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Topics - Deerslayer

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241
General Discussion / Slope Soaring
« on: April 21, 2011, 06:31:07 AM »
I used to do some slope soaring, about 30 years ago. This can be a relaxing and/or exciting aspect of aero-modelling.

A number of our Members have some sort of sailplane, typically e-powered with retractable props, such as the Radian. While not designed specifically for slope soaring, you can have lots of fun with these. As well, you will learn how to use real piloting skills to accomplish long flights, rather than just jamming on power whenever you lose altitude. It really is rather boring, I find, to just drag a sailplane through the air with a prop like a powered sport plane, rather than via one's soaring skills. Knowing that you WILL land very soon, unless you read the air and apply your knowledge and skills well, is a great part of what soaring of any kind is all about. That's where the rewards lie.

 All you need is a hill or ridge or bluff, plus some wind. The latter can be anywhere from a gentle breeze to a near-gale.

How it goes depends upon the type of sailplane and the pilot's experience. Initially, I used to slope with a rather unlikely and close to unsuitable combination - a 8 foot span, poorly-trimmed Olympic II rudder/elevator thermal sailplane being driven by an absolute beginner who really didn't know much about what they wrtr doing. Nevertheless, things went reasonably well and I had many hours of enjoyment.

Fort Henry is a superb location. Typically, we have SW winds most days through the warmer part of the year, so the west side of the hill is the active location. (On some less frequent days, usually in the fall/winter/spring seasons, the gentle north side is the place to be, and is also a perfect place for initial test glides of a new sailplane on any calm wind day.

Back in my slope soaring days, the Parks folks kept the entire hill cut and groomed. Very nice to launch and then sit back and play in the air. Today's situation is that this is a hayfield, but still an excellent place to fly - I have no idea what kind of critters prowl around in the long grass, so I might be less inclined to sit or lie down there these days.

I have often looked at my 20 year old Taube and thought, "Hmmm, take off the engine, bolt on a foam nose nose section with suitable weight inside, take off the landing gear and voila! a real bird-like slope soaring machine, at least for moderate to strong wind days. The Taube handles superbly, it has reasonable gliding characteristics, at least by slope requirements and it has beautiful form.

Another possibility, which I will definately try, is to take one of my Bat wings, just remove the prop and try it out. Many slope soarers are plank wings, they handle and penetrate very well, yet mine will slow down to a crawl for landing. If I like the way this works, I may build a nose to snap on in place of the engine and have a real dual-purpose machine.

So, does anyone else have some slope soaring interest? If so, perhaps we could get together sometime to give 'er a go.


242
Generally speaking, an aircraft will fly better if its basic geometry is correct. Amongst other things, a fuselage should be perfectly straight.

Many years ago, after having almost completed a fuselage, I realized that something just wasn't right. Yes, I had built it right on top of the plans, properly pinned down, yet it seemed to be somewhat curved. It was! So, I lifted it off and carefully checked the plan with a straight edge. The center line, rather than being perfectly straight, was considerably bowed! Rats! Of course, the bulkheads and fuselage sides were properly matched to the plan, equidistant from this center line, so the resultant fuse was a mess!

What to do? Trash the fuse and start over? Ignore the problem and finish this banana, as is? Unglue, cut, refabricate some parts, bend and fill and attempt to correct the problem? I chose the latter, and the finished product looked perfect. No real feeling of satisfaction, however, it felt more like a salvage job than a major achievement. I never did feel good about that plane, even though it flew well, as it reminded me of my cobble to get back on track.

Since that time, I have always checked the plans for accuracy, particularly the fuselage and spar. Amongst minor deviations that I have found, my Senior Telemaster had a curvature on its 4 foot plus fuselage center line that amounted to 1/4" at the mid-point. Just recently, I set about laying out the fuselage for a very large (11 ft span) sailplane. This fuse is almost 5 feet long and I found about a 3/16" deviation at the mid-point of the center line.

This is a more common problem than one may think, and it is not a design error. By whatever means plans get reproduced, they may get distorted. I suspect that it is simply slippage in a copying machine. Realize this possibility, verify accuracy of your plans and then deal with any deviations from normal.

Once you find such a problem, it is no big deal. Simply find the  TRUE center line, and reference all components placement from there.

When I lay out the plan, with wax paper on top of it, on my building board, I set up a simple snap line:

Place pins at the extreme ends of the original center line, then stretch a sewing thread tightly to them. Voila, you have your new center line. You may choose to mark in this new center line, or perhaps just add a couple more pins along its length to retain the thread in position while building on top of it. Check it with a good straight edge. Leave the thread in place and go ahead and build. Mark your bulkhead centers and ensure that they all sit on this new center line.

