Chinese vendor: Sinmic impressions youtube series

[William Dillon]

Hi all,

I haven't seen any information about the vendor that call themselves "Sinmic." I purchased a K40-style laser machine from them. I've recorded basically everything that I've done with it so far and my impressions. Ultimately, I don't really recommend doing business with them. At a minimum, they're guilty of pretty egregious specification embellishment. I posted the first video last Wednesday, and I'm expecting to post one a week until at least February.


http://youtu.be/k7dUqmBl5Ro

[Dave Sheldrake]

Very good Will and I'm looking forward to seeing the next part.

A few points:

The machine is shown as CE marked (for sale within the European Community as safe for purpose)

Initially I noticed two BIG holes in that...

There are no bonding straps between the moving doors and the main body of the machine,
The cabinet can be opened allowing access to the electrical components when under power,
The Tube cover can be opened when under electrical power giving direct access to both high voltage and radiation producing sources,
The guarding can be opened when the tube is lasing (no door interlock),
There are no radiation hazard warnings fixed to the case or work area,
The machine holds a plate saying laser engraving "Machine" (more on that in a minute).

That's just a few observations.

I just had a friend who is an HSE inspector watch the video, his only comment was "If you fit one of those in here I will shut you down"

The term "machine" for the purposes of CE requirements requires that "Machinery" conforms to both electrical and radiation hazard laws here for use in an industrial environment, this machine does not thus the CE marking is invalid (without it this equipment cannot be imported into an EU country legally)

UK HSE laws http://www.hse.gov.uk/guidance/index.htm

without bothering to look at the numerous laws that this junk pile is in breech of it does beg the question "How are these kind of things permitted to be imported"

For personal use inside the EU it is likely people will get away with it, the problem is when people come to sell them, the penalties for selling non conforming machines include fines of up to £5,000 ($7,500) and 6 months in prison for each violation.

I've personally seen one case where a young lady was fined so heavily she lost her house (£150,000 in accrued fines) and had her equipment confiscated & destroyed.

If a supplier can outright LIE about CE conformance then that does beg the question...what else are they lying about?

cheers

Dave

[Bill George]

And of course the UL approval rating when the wiring is not even close to any US electrical Code. Seems like if you can buy (make) the decal and stick it on the machine, that's all you need.

[William Dillon]

Very good Will and I'm looking forward to seeing the next part.

A few points:

The machine is shown as CE marked (for sale within the European Community as safe for purpose)

Initially I noticed two BIG holes in that...

There are no bonding straps between the moving doors and the main body of the machine,
The cabinet can be opened allowing access to the electrical components when under power,
The Tube cover can be opened when under electrical power giving direct access to both high voltage and radiation producing sources,
The guarding can be opened when the tube is lasing (no door interlock),
There are no radiation hazard warnings fixed to the case or work area,
The machine holds a plate saying laser engraving "Machine" (more on that in a minute).

That's just a few observations.

I just had a friend who is an HSE inspector watch the video, his only comment was "If you fit one of those in here I will shut you down"

The term "machine" for the purposes of CE requirements requires that "Machinery" conforms to both electrical and radiation hazard laws here for use in an industrial environment, this machine does not thus the CE marking is invalid (without it this equipment cannot be imported into an EU country legally)

UK HSE laws http://www.hse.gov.uk/guidance/index.htm

without bothering to look at the numerous laws that this junk pile is in breech of it does beg the question "How are these kind of things permitted to be imported"

For personal use inside the EU it is likely people will get away with it, the problem is when people come to sell them, the penalties for selling non conforming machines include fines of up to £5,000 ($7,500) and 6 months in prison for each violation.

I've personally seen one case where a young lady was fined so heavily she lost her house (£150,000 in accrued fines) and had her equipment confiscated & destroyed.

If a supplier can outright LIE about CE conformance then that does beg the question...what else are they lying about?

cheers

Dave

Very interesting. Thanks for the feedback. It's a good thing that I'm not reselling (or otherwise trying to make money with) this machine!!

Being in the US, I can say that the only hurdle during importation amounted to the laser tube mfg. (not the machine mfg.) saying "the tube output is what we said it was, we promise." Then I filed that paper with the FDA. Other than that, customs got their cut and I was done with it. If you think what you saw in the first video was bad, just wait until this coming Wednesday. I teardown the included 110-220v step-up converter that was included. There's no way that thing is even remotely safe. I just threw it away. Interestingly, the replacement I bought on Amazon.com was better but not really what I would want it to be. Also, it included a sketchy CE logo. In that case, it was sold by amazon, so I think that they do have some liability in selling it if it wasn't in compliance.

Wasn't there a case recently in the UK of a woman buying a 5v usb phone charger that died while she was listening to music with her headphones while it was plugged in. I think she bought it retail at a drug store (chemist in the UK?)

