Author Topic: Cubiio laser  (Read 16519 times)

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Offline rpannenTopic starter

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Cubiio laser
« on: August 18, 2017, 10:23:29 am »
This will create a lot of laughter at certification labs: https://www.kickstarter.com/projects/880456201/cubiio-the-most-compact-laser-engraver
 
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Offline Kean

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Re: Cubiio laser
« Reply #1 on: August 18, 2017, 10:49:58 am »
I'm surprised they even bother to mention certification.
The fact they've reached over half a million bucks in pledges in just 3 days is concerning.
This will have very few use cases if it ever ships.  There will be many disappointed backers (as usual).
 
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Offline Rbastler

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Re: Cubiio laser
« Reply #2 on: August 18, 2017, 10:55:34 am »
I wonder if most bakers will get it, if it ships. Customs may take it out and destroy it.

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Offline frozenfrogz

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Re: Cubiio laser
« Reply #3 on: August 18, 2017, 11:18:15 am »
Also had this in my "news" feed today.

What could possibly go wrong!
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Offline chris_leyson

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Re: Cubiio laser
« Reply #4 on: August 18, 2017, 11:26:09 am »
Not a bad price for two galvos and a 1W laser.
 

Offline abraxa

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Re: Cubiio laser
« Reply #5 on: August 18, 2017, 08:49:34 pm »
So... uh... 500mW output without the "shield" and it says metal can't be engraved or cut. How many people are going to try it anyway, pointing a 500mW laser at a highly reflective surface in the process? Potentially not even wearing safety goggles? Anyone wants to bet? I can see a class action lawsuit coming up...
 

Offline IanMacdonald

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Re: Cubiio laser
« Reply #6 on: August 19, 2017, 08:22:13 pm »
We have enough trouble with idiots getting hold of powerful laser pointers and aiming them at aircraft or vehicles, without something like this being sold.

The government's talked about airgun licensing because of a few incidents of misuse of such. To me this is overreaction, but a requirement for a license to own a laser of (say) 1W or more would not be unreasonable. Potentially these things are more dangerous than an airgun.
 

Offline frozenfrogz

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Re: Cubiio laser
« Reply #7 on: August 19, 2017, 10:16:26 pm »


Sorry guys ’n gals. I just could not resist  >:D
« Last Edit: August 19, 2017, 10:18:03 pm by frozenfrogz »
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Offline usagi

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Re: Cubiio laser
« Reply #8 on: August 23, 2017, 04:25:06 am »
for lasers, especially for engraving, focus is absolutely critical.

there's no way they'll be able to focus in that tiny cube.

"Of course, the details of virtual lens algorithm are patented and confidential."

patented and confidential? simply not possible. patented = published and open to public examination. therefore, this kickstarter is complete bullshit.

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Re: Cubiio laser
« Reply #9 on: August 23, 2017, 08:24:14 am »
Although something like this could be made to work - CD mechanisms do dynamic focus, and you could use various means to measure the distances for a non-flat surface, safety kills it stone dead as a product.
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Re: Cubiio laser
« Reply #10 on: August 23, 2017, 08:33:34 am »
"Laser Engraving is just as easy as having a cup of coffee"
And just as painful as spilling a hot cup of coffee in your eye.
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Offline RGB255_0_0

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Re: Cubiio laser
« Reply #11 on: August 23, 2017, 09:10:55 am »
Your toaster just set fire to an African child over TCP.
 
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Offline LaserSteve

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Re: Cubiio laser
« Reply #12 on: August 23, 2017, 04:07:22 pm »
For what its worth, it is some how related to a Taiwanese maker of full scale laser markers.. That presentation video, with the speeded up laser marking, must have cost between 25,000 and 40,000 USD to make..  I'd like to be a fly on the wall at the CDRH offices in Maryland when the consultant shows up to try to push the approval thru..  No keyswitch, no warning stickers, emission indicator is non-compliant, etc...

Really the US rules could permit it, provided it is operated in an enclosure to keep the emissions Class I.   However the limit switches on such an enclosure have always been required to be hardwired.

As for free air laser engraving, this is not anywhere near Class I or IIIA accessible energy limits, , so NO way... Again, unless some high Dollar Laser Safety Consultant, (I know three  of them) finds a loophole I'm not aware of.

Interestingly enough, they may, in some cases,  be required to have a US National do the paperwork and accept responsibility, once a notification of potential liability occurs from the Government.


Steve
« Last Edit: August 23, 2017, 04:11:15 pm by LaserSteve »
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Offline usagi

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Re: Cubiio laser
« Reply #13 on: August 23, 2017, 04:51:36 pm »
they'll just manufacture it in taiwan and find some backchannel importer to smuggle them into the US, like a lot of chinese lasercutter companies do.

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Re: Cubiio laser
« Reply #14 on: August 23, 2017, 05:30:18 pm »
Something else you can see in most of the demos is theu are blowing air across the surface to.clear the smoke.Might make for a less attractive vid if you see the kid coughing from the fumes.

Not to mention the whole "setting things on fire" hazard...
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Offline Macman

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Re: Cubiio laser
« Reply #15 on: August 24, 2017, 12:10:15 pm »
I dread to think how much their product liability insurance would cost them (not that I really expect they will bother getting it).
 

Offline chris_leyson

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Re: Cubiio laser
« Reply #16 on: August 24, 2017, 12:48:55 pm »
Thanks LaserSteve, good points about the lack of keyswitches, laser safety warning lights and not a single laser warning sticker in sight. OK so they have a teeny tiny LED for a warning light but you can hardly see it. I read somewhere that the optimum focal distance is 150mm to 160mm, so it's fixed focus. As for "Traditional galvanometer laser machines correct image distortion problem by using "f-theta lens" and the "virtual lens algorithm" patent bull shit, the scanning angle is very narrow so you don't need f-theta lens and some simple image pre-distortion algorithms will fix things, hardly worth a patent application.
 

