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KRCM

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Topics - Deerslayer

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31
Some of you may know Levin, a.k.a. Flight Kid.

Apart from hanging out with us and flying, he leads a very challenging academic life. Recently, he participated in the regional Science Fair at Duncan Macarthur Hall.

Harold and I were privileged to obtain a sit-down VIP visit with Levin at his display. We were unable to stump him with our questions; he really does know what he is talking about!

Levin's project was the laser CNC system which he designed, built, programmed and documented. His dad helped with the cutting of the wooden components and perhaps in the de-bugging associated electronics, but L learned/utilized the GRBL programming language and all of the other associated technological aspects. The device works, although he was not allowed to activate the laser at the Fair, due to safety requirements, quite understandable, even though he currently has only a 5mw or such laser from a CD drive. He plans to purchase a higher powered laser and be able to cut foam for ... guess what ... flying machines!

I suggested that he bring his travelling road show out the to field sometime this summer (perhaps at the FDFF) and display it.

Harold and I were really impressed with the tremendous efforts and variety of projects at the Science Fair. We walked away feeling really positive about those who will be the future Engineers and Scientists and leaders. Great work and Good Luck to all of them!

Perhaps our guy will choose to comment in here, with more explanation, if he ever gets some time!

Meanwhile, here are a few pictures taken at the event.

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Well, guess what I found out at the Toyground! (Pictures attached.)
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Grasscutter was rootin' around with a digger that he "borrowed" from ... don't ask! So, what is he up to? Well, he started out strip-mining an area just east of the building (there is only one building now). He seems to have hit bedrock before encountering any gold or human remains.

You never saw a guy so happy as this fellow playing around in the dirt. By the way, who would have guessed that there is actually some high quality soil between the grass roots and the rock around here? Look at the giant pile!

His next step was to call in a load of crushed stone and start filling the hole up again.

So, what is he really up to?

This is the first step of expanding the dining/observing area. A concrete pad will be poured and, if the money doesn't run out, the clubhouse overhang will be extended over it.

This will provide a very nice shelter for the Peanut Gallery, as well as a place to set up or work on planes, as well as to prepare food and eat it.

KRCM owes Marvin a hearty thanks for scrounging up the excavation equipment and knowing how to use it.

As I was leaving, Mike was on his way out with a surveyor's level so that Marvin could begin the levelling and tamping of the stone. (It looked to me that a couple more loads would be needed to establish the base for the 5 inches of concrete to cap it off, so he may be at this for awhile yet.)

Marvin - how about an update?

33
General Discussion / Classic Canadian Test Pilot Documentary
« on: April 05, 2018, 07:15:26 AM »
This is a superb film, produced by the National Film Board with Fred Davis as the reporter. Some may recall Fred from his days as host of Front Page Challenge. DeHaviland's chief test pilot is featured. It is hard to realize that some of the air work overlooks the farmland area way out at Downsview (it was sort of Canada's Area 51)! In the segment on the water, you can pick out the old Five Roses (I think it was) grain elevator and the Toronto Island ferry scooting across the harbour. Some of us can, at least dimly, remember seeing some of these state of the art aircraft at places like the old Trenton Air Show. Fine viewing, hope you enjoy it!

https://www.nfb.ca/film/test-pilot/

34
I have had bad experience over many years with various connectors and their installed wiring. The pins may pull fullu or partially out or the wire may break at the pin, usually after significant use but sometimes right from the manufacturer.
This is a real problem with some FPV camera cabling, where they use extremely small connectors and wire and the assembly may well be subjected to constant buffeting by an airflow.

What I have been doing for some time, is to use some of the red RTV and force it into the end where the wires exit and out a little way onto and through the wire bundle. If you have trouble getting a neat looking job, just lick your finger tip and lightly smear the RTV, as it is a silicone and will smooth out without sticking to your finger.

After overnight drying, this makes an excellent strain relief. I also use further support for cabling, especially these really stiff yet delicate ones which may be exposed to handling and air turbulence.

I often use pipe short pieces of pipe cleaners, one end or the center of a short piece hot glued to a structure and the open end wrapped a turn or two around the cable(s). Easy to set up, looks neat, easy to undo and redo, if required. At $Tree, they have packages containing a lifetime supply (unless you are a pipe smoker, I suppose, but then you may have a shorter life anyway?). They are packaged in several colors, so you can even code certain wires or bundles if you wish. Also, these can be handy to code LiPos (Red = needs charging, 2 Reds = suspected bad cell, etc., Yellow = in storage, Green = good to go).