[William Dillon]

And of course the UL approval rating when the wiring is not even close to any US electrical Code. Seems like if you can buy (make) the decal and stick it on the machine, that's all you need.

What kind of stuff should I fix to make it safer? I'm building a new controller for the machine, and I'll be re-wiring it. I'm already planning on adding interlocks to all the doors. I'll add the ground straps for the doors, that's a good idea.

I'm considering having the switches on the tube access panel and the electronics bay kill the mains, and having the work area disable the laser (through the power supplies protection circuit).

[Bill George]

The biggest issue I noted was the use of 120 volt plugs for 240 volt connections. And of course using a Green wire for power which is a big no. The UL approval process I know very little about. If the machine is made from actual UL approved parts that would be a different story.

[Mike Null]

You can be sure the Chinese machines do not have blanket UL approval. If there is anything on them that has UL approval it's likely to be a switch, motor or other electronics part.

UL approval is a lengthy process and the machine must be sent to Oakbrook, IL USA for testing and evaluation.

Whenever we introduced a new appliance we had to go through the UL process and it's a slow process and you can't buy your way to a speedier inspection and approval. Once you have approval you can produce derivatives and just get approval on the derivations.

[Paul Phillips]

UL approval is no joke, as a manufacturer of electrical signs we have to be UL certified, we have an inspector come out every 2 months to check up and look inside our sign cans to make sure everything is up to code, our supervisor goes through many hours of study and training and labels are kept under lock and key. If a sign catches fire and and it doesn't have a UL label on it, WE are the ones responsible! BTW, UL labels have serial numbers on them that are given out by UL, you can fake them but if you're caught I imagine there would some serious consequences, unless you're from China of course. :)

[William Dillon]

UL approval is no joke, as a manufacturer of electrical signs we have to be UL certified, we have an inspector come out every 2 months to check up and look inside our sign cans to make sure everything is up to code, our supervisor goes through many hours of study and training and labels are kept under lock and key. If a sign catches fire and and it doesn't have a UL label on it, WE are the ones responsible! BTW, UL labels have serial numbers on them that are given out by UL, you can fake them but if you're caught I imagine there would some serious consequences, unless you're from China of course. :)


That's really the problem with the whole deal, isn't it? How much trust can we have in a label that is very easily copied in a place that is (most likely, IANAL) jurisdictionally out-of-reach? Especially considering the factories that produce some of the counterfeit-labeled devices produce legitimate goods as well. It's scary in some sense that it has become the responsibility of the consumer to evaluate for themselves whether something is safe. I've purchased things in large chain stores in the US that make my skin crawl when I open them up. I have to wonder how they ended up there and whether they have been honestly checked out.

The only reason was comfortable buying this unit is because I'm fairly comfortable with electronic things, and I know enough to be afraid of them.

By the way, I'm not sure if it would make a difference, but from the factory, the electronics bay and the tube bay doors were screwed shut. That might help with the CE thing (probably not enough).

[Dave Sheldrake]

Want a giggle?

You can buy fake RECI tubes now! China is even copying their own stuff!

[David Somers]

That is a real giggle Dave! I wonder what a Chinese manual translated poorly into English looks like when it is translated back into Chinese?

Hmmmmmm.

[Dave Sheldrake]

Like a half dead spider has crawled through an ink blot usually :)

[William Dillon]

I just posted part 2. If you thought the construction seen in part 1 was bad, you're in for a shock (pun definitely intended).


http://youtu.be/xUOosypdlHE

[William Dillon]

http://youtu.be/PI6TKkP4mqE

This video follows me through several tests relating to the water-cooling system of the laser engraver. I also tear-down a pair of impeller-based water pumps. Finally, I fill the system with water and check for leaks. What fun!

I do have a question for the experts. I really, really want to keep that flow sensor in the loop, but I'm worried about flow restriction.

In practical terms, how much fluid flow is necessary to keep the laser gasses cool enough? It seems like the water temperature isn't appreciably increasing, however in the case of zero water flow, the reservoir water wouldn't increase, so that's not necessarily meaningful.

In the video you can see where I installed a thermocouple to measure the glass temperature. I tried to pick an area where there isn't a water jacket, but is as central as possible. I'm hoping that the internal part of the tube's glass construction is close to the same temperature as glass isn't an awesome conductor of temperature, but it doesn't suck either. Is this going to give me somewhat meaningful information about tube temperature?

[Clark Pace]

So I have a k40 III a few years ago. Mine came in good condition now problem really. Although I shielded the tube. Some laser come with a rubber shielth, some don't. But I insulated it anyways. While not very good for doing professional stuff, I had a lot of fun with it. It would cut 3/16 reliably, and could engrave small items pretty good. I am glad I purchased it. It gave me a good sense as how the china stuff it built, and prepare me for my bigger china laser when it arrived.

