SMALLnet post419

I am a handicapped person who still (after 60 years) loves to fly models. I am in need of an Ace single stick assembly to rebuild the transmitter I have been flying with. Is there anyone who can help me? Thanks for any and all you can suggest. Charlie Ziehl

Rubber band a 36" straight stick of balsa under each wing about halfway out. (Use the same size, fairly stiff, sticks for each wing). Even if the airfoil isn't truly "flat-bottomed", you can set them similarly along the bottom surface by eye.

Then walk away to one side of the plane, and sight down the pair of sticks. If both wings have the same incidence, the sticks will appear to be parallel. Then move the sticks to the tips (equal distances, of course) and see if both wing tips have the same washout. In fact, you can use four sticks at the same time, putting one stick halfway out from the root on each panel, and one at the tip.

That way you can see if you have warps, equal wash-out -- or horrors, wash-in! --- Patrick LeRay

With my incidence meter I found more wash-out in my Playmate's right wing than in the left. Probably that's what caused the right turn trouble. I also increased downthrust and added ailerons. The wing balances, and the incidence on stabilizer and wing are 0-0. I've been away on business, so haven't yet tried flying the Playmate again.

...Curt's message brings up an important consideration that's not as well-known as it should be. Model airplane wings -- or any portion thereof! -- stall at less than 10 degrees angle of attack.

The reason wash-in is deadly is that it makes one wingtip stall. Most of the wing continues working; so the result of one tip's stalling is that the local loss of lift and sudden jump in drag cause a snaproll toward the stalled-out side.

Many modelers consider ailerons as an all-purpose lateral control. Yet a down-deflected aileron can act EXACTLY like a washed-in wingtip, and produce an unexpected snaproll.

As a general rule of thumb, downward aileron deflection should never be greater than this: With the model set up level, as for incidence checking, apply a straight stick to the wing undersurface (as in Patrick's method) that just touches both the TE of the "down" aileron and the underside of the front part of the wing. The incidence of this stick shouldn't exceed 10 degrees. [JW]

They provide about 1/2 hour of power per charge. Don is/was selling them for $45.00 for two packs plus the charger, set up and ready. My batteries came charged and ready to fly.

Lithium Ion batteries do not lose their charge with time, so you can charge them at home, then go fly.

Don has a great reputation and is very much respected on the E-flight and Slow Flight (SFRC) newsgroups.

Here are three links to information about using Lithium Ion batteries to power model airplanes. I believe the first link has the most technical information. The second and third links describe the process of stripping off the plastic case from a specific battery pack, that results in an 830 mAh, 8.4 volt, 2-ounce battery pack.

From what I've read, it is very important to use a suitable charger, or the cells may explode. It's also important to not exceed a discharge rate of about 1.5 amps or discharge the cells too low, or the cells will be damaged. The batteries come with electronics to automatically protect the cells.

I ordered a set of batteries and charger, and the service was excellent. I have not flown with them yet, but bench tests look promising, and there have been messages from lots of happy flyers on the E Zone.

I hope it's not true that the MP Jets .061 is out of production. This is one of my best engines! (Both the glow and diesel.)

...Bad news, Oscar. I checked with Ed Carlson, the exclusive US importer of MP Jets engines. Ed says that the .061 IS out of production now. He still has a supply of the glow version, but no more diesels. He HOPES that .061 production will resume "next year sometime" -- but that's all...

By the way, I was mistaken about the degree of similarity between the glow and diesel MP's. Ed says that the cylinders and porting of the two engines differ significantly.

According to Ed Carlson, the MP Jets company is now producing "plastic model stuff". This is another indication of how greatly electric power has taken over in the former "1/2A model powerplant" market.

True, much of the decline in 1/2A use is due to the disappearance of the engines themselves from hobby shops. 50 years ago we had a fabulous wealth of selections. K&B, OK, Atwood, and Mel Anderson each produced a wide variety of under-.10 model motors. McCoy, Fox, Allyn (the Sky Fury maker), and O&R all made 1/2A's. Cox was just then beginning their fantastic lineup of glow .049's.

Now they're all gone. [JW]

Back in February, I asked about running diesels in cold weather. Many thanks to those who responded. The consensus is that no special fuels or techniques are needed. Starters can be used, and in certain circumstances can be useful -- but must be employed with "diesel technique" in mind.

Just as with glows though, starters ought to be unnecessary except where compression seal is not optimum. I've made up a starter (using electric drive components) with low torque and speed that seems to be just right for 1/2A, so I use it most of the time. Many of my glows have so many hours that the compression seal is gone. Despite that, once started with an electric starter, these deliver nearly as much power as when new.

I've been busy lately with running an early AAN Norvel with an RJL diesel conversion head. I'm happy to say that the conversion is a resounding success. This project had been commissioned by my good friend, Raj Massilamoni in Singapore. I've done a number of Norvel style throttles for him to try on various vintage diesels that he owns.

This particular Norvel he had entrusted to me to test run for him, and I'm grateful for that. Using a throttle onto which an adjustable airbleed was added, we achieved 4.5K up to 12.5K on a 7 X 3.5 Cox grey prop. Fuel was 40% kerosene, 33% ether, 25% castor, and 2% amyl nitrate.

Idle is forever, rock solid; and transition is very good. Just a hint of smoke with no hesitation. Linearity is on par with glow except that mid-range is just a hair rich. The top end, once adjusted, emits a sweet, although loud, growl; somewhat louder than my 1/2A PAW. The steadiness of rpm is truly inspiring.