Enjoy your new, straight as an arrow, aircraft!

243
Plans, Projects, Building and Flying Tips / Lite Ply - what is it good for?
« on: February 28, 2011, 07:52:00 AM »
Absolutely nothing! at least the cheap crap that shows up in ARFs and many kits.

But, that's just my little opinion.

I hate the stuff, but is showing up in most kits, all ARFs and so it is pretty hard to ignore.

Combine its inherent flimsiness with the fact that it get used in places where you really need uni-directional strength yet half of the plies go at 90 degrees to that desired line and you start with a minor problem. Now, add in the concern that the wood itself is very brittle, not very strong in tension, pulls apart easily and seems to be stuck together with almost no adhesive and it gets even more interesting. Then, you (or the ARF elves) build an airframe with it, probably using CA (which has questionable stickum power on a dry wood such as plywood at the best of times) and there you are!

Oops! I almost forgot something.  In the spirit on building electric aircraft 10+ years ago where every milligram of weight was a burden to the weighty NiCD batteries and brushed motors to drag up into the air, people punch massive lightening holes all over the place. Many are in EXACTLY the wrong places - they compromise the strength of the airframe. Sometime for fun, take a big piece of balsa or liteply and punch out some lightening holes, then weigh the holes - you may have second thoughts about just how much of this lightening technique to engage in.

The manufacturers have completely ignored the modern era, where weight savings are nice but are way down on the list for many owners, well after durability. (But, these flimsy structures may generate future sales?)

I have limited experience with ARFs. I have flown lots of them, but only owned one. On many ARFs that I have examined at our field, I find that the landing gear gets bolted on with massive stainless steel bolts, threaded into tiny plywood blocks that are, in turn, stuck into ... you guessed it ... an "enlightened" liteply structure woodpeckered with giant holes. WHEN (not if) you bounce hard or land in the rough, it all comes unravelled - if you are lucky, the gear doesn't come back and take out part of your wing as well. Repairs will require beefing up the whole area, and adding decent support blocks plus plastic bolts - unless you really enjoy repairing after ever few flights. You may find out that you may have to go quite a distance to find a substantial structural part to attach to.

I have a 16? year old Seamaster. Yes, Gary has airplanes that do survive his style of flying for extended periods of time - isn't that amazing?. This is a terrific aircraft, one of my all-time favorites, great on snow/ice as well as in the water or even on wet grass. It is no Hangar Queen, and it has been FLOWN HARD.

The Seamaster looks sturdy as hell. It is NOT an ARF (although I think there is an ARF version available now). The wing is really tough as nails. The fuselage LOOKS tough. Well, I have recently had a couple of minor incidents - due to a mischevious electrical issue (DO NOT use switches that have been around for many years an that have seen all kinds of flying conditions). I did a fuselage repair - guess where? Right at the area where one needs very high strength, this lite-ply fuselage has giant lightening holes! With a T-tail, especially with the engine pod up in line with the whole affair, you have great buffeting and vibration. This is a highly aerobatic aircraft, so the torsional stresses, combined with large flight and maneuvering loads, concentrate stress just ahead of the tailfeathers. I was always used to seeing the tail movement when the engine was running on the ground, but it always flew well, so who cares?
Well, then the tail partially separated, I did!

Sure enough - the breakage was right through the thin area at the lightening holes. The wood is brittle as aged twigs. So, I added some more acceptable plywood plates on each side of the fuselage exterior, used Weldbond (NOT CA!) and recovered it.

My Seamaster now exhibits very little tail vibration and flies better than it ever did. Point made!

Yesterday, prior to taking the Seamaster to the field, I noticed a liteply bulkhead crack and a broken joint where it butts the fuselage at the rear of the wing saddle area. So, I have been doing more through inspection of any other accessible joints, so far so good. To repair this bulkhead and its attachement, I cleaned the area with acetone (I had coated all surfaces with Balsarite at build time years ago, for fuel and water protection), then spritzed the ply with a water mist. Then, I brushed on some Ultimate (polyurethane) glue. finally, I spritzed the area again with window cleaner. Now, I have a nice and tough repair, with a great fillet formed by the expanded glue. Good to go for another 16 years - I hope ...


Just sayin ...





244
Any KRCM Member can post pictures in here. Please start, or follow the appropriate Topic and provide a brief description of the Event, Location or Activity you are displaying.

