SMALLnet post312

Hello, odd lac ta talk to ya bout Nower-vail. He sure is powerful, and purty too. He works hard and when he rests he's idle. Fact is, he gots a lower idle than those twice his size. An boy, he is smooth. I ain't seen nutt'n so smooth.. Why, he can transition from a real fire-breathen monster to a purrin' pussycat in nutt'n flat. But Land-O-Goshen, he sure needs some adjustin' sometimes cuz he gets outa-kilter ifn he drinks from the wrong cup. His rubber- ducky cup'l start'm ta actin all strange. But, all in all, cousin Nower-vail is right nice mosta the time, an we'uns 'njoy 'em cuz he don't cost too dang much. ta keep 'round.

...Bob is also liquidating a small collection of engines and control- line items on behalf of a fellow modeler with severe health problems. E-mail to Bob for a list of these. The engines are mainly diesels.[JW]

Thanks for the responses in SMALLnet and direct from colleagues about the Norvel's Revlite engine. I now know that "Revlite" is an engine technology, not an actual engine, i.e. nickel plated aluminium piston and ceramic coated cylinder. How do I know that ? It's in Norvel's September 1999 catalogue which is where I should have looked in the first place, Ed. The .049 and .061 sizes don't have this treatment, which only starts with the .074 size and up.

Which raises the question - what's the BigMig .074 engine like - anyone tried it ? I see its rpm range is given as 3500 - 19000 with a 7 X 3. Now that's a respectable throttle range and idle rpm, whereas the top end rpm only is given in the catalogue for the .049 - .061 sizes. Is that significant ?! Now I wonder if any SMALLster has tried the .074 size in an AquaStar ? It's only about half an ounce heavier - I could move the battery pack back a bit. It also has "big" engine features I like - muffler attaches with bolts (not a spring) and removable carburettor with extended needle - no provision for idle adjustment though. And, SMALLsters, it's an ounce lighter than that TT 07 which has been getting so much attention in SMALLnet - and revs 6000 rpm more on a 7 X 3 APC. Do we have a "lurker" here ?

I'm still looking for a reliable idle from the .061 Norvel. One suggestion not mentioned about obtaining a reliable idle from these small Norvels is that tank pressure is erratic due to the muffler being held on with a spring - a positive seal is not possible with this method. This was passed on to me by a colleague but haven't tried it yet. We tried all the other suggestions - more shims, Cox heads, higher nitro fuel - which didn't work. We haven't tried restricting the exhaust yet because we couldn't find a suitable length of tubing. All this engine "testing" is tedious, isn't it ?!

Thanks also for the direct responses to my post about the Butterfly. Here are the answers :-

Yes, I fitted the OS Max 25 from new before it was ever used as a seed bomber. No, I never had problems of flutter even in the most violent manoeuvres. Yes, it flies inverted and will do successive outside loops. Several asked for details of the seed mix we dropped -it was a mix of grasses, shrubs, bushes and trees indigenous to the region - to bind the top soil together. Why was it necessary to airdrop the seed rather than sow by hand ? The slopes were unstable thus unsafe to clamber about on. What area was covered ? From about one to four football fields. One seed pack bursting open on impact would cover about four to five square yards - one "bomb" load would cover over one hundred square yards. And why did commercial attempts fail ? The slopes were too steep and the valleys too narrow for aircraft to manoeuvre safely. The Thai Army tried firing seed packs with mortars onto the sites from the foot of the slope but most fell short.

Regards from Picton, Ontario, my new place of residence. It will be some time before my workshop is operational, but as you can see, one computer is up and running (on a new computer desk). It looks as if I might be able to handlaunch small and quiet planes from the back of my property and fly them over neighbouring farmland.

Regarding the Norvel rubber bulb problem, one solution is to use a plastic Valvespout refueller. I re-introduced these to North America a few years back, and Eric Clutton now stocks them too. Eric usually has plenty of them with him at shows. But if you expect him to bring some along to a SMALL meet, it would probably be wise to phone him ahead of time. Valvespouts are virtually 'required wear' for diesel users, but we are graciously pleased to allow glow flyers to use them too.

Come on guys, rubber fuel bulbs went out with the Civil War. Use a fuel pump, Rubbermaid plastic 'refreshment' bottle, anything but a rubber fuel bulb. Or buy a cheap bottle of shampoo; when it's empty, put a Sullivan tank stopper in it, and you'll have a great 'fuel bulb'.

Re: AT-6 spins. I trained in them during my Air Force pilot program. A rearward C. G. was an absolute No-No. In Advanced, we had the older D models. In order to modernize the radios, they put them in the baggage compartment, behind the rear seat. We were warned not to spin those planes. One instructor and student decided to try a three turn spin...31 turns later the instructor finally got it out, about two seconds before they were going to bail. 'Nuff said!