This throttle had a reduced bore from stock. A stock barrel, as well as a bored-out barrel, was tried. The larger bore yielded a healthy 13K rock solid. Idle suffered though, at 6K.

Very important to this project was the use of a throttle with an adjustable airbleed. For those who might recall the discussion of sub-piston induction, I think it's quite significant that this engine has that feature and yet throttles very well, diesel or glow, as long as the idle mixture can be adjusted.

On the subject of excessive cooling in the winter. The Norvel is a modern engine using a tight, squeaky fit at TDC when cold. The fit improves to just right when the engine's up to running temperature. If it doesn't get up to normal temperature due to excessive cooling, as might happen in cold weather, there is the chance that the engine's fit will be ruined. This is why you never break in this type of engine by running it rich, as you might do with older engines using steel sleeves and cast iron pistons.

Dave Gierke, noted engine expert and columnist addressed this issue in one of his columns several years ago. His tests and experiments led him to the conclusion that, just as with running this type of engine excessively rich, running it with excessive cooling can, indeed, ruin the fit. It was from this that I expressed my concern about cold weather running.

The Norvel had me particularly concerned as it has very large and effective fins. Extensive running in the cold has proved to have no harmful effects. So, while turning down the fins of the Norvel can't be considered "butchering", it has been proven to be unnecessary.

While working with this engine, I found it relatively easy to start, even for a diesel novice like me. I drew fuel up the line by choking but no further than the edge of the carb. Then I closed the needle valve completely. I backed off the compression, gave one shot of prime, then flipped five or six times.

No results from this prompted a quarter turn of the compression screw, another shot of prime and another several flips. I repeated this procedure until I got a brief burp. Then I opened the needle a quarter turn at a time.

Eventually the engine fired and kept running. I backed off the high-speed needle, and the smoke indicated a slightly rich setting. A minute or so of running at this setting allowed the engine temperature to stabilize. Then I turned in the compression screw bit by bit until maximum rpm was achieved. Then I backed off a bit. Then I turned the needle in slowly until a sweet-sounding growl emerged. Masculine is the only way to describe it. Loud, but nothing like the shrill screech of a glow. Nice.

The downside is that although the RJL head works extremely well, the compression screw has the habit of spinning around under vibration. You need seven fingers on one hand to hold the screw steady while also manipulating the locking lever. This with a meat cleaver spinning at 12.5K just inches away.

As a result, I was happy to come up with a technique which worked on this particular engine, without needing to adjust the compression screw once it was set. Running off the prime three or four times would bring the engine's temperature up to the point to where it would keep running with a neat burrp, burrp, sound. A minute later, the temperature would stabilize and a solid, steady, top end would result.

This may not work with all diesels but I was pleased at how easily the modified Norvel started with this technique. It must be kept in mind that the next flying session will likely be at a different temperature and humidity, so the compression will most likely need to be adjusted along with the needle.

A muffler was tried. The high speed and idle were adjusted to suit and power and handling were the same. Another plus for the Norvel diesel was the fact that the engine could be started with just a heavy prime into the intake. It took five or six flips and the run off of several primes to get the engine up to temperature -- but from there, the burrp, burrp would transition into a solid run.

Future projects will include testing my tuned muffler along with a tuned pipe. Has anyone had any experience with tuned pipe diesels?

One last note. If anyone has any worn-out Norvel AAN (shiny fins) pistons and cylinders they'd like to have revived, I'd like to try an experiment that would restore the fit and perhaps improve durability.

I'll do the first three for free excluding shipping. I'll pay the shipping back. I live in Canada. Please contact me directly.

...John Clapp of FAI Model Supply has exchanged a few e-mails with me about the availability of FAI TAN rubber. So far there's been no definite news about renewed production of TAN II.

However, John says that a modern version of T-56 rubber -- mainstay of rubber-power flyers in the "Good Old Days" -- will soon be available from FAI. It will be designated as "Sport" rubber. [JW]

I have been reading the SMALLnet for some time now and enjoy it very much. I don't know if this will be of any help to the person requesting plans for the Chester Jeep racer, but Dave Livesay has a website that offers plans for the Art Chester "Goon".

The site also includes an index of plans that can help find the exact magazine issue in which a certain plan appeared. The address is: < http//www.geocities.com/dmlivesay/ >.

The plan for the "Goon" is in the PEANUT section under RACERS, and is also in the CADD PLANS. If you have a program that can read these, they are very nice.

I hope that this is of some help and I look forward to reading the next Posting.

...Kevin, the Jeep and the Goon were about as different as a Mustang is from a P-40. Their designer, Art Chester, named his raceplanes after characters in the Popeye comic strips -- and it seemed to me that the Jeep and Goon reflected in their overall styling the characters they were named for.

The Jeep was a friendly-looking craft, while the Goon had a cold, deadly air to it in my eyes. Both designs do make good-flying models -- and the Jeep would have been much more popular in model form if it hadn't been for the difficulty of reproducing its curved-in-front-view landing gear struts.

The Goon had retracting gear and no wing lift struts. With its short-span wings and long fuselage it makes a dandy rubber-powered competitor in the limited-wingspan free flight events such as "Peanut" and "Walnut". [JW]

SMALLnet Posting post419