Offline LaserSteve

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Re: Cubiio laser
« Reply #17 on: August 24, 2017, 05:10:59 pm »
A real question is did they correct for the laser diode's inherent astigmatism..  A 100 x 300 uM spot has inherent implications for marking, compared to a 100 um circularized spot.   Divergence out of the uncollimated diode might be 15 degrees in the slow axis and 35 degrees in the fast axis.

  For small scan angles, say less then 10 degrees,  the inherent mechanical  tangent distortion is near  naught, provided your target is very parallel to the scan head. Tangent  Correction math is easy enough for a fixed focal length and scan angles to 25 degrees or so.   Keystoning however is another matter.. How you position  it for minimal keystoning or skew without tooling boggles my mind. You'd need to burn a test target.

I've had my hands on the high power 405 nm diodes, and the uncorrected astigmatism is horrid.  Not to mention there is heat dissipation to cover, and normally that family of LD runs  around 600-800 mA at between 4.5 and 6.7 volts of forward drop, depending on manufacturer so you have around two to five  watts of heat to get rid of.

The galvos, if they use galvos, are going to be another ten to twenty  watts of dissipation minimum unless they have something extremely custom made with high Ohm coils, which, if done, would run their slew rate into the ground due to inductance issues.  Normal coil is around 3.2 Ohms.


Where is the heat sink? Laser diodes don't live long when ran hot.

Steve
« Last Edit: August 24, 2017, 05:41:36 pm by LaserSteve »
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Re: Cubiio laser
« Reply #18 on: August 24, 2017, 06:54:44 pm »
I don't see that galvos should be too.power hungry as they don't need to scan particularly fast, and tbe angle is small
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Offline LaserSteve

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Re: Cubiio laser
« Reply #19 on: August 24, 2017, 09:25:58 pm »
If they are not moving, just holding zero position,  a classical Galvo amp (~5 mm mirror size) draws about 160 mA positive rail and about 120 mA negative railm and needs 12 to 24 volt rails for maximum performance. .When they move, if tuned for full scale marking or laser show speeds, they can have 6 to 8 amp peaks during acceleration and deceleration. A good galvo amp puts minimal energy into holding position, probably  600-800 mA DC  for full scale deflection to one side.  You'll have two of those.  The 40 mA difference between rails at idle is the position sensor LED drive.  You will have an X and Y axis on this system so there are two sets of idle currents.

I doubt  they are using Class D, its often very difficult to close a DC feedback loop as needed with the galvo, around a commercial IC based  Class D amp.

For those who do not know, low inertia galvanometer scanners are one of the fastest precision controlled objects on a the planet when they have either a capacitive or optical position sensor and a good PID loop with notch filters.  Bandwidth can approach 7.5  KHz for very small angles on the latest systems.
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Offline edavid

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Re: Cubiio laser
« Reply #20 on: August 24, 2017, 10:50:18 pm »
Why would such a slow device need galvos?  Wouldn't stepper motors be good enough for scanning?
 
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Offline chris_leyson

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Re: Cubiio laser
« Reply #21 on: August 24, 2017, 11:20:42 pm »
Hi guys, I recently had to re-design a galvo driver for a Cambridge Technology 6200H to replace a legacy design that would just about generate enough torque to overcome bearing friction. Anyway, the specification was that it had to run from a single 5V supply and the maximum slew rate only needed to be around 10 degrees (mechanical) /ms. Bridged pair of OPA567 op-amps for the driver stage with current limit set to 1.7A. Peak galvo current for a step input was about +/- 1.5A giving a risetime of 1ms or so, the mirrors were larger than usual. I think the overall loop gain from transimedance input stage to galvo drive output was a little over 130dB. Not exactly a really fast galvo driver but it did the job and would probably be more than good enough for a toy laser engraver.
It was based on the classic Cambridge design with a few tweaks here and there and I will publish it on the forum if anybody needs a 5V galvo driver for small galvos only.
 
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Online mikeselectricstuff

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Re: Cubiio laser
« Reply #22 on: August 25, 2017, 07:38:01 am »
If they are not moving, just holding zero position,  a classical Galvo amp (~5 mm mirror size) draws about 160 mA positive rail and about 120 mA negative railm and needs 12 to 24 volt rails for maximum performance. .When they move, if tuned for full scale marking or laser show speeds, they can have 6 to 8 amp peaks during acceleration and deceleration. A good galvo amp puts minimal energy into holding position, probably  600-800 mA DC  for full scale deflection to one side.  You'll have two of those.  The 40 mA difference between rails at idle is the position sensor LED drive.  You will have an X and Y axis on this system so there are two sets of idle currents.

I doubt  they are using Class D, its often very difficult to close a DC feedback loop as needed with the galvo, around a commercial IC based  Class D amp.

For those who do not know, low inertia galvanometer scanners are one of the fastest precision controlled objects on a the planet when they have either a capacitive or optical position sensor and a good PID loop with notch filters.  Bandwidth can approach 7.5  KHz for very small angles on the latest systems.
But for this application they don't need to be anywhere near as fast as laser-show galvos.
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Re: Cubiio laser
« Reply #23 on: August 30, 2017, 01:51:37 pm »
Youtube channel:Taking wierd stuff apart. Very apart.
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Offline ferrix

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Re: Cubiio laser
« Reply #24 on: August 30, 2017, 04:20:12 pm »
That was a great read.
 


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