SMALLnet post363

Of primary interest is the listing of construction articles that have appeared in most of the model magazines over the years. Dave's site has been mentioned before, but it is worth repeating. < http://members.xoom.com/dlivesay/ >.

Ain't gone missing, just been sort of quiet around here for a while. Anyway, I saw Dare's big ad in the latest FM and they are peddling a profile P-36 Hawk ukie - for Speed 400 electric power.

Well, I have all the bits and bobs needed; my local hobby shop is (hopefully) getting me a kit.

Now - what is the world's favourite control line for small models? Call it a very quiet 1/2A and that will do. Don't want to mess with steel wires, surely the world has moved on from that white thread stuff we used to use?

...Dereck, there's a kind of fishline called Spider Wire that has all the characteristics you could want for small control line flying. The stuff comes in various sizes and at least two types; the best for C/L use is "braided" and WILL NOT STRETCH.

My son David (and many other free flight flyers) uses this for dethermalizer hold-down purposes, and I've heard from R/C flyers who like it for pull-pull controls.

Spider Wire isn't cheap (I believe the lowest-price US source is Wal Mart) -- however, its properties are AMAZING.

The white Dacron "thread" that Sig has been selling for years as 1/2A control line isn't bad in lengths under say 30 feet. I have used it for years for teaching youngsters C/L flying, because it stands abuse better than .008 steel cable. And it's quite low- priced -- 60 feet for $1.75. [JW]

What with the recent discussion of compressed air flying, I thought I would mention some of my efforts. In addition to some FF C-A flying, I also have a small R/C glider with about a 32" span. It was mated to a 1 liter bottle and an Air Hogs motor. All up weight is 7.2 ounces, and flight duration is about 90 seconds in still air.

While the installation wasn't pretty, it did answer the question of R/C flying with an Air Hogs motor.

Have any of you kids out there tried the Ballooncraft indoor toy described in the current AMA magazine? It looks like lots of fun if you can afford the helium. There's a website with a video of the thing flying (floating) at < http://www.ballooncraft.com >.

For you CO2 cartridge nuts... there was also an Aqua Jet boat kit made by Scientific. I had one of these things and had no trouble accomplishing a near-instant release after popping the cartridge. The only problem with the thing is it was really overpowered and usually would never touch the water after it was released until the power ran out and it would fall back to the surface. In other words, the thing was a boat-shaped unguided missile.

I have a couple of Hoosier Whirlwinds I got from Bert Pond, and they both seem to work quite well. I had to return one to him for rework when it did not perform like the other one seemed to. Anyway, the second time around it ran great. So far I have managed to snap a prop blade once or twice, but with no damage to the Hoosier. Just dumb luck I guess.

A word of warning on those thin brass tanks that a few C-A purists use: If you can't store them with a small amount of pressure inside, leave them completely empty with the valve open. I once had a closed empty tank partly collapse due to a change in the barometric pressure.

One of my Hoosiers runs on a tank made of beer cans epoxied together (made according to an old model magazine article). It was constructed before the plastic pop bottles were discovered. Anyway, I was really nervous about filling this tank for the first time, so I hooked my air tank (old Freon container) to it and put the tank inside a closet with the hose running through the crack in the nearly-closed door.

At about 80 psig there was a very loud BANG, and I thought that one of the epoxy joints had failed -- but the thing was holding pressure. When I looked inside the closet and examined my tank I discovered that the normally concave ends of my beer cans were now convex. I've had up to 180 psig on this tank with no problems.

This tank slips neatly into the fuselage of my 6' Hobart cabin ship which flies at about my walking speed.

Speaking of tiny diesels, the late Malcolm Whitman Jr., once loaned me, for a look-see, a tiny jewel by name of "KALPER". The bore was about 1/8". Since he'd borrowed it from somebody else for me to look at, I didn't run it, but it was a mighty cute piece of work.

Input needed: Does freezing NiCADs harm them? The reason I ask is that a couple of small electrics have been left for 2-3 years in my garage. Over-winter temperatures drop as low as -20F -- but the cells appear to be all right.