But whether you have a US laser, a China laser or other. Always be sure to stay with your laser when it's working. Fires don't care where the unit was made, whether bad electrical work(china) or just a flare up. A local laser company about 1 town from me left their laser for only a few moments, and there shop was an entire loss!

[William Dillon]

So I have a k40 III a few years ago. Mine came in good condition now problem really. Although I shielded the tube. Some laser come with a rubber shielth, some don't. But I insulated it anyways. While not very good for doing professional stuff, I had a lot of fun with it. It would cut 3/16 reliably, and could engrave small items pretty good. I am glad I purchased it. It gave me a good sense as how the china stuff it built, and prepare me for my bigger china laser when it arrived.

But whether you have a US laser, a China laser or other. Always be sure to stay with your laser when it's working. Fires don't care where the unit was made, whether bad electrical work(china) or just a flare up. A local laser company about 1 town from me left their laser for only a few moments, and there shop was an entire loss!

Yikes! Yah, it certainly seems like a good practice when, in some cases, you're literally staring controlled micro-fires (and blowing them out). It seems to follow that it's not unexpected to have one of those little fires get out of control.

[Dave Sheldrake]

In practical terms, how much fluid flow is necessary to keep the laser gasses cool enough?

It varies from tube to tube Will, it's calculable though, figure on the tube being 10% efficient with the rest going to heat, a 40 watt tube will therefore need 400 total watts of cooling, take the thermal transfer rate of water allow for the glass insulation and work it from there. As a rough guide you will need 1,200 LPH to get decent results, 3,000 LPH is better and 5,000 will give noticeable results for stability. DC tubes hate temp fluctuation with a passion, keeping water temps to +/- 1 degree will make a big difference. (I'm not going into the whole sub zero thing as last time I did it caused a vendor problems when people wanted to buy -30 degree C chillers)


Is this going to give me somewhat meaningful information about tube temperature?

Not really, a laser has no appreciable temperature as such, it causes temperature through molecular excitation and it does it VERY quickly, knowing the tube wall temp won't really give you any meaningful data(it's only subject to stray photons not directed photons), the point temperatures at the full reflector and output coupler are what you need, I use an FLIR camera to monitor mine for hot spots but understand that it may not be possible for everybody to go buy one at $3,000+ a time.

cheers

Dave

[Dave Sheldrake]

Yikes! Yah, it certainly seems like a good practice when, in some cases, you're literally staring controlled micro-fires (and blowing them out). It seems to follow that it's not unexpected to have one of those little fires get out of control.

when it goes bad it goes bad quickly...

NOT one of mine

301912

cheers

Dave

[William Dillon]

It varies from tube to tube Will, it's calculable though, figure on the tube being 10% efficient with the rest going to heat, a 40 watt tube will therefore need 400 total watts of cooling, take the thermal transfer rate of water allow for the glass insulation and work it from there. As a rough guide you will need 1,200 LPH to get decent results, 3,000 LPH is better and 5,000 will give noticeable results for stability. DC tubes hate temp fluctuation with a passion, keeping water temps to +/- 1 degree will make a big difference. (I'm not going into the whole sub zero thing as last time I did it caused a vendor problems when people wanted to buy -30 degree C chillers)


I remember reading about that on a creek thread somewhere. That's pretty funny. I'm too concerned about condensation to start getting too much into active cooling at the moment. It can be quite humid in Oregon (though not indoors in winter).

The laser power supply is rated at 300 watts, and it's easy to assume that it's all becoming heat and budget from there. I'm certain that I'm not anywhere near the 1200 LPH mark, and I think heroic measures would be required to make that happen. The tubing used to connect to the laser tube (from the factory) is on the narrow side. The 1200LPH pump that was included with the laser could not achieve 1200LPH with 2 feet of tubing, either. (I tested that in the video)

By noticeable results, do you mean that there is more power and/or less banding?



Not really, a laser has no appreciable temperature as such, it causes temperature through molecular excitation and it does it VERY quickly, knowing the tube wall temp won't really give you any meaningful data(it's only subject to stray photons not directed photons), the point temperatures at the full reflector and output coupler are what you need, I use an FLIR camera to monitor mine for hot spots but understand that it may not be possible for everybody to go buy one at $3,000+ a time.

cheers

Dave

So, in essence what you're saying is that little glass loop of coolant that is stuck onto the ends of the tube is really the bit that is super important? With the FLIR One's available in the $250 range, it's awfully tempting. But, I don't have a compatible phone.

