Posted a couple new things to Thingiverse.com recently, the one above is a small magnetic pickup tool for my Stanley Screw Organizer Case.  It uses a 5x15mm cylinder neodymium magnet and fits in the compartments of the organizer.  Seems to work pretty well.

Also posted are some screw covers designed for #8 screws.  I designed them to use M5 washers as well and the covers snap on the base thanks to a very small ridge that locks them on.  These were printed in PETG which I hope will stand up in the weather.

I'm also working on a remix of T77Chevy's "filament guide cr10s pro" which looks perfect, except that I need a larger diameter wheel on my printer since the filament path goes almost straight up to the top of the enclosure.  The model I am working on will have a 45mm wheel and a will have a version with M4 hardware and one with no screws needed.  It should be posted soon, I just need to print it.  My current filament guide has served well, but it is warping from the stress and it's time to replace it.

Update 8/29/2020 - The filament guide for the CR10S Pro is now posted here.  Pics of it in action are below.

This is an organizer for diabetes testing supplies that I am working on for a family member.  It has a couple of removable compartments which should be easier to fill or dump out.  There is also a place for a meter, a box of test strips, some swabs and three pens.  The large open compartment in front is for whatever else needs to be stored.  The design will require some M3 hardware and M3 inserts to hold the hinges in place. 

I'm printing this now and expect it will be posted next week.

Update 10/24/2020 - This project has been completed for some time and is posted here with some minor improvements from what is shown in the above pic.  The pic below shows the printed design, which is almost identical to the one posted on thingiverse.

While we stand by and eat Cheerios and Big Macs, our country is being stolen from under our noses.  Many don't seem to mind though, as long as Netflix and Facebook still work.  And yet we may be living in the transition period from a representative democracy to a more authoritarian, right wing minority dominated government with shades of a kleptocracy.  If we are unlucky enough that should come to pass, then it should be no surprise when you see the people that Trump has  associated with, and his apparent lack of giving a shit about the Constitution.  It should also surprise no one if Trump will do anything to win, even if that means grounding the ship of state on the beach, so he doesn't get his feet wet on the way to his next inauguration. 

The theft of American Democracy will not have happened overnight though.  It has been engineered, gamed out and fostered for decades, and will continue even if Trump fails to suppress enough voters this time around.  The engineering of minority rule of the right wing of the Republican Party in this country has bounced from one step to the next.  From gerrymandering districts to cram likely Democratic voters into a few, while insuring many more have just enough Republicans to win, to the enshrinement of the concept that Money = Speech by the Supreme Court in Citizens United (which was about anything but citizens being united), to the gutting of the Voting Rights Act, to the fraud that voter fraud is a real problem requiring fixes that (surprise) affect likely Democrat votes disproportionately, to interfering with recounts, to even purging eligible voters  from databases of registered voters.  Under Trump, the far right of the Republican Party has even taken a few pages from Russia's playbook, by exploiting social wedge issues to divide the country along religious and ethnic lines.  

It may just be politics to some, but how long do regular Americans continue to stand by and watch as the guardrails of our democratic institutions are dismantled, and their power as citizens is diminished?  If left unchecked, those tactics and dirty tricks can be used by any party in power, to stay in power.  History shows that as strong democratic institutions are weakened and dissolved, things usually do not end well for everyone, except (sometimes) those at the top.  It takes those democratic guardrails and traditions to insure a voice for everyone, and moderate the worst impulses of people in power at any one time, that is how the United States has lasted this long.  It is therefore no wonder that Trump has in his first term, targeted the very institutions which are key to checking his power (Federal Judges, Inspector Generals, and now apparently the Postmaster General of the United States).  I know some folks don't really care if Trump does what he wants, as long as he sticks it to the libbys and "makes them cry", but they should care that unchecked power has a way of being well.. unchecked.  Do they trust that the ever mercurial Trump, who would most certainly consolidate more power in a 2nd term, would not either lay the ground work for an even more imperial Presidency, or simply change his mind on their cherished issues?  Have they gamed out what a series of Trumps and Trumpites in the Oval Office would mean to their ability to disagree with the government, or do they plan to suckle on his tweets and carefully align their opinions with his?

For Americans who still believe in preserving what remains of their power as citizens and voters, this election will be about more than party first.

UPDATE 8/21/2020: This will not work as planned, using the RM4 Smart Relay.  I should have read the instructions more closely (or really at all since this was such an obvious oversight) - They say:

"The RM4 is 120V AC powered, and must be installed in a junction box. It does not work without AC power or during a power outage."

That said, I am now the proud owner of a UL listed 120V relay, sure I will find some use for it, but at least I did not pay full price.  I did test my smoke detector though and when it runs on a 9v battery it puts out between 6-7volts when measured between the signal and hot or signal and ground.  That is enough to power the IOT relay, but I will either need to find a place for that in my enclosure or I will need to find another opt-isolated 120V relay board to use with this arrangement.

