Wavy cut lines

[Tim Mellor]

Frustrating I gather the four white visible wheels are the idlers? The belts on mine are short enough not to need them I guess.

Not sure where your Laser came from but this is the seller of mine and there 9060 looks the same as your Y axis https://www.aliexpress.com/item/3281386 ... 3d9dtqGpoP

Will put the thinking cap on but without being there I am just about out of ideas. Seems you have the mechanicals square and free running so electrical (controller or motors) or settings (seems you have tried the ones required) are about all that remains.

[Ignas Kaz]

At this point i'm starting to seriously think motors and drivers.
I cannot identify motors nor drivers. Motors came preset to 0.5A, which seems way too low to be honest.
Drivers only go as far as 1.13A, but i'm afraid to crank them up to see what happens.
Drivers themselves are fine, i swapped them over to see what would happen - no obvious changes.
They function, thats about it.

At this moment i'm thinking just plunking the cash down for new motors and drivers, that i can be sure of the specs they come with.
Sadly, dual shaft motors are hard to come by in UK, damn things need to be ordered in china. Looooooong wait for a slow ship.
Or pay through the nose... There, also, are no local dealers in Northern Ireland anywhere close by.

Any ideas where to get cheap dualshaft nema17 with quick delivery ?

Also, out of curiosity, what motors/drivers do you have on your machine ?

#Edit# The white round things on my machine are bearing locating blocks.

[Gene Uselman]

Ignas and Tim are doing a great job of diagnosis on this problem and I suspect are wayyy better qualified than I to do that.

That said, I don't think that any of us have any idea of the manufacturing setup with the Chicoms. I am sure there are a few large companies that are capable of designing and building a laser in house [Shenhui comes to mind], then there are companies who farm out the design [Bodor's BCL0605MU is a Swiss design that they then modified in house and cost me much gnashing of teeth] and build at least parts of the final machine, and finally [and I think this is most common] there are hundreds [or thousands] of small companies who assemble lasers from cabinets that they buy, and from components that seem to float all over China with no brand name and if they have brand names are likely fakes. That complicates things here in the US [and UK and probably most of the world] where we can [mostly] assume products are built to some sort of codes in factories which have [mostly] qualified workers. This put us at a disadvantage as we are not used to thinking this way. Most of the machines are built to UK Electrical standards simple because that is the worldwide standard [mostly] and not to US Underwriters Lab standards. There, a lot of words, use them or don't and I accept no responsibility for them... or anything.

[Ignas Kaz]

Did some more daring tests - cranked up current to 0.78A. Got noisier but otherwise no change. Still wavy lines.
Then lowered to 0.32A, started stalling at 200mm/s.

GAH!!!!!!!!!

[Tim Mellor]

Now I am sipping on a second coffee and the brain is starting to function.

The Steppers on my 3020 bed look identical to those on your 9060 bed. They are Nema 17's the Y gantry one is the same Length as the ones my 3D printers used as Extruder motors. Nema 17 dimensions - https://reprap.org/wiki/NEMA_17_Stepper_motor My Y motor is 44 long and my X is 34. What I don't know is how many degrees/step and they have no labels. You could however 'reasonably' assume they are 1.8 degree motors as they are the more common ones. To eliminate the X axis from being part of your issue if you know of a local with a 3D printer bribe them with future Laser cutting favors to borrow a motor and bolt it in and re test.

In theory the X axis motor won't care if the gantry is 200 or 2000mm long as the weight being moved is approximately the same. The Y motor is a different matter the increased Gantry weight has to be accelerated and moved and it is being done with what I would consider a 'small' motor. It doesn't mean 'to small' necessarily just it looks underdone. Any others with larger bed lasers care to comment?

There is maybe an option to redesign the Y drive to allow you to use two single ended motors. Depending on your controller does it have a spare output channel as I think Ruida's are four channel? If it does then another driver and a pair of steppers at either side of the Y drive with some reprogramming is an option. This assumes the software can handle it? Again others may like to comment.



Edit - Having a proper read of the Ruida manual and it's Chinglishness There is more than just one Acceleration set point depending on what mode it is operating in. May not be the issue but the following stood out.Page 47 and 48 of the manual I linked earlier.

Turning Acceleration: the acceleration speed at the closed-angle corner when cutting. If the two speeds are set too large, vibration will be happened when turning; if set too low, it will influence the cutting speed.

[Ignas Kaz]

I'm interested in current rating of motors. But yours have no markings, so no way to know. And also, at this point its moot.