[William Dillon]

As I've mentioned in another thread (http://www.sawmillcreek.org/showthread.php?224059-Chinese-laser-Tube-current-and-X-axis), I went ahead and ordered an open source laser controller kit (with PWM). It seems like a nice system, and I'm looking forward to having a little more control and ownership over how the machine operates. The PCBs arrived, and I shot a video of the assembly and testing of the main board.


https://www.youtube.com/watch?v=yJImenhGE58

[William Dillon]

This video is composed of three parts. The first investigates a novel method for aligning the mirrors of a laser cutter. The second shows the traditional method. The final section shows how to change a lens (convex side up!) and reviews a Chinese eBay vendor for IR lenses.


http://youtu.be/lB-NCmSGg3Q

[William Dillon]

http://youtu.be/7QeJlY_6kRs

In this video, I go into more depth with the problems that I had with MoshiDraw and the MoshiBoard. Talk about pulling my hair out!!! Also, I posted in another thread about that hissing/screeching noise that I was getting in the laser tube. I wonder if that was contributing to the erratic behavior that I was seeing.

[William Dillon]

http://youtu.be/7GoERtNL5-0
In this video, I remove the old controller board and install the LaOS board into the laser cutter. This ends up being fairly involved. I was going to have installation, configuration/testing and engraving in one video, but it was WAY too long.

[William Dillon]

http://youtu.be/pc2N2bLyDtA

In this video we configure the LaOS board for my laser cutter, and discover a failed solder joint and two firmware bugs.

[William Dillon]

http://youtu.be/T95bSgv3_X4

In this video, the LaOS board is tested while firing the laser.
It turns out that it exhibits the same problems as the MoshiBoard.
I eventually fix the problem, in a bit of a brute-force kind of way.

[William Dillon]

http://youtu.be/C84alTp_tMg

Phew! That was quite a journey. I'm finally reliably engraving with my cutter. I'm certain that I made the process more complicated than it needed to be, but now I fully understand how this machine works. In my opinion, that's when you truly own something. Thanks for following me along the journey. I may post another video or two eventually when I tie some of the loose-ends, like the power supply and safety/interlock system.

[William Dillon]

Well, I'm basically finished making these videos. Thanks for watching. I have one last thing to add that might help others considering a china purchase, and that's about customs...

My new Chinese laser cutter! (http://www.housedillon.com/?p=2062)

[Inge Palmar]

The machine is shown as CE marked (for sale within the European Community as safe for purpose)

Well, mostly CE marks in china means "China Export" hehe
it is a bit confusing since it looks the same as the CE marks in EU country.

I was supposed to order this machine, and upgrade it. But I have second thoughts about it. ;)

[Chuck Stone]

it's hard not to have second thoughts when the whole unit sells for less
than you'd expect to pay for a decent fume extractor and air assist alone.

There's a lot of people thinking they'll get into engraving for $500 and I
have to bite my tongue most of the time. I'll mention things to look for, watch
out for etc... but I think I come across as someone trying to keep potential
customers out. And so many of them laugh about the 'dummies' who paid
thousands for a laser engraver.

I hear some saying they'll use it as a 'starter' laser and sell it when they
can upgrade. But I wonder if they'll meet code and be legal to sell? I'm
not going to buy one just to find out. HA!

It's hard to watch .. these are not idiots, but they have no way of knowing
just how difficult it might be. And how would you know, except to work on
a larger unit for a while and then buy the desktop laser. But then migrating
would be a bitter pill.. almost as hard as going from Corel to Moshi..

[William Dillon]

it's hard not to have second thoughts when the whole unit sells for less
than you'd expect to pay for a decent fume extractor and air assist alone.

There's a lot of people thinking they'll get into engraving for $500 and I
have to bite my tongue most of the time. I'll mention things to look for, watch
out for etc... but I think I come across as someone trying to keep potential
customers out. And so many of them laugh about the 'dummies' who paid
thousands for a laser engraver.

I hear some saying they'll use it as a 'starter' laser and sell it when they
can upgrade. But I wonder if they'll meet code and be legal to sell? I'm
not going to buy one just to find out. HA!

It's hard to watch .. these are not idiots, but they have no way of knowing
just how difficult it might be. And how would you know, except to work on
a larger unit for a while and then buy the desktop laser. But then migrating
would be a bitter pill.. almost as hard as going from Corel to Moshi..

Ha! Yep. All true. I'm basically saying the same things now. I'm not against the chinese machines in general, but I think it's like current 3D printers. It's not for people that are doing anything commercially, and you had better be patient, and a "tinkerer."

[Dave Sheldrake]

Ha! Yep. All true. I'm basically saying the same things now. I'm not against the chinese machines in general, but I think it's like current 3D printers. It's not for people that are doing anything commercially, and you had better be patient, and a "tinkerer."

Depends what the machine is, a K40 most certainly isn't for commercial use but some of the bigger machines are.

[William Dillon]

Depends what the machine is, a K40 most certainly isn't for commercial use but some of the bigger machines are.

Fair point. Yah, I was referring to this model.