SMALLnet post328

I have a PAW .03 R/C that has been a wonderful motor for my Clancy Yard Bee. Lately about 60 seconds after I toss my Yard Bee skyward the compression backs off a bit, causing my engine to burp rather than zip through the sky. I wanted to make a locking lever, but there were only one or two threads showing on the compression screw above the head. Mr. Clutton recommended a spacer on top of the contra piston. So!

I unscrewed the head, measured the indentation in the top of the contra piston, made a spacer from a steel washer approximately .23" in diameter and .05" thick, placed this spacer on top of the contra piston and re-screwed the head back on.

The stock PAW .03 locking levers look crude, so I made my own. I found a nut whose threads fit the compression screw (from a PAW .06 throttle), ground a small flat on one of the hex points (there's more meat on the point side), and drilled a cross hole that 1/16" music wire would fit tightly into. I then used a big soldering iron to finish.

I now have a professional-looking locking lever; I will test it and report again soon.

Oftentimes when we fly in a park or schoolyard, we get a small audience. Understandably, we are reluctant to let them try our planes. However, a powered parachute or hang glider could allow them to try out some flying.

Such a model would powered by a Speed 280 or 400, be easy to fly (joystick movements might be similar to a video game), easy & cheap to repair. It would be slow so you can fly in close. Does anybody supply plans for such a "plane"?

I have a bunch of 50 mAh Sanyo nicads for sale, $1.50 per cell, minimum order 12 cells costs $18.00 and includes postage. Please contact me directly. TIA Don M.

A while back someone was asking about Quick-Bild kits from HOBBY SHACK. While looking for a set of plans for another man I found a set of the Pilot Q-B 20 plans. I will send them for the cost of reproduction + $3.20 postage.

J.C. Hill-Tout < > responds to the remark in the previous Posting about the sorta-semi-scale Antoinette of JW's that's likely still sitting atop the big basketball scoreboard in a college gym:

Wheee! I am glad that I am not the only one who has lost a model while flying INDOORS! I lost a Peanut Nesmith Cougar at a contest in Vancouver British Columbia, when it got caught in a "thermal" caused by the lights in the center of the dome. I understand it was retrieved some years later during maintenance in the rafters. Losing a model indoors is a unique experience just the same...

How to clear any debris in the combination tank/engine mount? (On this one, I drilled and reamed a 1/4 inch hole in the top and inspected with a fiber-optic light. All I could see is a very close gap between the rear of the tank and the outflow port. Could blow toward the tank, but could hardly get any flow toward the engine.)

Fuel tubing. (Large ID tubing is prone to air leaks at the carb nipple. Smaller tubing seems too restrictive to good fuel flow.)

...Charlie, 15+ years ago when I was writing a model engine column for Model Airplane News, I received more readers' letters about problems with Cox engines than for ALL the other makes of model motors combined! To answer all these queries (most of them covering the same kinds of problems) I composed and computer-printed a little booklet of "Cox Fixes".

Unfortunately I can't find a copy of that right now. Maybe later...

However, I can answer your queries briefly. First, to stop glow heads from unscrewing, the quickest effective "fix" I came up with was to squash the head threads a bit with ViseGrip pliers.

Yes, I know that sounds horribly crude! But Vise-Grips provide a convenient "graduated pressure" gripping device. The adjustment screw allows small increments of increasing pressure to be applied to form "flat spots" on the head threads, until a good "interference fit" is achieved.

Your second "problem area" seems a bit obscure. I take it that you're referring to reed-valve Cox engines such as the Black Widow. Keeping the interior of their tanks clean & "debris-free" involves nothing more elaborate than a thorough cleaning of the separate parts. Don't neglect the screws: particles of dirt can lodge in their threads, then come free when the tank is filled with fuel.

And ALWAYS use filtered fuel in Cox engines!

When re-assembling the tank mount, make CERTAIN that the tiny sealing washer between the central air inlet tube and the tank back is intact and properly positioned. Even a tiny flaw in this sealing area can ruin the engine's reliability. Yet replacements for this little ring gasket can be hard to obtain.

If you intend to do much flying with Cox reed valve engines, buy a BUNCH of these little parts -- and if there's any doubt about the integrity of the seal between the tank back and the air tube, REPLACE the sealing washer.

As for the fuel tube, that's always been a problem area. I've tried various sizes and types of plastic fuel tubing, but the only kind that really worked and lasted long for me was made from a hard-to- find material called KEL-F. I bought several feet of that about 25 years ago from an aircraft supply house in California; by now it's all gone except for a few inches.

