Tom @ Buzzard Bluff

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Unless it's watching a Pee Wee with a CO2 conversion turning a 9 1/2" P-30 prop at near the same RPM. I flew a R&N Models 'Baby Boomer' with the wings stretched a bay on either side with that set-up back when Futaba S-33 servos were state-of-the-art and cost more than you could tell the wife. Flew pretty darn good considering I had little idea of what I was doing.
But CO2 IS a viable option. And, like electric, there's no goo to clean up. Tom

Ragwing

My Feedback: (2)

That is so cool guys. I was having trouble deciding what my next project should be, but now I've almost made up my mind:

Earl Stahl Howard DGA, Earl Stahl Gypsy Wakefield or Comet Sparky

I'm guessing about 32-44" depending on the model, super light, rudder and elevator. How does that sound?

Keep up the good work, I can hardly wait to start doing some experimenting of my own!

Cute Plane Jboy!


Derek

SERCEFLYER

Derek,

Sounds to me like you are a rubber-burner at heart. That's what this hobby is about: no matter how impressive our radios and engines get, it will always be about our memories of building that first fuselage model and seeing the sunshine lighting up the tissue and frame... "angels in the twilight," as Bruce Matthews once cleverly put it.

This is why I've been doing this Cox Pee Wee "research." I want to create an engine set-up for small, light, slow, scale, rubber-burner type flying. The set-up with a 6X3 prop makes sense for models up to about 9 oz and the 7X3 for models up to 5 oz.

Do build one of those models--- I've beaten you to the Earl Stahl Gypsy-- my all-time favorite design. (It'll be ready this summer) Build the Sparky, and maybe we can get together in Seattle sometime...

George

BMatthews

Well, it's nice to see that my verbiage is still remembered by an appreciative audience...

From my two model history with 1/2A Texaco models I can suggest that the PeeWee Texaco conversion will probably fly a model of about 170 to 220 sq inches give or take 10 or so. As for weight that 2 and a bit ounces pretty much limits you to a 5 or maybe just 6 oz AUW. That's rubber model stuff in anyone's books.

As much as I love the looks of them I can't see putting a PeeWee in the nose of most super light sport or competition rubber models and having them balance very well. The nose of most of them was just TOOO long. Unless, of course, you shorten them but then many of them just would not look right at all.

However a great source of Earl Stahl and other scale rubber models that would do well wth this PeeWeeTee engine setup are available at www.theplanpage.com , http://www.ualberta.ca/~khorne/ and at www.smallflyingarts.com . In particular check out the Comet Senior Dart on the plans download page there. This one has a cute factor that is just off the scale! It would be a great one blown up to about 36 inch span for this engine mod and 2 channel parkflyer gear. But all three sites are loaded with PeeWeeTee possibilities.

Serce, I apologise but the details on modifying the zinger baseball bats into slick looking low power props will have to wait until first thing next week. I got waylaid tonight. And the rest of the week and weekend is spoken for completley. But trust me, that 2x4 Zinger CAN be modified into a lovely and light prop for the PeeWee.

And in closing the original Keith Laumer Twin Lizzie or Buttons would also make a nice PeeWeeTee project if lightened a little by reducing a few wood sizes and selecting light stock. Or you could ask me nicely and I'll scan the plans for the Firefly. A rubber model that was intended for sport flying and to look like a "gassie" for those kids that couldn't afford a spark engine. The nose is short enough that the PeeWeeTee would drop right in with no mods. Wing area is around the 160 sq in mark and the span is 36 inches. A teaser follows.....

jessiej

[But trust me, that 2x4 Zinger CAN be modified into a lovely and light prop for the PeeWee. ]

I don't know exactly when the change came about, but at one tine the smaller wood prop sizes from Top Flite Tornado, Rev-Up etal were quite attractive. Now it seems as though they are all modeled after some caveman's personal sidearm.

I don't know if the change to clunky hubs is due to concern over liability or if the faster turning engines of today may actually need all of that wood. I have run some old 5 & 6 inch props up pretty fast on Norviles as well as some of my carefully thinned and reshaped props with no problem. (Except for the glow igniter getting into one of my several-hour carved jobs[:@] Taught me to be more careful with the igniter. Usually if I get anything in the prop it is only my fingers.

jess

Tom @ Buzzard Bluff

OK, OK---you've got me involved in this adventure now. I rebuilt a couple of Pee Wees yesterday. But I've forgotten where I used to source the tiny tubing for the internal fuel pick-up tube. I tried some small diameter fuel line but it didn't work. I just came in from the shop. I replaced the fuel tubing with some small Teflon tubing. I was able to get the tiny spring inside it and form it using heat, but I'm not confident that Teflon will stay on the nipple so I'd like some help finding tiny tubing.
Next problem. Where I live in the Ozarks is a high humidity area. I've been told in the past that running Cox engines in high humidity would exacerbate varnishing the cylinder. Any comments from the Memphis gang? I also was told to add a small amount of Hoppes #9 lead remover as used to clean gun barrels to prevent or eliminate varnishing. Anyone know if that works and how much to add? I used to use it without ill effects on the engine but I never knew whether it actually helped or not. In any case I have been away from the small engines too long to recall the proper quantity to add to the fuel.
The only high nitro fuel I've been able to find locally is 35% for the AP Wasp. It has no mention of oil content. I added 2 oz. of Bakers best to the quart for insurance. Does anyone have any experience with this fuel?
Any help or advice will be a kindness. Tom

Japanman

I can help you out with the tubing,
Just p.m me your address and I`ll send some on it`s way.