My reasoning is that since the electrolyte is sodium hydroxide in water it may or may not have frozen since the casings aren't swollen. As far as flying NiCADs in the winter, I've never noticed much difference in performance -- but of course the cells are indoors, or in the car until just prior to flying. Air sluicing in the cooling louvers must be, some days, around 15-20 degrees, but the battery is still warm at the end of the flight -- although not as warm as in the summer.

I have built quite a few compressed air motors in the past. The classical rotary valve type is not difficult. Trick is to start with fishrod ferrules for piston and cylinder, and lap them together to a "popping" fit. The most important element is the rotary valve; any leakage here saps power and duration tremendously. While the rotary valve is the classic and it works quite well if well built, it still is not the most efficient thing because the airflow goes through it to the intake pipe at top stroke, and then reverses and comes back through it on the exhaust stroke. Some old timers drilled a few small holes in the cylinder to uncover at bottom stroke to relieve some of this back pressure.

I came up with a rocking valve that used a flexible air line that went back and forth with it. Worked great. It was a further development of the oscillating cylinder engine -- except that the cylinder did not oscillate. For anybody who is interested, I published a single-cylinder version as the "Typhoon" expansion engine in the September 1960 issue of American Modeler.

There was a model kit sold under the name of "Ray Rocket", sometime back in the 50's. As I recall it, it was a semi-pylon with a CO2 cartridge buried in the pylon. I never saw one fly, but was told they flew fast and furious for a very brief time. There was some kind of piercer gun that held the plane by the cartridge nozzle, from which it took off in a rush when the gun fired a phonograph needle into the seal. I can't imagine piercing a cartridge first, then trying to hand launch.

...Roy, thanks very much for jogging my memory with your mention of the Kalper! My late friend Dick Schumacher -- one of THE pioneers of small R/C flying -- had a Kalper in a tiny FF scale "Rose Parakeet" biplane. It was published in MAN 50 years ago, and I'd forgotten it until you wrote in about the Kalper.

That model would be JUST RIGHT for an R/C model powered by one of the new Gasparin CO2 motors! I had been thinking of a Sorrell "Guppy" -- which is a cutie-pie biplane too -- but the Parakeet is slenderer and (I think) would make a better subject for 3-channel control.

As for the "Ray Rocket", the model I had was from Ray all right, but I built & tried to fly it in 1946 or '47. I can't recall much about it, since it didn't provide me with any fun -- but I sure don't remember having the option to "shoot it into flight" with the cartridge-piercing gun. Maybe my kit was an early one, and the company later issued an improved version? [JW]

Speaking of cheap DC power supplies for use at home in the shop. My eye was caught a few years ago by a section in a sales letter by an outfit in the UK called "Greenwald". They sold an amazing variety of stuff (mostly electrical/electronic) which obviously had its origin in bankrupt stock/obsolete/sell-off items, and catered for home tinkerers of all sorts of projects (the type that is prepared to adapt a cash register display, and un-solder 24-pin chips off circuits boards, you know the character type (what fun)).

To get to the point, they usually had a page with a bunch of switch-mode DC power supplies and I spotted one that gave (amongst others) a variable 8-16V/12A output for $20.

I was too late to get one, but I did get a 12.8V(fixed)/7A one that I hook to either an Astroflight or Hitec charger (thanks, Dereck W) for charging electric power flight batteries at home. It works a treat and cost $10. Most of these cheapies will give zillions on amps at 5V (+ & -) but not much on the 12V output, so you have to keep a look-out for the ones that do come along.

The "Greenwald" company must be duplicated in the good ol' US of A; ask an electronic/PC Computer nerd (now an expression which carries some kudos for certain subjects, how weird !) where they get their supplies. I'm sure you will be pointed in the right direction. You could also search the web, which, coming to think of it, is probably quicker.

I saw a post regarding the late, lamented Cox .010 as used for micro R/C akro work. Since I have been tinkering in this area for some time, I have found that it is possible to get an acceptable level of performance in micro aerobats using electric power.