I started flying the SNJ at NAAS Corry Field in 1953. I honestly don't remember it being difficult to recover from spins, but on the other hand, I don't remember what I had for breakfast this morning, either.

The power burst was a way to get out of a flat spin, but I never got into one. I do remember it was a tight program. The Korean War was all but over, and the Navy didn't need new pilots. A student had 11 hops of 1.3 hours each to solo, or it was back to Tin Cans or Auxiliaries. That provided motive.

In 1959, I returned to instruct in T-34's at NAAS Saufley. Real pussycat, that plane. We had to demonstrate an inverted spin to every student. Bad trip. The kids puke ended up above him on the canopy, instead of down on the deck. Hey, it paid $800 a month.

One must remember that the Harvard/AT-6/SNJ was not designed to be a civilian recreational aircraft. It was a military advanced trainer, designed as a "stepping stone" if you will, between the basic trainers and the front-line fighters of the day (WW II). As such it does not have the good manners of aircraft like the Cessna 172, and will not put up with hamfisted handling. In other words, it bites back, as a lot of otherwise good pilots found out while doing aerobatics or even steep turns at low altitudes. It has a rather nasty stall under power. One must expect models of the aircraft to have similar flying characteristics to those of the full scale one. My last words on the subject, I promise! George

On the T-6/Harvard thing. When I flew with the Ramsey MFC - now becoming a great hotbed of ideas for 10 - 15 powered trainer and sports model development, BTW - one member tried to convert me to large modelling by letting me fly his Saito five pot radial-powered 100" Ziroli Harvard! He just handed me the transmitter, started the beast - it had the same glowplug 2V sealed battery on-board that I had in my flight box - and told me not to try and roll inverted low after take off!

Well, off I go, suck up the gear and feel her out. Not bad, bit sluggish when you're used to a 44-ounce Little Special or Bubbles with a 25, but superbly built and a pleasure to fly. Soon, he digs me in the side and tells me I haven't been seen to fly this long without some aerobatics. The monster rolled fine, then came a loop and I found out why he was grinning.

I went into the loop, got on top and pulled a little. The Harvard did a leisurely half snap and ambled off in level flight. Next time, more entry speed, more power on the top and keep off the pull a little.

At the time, our club groundsman was a retired chap who treat our 80 acres like his own lawn, so we always had a smooth surface to fly off weekends. Turns out this quiet and seldom seen fellow had started his working life as a pilot in an unpleasantness later known as "The Battle of Britain" and had practised his trade in Harvards prior to getting the keys to a Spitfire. He'd talked over Harvards with the owner of this Ziroli overcast, plus they had checked around owners of smaller Harvard models - the outcome was that, if you make a model close enough to be recognisable as 'scale', there is a good chance that it would behave just like a real one.

The owner of the Ziroli figured pretty much that I would loop his just right for a snap off the top, which this large and admittedly nose heavy model would do with little danger.

On Foamboard (FB) - After reading of Roy Clough's experiments, I decided to have a go with this stuff - I cannot recall seeing it anywhere in England, but have found it readily available in 1/8" and 1/4" around DC since moving "Over Here". Being a cautious cuss, I built a low wing, fully aerobatic low winger which could be described as a kissing cousin to a Quicky 500 racer. Caution made me fit an OS25 FP at first, this was retrofitted with an OS25 SF ABC after a careful test program (one weekend, flat out doing any aerobatics I could think of :-).

"BEEP" - I forget what it meant, but it stood for something - used FB anywhere I would have used balsa sheet. Ribs, fuselage sides, top and bottom were 1/8", tailfeathers were 1/4". Spars - spruce, LE, TE - balsa. FB was doubled with 1/64" ply attached by coating mating faces in Elmer's, letting dry and ironing the two together - maybe not the best but it worked. Otherwise, a sheet box fuselage, D box wing with strip ailerons and sheet tailfeathers. One lost a wing in a mid-air, the second with a fully symmetrical wing lasted a long while until a plastic pushrod fractured just ahead of the elevator horn, while travelling across the field around its considerable Vne. ["Never Exceed Velocity"]

The subsequent wings level arrival - still at considerable speed despite going to idle - proved that the FB is strong stuff. If I was the repairing kind, it could probably have flown again.

I've since used it a fair amount, as a substitute for 3/32" / 1/8" balsa. Though it would cause a weight increase in a very small model, it works fine in around 20 - 25 sized models. One aside - Keith Shaw, renowned electric flier, uses FB extensively for formers in his large electric models.

One point from Keith - who often only builds one model a year (but what models!) - he uses a flexible glue, such as RC-56, rather than even 'white' glues to attach FB. Otherwise the glue tends to create a brittle area around the joint and hence tends to crack. One point from me - don't attach anything important directly to the FB - it is only paper stuck onto white foam after all!