245
Plans, Projects, Building and Flying Tips / Bat Wing
« on: February 21, 2011, 12:52:53 PM »
Some folks have seen one of my "Bat Wings" fly at our field (pics attached). I can unreservedly say that this is some of the cheapest, most exciting and skills-developing aircraft that I have flown. And, it looks a lot more difficult to fly than it is - it's really a pussy cat when you back off on the power and it lands like a sailplane.

Recently, I flew it at Brockville and was astounded to get requests for the "plans"! What plans? Well, there are some basic measurements, an airfoil template and some pictures, that's about all - so far.

This machine is really of the "combat" variety, i.e., tie a short fishing line plus some crepe paper onto it and find someone else with such a setup that you can do battle with. It flies just as well with the streamer as without, albeit a bit slower and easier/smoother under full power. It is so small and light that it would be hard to really "kill" the plane itself or damage either the motor or onboard gear.

I have built 3 or 4 of these so far; 2 are of conventional balsa ribs/sheeting, while the third is of white foam, partially sheeted with balsa. My next one will probably be blue foam ribs, with either balsa or some sort of cardboard sheeting. If I do this, and if I cover with cardboard, I will not add covering material to the body, just spray on some flames or whatever plus a clearcoat, at least around the slime region.

These things only require standard (like S248) servos and 3 channels. If one had an old 4-channel radio, without mixing, then you would just buy a little mixer thingie for less than $20 to make the elevons work. This would be a good use for your older 72 MHz radio gear.

THE ENGINE for this is the little powerhouse that OS makes, the LA 15, swinging a 8x4 prop and supported by a 2 oz tank buried up in the D-tube of the wing.

Now, could this be e-powered? Well, the verdict is not clear. I built one and my son Dan put an electric on it. However, he found it pretty uncontrollable. The problem was C of G and he did not pursue the exercise further, so I converted it to glow. About that C of G problem: he did not bury the battery pack right up front, as the ribs were solid and he didn't get around to hacking out space. To try to compensate for the weight distribution, he slung the little motor out quite far. I am 100% convinced that one must have the C of G exactly at the spar and the prop must be at exactly the right distance from the leading edge. That can probably be accomplished, and I would like to see someone else try it.

So what's the point of all this? Well, does anyone else have an interest in building one of these? If so, please let me know. I am willing to provide directly, or perhaps I will post in here, some pictures, the airfoil template, etc. and appropriate measurements. Or, since I have already had some requests, I suppose I may do something a bit better to pass along.  I would, of course, supply the recommended and safe launch instructions, that being critical to success and having been learned the hard (ouch!) way.

Any interest? 

246
General Discussion / Fuel
« on: February 20, 2011, 08:58:16 AM »
Here is my attempt to re-open the age old controversy: castor oil or no castor oil!

Oil choice is in the realm of religion - it's all a matter of opinion, but my view is the only one that is correct. Anyone who has owned motorcycles and checked into the forums will see the endless "oil wars" up close!

OK, I am  not really trying to start a fight. Besides, it seems like we "slimer drivers" are reducing as a percentage of the overall r/c powered aircraft community and the older ones have already made up their minds. However, in case there are folks starting out, here is what I have experienced in over 20 years of using "synthetic" rather than castor oil blend fuels.

I have been using Cool Power, the same regular sport fuel with 15% nitro, on engines from .15 up through 1.20, both 2-stroke and 4-stroke. IT has worked well for me, after being the first "synthetic" I tried, and I just never felt the need to experiment further  A lot of engines, a lot of use, some from right out of the box, others purchased after various stages of use/misuse. One helicopter, with a SuperTigre .34 that just would not run reliably, immediately transformed into rock solid reliability when we changed to this fuel and a different plug type.

The ONLY bearings I have ever changed are: one set in a Saito .56 which I bought new and put through a lot of use for a couple of years and which made a lot of rumbling noises before it eventually ate a bearing; a couple of engines which I purchased used and were gummed up almost solid with the castor residue. One of the latter was formerly owned by my much older and more experienced friend (remains nameless here) who steadfastly maintained that you absolutely had to have castor in your fuel. Others will say that if you ever get a "lean run", through deliberate or accidental overly lean mixture, only castor will save you. Well, I have had that happen, too, and with no obvious detriment to my engines.

A couple of used engines that I have looked like they had hardly been used, yet when I popped them open, the bottom end and bearing areas were almost solid with castor crud. Sometimes, I would almost have to chisel and blow torch the carb throttle body to get it free to move.