As an alternative, I tried using soft aluminum tubing; pre-bent to fit the tank interior. (I used Weed-Wacker nylon line inside the tubing to prevent kinking while I made the small-radius bend.) I connected the aluminum tube to the fuel nipple in the Cox tank back with a short piece of vinyl tubing.

One more possibility is to buy some thin-walled Tygon fuel tubing from Eric Clutton. I got some of that from him at Maumelle, and use it for my PAW .03 diesels. It's great stuff -- but I haven't yet tried it in Cox reed-valvers. That's mainly because I've found the PAW's SO much more reliable & adaptable than Coxes, and I do very little foozling around with C*x power plants any more. [JW]

With the demise of Sky Hobby, does anybody know a good alternate source for Ace R/C small parts? Also, does anybody have a set of plans for the Mark's Models "Bushwhacker", or the old, original Sterling Piper TriPacer, that they would be willing to copy for me? (I will reimburse fully for efforts!)

Finally, I must add that I used to fly a Tee Dee .051 with the Tarno carb and the C*x annular-ring muffler on a Ted Strader "Corky II". The engine ran great, but the plane was not so hot.

(No ROW, nasty stalls, sorry Ted. Loved the "Whirlwind" and the "Miss L" however!!!) Dave Fritzke

I have to say that I was really surprised that I got no response when I tried to get in touch with any Slow/Park fliers in the Largo, Florida area. I thought surely there would be some, oh well.

Norvel has a winner with the Ucan2 powered with a BigMig .074. This is a heck of a good airplane and engine combination that flies as well as it looks!

By the way, a Ucan2 and a Norvel .074 will be a prize drawing at the October 7th Model Airplane News Dallas "Small Steps" Fly-in.

I'm surprised that there haven't been any comments or feedback on the new Cox electric free flights available at WalMart and other discount stores.

There is a high-wing Cessna-type model and a Mustang style, that come with motor, batteries, switch, charge plug, and charger unit. These look like a good buy and a good "learning platform" for beginning electric flying.

All this costs less than $15, which seems to be a fairly good bargain considering the costs of other model products. The power systems could be used in other planes, I'm sure.

There's a model plan featured in the August issue of Model Aviation magazine for a plane using the Air Hogs compressed-air power system. Maybe later someone will come up with a design using the Cox electric power system.

...Mike, I've seen that Air Hogs free flight design of Ken Johnson's in action, and it's truly impressive. (So is the other airplane that Ken is holding in one of the MA article photos.)

However, I've also seen a couple of the little foamie Cox electrics in use, and they are tricky! Their small dimensions make flight adjustments quite sensitive. You really have to know what you're doing to achieve satisfactory performance from these.

A FAR better line of RTF molded-foam electric-powered free flights is available. I forget the brand name, but one of the designs is a pod-and-boom type with the motor mounted as a pusher above the wing trailing edge. I believe that the selling price is about the same as the Coxes, and the model "systems" contain motor, battery pack, charger module (less batteries), switch etc., just like the Cox package. But these are larger airplanes and much easier to adjust for stable flight. [JW]

...Come to think of it, I recently came across a well-recommended source for HiTec receiver crystals. That's Cermark: 107 Edward Avenue, Fullerton, California 92833. Phone: (714) 680-5888 web site < www.cermark.com >.

They have HiTec crystals at $7 each; and also carry a most complete line of Sanyo nicads. They will sell single cells, and assembled receiver, transmitter, and electric-power packs.

...In some recent Postings there have been reports and comments on some of the newer .10-size glow engines. Right now I'd like to put in a plug for Enya .10's. They aren't advertised nearly as strongly as the newer ABC types -- but my experience with Enya .09 R/C engines has been highly satisfactory.

Because I hand-start all my model engines, I far prefer the "snappy feel" of a well-fitted lapped piston glow engine to the "pinch-at-the-top" effect of an ABC. And my two Enya .09's are as "snappy" as anything I own, even though one is probably not fully broken in yet.

My Enyas have excellent throttle response on suction feed, with neat and rugged air-bleed type carburetors. So far I've only run them on my "old standard .09-size propellers": 8-4 Top Flites and Graupners. Offhand I can't provide rpm figures -- but those don't mean a lot because of the variation caused by fuel differences and changing atmospheric conditions. I can report good idling performance, however: under 3000 rpm. [JW]

SMALLnet Posting post328