Original Post:

There are some cool designs on Thingiverse for a Smoke Detector Cutoff for a 3D printer as an extra layer of protection in the event the worst occurs.  The best I have seen are HenryArnold's design here which uses an IOT relay, a couple power supplies, some diodes and a off the shelf smoke detector (hardwired).  The benefit of this design is that it is mostly using components that plug in with very little soldering.  The downside is that it has several points of failure (power supplies and the IOT relay).  It is a pretty brilliant design though, and it is all low voltage.  The other design I really like is NikDFish's design which utilizes off the shelf smoke detector and relay parts.  His design really utilizes the hard wired smoke detector in a configuration that was intended, with an off the shelf smoke detector relay used to control the printer power.  The only downside there is that the detector is going to run on 120VAC and that means running that into the printer enclosure.  I would much prefer to keep things low voltage if possible.  There are apparently 12/24VDC hard wired smoke detectors but they are very expensive and I don't think they have the required alarm outputs.  I think the way I may go is with a hybrid approach using the best of both of these designs.  I hadn't planned on working on a new design and still may not (I really don't like soldering), but the more I thought about what I'd like to have, the more I thought it may be worth the effort.  Like most of my projects though, there is a good chance I will get distracted by a squirrel or something and sideline it, but if that happens I will probably use one of the well tested designs mentioned above.

What I want from the system is:

• Uses off the shelf smoke detector and smoke detector relay components  (Update 8/21/2020 this does not appear possible right now)
• Requires no, or minimal changes to the smoke detector or other off the shelf components.
• DC powered only
• Battery backup in case the mains power supply goes out
• Latching relay output (to keep the printer shut down)
• A logic level (5v/3.3v) output which goes low when the alarm is triggered (future expansion or smart home integration) -  Update 8/22/2020 The Sonoff Mini Wifi should cover this if I use it
• (low priority)  A 9v or 12v output that latches high when the alarm is triggered (for lights or an additional siren).
• (low priority)  A 2nd alarm input option to kill power using the relay (the thought was to have the ability to connect another detector or a temp sensor that would trigger it to power down).

The smoke detector options I am looking at using are:

First Alert BRK 7010B Hardwired Smoke Detector

• Photoelectric
• 9V battery
• Hardwired

First Alert BRK 3120B Hardwired Smoke Detector

• Photoelectric and ionization sensors
• 3V (2xAA) battery
• Hardwired

And I also plan to use this Smoke Detector Relay (Update 8/21/2020 - this will not work since it only operates on 120VAC):

First Alert RM4 Smart Relay

Basic instructions for the RM4 Smart Relay

UPDATE 8/22/2020 - The Sonoff Mini WiFi looks interesting but  is not ideal since it relies on software to trigger the relay based on the GPIO.  Still I may use it for this project since it has smart features, and offers the possibility to add some more inputs.  I plan to test the smoke detector out to the logic level inputs on the Sonoff Mini via an optoisolator board.  This does make things a bit more complicated, and I may still just use an relay board with an opto-isolator like I already have, but even if I do, I could use the Sonoff in series with it so I can power things on or off using the Octopi, or find some other use for it. 

I really like the BRK3120B since it has the dual sensors, but I already have a BRK7010B photoelectic around here somewhere, so I may just use that.  The only major difference that will affect my plans is the battery voltage on the BRK7010B is 9v and the BRK3120B uses 2xAA batteries (3V).  In either case, I plan to power the detectors using their battery backup circuits which would be wired into the appropriate DC regulators, with a backup battery that will go online in the event that the DC regulators fail.

My current plan is to break the project up into two parts.  The first is the input power, battery backup, battery indicator LED and the battery reverse polarity protection.  The more difficult of these to do will be the 3V system since there are fewer volts to work with, but I made a schematic which I need to test out (below), that should include all the things I need.  Note the resistor values are going to change and this is a rough draft - has not been tested.  Also, I am no expert so I will probably fumble my way through this project.  If I go with the 9V system it will be a bit simpler with just a diode for the reverse protection and I will swap the input for 12V with a 9V DC-DC regulator after that.  I already have tested the 9V battery backup setup and with some tweaks it could probably work here also.

The second part (output relay, logic level output and 9v/12V output) is pending, since I need to get a RM4 smart relay (and I plan to get it from Ebay where they are alot cheaper than Amazon).  I want to test the first part though before I spend money on a relay.  Update 8/21/2020 - The RM4 will not work for this project since it only operates on 120VAC (it will not operate when the smoke detector is on battery power).

None of the above is my original design, these designs were used as templates:

Backup Battery
https://www.disk91.com/2014/technology/internet-of-things-technology/make-an-usb-power-supply-with-backup-battery/

Low Voltage Drop Battery Protection
https://www.eevblog.com/forum/beginners/reverse-battery-protection-with-single-cell/msg274550/#msg274550

I used to be into running and biking, even though I was never very good at either.  But this last year I don't think I had done either, until recently.  I can't blame Covid for that though, my slide into the couch potato life began much earlier, and having a job which keeps me pinned to my desk for 10-12 hours a day does not help.  I'm lucky in that I can work from home though, and therefore have not caught Covid.  However the 2020Covid-life has dealt me one favor, and that is simply the realization that although this year seems mostly wasted, there are still things I can do to improve my situation.  So I am trying to get back into running with a couch to 5k app on my phone, some ElectoMix in my bottle and an Amazon Prime Music playlist to keep my mind off my aching feet.  I'm starting on week 4, so hopefully I will go the distance, but my current philosophy is to enjoy the journey and not worry where the finish line is (I'm not gonna sweat it if I end up repeating some days or weeks to get them "right").