35

https://www.marks.com/en/windriver-2000mah-rechargeable-handwarphone-power-bank-82615.html#82615%5Bcolor%5D=BLACK

In Canada, these are sold through Marks. I picked up a couple this winter, CDN$10 each, intending to use them as hand warmers while flying. They have lots of other uses.

One possibility would be to use as a flight pack on glow or gas plane. You will have a 5.5 volt, 2000 mah lightweight power source. All that is needed it to grab a USB cable, chop off the appropriate end and install suitable servo connector to attach to your receiver, etc. As for recharging, any USB charger will work. This unit has an LED that shows if and when it is charging and will terminate the process at the proper time.
 
If you fly in winter, you could even put one or two of these in a LiPo pouch to keep some batteries warm and/or to prevent your field charger (such as a Cellpro) from going into "Cold Weather" charging mode instead of fully loading your LiPos.
 
I got caught with a low charge on my Mobius FPV camera one day out at thefield, but just plugged it into one of these and was back in business awhile later.


36
It's a nice later Winter (or is it Spring?) day, I have the field all to myself, a great fire in the stove, it's time to play around with a bunch of my flying machines.

Meanwhile, the (Signals Corps?) have been encamped over on the DoD property for several days now, with a large tent and some vehicles sprouting rather interesting looking antennas. So, as part of my flying activities, I did some reconnoitering (fancy term for spying!) of the area.

The Crack Beaver is a light, high performance/wild 3D machine - not the first choice for FPV, but it was begging to have a little go at it anyway. Well, here is a brief video depicting my setup from both aerial and ground viewpoints.

https://youtu.be/4mUzQ4LjgjY

37
FPV at KRCM / Head Tracker - Part 1
« on: February 24, 2018, 07:23:17 AM »
Where's your head at, Boy!?

Haven't we all heard that? Well, some of us may have, perhaps on more than one occasion!

Wilf and I bought HeadTracker modules from SmartFPV. These units originally were designed by Dennis Frie and have a complete DIY writeup  and a very popular forum in rcgroups. This  company has prompt and efficient tech support, a real bonus for some of us.

We are learning and experimenting now. What is this and how does it work?

The module contains accelerometers and magnetometers for the three axes. These are monitored by an Arduino. Its output is a PCM pulse train that provides commands to up to 3 channels within the stream that will eventually emerge from the rc transmitter.

The unit is cabled to the Trainer port on the Tx. Whenever you select the Student mode via a switch, the HT is in control of whichever channel(s) you had selected. If you de-select, the affected  channel(s) are immediately returned to neutral and control is relinquished to the Tx.

So, the idea is to mount the HT on the FPV goggles or helmet. Then, you connect your aircraft's camera moving servos to one or more channels - normally, for Pan and possibly for Tilt, although Roll may be of use in some situations. 

When head tracking is enabled, the camera will follow your head movements. It's that simple. You get more of the feel of actually being in thr aircraft while flying, as well as being able to do ground ground obstacle checks while taxiing under the hood. Nice,

Well, there can be a lot more to it, but that gets us started!

Meanwhile, I have another HT on order, to serve as a spare as well as for another, unconventional use of thr technology, or perhaps to pass along to someone else who may become interested in trying out this stuff. I will put a little writeup in here as my "secret project" progresses, warts and all.

38
General Discussion / REAL Indoor flying!
« on: February 21, 2018, 10:53:18 AM »
Everyone that hangs around our Toyground knows the local masterful Circle Flyer. His name starts with a "D" and has a "Wayne" in it (perhaps that is his alter ego?). Unfortunately, the poor fellow has an actual job, so he cannot come out and play as often as some of us n'er-do-wells. We have often wondered how he keeps his tenuous grip on sanity.

 Well, here is one possibility! Perhaps we can get an invite to slide on over to his house, have some beers and watch how he keeps in practice?

https://www.youtube.com/watch?v=LaAhHLFerRc&sns=em

39
General Discussion / Real Indoor Flying!
« on: February 04, 2018, 09:18:40 AM »
This is one of the best examples of indoor flying. Note, all that is required is a standard sized basketball court and some really great ideas:

https://www.youtube.com/watch?v=C46SIbQyvVM&feature=youtu.be

40
This is a copy of the posting I made in another Forum, where the BGL-6G-AP GPS-capable stabilization system is discussed, Wilf and I have these units and have done a lot of experimentation with them.  Don't worry, there really is a video in here, at the end of the discussion.  :D

                                      -------------------------------------------------------------------------------------

This may be of interest to others:

I have had the unit on a flying wing for a couple of months, as a test bed. Yesterday, we were flying in extreme winds - significant wind gradient plus high level of turbulence. (Don't worry, there is a Video link at the end of this).

