combatpigg

My Feedback: (3)

This is definitely one of those "Why don't you Go Electric" projects....
You could use two direct drive props with a "dummy" belt or non functional chain drive to give the project the original flavor of how the Wright Brothers powered their plane.
The original plane has 40 feet of span and I had a 40 inch wide sheet of 1/4" thick Depron lying around..so guess what scale this is..?
The "motor stick" is 1/16" wall aluminum angle. I gutted a couple of .049 reedies to use as bearing supports for the pulley / prop assemblies.
The pulleys have about a 3 to 1 ratio. The belts are 2 inch diameter rubber O-rings stretched to about 5 inches.
I ran it tonight and the props turned at 7500 rpm with the engines spinning to what sounded like the low 20K range. The engine needs a car head for cooling. One of the belts bounced out of the prop pulley groove but stayed on the shaft.
The thrust was pathetic, just a whisper. I have some Slow Fly props on order from FPV.com, so I'll keep my fingers crossed.
At least now I can proceed with the airframe and pray for more thrust...

Pond Skipper

What size props did you order?

I have used GWS gearboxes and props back in the day for sheet wing racers
the 6x5 did well on sub 10k rpm and could be pushed to 12k on a 7oz plane without breaking at the hub.

6pcs GWS EP Propeller RD-6050 / 6.99

combatpigg

My Feedback: (3)

I ordered mostly 8 x 4.5 props with wide blades. They look like a soft plastic and fairly lightweight. I saw some carbon 7 x 2.5s in matched sets for $30 but didn't want to commit till I get a realistic idea about what is feasible. The unknown is friction losses in the belt drive and I probably wont get much play time on this rig before those crankcases get worn out. I filled them part way to slosh fuel / oil into the shafts for the test run.
The on line thrust calculator gives me hope that a pair of larger props might be enough. Once everything is built and running I'll go back and take as much dead weight out of the "power plant" as possible.
What's fun about this project is so much uncharted territory for me. Too bad one of our local WWI scale model builders is gone because he knew how to really build these early model planes with great detail.

Pond Skipper

I would seriously consider using bearings on the outboard props you will gain some rpm to boot. The bearings with a flange will serve you well.

Example here these parts are cheap and abundant online simple brushless outrunner footing firewall mount has 8mm bore accepts these bearings with a lip 8mm x 3mm bore.
You could save some weight I would imagine. Mount and 2 bearings 3.6g

Shown with one of my custom wound motors for reference and a Cox 4.5x4: 3S at 31.6k rpm static 3000kv motor with a 12amp esc. 18oz thrust at 120 mph. 27g with prop and spinner!

combatpigg

My Feedback: (3)

I've got some 3mm bearings and axles on hand for a more intricate contraption, but I'd rather see if this easier to build set up has any chance of flying.

Pond Skipper

Should take to the air in low wind conditions.

combatpigg

My Feedback: (3)

Hopefully..!
Italmost took "The Hand Of God" to make the original plane airworthy with the amount of power, propellor technology and such that was available at the time.
I'm sort of "in love with" the idea of building a powerplant that is 80% COX derived. Mainly because I'm lazy and have high hopes that I can get a COX based contraption to at least do a 100 yard hop like the original flight did.
The original had a good amount of anhedral, so I'm hoping that elevator and rudder are all I need for controlled flight. In other words, I'll pass on the whole wing warping deal for now.

combatpigg

My Feedback: (3)

Here's a couple ofexamples that put my attempt at a SPAD Wright Flyer to shame.....

Pond Skipper

Anhedral do to wing weight sagging the rig down?

combatpigg

My Feedback: (3)

I plan on using Spiderline for the rigging and I'll pull the anhedral droop using the undercarriage for leverage.
I don't recall if the Wright Bros did it intentionally or not. I think the concept of beneficial dihedral didn't appear until much later..like after WWI...?

Jaybird

I think they intentionally used anhedral as the seabirds they observed had it.

Jaybird

combatpigg

My Feedback: (3)

It makes sense. They were no doubt looking for every advantage they could imitate from nature. They did a lot of testing with kites and I wonder if they explored the effects of dihedral..?
Back then, the other designers in the World had no concept of "bank to turn" and it looks like the Wrights experience with riding bikes gave them the intuition that planes should bank also.

