ChrisWx

Screw-type fittings are more expensive, but a screw-on cap with a gasket would definitly be air tight.

Couldn't this be solved with a PVC ball valve? Drill the right size hole in the cap (toward the front edge, so the tree it's attached to won't interfere with filling), glue an adapter in the hole that will fit a 1" PVC valve, then put a cap (no glue!) on the open end of the valve to keep dirt out. The valve alone should provide a good seal, but the cap will help out just in case. I admit that it would only be economical to fill the watering station when it was close to empty - otherwise any extra water in the pipe when you open the valve will just spill out.Take a small section of left over 4" pipe, put a cap on one end and glue in a female fitting that fits the other end of the valve, and you have a 'Funnel' that stays put when you fill it. Drill a small hole near the to...

Couldn't this be solved with a PVC ball valve? Drill the right size hole in the cap (toward the front edge, so the tree it's attached to won't interfere with filling), glue an adapter in the hole that will fit a 1" PVC valve, then put a cap (no glue!) on the open end of the valve to keep dirt out. The valve alone should provide a good seal, but the cap will help out just in case. I admit that it would only be economical to fill the watering station when it was close to empty - otherwise any extra water in the pipe when you open the valve will just spill out.Take a small section of left over 4" pipe, put a cap on one end and glue in a female fitting that fits the other end of the valve, and you have a 'Funnel' that stays put when you fill it. Drill a small hole near the top of the funnel for fastening a vent tube. Use 1/4" or 3/16" flexible tube as the vent. Place it in the funnel so that an inch or two will be inside the water pipe when the funnel is attached, then use a cable tie or two to hold it in place (best to use two cable ties, one around the vent tube, and one through the first cable tie that holds it to the funnel). It might be better to cut the end of the vent tube at a sharp angle. Face the angle opening away from the filling hole when you attach it to the funnel, and it should prevent the water coming in from being sucked into the vent. Be careful not to crush the flexible vent tube with the cable ties, or it won't be able to vent.Filling is a little complicated, but better than removing the watering station from it's support. Remove the valve cap and open the valve (and watch your shoes if there's any decent amount of water left in the pipe!). Thread the vent tubing through the valve and into the water pipe as you attach the funnel. Add water! Depending on how and where the water feeder is fastened and how big you make the funnel, you might be able to up-end a gallon water jug and just let it drain.

This is such a beautiful planter! Could you give a little more detail about the self-watering part of the design? I assume there is space under the planting pot, where the water can collect and be wicked up by the cord, but how much? Is there a hole for filling it with water, or do you just let it percolate through the soil? Thanks for posting such a great design. It's an inspiration.

This is a beautiful planter. Could you give a little more detail about the self-watering part? How much space is under the pot to hold water, and how often do you need to water it? I don't have a 3-D printer, but there are several shops in the area that would print it for me. Thanks for the inspiration!

Thanks! Yeah, Amazon.US doesn't carry them under ThePiHut, but I found them by using the exact name ThePiHut uses: "USB to microUSB OTG Converter Shim"https://smile.amazon.com/CHENYANG-Ultra-Adapter-Connector-Tablet/dp/B015GZOHKW/ref=sr_1_3?keywords=USB+to+microUSB+OTG+Converter+Shim&qid=1575481830&sr=8-3

Where did you get that USB A to micro B adapter on the WiFi dongle? Or did you make it? REALLY need one of those!

I Love molasses cookies. Sadly finding GOOD molasses in my area is almost impossible. Anyone have a good brand I can buy on line?

Could someone who is truly bilingual translate this for the author? For such a well crafted piece, it is a shame we cannot understand the description.

Regarding the water comment - energy cannot be removed from the system. Water would slow the spin induced by the sling, which would affect wind resistance and accuracy, but wouldn't affect the tuning of the trebuchet at all - since tuning is what you used it for, not the competition, it's perfect. With such a short time of flight, the effect on distance would be barely measurable in any case.I would Love to experiment with this design. Some kind of mechanism to fine-tune the finger angle for release time would be awesome. From the slo-mo vids, your release angle was, as close as I can tell, a perfect 45 degrees - great for distance. I have to wonder what it could do regarding projectile speed with a later release. Wouldn't get the distance, of course, but it would pack a mean punc...