I set the plane out a somewhat downwind and the selected RTH. It immediately oriented itself and then flew upwind toward the Home point, as expected. I had, let's say, 1/3 throttle to maintain good progress.

Aside: the BGL's Return To Home control strategy is to self-level if necessary, head straight back to its Home coordinate, then circle or sometimes follow a figure-8 pattern centered on Home. It will attempt to maintain a constant altitude, provided it can maintain airspeed; if you chop the throttle, or are a pure sailplane, it will gradually lose altitude and may even stall or perhaps snag a nasty tree or such before you may regain control.

The plane arrived in the vicinity of Home and began its circle. Now, as one would expect, there will be some drifting and the resultant path over the ground would be somewhat elliptical. However, to the airborne pilot, maintaining a constant bank and airspeed will still result in a circle within the air mass. Now, one would expect the RTH function to be trying to maintain a circle with respect to the ground, as it is using the fixed Home coordinates and its GPS to set up a fixed radius circular or figure-8 pattern w.r.t. that ground Home point. Therefore, I expected to see it altering its bank angle accordingly, within limits, to try to retain its circular orbit. Not so much!

With this strong wind, the plane made its first turn and flew WAY downwind before beginning to turn back to Home. For awhile, I could observe it making some control corrections, probably experiencing some turbulence even at its "3 trees" altitude. I really began to wonder if something had gone wrong, but it eventually managed to turn back and beat its way toward Home. I had been just about ready to switch off RTH and take over with full throttle in order to get back. Well, she did make it back without my interference, but I had to use a high throttle and I watched as it sort of zig-zagged along its path back.

I repeated this test, with exactly the same results.

Now, this was a bit disturbing, but it was a good learning experience.

The BGL limits its bank angle to something that would be a shallow to medium turn while in RTH, regardless of its reference to the Home coordinate.

So, if I have this unit installed in, say, a sailplane that may not have terrific penetration and if I were to lose sight of it, I better crank up the motor and hope! As we know, you normally thermal in a circle within the rising air mass which, in turn, is being shifted downwind. Think of a funnel that is tilted and you are keeping inside of it. As you go higher, the migration downwind is likely to increase, as will be the effort to beat back home once you leave said thermal, especially when you encounter the surrounding sinking air.

In considering using the RTH feature under Failsafe, the question is, does one kill the power or set it to something like, say, 1/2 throttle? Not an easy answer, as circumstances vary. Besides, you may have no choice anyway! Not all receivers handle a loss of signal the same way. and ESC's tend to shut off the throttle if no signal is seen for a very few seconds. So, all you can do is hope for the best! Also, you may want to bump up the throttle immediately upon activating RTH, if you cannot see the aircraft or if you suspect that it may have failed safe into that mode. If you in no-power soaring mode and go into RTH, the aircraft may not make it back, especially if it has to do much banking to achieve a straight line flight path and/or if it does a lot of the weaving back and forth that I observed. Of course, you want to know that your airframe, especially a large foam sailplane, can stand high airspeed and gust loading combined, or it may relocate itself in pieces!

I think about this stuff. It's all part of this weird hobby. We have so much terrific technology available, it is fun to learn what it can, and can't, do.


https://youtu.be/NW2R5hyj3nA

Thoughts?

41
General Discussion / Vortex Generators
« on: January 08, 2018, 10:56:41 AM »
Vortex Generators (VGs) have been around for many decades. I first noticed them on airliners I flew on back around 1970. You may notice them on smaller airplanes, especially of the STOL variety such as some bush planes.

About four years ago, my son started flying a Cessna 206 floatplane for his client. He installed a VG kit on it. The kit was a properly engineered and certified modification, cost $2500, which he installed over the course of a day or so. There was some huge number of these things, epoxied onto the top of the wings and onto the underside of the horizontal stabilizer. Their effect was to improve airflow separation over these surfaces. This resulted in approximately 5 knots lower stall speed or could allow a higher payload capacity. Floatplanes often have to squeak into, or hop out of, very confined areas with nasty trees, etc., in close proximity. The VGs were the one thing that could be done to improve things.

At that time, I became interested in finding out the science of VGs and how their effects are investigated and quantified. The information is out there, and there is fluid dynamics math, but some of it left me a bit bewildered.  I like pictures and videos! (Be patient, there is one coming up shortly...)

More recently, VGs started showing up on RC models. The Visionaire, Carbon Z Cub, Scimitar, all of which I have owned, are just a few that come to mind. Do they work at this small scale and low Reynolds Numbers? Hard to quantify, but experienced pilots report that they do make a difference, at least on some airfoil and airframe configurations.

