problem with circles and jagged lines

[concretevapor]

since my laser started working 10 days ago, i've done countless tests with various parameter iterations.
there was some progress but clearly not enough.

i made some tests with squares, circles and lines at various angles.

squares are not perfect but ok
lines are also the same

the major problem is that sometimes the cutout lines would be jagged, but not in a pattern, rather arbitrary. for instance, when i compare some letters i cut out, the errors on same letters are not consistent.
AND THE BIGGEST PROBLEM IS
circles up to 20mm radius are ok but above that, the starting point wont match the end point, not only that but the shape would be elliptical.

i tried to make sure the belts are nice and evenly tight. everything is nicely oiled.

these didnt help, the problems still exist. and suggestions to what i should try next?

[Tech_Marco]

Try changing the "Pulse Edge" from 'Rising edge' to 'Falling else' or the way see if it help
Also, try lower speed see if it made the difference.

Marco

[concretevapor]

changing RISING EDGE to FALLING EGDE fixed the initial problem. check out the results

THANK YOU MARCO!!

i was making all these tests with 10% power on a sheet of printer paper.
after getting better results stepped up the material to 4mm corrugated cardboard.
with 4mm of material, i have to make several passes (8 passes) in attempts to cut through with 30% power. (more power with less passes idea wouldnt work for this material, as the piece catches on fire, corrugation=glue+air=fuel for fire)

-making several passes/cuts revealed a fresh error, repeating cuts wouldnt align. (cutting text was much worse)

-jagged lines are not as extreme but still there

while the circle and square tests (sort of) pass, the ellipse test is (clearly) failing. please see the attachments

test pieces were affixed via cellophane tape to avoid any sort of vibration related movement

has anyone ever had anomalies as such? any idea why?

[Tech_Marco]

What step resolution did you use on stepping motor driver? I suggest to use 1/8 or 1/16 (preferred). How fast did you run the ellipse? For K40, I could run 4~5 times of the same play without any shift. In most case, it's mechanical issue. Double check the motor and the belt tension, especially for the 'Y'

Marco

[waltfl]

Hi there
first check the end pully on the X axis some new ones was not tight on the L bracked , just wobble on the pully if it moves you need to take out the L bracket and tighten the nut undernice.
try to move the X axis ( gantry by hand with power off and feel if there is something what stuck the weels on the laser head.
make the square test and be precise measuring the burned square with a caliper a tape is not precise enough!
dont use the PPI till everythings is perfect.
one more thing, check the gantry wheels if they are snag on the rail and not loose maybe they need to be adjusted
cutting corrugated cardboard is a bad idea anyway, because of the corregation what has empty spaces in between.
if you need more help send me a email direct to my addrress a542002@hotmail.com
greetings
waltfl

changing RISING EDGE to FALLING EGDE fixed the initial problem. check out the results

THANK YOU MARCO!!

i was making all these tests with 10% power on a sheet of printer paper.
after getting better results stepped up the material to 4mm corrugated cardboard.
with 4mm of material, i have to make several passes (8 passes) in attempts to cut through with 30% power. (more power with less passes idea wouldnt work for this material, as the piece catches on fire, corrugation=glue+air=fuel for fire)

-making several passes/cuts revealed a fresh error, repeating cuts wouldnt align. (cutting text was much worse)

-jagged lines are not as extreme but still there

while the circle and square tests (sort of) pass, the ellipse test is (clearly) failing. please see the attachments

test pieces were affixed via cellophane tape to avoid any sort of vibration related movement

has anyone ever had anomalies as such? any idea why?

[concretevapor]

thanks for the responses, really appreciate it

unfortunately, i have to take a break from working on my traumfabrik(dreamfactory) for some days.

i have been slacking on chores and other responsibilities to make time for the laser and its catching up big time! i actually decided to get rid of all of my dishes and silverware except for a pair of each. now how about that. i wish it was just the dishes.

ill have to remove the xy stage from the blue casing to get to the belt more comfortably, while at it, i'm thinking to replace some cables, which are really short and annoying. add 2 more limit switches.

what do you guys think of cable shielding? would i benefit?

Marco, the speed was set on 200, i tried 150 and 100 as well with similar results.
the drivers are set at 8step, i tried 16, but the results were too steppy, perhaps the stepper motors cant handle that. i also tried 2 and 1 out of curiosity, didnt help much.
my calipers ran out of batteries so i was measuring with a really nice ruler. ill update the um values after my mitutoyo is powered up again, i knew i should have purchased the dial caliper instead! that was 6 years ago

ill attempt to do all you guys have suggested within the next 10 days.

thanks again for the support!

[wctx1977]

Hi concrete!
You may want to check all mirrors to see if they are very tight in place including the laser head. Also you should try the head for any play from the bearings. I hope you can fix it.

[waltfl]

Hi there
how comes you mixing german words in it?? I am a german too in florida since 20 years.
no shilding of the switch wires brings nothing. do you still have the original stepper motors in it?
I have replaced them with the next higher power version because I had similar problemes in the beginning with this machine
not anymore I also used the 2M5042 driver they seam to be more realiable .
good luck with your shores why you just use like usually here some of the paper plates and plastic forks and knife and then throug it out ?
one less chore, ha ha
greetings
waltfl

thanks for the responses, really appreciate it

unfortunately, i have to take a break from working on my traumfabrik(dreamfactory) for some days.

i have been slacking on chores and other responsibilities to make time for the laser and its catching up big time! i actually decided to get rid of all of my dishes and silverware except for a pair of each. now how about that. i wish it was just the dishes.

ill have to remove the xy stage from the blue casing to get to the belt more comfortably, while at it, i'm thinking to replace some cables, which are really short and annoying. add 2 more limit switches.

what do you guys think of cable shielding? would i benefit?

Marco, the speed was set on 200, i tried 150 and 100 as well with similar results.
the drivers are set at 8step, i tried 16, but the results were too steppy, perhaps the stepper motors cant handle that. i also tried 2 and 1 out of curiosity, didnt help much.
my calipers ran out of batteries so i was measuring with a really nice ruler. ill update the um values after my mitutoyo is powered up again, i knew i should have purchased the dial caliper instead! that was 6 years ago

ill attempt to do all you guys have suggested within the next 10 days.

thanks again for the support!

[concretevapor]

hi Waltfl
i live in berlin since 2010 as an industrial designer working in architecture and art fields. thats where the german comes from, hehe still yet to learn a whole lot more of the language but this language gives you great flexibility in creating your own terms, haha i love it.

yes i still use the same steppers that came with the machine. it is tempting to upgrade, but im going to wait a bit as i had to pay a lot of tax for the parts coming from lightobject.
what steppers do you suggest?
my drivers are tb6560

when i own this machine, i am definitely upgrading to an A0 size to make some money with it, but that's miles ahead.

my girlfriend and i attacked the chores, and now living in peace, but i think spring cleaning will come a bit earlier than anticipated.