Wow, it’s been a while since I’ve updated the blog, sorry for the long delay I have been extremely busy with work and non computer related hobbies. It’s incredible how the time flies. We’ve been working on digging the trench for the sidewalk, the soil is tough to dig in and is taking some time, although it’s not nearly as tough to dig in as the back walk was. This soil has much less rocks in it, it’s just that there is a lot more of it to remove.
Here is the most recent picture of the walk aka the kiddie pool during a recent rainstorm. It’s important to remember to add proper drainage to your digging areas, or this happens. There is a drain trench that leads to the roadside cliff edge, but it’s not deep enough. If it were not for this drain trench, the excavation area would have been filled to the top. This weekend I hope to get more material removed, it’s quite a piece of work for me because my body deteriorates quickly with heavy labor due to the rheumatoid arthritis, however I know we’ll get it done eventually, and most importantly before winter. The stairs will be getting removed and the sidewalk concrete will extend to the edge of the deck, then new steps will be built and secured to the concrete pad to make everything nice and solid. The steps are in not-so great condition, though still strong but I think new steps will look great.
Aside from ditch digging we built a model biplane over the weekend and got some airtime on it. The biplane is a Electrifly (Great Planes) ‘Reactor Bipe’. It’s an electric biplane with a 38″ or so wingspan. I probably would have been better off buying some repair parts for the heli and a new radio but this looked really neat and hopefully it’ll help me blend in with the plane guys more at the R/C field. The electric motor is a .15 equivilant size, theoretically, though I somewhat doubt it, it still does a pretty good job.
The Reactor Bipe was originally built with the suggest Futaba 3114 servos, but these tended to strip really easy and it got frustrating running out of servos. I purchased some new gearsets for the servos, but they will be used in some other, lighter project because they just really don’t hold up in this application. I replaced the servos with the Hitech HS-65MGs I was using in the Mini-Titan helicopter and things improved GREATLY, these servos really have the needed strength for the large control surfaces and are pretty fast as well.
The Reactor built pretty quickly, you do have to be careful about a few points. I noticed after assembly that using the pre-cut hinge slots that one ailerone was a bit lower than the one on the opposing wing. Double check the position of the hinge slots and everything else if you are concerned. Additionally where they recommend to use 30 minute epoxy, I’d definetly go that route. The manual for the tail includes and update sheet to use CA to adhear the horizontal stab, rather than epoxy. I suspect this is because epoxy could drip and cause the elevator tie rod thing to become bound. Even with CA this is possible, be careful when applying the CA glue to the horizontal stab. Additionally when gluing the control rods to the clevises, make sure the thin CA doesn’t drip into the joint. It will adhere them solidly, and while you think that you escaped disaster because the arm and surface still moves, you’ll quickly discover that this is only because the clevis is slowly twisting itself apart, instead of actually rotating in the control horn.
The manual comes with recommended control throws for low rates, high rates, and 3d. If you use the recommended control arm holes and low rates, you’ll find that the control is very grainy/low-resultion. You have to turn the travel/ATV down so far, that you are only using a very small portion of the bandwidth for each channel, and you can actually see each step in the control surfaces. This is bad because you loose a lot of precision. I would recommend using the outer holes in the control horns on the control surfaces, and the inner holes on the servo control arms if you just want to start out easy.
I’ve put in 4 flights in the last two nights, all of them were great although the plane is pretty ‘touchy’ on the controls. I will probably work in some exponential to make the middle of the controls softer, as I feel this would be okay for a plane (I don’t like expo on helis).
COPPER VAPOR LASER
Another side project which has been absorbing my time is the Copper Vapor Laser project. I’ve been building a tube furnace for this laser since the bore of the laser, where the copper vapor and helium (or neon) is energized by the electricity needs to be heated up to 800 degrees F for a copper chloride/bromide type solution. While the tube furnace I am building is overkill as I actually wish to build a version of this laser using elemental copper. The disadvantage of using elemental copper is that it requires extremely high temepratures, in the range of 1500 degrees celcuius (almost 2800 degrees Fahrenheit). Because of this I have been lovingly crafting the furnace out of high temeperature ceramic fibers (Inswool), ceramic boards (Insboard) and a variety of refractory mortars. For the bromide/chloride lasers, heat will be provided by a nichrome heater element(s) with no problem. In order to reach operating temperature for the elemental copper vapor laser, I will probably use one or two propane torches inside of the cavity.
The bore for the CuCl/CuBr laser is a quartz tube, the bore for the elemental copper (Cu) laser will be a high temperature alumina ceramic bore.
The advantage of an elemental copper laser is that you do not require a double pulse power supply. With a Cu Chloride or Bromide laser, you have to hit it once with a disassociation pulse, and a second time with the lasing pulse. With elemental copper you don’t need to disassociate the copper from a bromide or chloride solution, so one step is saved there, at the cost of extreme temperatures.
Copper Vapor Lasers have been used in some of Pink Floyd’s shows, they produce powerful golden yellow and soothing green laser lines (beams). Additionally CVL lasers have been used for the purpose of enriching uranium. While I am a scientist at heart and love to explore all sorts of different realms, I don’t think that enriching uranium would be a recommended pastime, so I probably won’t explore that part of science!
Here are some pictures of the tube furnace in progress. I’ve gotten much further, but don’t have pictures at this time. I will update my laser site later. This is the furnace for the CuCl/CuBr version of the laser. For the elemental copper version of the laser, this will probably end up encased in an additional external Inswool blanket wrap to bring up the insulation value and retain more heat inside the core.