Joe Fisher

My Feedback: (4)

Some years ago I was with my grand son in Wal-Mart and he got me to buy an Air-Hogs delta wing. We couldn't get it to fly at all. It was completely uncontrollable. I took if apart and saved the hard ware. I have an old kit 30" span Wright Flyer glider. The kit is bamboo and tissue. I have thought about building the kit and installing the motors and receiver. The props are counter rotating and very the power to the sides for directional control and up and down. It might work.

Mr Cox

A quick search regarding dihedral seems to indicate that people were trying this on gliders well before the wright flyers, and that the wright flyers also added dihedral to later designs; https://en.wikipedia.org/wiki/Early_flying_machines

So I guess the anhedral came from wing sagging, as they did not have any of the wire support that one will see on e.g. the Eastbourne 1913 and similar constructions. The anhedral on the wright flyer might well have gone away once it was airborne too.

I have a modern kit for the Eastbourne, just haven't been able to find a proper three cylinder engine for it...

Pond Skipper

I would play it safe and add dihedral if this is a rudder / elevator effort.

combatpigg

My Feedback: (3)

The only manned glider pilots I heard of before the Wrights was the German, Otto Lilienthal and some cowboy in late 1800's SCalifornia. Were they using dihedral..?
Dihedral would make the 1903 fly much better, but I want to try it with droop.

j.duncker

My Feedback: (2)

It would just look so WRONG with dihedral.

Resist the temptation.

Pond Skipper

Yea that would make it neat to see fly.

But then you will need ailerons or wing warping or be prepared to slip in to a tip stall / spin dive when you try to turn.
All the rudder in the world wont save it. Note the Wright brothers improved the design over time and historical information has been released as to what they did to improve turning. Would be cool with a exhaust throttle sleeve or air choke at the intake.

Tom Nied

I think it will, if you have wing warping. Put ailerons on it and you might as well invite Glen Curtiss to the maiden.

combatpigg

My Feedback: (3)

As slow and underpowered as this thing might be, I'll settle for what the Wright's did on the maiden!.
I plan on using bamboo skewers to act as interplane struts that are simply stabbed into the wings with a dab of glue. Once the thread cross bracing is in place, it's hard for me to imagine how to intentionally warp a structure [for roll control] that is braced so well to resist warping.
I realise that it doesn't take very much of a warp to cause the plane to bank, though.
A properly built airframe in this scale would look great built out of birch dowel, maybe with a light oak stain and of course covered with tissue and dope.

combatpigg

My Feedback: (3)

All I remember about Curtiss at this time was that he attended an Air Show in France that the Wright's didn't attend and he won a cash prize with a plane that barely was controllable.
I believe some of the earliest exhibitions were held inside packed stadiums and the planes were supposed to fly laps in front of the crowd. That sounds like more fun than watching the Monster Trucks...!

Pond Skipper

Here you go an improved version in 1909 that turns better here is a in flight pic notice there is O anything but level flat wings

combatpigg

My Feedback: (3)

Such a neat little plane.
I seem to recall 1909 as the 1st year of the Model T Ford and Ty Cobb lead the American League in HRs with 9. I'll bet he had to "leg" all of them out. The Carter and Holley carburetor companies were getting geared up to supply "Dignified Acceleration" for the major automakers.
They started brewing beer commercially in Shiner Texas....and yes there was refrigeration by then..!

combatpigg

My Feedback: (3)

Some more progress....
I tried to rig some anhedral, but the airframe is too stiff and it would be self defeating in the air I believe.
I think the wing tips can be warped for roll control. A working rudder might clutter the area where the electric starter and my hands need access to adjust the engine. I'm considering a detachable fin that I can quickly install once the engine fires up.
Nobody would pick this model up and be impressed with how light it is. At this point it weighs 12 ozs, so 16 ozs might be a realistic guess once the model is ready to fly.
Hopefully it doesn't take too much guess work to arrive at a working drive system. This set up is geared with enough load to make the engine not want to take over for the electric starter. Once the "hand-off" is made the engine runs with relative ease, but there is a critical period at cranking speed where the torque of the engine is swamped by the load, friction of the dummy crankcases, belt tension, etc.

Pond Skipper

Engine bracket looks good Chuck!
Note the pic in post #22 1909 flyer has the rudder moved back further than on there 03 effort for sure helped in the turns.
I imagine you will be able to tackle a move out of the way rudder assembly with the control linkage intact for easy start up.
Are you going to use a throttle sleeve?