Well, yeah, that is a little expensive but that’s what turned up in the short time I had to search. I was tasked with doing this for 220-260 VAC single and 3-phase devices a couple years ago but the project fell through before things got too serious and I don’t remember what we found back then now…
Looks like there are some cheaper options on Ebay but the Chinese aspect of most there would have me researching them a bit more unless they were cheap enough to be considered throw away.
I have a meter I put together myself, all up cost less than $15. I find it very useful, no “smarts” but gives me the information I need.
The parts were sourced from eBay and Banggood I think, roughly boxed in MDF cut on my little CNC router.
If you want to send me the parts list I will see about making one.
I have included 2 eBay searches, the first for the power meter and the second for the outlet plate (I favour the units with switches). I tend to pick the cheapest items where the supplier has a “reasonable” rating.
I should probably say that if you’re not sure how to wire these together right now then you might like to find someone that is. Messing with 120/240 VAC is not recommended.
Cheers
I got a couple of indicators ordered. I am going to just hard mount them on the laser.
Brian
I got the power displays in today and I installed a couple. The first one shows the power used by the machine as a whole and the other is showing the fan power use only, as requested. Take a look at the video on Youtube.
Here’s a link to the youtube channel https://www.youtube.com/channel/UCGElwMcUgS6dSS1Uhfq4CUg
I saw a similar machine here in Slovenia for about the same price.
But after they did a test engraving for me I noticed the power regulation was way off.
They did an engraving in wood and the right side of the engraving had noticeably less depth by looking at it I would say 20%, by feeling it more like 30% difference in depth.
As it was just text and not a picture I highly doubt the source file was the problem. I also don’t think the problem would be the regulation of power as the transition was way to smooth. Almost looked like the bed was way off horizontal alignment and the laser was out of focus.
Only for that reason I decided to stay with GF, even though I payed almost the same for it with shipping. 
They also had this HUUUUGE 1300mm x 900mm machine with a pass through (they said people use it for engraving doors) for about 6000€.
Yeah this thing here: http://h-space.biz/HS_1390.html
Oh and also, the reason I decided NOT to go with them is because their (the people selling it) care for safety is non existent. The whole thing open with everyone looking directly at the laser point.
When I asked them, aren’t you gonna cover it, they laughed and said you don’t need to. They actually made fun of me telling me the only thing I have to care about is having kids. Ha Ha, u so funny. Like I’m gonna buy anything from you now…
Are you sure the laser actually pulsed? I’d expect a 90W laser pulsing at 90% would use at least 81W (that’s with perfect efficiency). Given that it is probably 20% efficient, you’d expect a ~400W jump when firing 81W.
I reviewed your previous power video and the full wattage pulse used ~200W.
thanks for this , this is more in line with what my expectations where. And kind of debunks the the whole gf taking 800w and the filter taking 600. That square fan you have is supper inefficient and is by far the lions share of consumption. On the laser is the lighting led or incandescent (wondering what the 200w baseline consumption is being used by)
i bought 4 of the displays. I’m going to use them on different parts of the machine to determine what is using the bulk of the power. I want to make this a little more energy efficient.
Safety is very important when using a machine like this. The power regulation is done through the controller. I haven’t seen any issue with power regulation.
I finish my master’s degree in 3 weeks and will try to do more once I am finished with that.
How much power do you expect to save and where will it come from without affecting machine performance?
Good luck on the MS defense!
Probably not a power regulation issue. That’s typical of misalignment of the bed & mirrors in the Chinese lasers. High precision manufacturing it’s not. 
I’m doing my M.Ed. The last three weeks are a killer. I’ve got a research study I’ve got to do. It’s taking me away from my toy. I get on here when I get tired of writing.
this is the fan I run in my tower garden, I could not be more happy with it a fantech prioair 8 ec. at full tilt its 120~watts and 800~ CFM it does cost a few dollars for this one because it is also 0-10v speed controllable so I have mine to programmed via a apex to set speed based on temperatures, but no reason you couldn’t create a 0-10v ardrino or something to spin up or down based on other conditions. or just used the rheostat that is included also PWM is a option for control. so ya anyway really nice fan really low power usage and really high movement, also no mechanical noise at all.
at 100% it is a monster off the leash feeling the air blowing 40 feet away
http://www.fantech.net/prioAir-8-EC_enus-49316.aspx
very very much recommend it
I will look at it.
My sympathies on the writing. That was always the least favorite thing for me to do, but kind of essential in an R&D field.
If the change was gradual it was probably a alignment problem. I had that problem in my laser this last week. I re-aligned it and noticed that i was losing about 15% of the beam off the edge of the last mirror. So the farther i got from home, the more power i lost. Super easy to fix, i wouldn’t let that turn you off from a machine at all.
The writing is a killer. My brain hurts! Just two more weeks. My first master’s in engineering wasn’t as hard as this one in education.
Good to hear. About to start an EdD (in education obviously). The certification courses I had done when I was going to go teach High School were laughable after my life in Physics. So I was afraid that this upcoming degree would also be a complete joke.
I would far rather have backbreaking work, and thus respect the other members of my cohort, than to have something I can breeze through.