And for Dave Segal - I don't think you will ever get rid of the Speedy Bee "barrel roll" tendency. As you have two wing servos, it won't hurt to mess around with the differential. A Lazy Bee with rudder and elevator actually does a very fast outside barrel roll if you really crank up the control throws, though most folk just perceive a very fast roll, so adding in rudder is a possibility.

Take it high and try it by adding the rudder manually. If that improves matters, you can then work on a computer mix setting to suit yourself, if you prefer this way.

My IMA "Pou de Salle" is still in the kit pile, as I try to get ready for a trip to the NC "Triad Electric Weekend", but I just got my Castle Creations "Pixie Lite" ESC for it, to go with a SH&R receiver - the one with the Futaba connector block. This looks like a fun model, though it comes recommended for experienced fliers. IMA's webpage is at: < http://members.xoom.com/ima/index.html >. They are a very online company - even the instructions for the Pou de Salle come on a 3.5" disk.

This novel approach is certainly more comprehensive than most manuals and has several language versions on the disk - the English is excellent. Will keep you posted on this one.

I had a weird experience with buying batteries from an "alternative" source. I was looking for a battery pack for my HLG (now deceased) and happened to be in a "Batteries Plus" or similar store. They have racks and racks of rechargeable battery packs. I found a pair of suitable two-cell packs for a reasonable cost. They were little fat things that would sit just right in the nose of my then-new glider.

I went to the counter with them and my other purchase. The girl there said, "We don't sell many of these batteries, why do you want TWO packs?" So I told her, and she refused to sell them to me, saying that it was against the company policy to sell batteries that were not going to be used for their intended purpose.

Evidently the "company" was afraid that someone would buy a battery and solder it and burn himself then sue the company. No amount of reasoning would help. She said that the store manager had been threatened in a similar circumstance.

What to make of this? I don't know, but I avoid that store and will probably not darken their door again. Or maybe this is just another symptom of lawyers ruining the country, eh? Mark

Mike, you wondered about using rechargeable Lithium 3.4 volt batteries for your JR Receiver. I've been using two CR2 lithium (non-rechargeable) batteries as a Receiver pack. Fabricated a holder from a Radio Shack AA holder and some balsa. I went this way because they're rated at 750 mAh, and the two, together with the holder, come in at 1.1 ounce. (!) That's 0.8 to 0.9 less than four AAA nicads or dry cells in a plastic holder.

Like you, I was worried about frying something, so I called Hitec. They said the Receiver has a built-in voltage regulator and there'd be no problem with 7 volts (nominal), running through it. There haven't been any problems so far. After at least an hour of "switch-on" time, the voltage tests only slightly lower than when new. I'd felt that if 750 mAh was the claimed capacity, for safety's sake I'd assume it was more like 600, and at 150 mA draw for the Rx and two CS-20 servos, that'd still give me about four hours of "switch-on" time. So far that seems to be holding up. (They're pricey, but I hit a two-for-one sale at Eckerds.)

So I know that 7 volts is OK with Hitec's HS3 Receiver, but like JW said, check with JR to see if there's a voltage regulator in yours.

...Patrick, I assume that you're aware that the servos run off the same battery pack as the receiver, and have taken that into consider- ation. Let's see now, at 7 VDC, the starting current would be about 45% higher than with 4.8 VDC input. I wonder if the servo motor's tiny brushes and commutator can take that much of an overload. [JW]

Rich Border wrote of trouble with Monokote on his foamboard model. Yes, indeed. You need to use Econokote...it's the low-temperature alternative. Dave

Chris Parent has the solution to coloring tissue. You use pastel chalks available from any art supply store. Scot Dobberfuhl urges experimen- tation because the shades that come from using, say, chartreuse on red tissue will surprise you. I think Larry Kruse had a discussion of this in his column recently. Maroon, green, Olive Drab, khaki, purple, brown and various blues all are available with this method.

One grinds the chalk, then works it into the rough side of the tissue. A light coat of dope after covering fixes the color.

For opaques, I've used Floquil-tinted nitrate. You'll be surprised at how little Floquil is needed, because of the finely ground pigment, to yield a transparent finish. Again, experiment.

On the cutting edge, Aeromodeller recently had an article on color- copied covering. Color for four different WW-I aircraft accompanied the article with the urging to take these to a cooperative copy shop -- with your tissue spraymounted to regular paper, rough side down; and have them enlarge the magazine illustration, color-copying the result onto the tissue.

This suggests that all of the color three-views which have appeared in the last 25 years would lend themselves to the same use. I've not tried this yet, but it seems an easy solution to such as tissue stars and other insignia and decorations.

I've got a double-Stahl PT-19 under construction. The wings are covered with yellow tissue. My intent is to airbrush the white of the stars onto the wing, then try adding color-copied-onto-tissue stars atop this.