I never use after-run oil, except in the case where I remove an engine from an airplane, knowing that it will be stored for quite awhile. Then, I may squirt some 3-in-one, some ATF, or better still, some Mobil 1 synthetic 10W40 motorcycle oil that I happen to have handy. Otherwise, the plane is either sitting horizontally, or preferably hanging from its prop. Some have hung for as long as 3 years, been dragged out to the field and started on the first or second try. Usually, some nasty- looking crap comes out of the exhaust at first and then it is clean and clear. That would be any crud or corruption that had collected in the lower or rear of the crankcase - and therefore NOT in around the bearings.

So-called synthetic oils (there is a name that gets badly abused by manufacturers for marketing purposes) have 3 very admirable qualities, all of which are important to me. They really cling well to the steel parts of the engine. They withstand very high temperatures (if you delve into the science, you will find that they maintain film strength at much higher temperatures than do vegetable oils - like those from the castor bean - or the so-call "dino" oils. And, finally, they maintain their viscosity grade over very wide temperature ranges, including toward the lower end of their design range.

Our model oil does not have to last long - apart from the film left coating the bearings or sleeves during storage, the rest of it is flushed through the engine in milliseconds.

I have rarely ever changed a glow plug in 20 years! Prior to my conversion, I used to be frequently changing crudded and unreliable plugs fairy frequently.


Remember, the non-vegetable oils you buy today bear little resemblance to what was manufactured 10 years ago. That is one area where technology has made giant leaps forward. Do not compare things as they were in the gold old days.

OK, bring it on!

247
Plans, Projects, Building and Flying Tips / Penny Tech
« on: February 14, 2011, 07:10:56 AM »
This would be a good place to post some of your really good, but cheap, ideas for making one's modelling life easier.

248
General Discussion / Winter Flying
« on: February 07, 2011, 07:17:08 PM »
Well, since it seems like we have it for about 6 months or so some years (this being one of them, it looks like), why not enjoy it?

Have a good location to fly from, dress warmly and ENJOY!

As the real estate folks say: Location, Location, Location. Winter works with us in this regard. As well as our own Club field, there are almost unlimited possibilities for great flying, safely away from other people and/or buildings - and perhaps even away from those pesky trees. (My personal airfield is our bay on Lake Ontario, with a vast expanse of clearance, yet I tagged the only tree within miles the other day - D'oh!!!)

Although I really enjoy flying here, it is still better to go out to the KRCM Field when the handful of die-hards are burnin' up the air out there.
I miss the "good old days" when, on any typical winter Sunday, the club house would be packed with flyers and the pit area crowded with airplanes.

I have attached a panorama of the Preston Cove Airfield, which is just outside of my "hangar". The nasty tree that bit me is out on the point to the left - well outside of the turn to final approach, unless you suffer a momentary brain fade and screw up said turn! In fairness to me, I was battling a control issue (later found to be a defective on/off switch). At least I have a couple of chainsaws nearby, should I ever need to get more serious about a rescue.

Please tell us about / show us your Winter Flying activities, survival tips, etc.

249
General Discussion / What's on YOUR Building Board?
« on: February 02, 2011, 10:38:29 AM »
Let's see what you're working on. Nothing inspires a builder like seeing what other folks may be up to. Often, a project is most interesting to an observer while it is still under construction. That is the time we get to see, and learn from, what others are doing and how they do it. Questions may even be asked. Answers given might help you, or others, to improve building skills and techniques.

So, come on - don't be shy!

250
General Discussion / What's in YOUR Cave?
« on: February 02, 2011, 10:35:47 AM »
Everyone assumes that model airplane designers/builders live in caves somewhere, occasionally emerging into the world to try out their latest creation (or fix-up, following a prior excursion). So, what does your cave look like? Here is mine (attached photo).


A couple of notes:

First, this picture was taken by combining 3 successive shots into a panorama, using AUTOSTITCH. This program is available, free - just Google for it. It is very useful, usually for outdoor scenes but also for situations, such as in my attached picture, where you have a confined space. Yes, there will be some distortion, but even that can be largely taken care of. (I have some learnings which I may try to pass along sometime in that area).

Next, a couple of the "features" of the Preston Cove Hangar:

My main building bench, the latest of many that I have messed around with over 30 years, is moveable. It is approximately 4' x 4', so it can support a fairly long wing or fuselage if that is set down diagonally. I seem to be constantly moving it around, partly because I have a TV in the corner but mostly because I tend to move my bench rather than the pile of tools I have cluttered around on it, as I am working on different parts of a project or on a couple of smaller projects.

