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SIK-89 Laser review

(There are some more pictures, including funky long shutter ones HERE)
Please do not use pictures without my permission! Email me at ethan AT 757 dot ORG

So I couldn't resist. I kept seeing these low cost DPSS based laser display units on eBay. Some of them had DMX-512 control, which is awesome. I did my best to compare the units, and decided to pick out a low cost one to see how well they perform. I purchased a Sik-89 unit from SIK lasers. It appears to perhaps be similiar to the 20 Centz units, and the big dipper units, but I'm not 100% positive.

While the cost of the unit isn't too bad, the shipping charges from China are a bit rough. None the less, I picked out a lower cost unit with DMX-512 support and ordered it. I was a bit nervous, as there are rumors of import problems due to the power output of the lasers. There is nothing illegal in the US with the device itself, but by our laws the device technically cannot be used in a public venue, or for public display. This is true of all lasers above 5mw, with a slight exception of a few higher power units that are being sold with large beams. I had no issues, and it arrived quickly.

I've been dabbling with lasers for a while, and also own an ALC-60X argon system capable of over 100mw (blue and green), a Uniphase 15mw 488nm argon, and a Spectra Physics system capable of up to 5 watts. The difference is, this one is small and no where near as power hungry.

First impressions.

So it arrived via DHL, and I eagerly unpacked the unit. It came with an instruction manual in Chinese, the laser, a 3 meter XLR male to female cable, and a european power cord. The power cord is the standard IEC style used with computers, but the device was marked 220v 50/60hz. I assumed it would have no issues running from lower input voltage, so I plugged her in. It came on, and was bright. Off she went.

My first testing was during daylight. The green output is stunning! The red output just can't match the green. This is in part due to the wavelength of the green light being closest to the brightest on our visible spectrum. The red was definitly visible during the daylight, and is definitly high power. It's just next to the green, the green is so bright it makes the red look dim. I'm sure up against my 15mw HeNe red laser, the Sik will make the HeNe laser look dim. It immediately went into action, and appeared to be in sound response mode.

Inside the box.

Me being me, after seeing it run I took it apart. It didn't take 30 minutes. the first thing I noticed was the transformer was marked 110v, which is awesome. They must have noticed I was in the states and switched out the transformer. The transformer feeds the main PCB which contains the power supply and the computer. The computer is an Atmel microcontroller, which drives two stepper motors (X and Y), and appears to have blanking output going to the lasers. In addition it has a connection to the board that handles the microphone and level adjustment for music, the board with the DMX-512 address settings, and the XLR connectors for the DMX-512 signal. In addition there is another board which contains the power supply/voltage regulators for the two laser diodes.

The mirrors are nice, thick, first surface mirrors. There is a beam combiner which adds some loss on the green laser, which is to be expected. There are no adjustments that I noticed to allow putting red and green right on top of each other, but hold that thought. I will most likely make it happen so I can get yellow.

The case is a stylish case, metal instead of plastic. I dig it. Mine came a bit damaged, but most likely from shipping. One corner was bent up, something I can easily fix.

A decent powered fan brings air thru the back of the unit, and pushes it out of the window where the laser radiation is emitted.


So I waited until nighttime, and broke out the fog machine. I setup the free Freestyler/DMX windows software on my PC, and plugged in the LPR2DMX interface on my PC. I tested with my American DJ 750 watt strobe light, and verified that DMX-512 was functioning. In the manual, I was able to figure out the numerical boundries of the DMX settings. The 1st channel seems to move it between sound activation, DMX-512 control of patterns, some pattern adjustment mode, and off. Another channel is used to control the patterns, and I believe there is around 20 or so. In the patern modification mode, all I could seem to get wasa square, but I could adjust the size and scanning speed. Overall it is pretty limited in the patterns.

Some units use dc motors that spin mirrors. These generate Liajasous patterns. Sprialgraphs and what not. This unit uses stepper motors. The interesting thing is my friend Ken Kurzweil built a similar device that ran from a PC parallel port. So I had a good idea of what to expect from the scanners.

The beams are really visible in the fog! The scan angle is very wide, and at a distance of 14 or 15 feet the unit filled the wall.

Limitations, and issues.

There are some bones to pick.

The scan angle is wide. VERY wide. TOO wide! I know most people are saying, "Are you crazy? We've been looking to get past 6 degrees for ages!" This device puts out alot of power. Because of this, it is not safe to aim into a crowd. It has to be fixed in a manner in which the beams are above the heads of the people. Because of the wide scan angle (both X and Y), this is going to make it difficult. If the X axis was real wide, but the Y axis was 1/2 or 1/3rd, it would be easier to manage.

Note, in the audio activation mode, it _will_ stop with a static beam! These should _not_ be used aimed into a crowd! This is true of any higher powered laser system that does not have a scansafe style system on it!

The DMX-512 command on channel 1 to "shutter" the unit mechanically moves the mirrors to fire the laser in the box. This is okay, except it is noticable since the steppers move at stepper speed, and you see a streak "out of bounds".

Seems like given the microcontroller has a good amount of rom, there could be more patterns. I've got some ideas ....

Both the red and green lasers operate most of the time together. Having DMX control to single it down to red or green would be nice.

When you issue a DMX-512 command to tell the laser to run a pattern, it runs the pattern in a loop. If you issue a new pattern, it will not break from the current pattern to go to the next until it is done executing the pattern. The DMX-512 data arrival doesn't interrupt the pattern until it's done running. If you anticipate and send the command a early, you can hit it right on a beat or break in a song.

Another issue is the patterns are all really fast moving. There is nothing that can be used with slower music. It's a dance machine, definitly.

Good things!

Very bright!!! Especially the gren laser

Internal power supply. No wall wart, straight up IEC connector.

It uses stepper motors to do the patterns. Stepper motors are slower than DC motors, but are able to do things like flat lines, squares, and other shapes generally associated with Galvometers. Because of the way stepper motors move, they jerk in stepping. In many of the patterns, this "jerking" creates nice solid beam lines in the fog. Make no mistake, this is an airial display unit.

Compact box that is rugged, ready for a C clamp to hang it!

Final opinion:

I love the green output. The red is neat, but if I had to do it again I would go for green only on this level since the unit doesn't do too much with variations of red and green. Both fire, and both are visible most of the time side by side. It does modulate them sometimes, but just not often enough. There are other models that have separate scanners for red and green, that is probably the way to go. This is the lowest two color model made with DMX. It said it did yellow in the eBay description , but mine does not, yet. I will make it happen when I get bored. yet.

Both lasers share the same power supply board. In the future, I may purchase a lower powered green diode, and move the 40mw and 80mw lasers to my own box running GS galvos that I use with the argon laser. Not sure.

In the future, I plan to post a picture of this unit next to a 15mw HeNe and the 100mw argon systme. I bet this unit makes both look dim! I also have already started making videos of it, and will post one of those in the future.

Note to Asian companies that make these laser display devices:

I am willing to share technical ideas on how to make your products better in return for hardware! Upon looking at this unit I was immediately able to come up with a number of ideas on improvements. I also may be able to do some manual writing in English!