...On the topic of custom-coloring model tissue, I owe Fernando Ramos an apology. I mis-edited his description of using plastic model enamels to make colored dope to order. Fernando no longer removes the enamel "vehicle", but mixes in the whole bottle of Floquil, Humbrol, or Testor's PLA into low-shrink nitrate dope. His reference to putting thinner into the enamel bottle was merely to make sure of getting all the useful pigment out of that and INTO the dope. [JW]

I am a Shreveport Louisiana transplant from Wichita Kansas. I am an avid reader of SMALLnet and noticed some of the responses on Rubber Power. I think the "SMALL" concept is a great one! I try to do it all...FF rubber...C/L...R/C gliders and powered planes.

I am a contract aero-engineer and move around a lot, and usually live in very SMALL apartments....away from my model shop in Wichita.

I have been building small rubber models on my coffee table here in Shreveport. I have found that I do not actually need all those tools in my model shop. I have been using a bulletin board as a building board and have had a blast building all those SMALL rubber projects I have wanted to do.

I am not as sidetracked by my C/L and R/C stuff as when I live in Wichita, and now get more of the rubber stuff built. I simply do not have the room for all my modeling stuff here. All my simple tools fit in an old shoe box. Anyway, I have a model airplane web site at < http://pages.hotbot.com/edu/jrenz/ >.

It is my Island Flyer Web Rubber-powered web site, which shows my small rubber-powered model. I have a "how-to-build" page with construction photos at the bottom. I can not say enough good stuff about this kit from R/N models! It will really fly great and is simple to build. I have built my third one now and ran the tissue covering through my HP printer. It can be flown on a small ball field with a small amount of rubber.

If anybody out there lives close to Shreveport, let me know. I am 3 hours straight east of Dallas. Mostly R/C guys down here. I just do not have my R/C equipment here, and the rubber powered stuff keeps me going though and helps my model appetite. Jeff

I was talking with a non-modelling friend this week. He said that he had bought a model set years ago from Radio Shack that had an elementary radio-control system and a motor/engine of some sort.

He seems to recall fitting a cartridge underneath the model. This sounds to me like CO2, but he thought that the cartridge said "butane". He can't recall any details of how he started the power plant, but he said that the model did fly.

Does anyone out there have any recollection of such a Radio Shack model, and could they give me more details? Thanks. Ian M

I bought an OS 20 4-stroke, used, at the field the other day. I foolishly believed a couple of other fliers that the lack of compression was completely normal for a 4-stroke. (OK, it isn't a glow .049, so I know nothing, all right?)

Anyway, it won't start, and before I hack it apart, I'd like a clue as to what to look for. I have some input from RC Online, but need more information on how to check the valve timing and set it up right.

The crossover from exhaust to intake valve timing seems to be about 20 degrees off TDC. I am reluctant to do more than remove the valve cover until I know more.

It may be that the engine was run lean and the valves or ring are fried also, as the top of the piston is brown.

It is a charming and discontinued engine, and I would like to restore it properly, so all help is requested.

I have Harry Higley's book on order, and perhaps that will give me the information I need... Larry

I'll have to find Darrel Peugh's address, and I'll post it. He has the Arne Hende engines.

Does anyone know where I could obtain a cylinder head for a TD .09 that accepts a conventional glow plug? I suppose I could drill and tap a Cox glow head, but I'd prefer to just buy one if they are available. I contacted Cox for a TD .09 RC head but they are out of stock. I thought RJL/MECOA offered one but maybe I was thinking of their diesel conversion head, because I don't see a glow plug head in my most recent catalog.

...David, I have reworked Cox heads to accept standard glow plugs, and there's a trick to it. You must counterbore the top of the glow head deeply enough so that the glow element of the plug will come out in the same location as the original glow head element did. Otherwise performance suffers a LOT.

Cox .09 glow heads are rather thick, and they require such a deep counterbore, the top fin gets cut away. That means the tightening slots are eliminated, and "alternative tightening provisions" must be provided. [JW]

"I put Deans antennas in my last 6 planes, and I've also recently been using a rubber ducky antenna on the transmitter. Yesterday I did the first serious range test - I found a huge thermal with my Zagi-THL. I was having trouble keeping sight of it. When I would lose it, I threw the stick over to one side and watched for movement as the model spun down. This worked several times, and I got the plane back, so obviously I still had control."

The Dean's antenna is great when "reduced" for smaller size and lighter weight. Remove the white coating on the antenna wire, peel the blue coating from the base, use a jewelers saw and cut the circuit board down in size to its bare minimum. The antenna wire (the stiff part) can be replaced, just solder on a new, thinner one. Then build the assembly into the leading edge of your wing structure with the lead going into the radio section.

SMALLnet Posting post312