Regarding the water comment - energy cannot be removed from the system. Water would slow the spin induced by the sling, which would affect wind resistance and accuracy, but wouldn't affect the tuning of the trebuchet at all - since tuning is what you used it for, not the competition, it's perfect. With such a short time of flight, the effect on distance would be barely measurable in any case.I would Love to experiment with this design. Some kind of mechanism to fine-tune the finger angle for release time would be awesome. From the slo-mo vids, your release angle was, as close as I can tell, a perfect 45 degrees - great for distance. I have to wonder what it could do regarding projectile speed with a later release. Wouldn't get the distance, of course, but it would pack a mean punch closer in! :-)

I'm betting it took exactly One launch for your Retriever to figure out what was going to happen the next time! I laughed at how excited he got when you called him over to launch it.

I'll have to agree with several other people about the encoders, but why pay $30-hundreds of dollars for the hi-res ones? If you're going to 3-D print the mount anyway, go ahead and print some gears! Better yet, since gears can have a little slop, a toothed belt, used in some 3-D printers, works better with less hassle. If you need more absolute position data, use both! Let the analog pot be your rough position indicator, and let the encoder do the fine positioning. That dithering or noise that analog pots do lowers your resolution, so use the encoder for the final 2-4 bits. If you use it in quadrature, meaning you sense all four level transitions, an encoder labelled as '24 ppr' can give you 96 increments per rotation. It wouldn't take much gearing to get that up to a usable leve...

I'll have to agree with several other people about the encoders, but why pay $30-hundreds of dollars for the hi-res ones? If you're going to 3-D print the mount anyway, go ahead and print some gears! Better yet, since gears can have a little slop, a toothed belt, used in some 3-D printers, works better with less hassle. If you need more absolute position data, use both! Let the analog pot be your rough position indicator, and let the encoder do the fine positioning. That dithering or noise that analog pots do lowers your resolution, so use the encoder for the final 2-4 bits. If you use it in quadrature, meaning you sense all four level transitions, an encoder labelled as '24 ppr' can give you 96 increments per rotation. It wouldn't take much gearing to get that up to a usable level.However, if you're going to pay a bit anyway, or just want the best accuracy with absolute position information, look for rotary encoders with Gray Code. They're expensive, but you'll know exactly where in the rotation you are at all times. The linear ones give amazing precision - they use an optical reader like a computer mouse and a strip of plastic with the gray code micro-printed on it.As for your math and program accuracy, it appears you did a fine job. You have to remember to take into account the actual arc resolution of the telescope and total field of view. For a relatively small focal length and aperture like this, the Arduino's accuracy is fine. There are math libraries that could extend the resolution a bit, but they take up a lot of space the stock Arduino might not have available. If you do wish to step it up a bit, the new Raspberry Pi 3 or 4 could be a fine compute engine with full Linux C++ math libraries and all sorts of support. If you want to save a few dollars, the Teensy 3.x line is extremely powerful for the price, programmable with the Arduino IDE, and a lot of memory for those larger programs and libraries.Keep up the great work!

Ok, while I'm all for neat gadgets like this, as far as security is concerned there are a lot of weak points. The weakest is the lock itself, which simply opens via a command over WIFI. That is not biometric, nor is it secure. A knowledgeable person could hack the WIFI signal and mimic the command. The app generator is a potential security issue. The app itself is a potential security issue. The protocol used to communicate to the NodeMCU, the NodeMCU's WIFI connection and the WIFI router it connects to could all be potential security issues.Like I said, I'm a big fan of new IoT devices, but the term 'lock' implies a level of security that is simply not here. And that is exacerbated by the author touting the security of the biometric app. Please take care with claims of security...

Ok, while I'm all for neat gadgets like this, as far as security is concerned there are a lot of weak points. The weakest is the lock itself, which simply opens via a command over WIFI. That is not biometric, nor is it secure. A knowledgeable person could hack the WIFI signal and mimic the command. The app generator is a potential security issue. The app itself is a potential security issue. The protocol used to communicate to the NodeMCU, the NodeMCU's WIFI connection and the WIFI router it connects to could all be potential security issues.Like I said, I'm a big fan of new IoT devices, but the term 'lock' implies a level of security that is simply not here. And that is exacerbated by the author touting the security of the biometric app. Please take care with claims of security when referring to internet connected devices.