Saturday, December 16, 2017

Ten Months Apart

This is photo of our front yard how it looks now (picture made on November 8 of 2017).

And this is the photo made on January 15 of 2017. As you can see it is quite a transformation.  This is the result of my biggest DIY project so far: conversion of lawn to garden. The are several reasons for our family to make that conversion:
  • First and most important: big water usage during summer months. It is usually hot  were we live and there are no any rains from May till October. Water bills easy could reach hundreds dollars. And in case state declares drought period, there could be charge for over-usage.
  • It is not that easy to maintain lawn in good shape. You see, even in the winter (rain season here) it is far from perfect, but I can assure you that during July or August  it is much worse. Brown spots her end there,  weeds in place of grass. 
  • I had to mow lawn two times per month and I did not like that. 
  • The last (but not least): to save the water our state willing to pay for lawn to garden replacement up two dollars per each square feet converted.
 So our family decided to proceed. The project started in January and ended in May. We did everything ourselves without any professional help. Here are project stages:

  1. Breaking the turf (grass) with garden shovel.
  2. Cultivating the soil with Tiller Joe electrical tiller/cultivator ( that step I repeated three times to fully destroy the grass).
  3. Fixing irrigation pipes, which were broken during steps 1 and 2. Replacing sprinklers with water pressure reducers.
  4. Planting drought tolerant shrubs and flowers.
  5. Covering soil with mulch,
  6. Installing dripping manifolds on top of water pressure reducers. Installing tubes with drip emitters.

I described this process in more details here: . In this post I would like to speak a little bit more about one topic which did not take enough attention yet. While converting irrigation from sprinkling to dripping I first tried Rain Bird Drip Emitter Conversion Kit which has everything:
  • raiser with pressure reducer.
  • Six port dripping manifold.
  • Fifty feet of dripping tube.
  • Six drip emitters.
  • Six stakes to hold emitters in place next to plant root.
It works OK, so I wanted to buy more of the same. But alas, my local Home Depot was out of stock. I decided to buy components separately. Raisers, tubes and emitters were not a problem. But there were no manifolds exactly the same as in the kit. So I had to try others.

At the picture above you can see everything I tried:

  1.  Raindrip Hydroport 4 Outlet Manifold 13400U (top left)
  2.  Orbit DripMaster 69005 4-Port Manifold (top right)
  3.  Raindrip QB10UB 10 GPH 4 Outlet Bubbler (bottom left)
  4.  Rain Bird EMT-6X Xeri 6-Outlet 1/2-Inch Drip Manifold (bottom right: the same as in conversion kit).

All manifolds but last one I did not like. While first three were more sophisticated compare to manifold in the kit (water consumption adjustment, changing of outlet angle position), they all suffer form the same disease: water leak at the foundation of outlets. One would say that such a leak is not important for outdoor devices, but I could not agree. Eventually I   ordered manifolds number four on Amazon and installed them.  No adjustment or changing of outlet angle, but no leak as well. I returned all manifolds but number four back to hardware stores.

Wednesday, November 8, 2017

Rumination of Uselessness

Let us return to the Useless Machine topic one more time.

Classical useless machine usually made out of four electrical components, namely:
  • Electrical battery.
  • Gear motor.
  • DPDT switch (usually toggle, sometimes rocker).
  • Micro-switch.
This is probably minimal set: it is hard to imagine anything more efficient. But once an idea came to my mind: maybe such a machine  is not absolutely perfect. Useless machine must cut itself out of power as soon as it returns to the original state. That achieved with help of the micro-switch.  Machine arm,while returning back, pushes switch, its normally closed contact becomes open,  machine fully stops and looks dead. But if tester tries to move an arm manually, micro-switch is released again, its closing contact provides power to the motor. That case is visible on the clip of Rocker Switch Useless Machine starting at second 19. So machine here actually is not dead, it just plays dead! That's  good opportunity for the new design : make the machine, which will allow manual rotation of the arm, when machine is turned off. In other words make the machine really dead at the end of its working cycle. To achieve that I decided to get rid of micro-switch and  use for backward movement an energy stored in the capacitor, charged while machine arm moves forward, . Below you can see circuit diagram of such a machine:
When switch connects motor to the battery and motor moves the arm forward, electrical current is flowing through  the circuit of diode and relay, mounted in parallel to the motor. Relay  is forced to close its normally opened contact. Through that contact (and small resistor) capacitor is connected to battery and receives some charge. 

When arm turns the switch back, motor is disconnected from battery, but connected to the capacitor in the opposite polarity. Motor rotates backward and returns arm to its original state.  Diode now stays in the opposite direction on the way of electrical current,  so relay contact stays open and capacitor is disconnected from the battery. Capacitor mostly is discharged providing the movement of the motor, the rest  will be discharged through the stopped motor winding. You see, in theory it looks simple. But I must tell you that this design is much more demanding on the spec of components, compare to classical schematic. After some trial and error iteration I came up to the next set component:
  • Solarobotics gear-motor GM17  ( I could not make it working reliably with GM2 or other motors with similar spec).    
  • Super capacitor 0.1 F. (I used NEC 5.5 V capacitor). Bigger capacitor would be fine but smaller probably not.
  • 5V relay. Here type is not that important. 
  • Schottky diode. Here type is not that important. 
  • Resistor 5 Ohm. It is optional but it keeps electrical current trough the battery under 1 Amp at the beginning, when the capacitor is fully discharged. Type does not matter here, but better to have 0.5 W.
  • Four 1.2 V rechargeable batteries. Type does not matter. 
As you can see on the video tester may manually  rotate the arm when machine is turned off.  Done!
I published more detailed description on instrcuctables site

Update 11/12/2017. fixed bug in diagrams: missing wire between switch terminals.