Presently I am flying a 2.2 ounce P-51 with aileron, elevator and throttle using the DC5-2.4 motor for power with 4.2-1 gearing. The battery is 50 mAh nicads. After dealing with the messy operation of the Cox powerplants (I have one with a home-made carburetor) the availability of clean QUIET electric power is a boon.

At the NEAT Fair I had the privilege of talking with Nick Ziroli Sr. about the small Speed 280 size Aeronca Champion he had published in MAN a couple of issues back. As the weather on Saturday was miserable, I did not get a chance to see it fly -- but I did go home with a set of plans and plastic parts for the Champ.

I have it mostly framed up now and am getting close to covering. I have purchased several packages of Litespan and some Balsaloc.

As I have never used these materials I was wondering if anyone out there in SMALLnet land could offer any hints or things to watch out for.

I must know about the 16" Sukhoi 31. I also need to know about using a separate tank on an .010 or .020 Cox. That absolutely sounds very fun. I have just mounted my .03 PAW on the Robart F-16 Top Gun glider. And I have completed the bench tests on my Norvel ducted fan prototype. First flight to take place as soon as the weather permits. Chris Feole

I'm sitting here looking outside; it's now about -9 degree chill factor out there. I live about 60 miles from our great flying site at Muncie, Indiana, and can't wait for spring.

I have seen a reference to a new lightweight radio with the name Berg. I wonder if this could be linked to Peter Berg. Last I knew of him, he was with Kraft, but has lived in Indianapolis.

I really enjoy your work; please continue. I do get in to Muncie often and can hope that you all can get there sometime. The new road is in, and we can now set up for free flight in all areas.

Eddie Warren < > responds to the news of Balsacraft's closing its UK operations:

Look on the bright side. This may have been the only way the company could survive economically. By making the move to the Czech republic, the company is most likely trying to make sure that Balsacraft will be around in the future providing quality products for you. The alternative may be the end for them.

I must echo the sentiments about SMALLnet contributions from people who do not give their full names, just their email addresses.

On several occasions I have replied direct to SMALLsters who asked questions that I felt capable of answering, but thought might not be of general interest. These have often developed into email friendships, much to my enjoyment.

For instance, I recently had quite a lengthy discussion with Dan McLeod about a twin-engined model he is planning to build, and I think we have both enjoyed the contact.

So please, fellows, do sign your submissions with your full name, as it is off-putting to have to address someone as WR67TO or something like that.

Sorry for forgetting to sign the letter RE: the biplane. Like many, I am one of those people that can't wait to pore over the excellent information in this group. Thus, I receive SMALLnet both at work (read at lunch, of course!) and at home. Sadly, we use AOL at home, and the e-mail there doesn't behave like normal pop3/Outlook.

I think there is a provision for autosignatures in there somewhere, and I'll try to find it tonight. One statement I am happy to make about this newsgroup: I would trust any of the contributors to look after my home were I to be away. How many groups would one say THAT about?

...Here's another money-saving tip! I discovered some time ago a source of high-impact-resistant foam rubber that's ideal for all kinds of modeling purposes. Besides packing R/C receivers and batteries in it, I use it for shipping delicate items. For example, I had Andy Clancy's prototype Stagger Bee biplane here a while ago, and when Andy needed it back I put it in a big box, wrapped like a mummy in this foam rubber stuff -- and the model made it from here in S.E. Alabama to Mesa, Arizona without a smidgen of damage.

(Later Andy sent me a later version of the Stagger Bee, packed conventionally, and when it arrived here it had been mashed as flat as the six of clubs.)

The stuff I'm talking about is carpet padding. I obtained an acre and a half of the stuff FREE from a floor-covering outfit. It was used, but still in excellent condition. I could have had seven MORE acres of this (it's about half an inch thick, pale green in color) but there was no way I could stuff more of it in my car and still be able to see out the windshield. [JW]

SMALLnet Posting post363