New EYEMAGIC Scanners EMS7000

[DZ]

You got to admit, I’m walking it in there, just a little to go and it’s going to be over 60kpps @ 10°, yeah buddy!

CT Killers?

Solarfire, can you post a pic without blanking? There's more to this test pattern that we can't see and in your latest pic there is a huge amount of undershoot. I threw together a couple pics just to show you what I'm looking for.

In the first one, we see 30K scanning at around 8 degrees, nearly spot on tuning:


Here's the same settings with blanking turned off:


Here we have the same scanner speed but at a much greater scan angle, the circle looks pretty close:


However, with blanking turned off we can see that the circle is a complete mess:


Images created with G-120 (G-120's!!!) scan head with Turbotrack2 amp. Image source was none other than an ass kickin QM2K

[mixedgas]

I took a look at the scientific lit on testing Galvos. There is not much.

It gets classed into:
(my Terms)

Small Angle Jump Tests
Large Angle Jump Tests
Turn Around Time tests
Linearity Testing.
Sine Wave Bandwidth Testing.


Some notes:

Angle tests are the time to settle to X% of the jump after a square wave is applied.

Turn Around:
Galvo is moving to a point at a velocity X, passes the point, and the time to get going to exactly opposite motion is measured)

Motion Linearity:

Linearity is shown as the ability to follow a sine or triangle wave, and how well the actual velocity follows the commanded velocity while traveling.

That is about it.

Steve

[mccarrot]

I wonder, if you only do beamshows on bigger angels. Shouldn't it be better to also tune them at this big angle?
Probbably with a simpler testframe.

[mixedgas]

I wonder, if you only do beamshows on bigger angels. Shouldn't it be better to also tune them at this big angle?
Probbably with a simpler testframe.

You still need the fast tiny stops for sharp looking beams. This means the classic tuning stays.
I'm getting ready for a funeral in the morning and do not have as much time to expand on that as I'd like to.
So stay tuned for part II later.

The engineers that designed the ILDA pattern were full time laser show employees. They worked with scanners for a living. There is much in the pattern that is not readily appearent to a new user 20 years latter.


Look guys, when you tune galvos, you need the minimum of the ILDA, Grid, Laser Media, and Quad square patterns. You need the ability to the blanking off on the ILDA and possibly the LM patterns.
The ILDA pattern was never designed for a speed test, its for information interchange. So I can show up in Tokyo with my gear, join a local laserist, and cross connect a ILDA cable, and run.
Prior to diode stuff, we actually could do that, with gas, because the color response was uniform. Now today everybody insists on one card per projector, which you don't need for the deflection portion.
Can you some times tweek things so graphics look a bit better, of course!

In fact, I'm amazed at the lack of analog size controls when I show up at LEMS. You can loose resolution when you do size control in software. So think about what can happen to the content in the pattern when you set your system to 8' without a analog size control on a 8 bit dac such as ISHOW. Much wailing and gnashing of teeth,

True, the ILDA pattern does not measure the small signal step time. It, instead, shows a 3 dB down point corresponding to small signal, galvo bandwidth, with the circle in the square unter standard conditions.

A large part of this debate is caused by a lack of dedicated tuning classes, which, when held at conferences, were widely attended, until say the past four years. Without that standardized information in your head, you can do a lot of subjective things while tuning the amps. Not to mention, the folks doing the tuning on the Asian factory stuff have most likely never even read the standards for the pattern.

How many of you here actually have any formal education in what a P-I-D loop is? How many picked up on the menaing of "3dB down"?
Again, a lot of this issue is education.

This is why to really compare, I'll pulse a galvo with a signal generator, as well as other tests.


Steve

[danielbriggs]

How many of you here actually have any formal education in what a P-I-D loop is? How many picked up on the menaing of "3dB down"?

Break frequency.
Note the decimal point.

[Solarfire]

DZ, DZ, DZ…Even Pangolin themselves explicitly state that for speed measurement of scanners via the ILDA frame, weighting lies mainly on the circle being in the square, the circle being round touching on all sides. They also state that accuracy is only given at speeds up to 36kpps that’s why the ILDA frame is not first choice, it’s a one trick pony and as soon as I’m done with this, these will be tuned for performance and not for reproducing the ILDA frame. Let’s face it the ILDA frame is out of date. I’m going to put the circle in the square as per ILDA spec but @ 10° and >60kpps, no more, no less, and then I have to get back to more important things. Just the fact that tuning is @ 10° and >60kpps disqualifies the ILDA frame due to it not being laid out for this. For me It’s already clear that these scanners will do 10° @ >60kpps, it’s just a matter of finding the correct speed @ 10° which lies between 60-64kpps, everything else is just plain denial.

