I picked up a cheap flow meter and gauge.
Is there anywhere to pick up 5v easily? I have a k40 with c3d conversion.
The original Psu offer 5v, but it’s not recommended to pick juice from here as it is undersized (1A).
Old phone charger around ?
What the output of your flowmeter (a value or it work like interconnect switch ?), what do you do with it ?
It’s just a visual flow meter with temperature. I will slap the temp gauge into a new panel.
I have some buck converters somewhere that I could drop from 12 or 24 if that is a preferred method.
I will try to find the specs (bought it months ago, but with my house construction, the k40 was brushed aside for about 8 months).
This is what I bought:
US $9.91 36%OFF | PC Computer 3 Way Water Flow Meter Digital Thermometer for Water Cooling System Kit Water Cooling Thermometer Water Flow Meter
https://s.click.aliexpress.com/e/c2V9mWuC
Now, description says 5-24v for input… Do I trust it?
Did you get the extra 24V supply for your C3D board?
-50c, in the range but not much more than a baby bath thermometer in the bucket.
Flow watcher more than meter, not able to use it as security in case the pump isn’t on, which limit the interest.
Long time ago I look into flow meter, but coding experience don’t allow me to interconnect with Smoothieboard. I was hopping one day that somebody would looking into it. (In todo list for Smoothie V2).
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If you are up on the control panel there is 5v going to the POT or the digital panel.
There are schematics in the posts on my blog.
The specs do not say how much power this draws but I would expect it to be minimal.
If you are running the C3D on the original supply its already marginal.
If not then there should be plenty of power for this.
This is a visual flow indicator with a temp gauge. It and will not shut down the laser on an over temp.
I suggest adding a flow switch as well (I have both visual and electric).
If you overheat you may not see the visual meter and you will loose a tube.
I have one that I use for my pool solar heater, but the hose size would be too big for the k40. It is a hall effect sensor (I have it and two thermistors connected to an esp8266. WiFi feeds a nano pi neo which displays temp and flow in my kitchen. )
I will look that up. But yes, I have no flow interlocks. Just my manual checklist of PMCS and preflight items.
You do not connect the flow switch to the smoothie, it connects in series with the LASER SWITCH’s circuit.
Anything that you want to use to shut down the laser is put in that circuit.
I recommend you take the time to add the flow switch and interlocks so both you and the machine are protected.
If the below references are to overwhelming ping me back and we can help.
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My old switch setup (use the latest): https://donsthings.blogspot.com/2017/05/k40-coolant-flow-and-termperature.html
Latest cooling and sensing setup: https://donsthings.blogspot.com/2018/01/improved-k40-cooling-circuit.html
Interlock info here: https://donsthings.blogspot.com/2016/11/k40-s-interlock-breakout-board.html
For Smoothie, my idea was to unable laser fire if hall flow meter ( in line after the tube), have a insufficient output due to air bubble or pump weakness. Display of info would have been easy on glcd screen.(+temp). The other circuit (psu loop interlock), would left the user in the dark in case of lock. @donkjr
FYI; Putting interlocks under any type of electronic/software control is not good practice for dangerous environments like lasers. In fact it would not pass certification.
The k40 interlock circuit is simple and has no active devices. You would have to deliberately defeat it as it fails OFF. As it is there still are some failure modes in the LPS that could leave the laser on like a shorted photocoupler.
I have written enough software to know that I do not want code protecting my eyesight :(.
To digress a min, my favorite story of bypassing interlocks woes occurred at a pharmaceutical company I worked for that had a small clinical batch mfg division. Tableting presses feed the powder for the tablet into a tooling set to press the tablet. Because it happens at high speed there are actually multiple sets of tooling on a carousel. One night a worker was changing out the tooling on one of the big machines by himself. The press had been designed so that you had to activate two switches at the same time on the outside of the machine to advance the tooling carousel to the next position, which meant your hands were out of the way. He was in a hurry so he used a binder clip or such to actuate one of the switches so he could keep one hand inside. Was going fine until his hand got caught in between a set of dies 
No one was around so he eventually figured he could reach into the machine with his free hand and grab a belt to advance the carousel to open the dies crushing his hand. Needless to say our number of days without a lost workday due to a safety violation fell to zero.
Don, I get that. I can’t tell you what I do for a day job, but suffice it to say, software interlocks and safeties don’t cut it.
This is only for my visual placation. At some point I will be adding safety switches. For now, my checklist will work, and should I blow the laser tube, my bad/my fault/my deal.
I will look at your website for ideas.
Thank you!
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So @y2kvfr to summarize, if you have the extra 24V power supply they recommended for the C3D board you could tap into that. If not, then your probably need to power it with an external power source since the stock LPS isn’t really sufficient, in our opinion, to power anything else. Also it’s recommended to have a interlock on your water flow 
Also I just realized you are Travis from the G+ group. The fez gave it away. Welcome brother 
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I figured you had trolled my profile by now 
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Here’s one I put together a while ago. In my next one, I’m going to use an Arduino that will include two temperature sensors as well as a flow switch interlock. You’ll be able to read the temperature and also set Min and Max for alarm status.
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Agree with you about interlock and people, but here it’s about to protect the tube from user, not the other way around.
Gaaaaahhhh!!! I just looked into this. I haven’t had any issues with my c3d board, so I haven’t been frequenting the FAQ there.
Looks like I may want to get a 24v PSU and make standoffs for my c3d.
Any reason for $45 shekel bux with the c3d PSU or would any do?