Machine is going back to seller.
I did a test that made up my mind for me.
I positioned head for the cut and lightly clamped linear guide rod to the frame - most of the wobblies went away.
Which is a DAMNING revelation - the guide flexes as x-y moves, no matter speed. It proved to me that any and all vibration
is transferred into this one single guiding rail.
There is no way to fix it as it is inherent DESIGN flaw. The guide rod is too thin for its length - 12mm diameter and 750mm long.
Could be an easy fix if i could replace rod to 16 or 20mm, but that requires i replace bearing (cheap) and gantry mounting plate
which includes slot for captured bearing - which is unavailable to buy ANYWHERE. Probably some specialised custom extrusion job.

At present i see this machine is nowhere near close capable of stated capabilities and suitable ONLY to raster engrave.

On monday i fire off sternly worded letter and demand my money back. Add a little money on top and buy a proper'ish 3 rail machine.

This machine has been a great learning tool, if not in lasering, then in engineering.
Its probably the very first time i am actually, properly, angry at chinese cheapnes, instead of usual "meh, they chinese, everything is crap".
THIS is on another level altogether. 4 months of life wasted (well, not experience maybe), oportunities missed (lost 2 very viable corporate
customers)...

Its 4am now, and i'm fuming so much i cant sleep... f this...

Peace out...

[Jeffrey Aley]

I'm interested in current rating of motors. But yours have no markings, so no way to know. And also, at this point its moot.

Machine is going back to seller.
I did a test that made up my mind for me.
I positioned head for the cut and lightly clamped linear guide rod to the frame - most of the wobblies went away.
Which is a DAMNING revelation - the guide flexes as x-y moves, no matter speed. It proved to me that any and all vibration
is transferred into this one single guiding rail.
There is no way to fix it as it is inherent DESIGN flaw. The guide rod is too thin for its length - 12mm diameter and 750mm long.
Could be an easy fix if i could replace rod to 16 or 20mm, but that requires i replace bearing (cheap) and gantry mounting plate
which includes slot for captured bearing - which is unavailable to buy ANYWHERE. Probably some specialised custom extrusion job.

At present i see this machine is nowhere near close capable of stated capabilities and suitable ONLY to raster engrave.

On monday i fire off sternly worded letter and demand my money back. Add a little money on top and buy a proper'ish 3 rail machine.

This machine has been a great learning tool, if not in lasering, then in engineering.
Its probably the very first time i am actually, properly, angry at chinese cheapnes, instead of usual "meh, they chinese, everything is crap".
THIS is on another level altogether. 4 months of life wasted (well, not experience maybe), oportunities missed (lost 2 very viable corporate
customers)...

Its 4am now, and i'm fuming so much i cant sleep... f this...

Peace out...

Sorry to hear that your machine is essentially unfixable.
For what it's worth, my much smaller 5030 machine has linear (HiWin clone) bearings for both axes. There is a heavy frame made of C-channel steel, on which the linear bearing is bolted (bolts every 10cm or so). This prevents it from flexing. I suspect this is similar to your X axis bearing. I mention this because I believe this is the type of design you will want, especially as you need a larger bed size.

I can provide photos if desired (or you can look through Russ' videos, as my machine is the same design as his blue & white.

Best of luck w/ the seller!!

[Ignas Kaz]

Its not fixable in its current state. Fixing it means throwing out ALL of XY motion, which leaves me with electronics and super expensive sheet steel box.

Fixing it requires cutting out all unneccessary welded case elements, drilling, machining profile supports, fitting stuff together, aligning rails, etc, etc.
Might as well build one from scratch.

This kind of design might have worked for a machine quarter its size, but definitely not for 6090.

As for your offer of photos, can you do a detail walkthrough of your machines motion with a camera ? Belts, rails, motors, gantry, in detail ?
I'd really appreciate it.

[Gene Uselman]

Could you post a pict of your 'rails'? As I understand they are round? Might be able to help someone else down the road.

[Ignas Kaz]

"Rails" and "they" imply plural. It is not. Get this, there is ony one 750mm long 12mm round rail with long (55-58mm) bearing on the left side of the gantry, bolted into metal sheet, which is part of the chasis. On the right the only restraint for gantry are one single plastic wheel resting on angle profile, drive belts and GRAVITY. The only support in Y is belts. I can lift the end of gantry by 5mm with pinky finger. Sadly i cant stick a phone into 30mm gap to show it.
Will try to get endoscope tomorrow.