http://www.pangolin.com/ILDAtest.html

[DZ]

DZ, DZ, DZ…Even Pangolin themselves explicitly state that for speed measurement of scanners via the ILDA frame, weighting lies mainly on the circle being in the square, the circle being round touching on all sides. They also state that accuracy is only given at speeds up to 36kpps that’s why the ILDA frame is not first choice, it’s a one trick pony and as soon as I’m done with this, these will be tuned for performance and not for reproducing the ILDA frame. Let’s face it the ILDA frame is out of date. I’m going to put the circle in the square as per ILDA spec but @ 10° and >60kpps, no more, no less, and then I have to get back to more important things. Just the fact that tuning is @ 10° and >60kpps disqualifies the ILDA frame due to it not being laid out for this. For me It’s already clear that these scanners will do 10° @ >60kpps, it’s just a matter of finding the correct speed @ 10° which lies between 60-64kpps, everything else is just plain denial.

http://www.pangolin.com/ILDAtest.html

I don't know what else to say, Solarfire, when you find or develop a new standard for measuring and setting scanner tuning, let us know, ok?

[andythemechanic]

Hey Solarfire,

while in your last pic the circle is somehow in the square, the rest of the image looks quite bad. I see bend lines that should be straight, wobbly lines,
lines that do not meet where they should, over/undershooting corners and the circle not centered. Before you tune to higher speeds I would fix this as you might overload and break you scanners by just scanning fast but not properly tuned. There is a good tutoral by buffo which mentions a lot of details of the tesframe which have to fit too. Contrary to your belief the Ilda testframe is more than just a circle in the square.

Andreas

[Solarfire]

Hey Solarfire,

while in your last pic the circle is somehow in the square, the rest of the image looks quite bad. I see bend lines that should be straight, wobbly lines,
lines that do not meet where they should, over/undershooting corners and the circle not centered. Before you tune to higher speeds I would fix this as you might overload and break you scanners by just scanning fast but not properly tuned. There is a good tutoral by buffo which mentions a lot of details of the tesframe which have to fit too. Contrary to your belief the Ilda testframe is more than just a circle in the square.

Andreas

Hey Andreas, as stated in the post with the picture, tuning is not finished, I didn’t have any more time last night to finish. The current image is at 64kpps @ 10° which is a little fast, @ 60kpps the speed was to slow so when the scanner was tuned so that the circle was perfectly round the circle was bigger then the square which it should be in, indicating that the speed is too slow. To get a rough feeling where I’m at, I raised the speed to 64kpps which now shows that the speed is too high. So now I’m walking the speed down to where the circle will be where it’s supposed to be and then I will fine tune.

As too my beliefs of the ILDA frame, Pangolin themselves confirm my beliefs. Just read the info in the link, mainly the last part. So much to the holy grail for scanner tuning.

http://www.pangolin.com/ILDAtest.html

[flecom]

Hey Adam -

Request for some further clarity, on what (would-be) a rather important-point:



..Can we *confirm* that these were the 5.3mm and not the 6.8 x 12mm mirs at FLEM?...Obviously, that would 'make a bit a difference' in real-world performance... Jus' sayin'..



..'as-advertised'...with *Frank's* size-of mirror? Again, an important-factor, please clarify...

Other-question, answered..

..I'm not trying to 'start any riots', here, just calling-for further 'clarity'...

ciao
j

the 7k's had the small sized mirrors... I have the "6.5mm aperture mirrors" on my 4k's which are advertised to be 30kpps scanners, and as reported they are pretty much incapable of doing the ILDA pattern until you turn the scan size way down

DZ, are you 100% happy that the PSU for the EMS amps in flecoms projector was supplying the required juice?

I am

TEST psu will be ANALOG non-switching 24V psus made with massive transformers and filter banks.

I was using a PowerOne linear regulated supply, no shit chinese SMPS' in my projector (although I use some nice Lambda switchers for my high current 5v stuff)

Hi DZ, the EMS7k's require 20-30V and 60W per rail minimum

the PowerOne supply I was using was capable of delivering this without issue, and its was linear regulated

I did not comment on this thread because honestly it did not interest me... my 4k's did not live up to their advertisement (both in the size of the mirrors and their performance) so I am not really interested in buying new EMS scanners... that being said I am not *unhappy* with my 4k's... they do the job, just not the one they were advertised to do