I found this video to be enlightening. The fellow is admittedly not an aeronautical engineer or fluid dynamicist but he has done a terrific job of explaining things and documenting his experiments. The RC plane test near the end is a particularly compelling argument to accept the value of VGs and not just grab the Exacto knife and slice them off (as some amongst us may have done in the past!).

So, please sit back and check out this:

https://www.youtube.com/watch?v=eP-YUDe9HF0&feature=youtu.be

42
Plans, Projects, Building and Flying Tips / Balancing Stuff
« on: December 14, 2017, 11:35:19 AM »
At least some folks make an effort to balance their props. Others just trust that things are OK as bought - count me in that sorry lot! I use APC props exclusively, unless something else was provided with the airplane I bought. I find them to be very high quality and well balanced. I have had a little, relatively unused, balancer thingy lying around in my flight box for "about a hundred years" (a FlyPaperism). Then, a couple of years ago I sprung for a more expensive and capable unit. Well, I had paid for it so I just had to try it on several of my APC props; I never could determine that I needed to do anything to improve them. Meanwhile, I got the Crack Beaver and its somewhat unusual props. When I checked them, they needed a LOT of balancing! So, perhaps buying the balancer was worthwhile, after all?

What about balancing electric motors? What about the balance of the whole motor+adapter+prop assembly? Well, I came across this very interesting article. He uses an iPhone app to do this. I have an Android tablet and phone, but, there are several apps available for Android which can do vibration or seismic analysis.

I hope someone else finds this interesting and perhaps even useful:

http://www.itsqv.com/QVM/index.php?title=How_To_-_Motor_Balancing

43
General Discussion / Bulk Orders
« on: December 11, 2017, 08:54:53 AM »
Occasionally, two or more flyers get together to order items from places such as Hobby King, Banggood, etc. It can get a bit messy estimating what it all may cost and later on, sorting out who owes exactly what. Attached is a spreadsheet that I created and offer to anyone else to use. 

Caveat! Although it has been thoroughly tested and I trust it, I cannot guarantee it. If you use it, check the results carefully to ensure that it is correct. This is a tool, not a replacement for your own judgement. If you find a problem, please Reply in here so that I may correct it.

Suggestions:

1. Download the attachment. I use OpenOffice and have saved it in as an older Excel file, so it should be readable by any spreadsheet package. If not, let me know and I can provide other versions.

2. Play around with it.
 The cells marked in RED are available for you to fill out. If your order is priced in CA$, leave the Exchange Rate as 1.0 and enter the Item Costs under the US$ -  everything ends up in CA$ anyway. If it is a USA order, set the exchange rate, e.g., .71 on a recent order I processed.
 Leave the BLACK cells alone. The one exception may be under the Shipping/Handling distribution. For example, one fellow orders a kit, or perhaps some LiPos, while another one or more just order some servos or other small stuff. I would divide the  Shipping/Handling
total charges in a fair manner and place those amounts into those cells.

3. If you have played around with this Template, make sure you do not Save it, else some future use may result in a garbage result due to an item or formula having been modified.

 If there are more Items or Buyers than have been set up on this sheet, it could be modified - very carefully! Perhaps it would be better to simply start a second sheet to handle the excess Items or Buyers. Then you divide the Brokerage, GST/HST and Shipping/Handling charges between the two sheets.

 Sometimes, I think that I might want to order something from Supplier X, but do not need it right away or would like to combine my items with someone else. I go to that site and add my stuff to my "Cart", then leave the site. Yes, I will likely get pestered once or twice that I have an incomplete order. I just ignore that, for now. Later on, another person(s) wants something and we decide to place a bulk order. I encourage him/them to do the same thing, i.e., stock up his/their "Cart". Then, if he/they can scrape out and email me a copy, I can go to my "Cart", add his/their stuff, get the estimated Shipping Charges, etc. and transpose the details to the spreadsheet. When we all agree,
I process the order. Upon delivery, I check and update the spreadsheet to reflect the final Exchange Rate, Taxes, etc. 

44
General Discussion / Servos - how they work
« on: December 06, 2017, 06:34:27 AM »
Here is an excellent and easy to understand video that shows what goes on inside that tiny electronics package in every servo. There are other videos that depict the mechanical actions. Sometime, grab an old servo and pull it apart to see for yourself. I have repaired many servos, as most likely cause of problems is gear damage due to binding or otherwise overstressing the system; for most servos, from the cheap Hextronic ones through to the most expensive, you can buy the gear train and spend a few minutes to restore one to new (sometimes better than new!) condition.

https://www.youtube.com/watch?v=tsrAP8EgcbQ&feature=youtu.be

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The attached document was prepared by the Zone Director and Club Presidents.

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