J.M

Ragwing

My Feedback: (2)

Sounds like fun, I think I will give the Sparky a shot, but only because you claimed the gypsy . I should be able to get started in a few weeks (once I get a set of plans and copy's of or actual printwood). My girl friend lives in Redmond, so I have a feeling I might just be getting over that direction this summer.

Looking at pictures of the Sparky, I do worry a bit about how long the nose is, but with a little ingenuity I should be able to mount the radio gear and battery far enough aft to balance. A PeeWee weighs around 27g, and radio and battery about the same. So with prop it should come out 2.5+ oz heavier than a rubber model. I hope that isn't too much, the Sparky only has a 32" wing. The sparky attached comes from a review over at smallflyingarts.com

Bruce, where the older Top Flite wooden props better than the new zingers? If so there are some commercial sources for old TF props. Is there much to worry about an electric prop coming apart due to the vibrations of and IC engine? Certainly the rpms are no worry.

Thanks!

Derek

William Robison

My Feedback: (3)

Derek:

The OLD Top Flite props were pretty good. The worst wooden props I've gotten in the past few years were Top Flite. Bought a dozen 12x8 wood props, they were so far offbalance I gave up on them.

The Zinger prop quality is aboout the equivalent of the old Tornado "Plasticote" props, without the plastic coating. Haven't seen a bad one.

A piston prop is always OK, so far as safety is concerned, to use on electric. The reverse is not true.

A piston engine has constant accelleration and decelleration in its rotation, with heavy torsional surges. This can only be eliminated with multiple cylinders, a heavy flywheel, or both. A piston prop has a heavy hub and sturdy blade roots to withstand this, but an electric prop, not worrying about the torsional vibration has a lighter hub and more efficient blade shaping near the hub since it doesn't need the strength there.

And there's the problem. An electric prop on a piston engine, sorry, too much possibility of throwing a blade. Not strong enough.

Bill.

BMatthews

Bill, normally I'd agree with the electric prop issue but with the PeeWeeTee turning so slowly and with such small torque compared to the hot wind electric motors or geared down motors with high torque that they are intended for I would have no qualms about using an electric pattern prop for THIS application. Or the electric patter 8x5 or 8x6 for an 049. Wait until you see how much of the hubs and roots I cut away on the wood Zingers for my custom props. And these same 4 props have served me faithfully for well over a decade of Texaco flying. For other sizes of props or engines I would never suggest using the electric props. It's just that the 049's and 020's generate such whimpy power pulses that I pretty sure there won't be any problems. Still, it wouldn't hurt to keep performing very close inspections on the props for the telltale white'ish stress marks around the hub that indicate problems.

But I'm talking about the electric pattern props that still retain a decently thick hub and blade roots. The parkflyer series is another issue. The parkflyer props are deliberately made with thin hubs and blade roots so they will bend or break hopefully before the lighter motor or gear shafts do for the parkflyer motors. Under no circumstances would I ever suggest those for anything outside of what they are intended for.

BMatthews

Ragwing, rather than try to put the radio equipment back behind the wing I would instead suggest that you shorten the nose by one bay. I would also suggest that you increase the size of the Sparky from 32 to 36 inch span to up the wing area a trifle. It's only got about 120 to 122 sq inches in stock form. A bit small to carry the weight of the radio and engine as replacements for the rubber. It would fly but it would not retain the floaty glide. An increase to 36 inch span would up the area to just over 150 sq inches. A better, but perhaps still slightly small, number to my mind. Larger yet would glide better but at 150 it would be a fine baseball diamond tiddler.

William Robison

My Feedback: (3)

Bruce:

I was speaking generalities, and of course going to specifics exceptions can be found. With sufficient knowledge and experience I'm sure some electric props can be used safely on some piston engines.

I've done some radical root chopping myself on speed props. Broke and sanded a lot of them, but I never threw a blade.

Here's a picture of the root of a chopped 4.5x7 that went over 100 mph.

Bill.

PS: Yes, I used the Miller bottle again. Haw. wr.

buzzard bait

I compared a Zinger 7x3 and a few other 7x3s of various brands on a PAW .033 flying a plane that was rather large for the power. The Zinger was very noticeably poorer at getting the plane off the ground. But thinning and re-shaping Zingers is fun and easy--haven't done any tests yet to compare, but you can make them look just like Rev-Ups. Jim