on my machine, there are small,black allen nuts (or whatever they are called, need a small hex tool) where the x-axis is attached to the y-axis rails. so one on the left, on on the right (will post a picture if i get a chance). these also seemed to have an effect on the accuracy of making circles. took about 1 hour and 50 tries to get these right. but could be my imagination or just pure luck.

I now have it at the point where most lines overlap, and a small circle of about 2mm looks like a circle and not a flattened egg.

something else i realized on curves / triangles not being closed right was that the head moves from one spot to the next before cutting again, and that was where the error started. So i drastically reduced the idle speeds, acceleration speeds, max settings and so on. now the head moves very slowly, but it helps on the positioning.
If I have these speeds set very high (or as they were), the machine shudders quite a bit when moving the head around, which i believe is the reason for this. will post picture later.

how is your power output coming along?

[QuickCutDieCut]

Hi Shenhui,
No not solved power issues yet but have looked up lenses and agree it should point up. It is a concavo-convex lens, similar to eyeglasses - light should hit the outside concave side and then get narrowed to a focal point, which with eye glasses I'm guessing would be somewhere near the retina and with a laser should be somewhere near the surface of the material to be cut.

My belts are tight so will check these and maybe back off a bit. I'll also have a look at the hex bolts you mentioned to work out what they do.

Maybe you can speed up the idle, acceleration speeds incrementally and hopefully you can get it to move reasonably fast again before the quality starts to suffer?

My user settings:
Attachment 235266

[shenhui laser]

@quickcut:
thanks for the pictures. I will play around with the settings and speeds when I get a chance.
On your power issue: your settings look right. So if the lens check doesn't help, you properly aligned everything, your water is on etc. then my best bet is that your laser tube is a dud.
but I am no expert on this, only had my laser for a few weeks and have massive issues myself.

[QuickCutDieCut]

I've played around with belt tensions and my settings but still not right.
my circles are still a little wonky and if I cut say 4 small rectangles, depending on which corner it starts cutting, it'll cut a fraction large and not close properly or a fraction small and leave a small overlap/tail.

Attachment 236826

Another thing is that in the laser software I should be able to re-order what cuts when etc, but no matter what I do it still cuts in the same order every time. eg it doesn't follow the dotted lines with the arrows that appear when you click on the "show path" icon. I can change the cutting order and the dotted line changes but the laser still cuts the same way.

If I could get it to cut all rectangles the same way then at least it would be easier to modify them to compensate for them not closing or overlapping.
Circles are another matter!

The annoying thing is that the bigger the shape, the better it cuts it.

[shenhui laser]

I had the exact same problem with mine.
this is a mechanical thing for sure.
check all nuts for tightness on the frame, motor of y axis (in the back) and the rods connected to the motor.

with mine, in the end it was the front left wheel that guides the left y-axis belt. it was crooked / misaligned. The height-adjustable table is screwed to the gold-color frame with some hex nuts. these are too long on my machine, and thus pushed that little white wheel to the side, so that the wheel was not parallel to the belt. I loosened the screw, pushed the wheel in the right way, and then the issue was gone.

I am almost sure its the same kind of issue with you, as the picture shows the exact same problems that I had. Basically, the belt rubs against the side of the crooked wheel, and thus gets misaligned.

hope that makes sense and helps.

btw, I figured out the problem with scanning / engraving on my machine, the white controller box actually was bust. got a new one, switched all plugs, issue gone.

good luck

[QuickCutDieCut]

Spot on Shenhui Laser!
I checked everything and found that there was a bit of play on one side of the y-axis arm.
The right side along the runner seems to be quite solid, but the left side I could move the arm up and down the runner a few mm's.
I located the stepper motor around the back and found the cylindrical aluminium coupling between the stepper motor shaft and the rod to the pully that drives the belts was loose.
Eg the stepper motor was really only driving the right hand side and so the left side was probably just flexing up and down based on what the right side was doing.
My little 5mm circles are now nearly perfect and my rectangles all look identical. I just cut a 295mm circle job for a customer and they look a hell of a lot more like a circle now than they used to!

It's still not perfect but I think it's now within tolerances I can work with.

Still not solved the power issue, must have a dud tube like you suggested. I've found that you can buy a relatively cheap co2 power meter probe and do some troubleshooting to find out where the output problem may lie. eg at the tube or maybe a problem with the mirrors or lens.

How to measure CO2 laser power on a Laser Engraving Machine and Laser Cutting Machine using a simplified (low cost) CO2 laser power meter

I just purchased a 100w meter for $107 USD ($135AUD) on amazon, will take up to a month to get to me. Hope it can tell me one way or another what is going on........

I'll let you know what I find out.
Glad to hear you have solved your engraving issues. Hope you got a new box under warranty?

[fixtureman1]

try in the vend settings change the x an y to neg or pos what ever it is set at now Before you do that read use the read and save those settings so you can go back if something goes wrong.

[shenhui laser]

the remaining challenge could either be something else loose or belt tensioning.
check belt tensioning first.
i do testcuts with letters WAWAWAWAW, as these show the lines well, and some circles.

[QuickCutDieCut]

Hi fixture man, not sure what you mean or what your post is trying to solve. Is it my output problem?
Do you mean swap all the neg's for pos's and vice versa?

I've just gone and tried to do what I think you meant - and I think it has improved my output. At full power and quite low speed, eg 98% and 10mm/s I managed to get it to cut 95-100% through 1mm thick rubber which is the best result I've had. It sort of makes it all the way through but looks just like a perforated cut where it doesn't quite penetrate all the way every now and then.

Still seems to melt a bit at the edges too and hence not a really clean cut.

Also when I turned off the machine because I wanted to have a look at the laser tube to check what was written on the stickers on the opposite side where I couldn't see and then switched back on my origin point had gone hay wire. The machine tried to drive the laser head back past the origin and I had all sorts of noises from slipping belts. For the life of me I couldn't get it to reset the origin no matter what I tried. Eventually I just manually (using the laser control panel buttons) drove the head past the origin so it kept making slipping belt noises until it stopped driving/making noises and now the origin is back to normal. It looks like it has limit switches but these didn't seem to work.

Any tips on resetting origins and whether they are in fact limit switches I'm looking at?
Attachment 237304

[shenhui laser]

yes, these are limiter switches.
if you did this switch to neg/pos, you are int trouble. these tell the head to move left or right, or front / back. so it cant find its origin point.
the noise you hear will eventually damage your belt.

i had the same problem, here is how i fixed it:
unplug plugs on the white controller box for x and y axis, and plug them into the plugs for U and Z axis. as these don't exsist, nothing will happen.
then start machine, change settings in vendor settings back to normal, safe, exit, shut down machine, switch plugs back into original sockets, problem solved.

also, this will not solve your power problem, its only about x and y axis.
power: still either a dud tube or misalligned mirrors.
try this: hold your rubber right at the hot end of the laser, fire laser and see if it cuts the rubber then. If yes, its the mirrors.
if no, then its the tube.
i have not tried cutting rubber, but i cut 3 mm plywood or acrylic at around 10mm / sec speed and 35% power. your rubber should be at the worst the same settings.

the dotted line thingy instead of a clean cut: that belt could be much too tight, loosen it and see if that helps.