I recently replaced my fixed flourescent light arrangement. I McGyvered an adjustable system, cobbled from bits and pieces of wood, bolts, bungee cord, a diver's weight, etc., I can rotate it to relocate it totally within a couple of feet radius, rotate the light itself and raise or lower it by about 2 feet in total. It is all counterbalanced, so I just push it around as desired. Why? I got tired of often working in shadows on my projects, or needing just that little bit of extra light for fine work. Yet, a table-mounted lamp mount (like on my other table, in the foreground) always seemed to be in the way. I have enough problems, without making my building work any more difficult!

But, that's just me: someone who is never satisfied, obviously has too much time on his hands ...


Not shown in the above picture is the rest of the clutter in my "hell hole" as the superior resident (SWMBO, as you married guys would know) of the house refers to it. Also, the big door through which I walk out of and down to the water to fly on floats or skis, depending upon the seasons, on one of the world's greatest airfields - Lake Ontario.


(Rolly, we should do a set of pictures and descriptions of your laser cutting operation, including how one goes about setting up something for cutting. The airfoil templates I drew up and you cut are one example of how easy it is and how it all works.)

So, what's in your cave?


251
Plans, Projects, Building and Flying Tips / Let's all stick together ...
« on: February 02, 2011, 10:29:17 AM »
 ... but perhaps not too closely! Huh?

This topic may be about adhesives, and some tips or techniques for their use. Please add your thoughts, comments, techniques, etc.


252
General Discussion / Major Fun !
« on: February 02, 2011, 10:27:57 AM »
Check out the video at this link (there is a YOUTUBE video in the first post):

http://www.rccanada.ca/rccforum/showthr ... post790079

I flew at Cobble Hills (outside of London) a couple years ago, having met Ted Banks through his column in the MAC mag. I never saw a bunch of guys having so much fun! Every Sunday is COMBAT at the Cobble Hills Fighter Group's field. Some Coroplast, and/or foam, a .26-size engine and some raw courage and you are in the game. Surprisingly, mid-airs seem to be a rarity during normal Sundays, considering that the whole point of the exercise is the cut someone else's streamer as numerous pilots mill around in the fray. These guys have some serious grudges with the Humber Valley (west Toronto) and, I suppose, anyone else from anywhere that thinks they are up to r/c combat. That is the subject of this video. The Albatross's are the design of a Humber Hawks chap, the Fokker D.VII's and the SE5's are a Cobble Hills fellow's idea. Any others ... well, who knows? Then, there are the WW2 planes, a separate Combat class. The only difference, as far as rules go, is that WW2 planes have no landing gear and are hand launched, whereas the WW1 planes have gear and must take-off from the ground.

Some of their planes look pretty ratty. Those would be the ones to watch out for, methinks, as you are probably looking at a veteran of many fights and fights. Others look "real purty", all smooth and painted up like a "workin' girl" on a Saturday night. Such aircraft probably will lose some of their newness rather quickly, if they aren't careful.

And, if you think that their planes are "interesting", you would be really intrigued by the (manditory) flying helmets they wear out at the flight line. Very strange - the pilot wears a helmet of, to my view, rather dubious protective value while the (manditory) observer dude doesn't have to. Either this is to make sure that the observer keeps really sharp, or that he's just a nuisance of low value. By the way, contrary to what some think, this style of Combat is no more dangerous that any other flying we do and injuries are unheard of.

That old expression, "There are old pilots and there are bold pilots, but there are NO old, bold pilots", comes to mind. Some of these guys are rather old and very bold and you wouldn't want to take them on in the air, for sure, so I think some of the Cobble Hills guys and their little friends from elsewhere have beaten the odds on that bit of wisdom!

Why aren't we doing this at KRCM?

253
I have a write-up on the subject of C of G which I will now post. As well, I will post a spreadsheet, in case someone else finds it useful. Feedback is most welcome, as I am always looking to improve.




Note: If you do not have Microsoft's Office components, i.e., Excel and Word, do not dispair! You need to get OpenOffice - and it is free. You just download it from http://www.openoffice.org/

If you wish to publish something, say, a technical article, and post it so that anyone will be able to read it, the best approach is to put it out as a .PDF file. You do not have to buy the full-fledged Adobe package to create such a document; you Export it as a .PDF from within OpenOffice.

If anyone is confused, or wants more information about this, just contact me and I will attempt to help you - or find someone better qualified to help us both!


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