Cox .01 /.02 /.05 /.09 /.15 Speed Planes

It’s a shame to hear about the back plates  no worries though I’ll just make my own in the meantime.
Would you be able to measure the diameter and depth of the part that slips into the crankcase and the oring?
Or better yet include a photo I’m sure I can figure the rest out.

The tracking for my .020 conversion shows it’s in New Zealand so hopefully it will be here Monday/Sunday  

What do you think about a single blade 1.5x5.2? I will probably mould it from carbon and machine a brass counterbalance, I also may extend the tip in the mould to make it a 1.7x5.2

I would not worry about the backplates yet they may very well show up.
Lets see what will happen to them, was told a run of them was made will
see where they end up being sold from.  

A single blade is tricky I noticed the 3 blade ran very smooth do to even disk load of
the three blades. It certainly is possible providing you can balance the prop to keep
the wear on the aluminum crank case to a minimum. But there is another huge factor
that can not be addressed the single load of the prop in operation will naturally pull
on the blade side as it lifts. Without bearings you can't control the adverse wear on
crank case. A 2 blade prop at least has counter acting lift from the opposing blade.
Yes typically you can up the dia. or pitch with 1 blade there is some natural reduction
in load. If you do try it monitor the wear / wobble in crank to case fit. Perhaps up the
castor content to 22% to compensate some. 2x5.2 if you make it can always trim
down to 1.7 if need be.

Any new vids would like a peek if so..

I set up the tuned pipe on the Nano III the NV was turned in to sync the pipe no tweaking.
Static: 28,262 rpm /  (26.586 with no pipe) a good jump up +1,676 rpm.
9.3oz thrust / 140w / 120.4 mph prop speed.

Update from the machinist!

"Well this project is finally over. I'll be setting up the lathe to run the
rest of the backplates Monday and if things go well should be able to go
public Monday night or Tuesday."

Yes! Excited for those backplates! Just picked up an aluminium tank mount for the TD .020, and now this! My spares inventory is getting heavy.

Woooo yeah!!!

Well.. my goodies showed up this morning, every thing is so so tiny!!
So far I’ve assembled most of it, I have a pee wee back plate on there so I don’t get dust in the case for the time being.
I have a few problems though, the thrust plate doesn’t have any splines to engage with the crank?
So do I just press fit this by winding the screw down with a prop on?
It’s super tight.
Also the Venturi body where the needle screws in looks like they’ve tried to recess the first 1/16 of the thread to make it easier to start the thread except it’s gone the full depth and the needle pushes all the way to the bottom
The only thing I can think of would be to crimp around the neck and hopefully cut the thread onto the NV, and a slice of fuel tube to seal any leaks?
Anyway not sure if this will work, I may just end up getting a genuine cox one.

Yay congratulations its a Wee Lil TD .020!

Yes this parts are small but the engine is mighty with it's front
induction system pumping in air and fuel at a much better rate
than the Pee Wee can.


No do not use the prop screw to set the prop plate.
If the bolt snaps your screwed.

Set prop plate down on flat surface
Take the fuel tank off to expose the back end of the crank.
Line up the crank and place a steel 3mm rod thru the back end of the crank
and with a hammer tap tap tap till the splines migrate thru the thrust plate.
The thrust plate is aluminum the splines will create the grooves easy enough
but you need to tap tap lightly insure it stays straight as it goes down may
have to angle the prop plate and tap the steel rod lightly until it's straight again.
Once seated rotate and check if it is flush. There should be a slight gap between
the thrust plate and front carb collar once completed .

Don't cut and crimp anything. Yes on fuel tubing no on the spring make sure the
tube goes over the NV body as show and over the NV as shown. Steel rod I use
to set thrust plates.

The type aluminum carb body you have has a slight issue  you will need to fix.
When the venturi screws down the NV body the body does not sit flush to the carb
body they can leak air there making fuel draw less consistent. What I did with the
one that Matt sold me was carefully file a flat spot about 1mm wide ring around the
intake hole of the carb body. Now this is best to do with the front collar removed
and the carb body removed from the assembly. Any aluminum partials from the file
work can be cleaned out easy. Oil the inside of the carb body and its threads before
assembling to help seat and seal. Oil the collar threads the TD tool has a special
function for the collar be careful not to mare the square slot for the tool to fit in.
Oil all thread. NV, Glow plug, prop bolt, rear bolts anything with threads to help
seal and help when taking it apart. Make sure the collar tool is flush well seated
before turning tight or untightening. It barely catches the into the square cut out
of the collar as is and will rip as it break free screwing up that cutout.

You need a TD starter spring, I will show you how to use them with aluminum carb bodies.
http://www.exmodelengines.com/product.php?productid=18274&cat=249&page=1








Should have never been a curved surface do not attempt to get completely flat with a file you will screw it up
any offset will cause a leak just a small introduction of flat area will help the NV body seal to it. You can make
a thin gasket washer for this if you do not want to file.


I have bought 1 assembled version from Matt, I'm surprised your's was not assembled.


When I tighten down the soft metal bolts I found them shifting causing notable wobble and
the spinner too robs top rpm. the solution is a quality hard bolt that will not flex when torqued
down. Less chance of a prop flying off loosing the spinner assembly in the grass. Major power
robbing issue if not addressed. I hate spinner wobble wears out the crank case over time.

I tested the NANO III today with some trouble with the clunk first toss nosed dived the
plane with a good smack breaking the prop. What I didn't  know at that time was the
clunk flipped forward in the tank. I had added down thrust and right thrust with the
car engine anticipating the need as speed was going to go up quite a bit. These offsets
help from using the control surfaces to compensate which scrubs speed. With that said
I dialed in some up trim for the second flight this time it launched but rough wanted to dip
and pull to the right, the old settings with the Cox engine would not do so the struggle
to correct had me flying a tiger by it's tail. The engine was throttled down but the unloading
of the prop was causing the engine to pop on and off the tuned pipe. Quite a handful till
I had the trims set then I punched the throttle wide open up high to monitor for aircraft
potential deflection at speed. All was well it went nice and straight a good shot across the big blue
sky it tracking very well at full bore. The clunk being up front cause fuel intake starvation
as the tuned pipe acted like a pump demanding additional air / fuel mix yet all the fuel was
plastered to the back of the tank as the plane accelerated. Quite a sight to see like a turbo
charged nitro beast it freaking shot off like a rocket burned off it's fuel charge and shut down.
The abrupt stop of the engine had my ears listening to the plane whistling over head till the
speed bleed off. I started the engine back up but noticed it would not run nose up so figured
my fuel tank was to blame I thought the clunk line came loose was surprised to see if flipped
forward. So took it home to work on and called it a day as the tank is glued into place. All
fixed now, will try again next weekend.  Least I was able to find out the unloaded speed potential
of the smaller Nano vs the Dart, once fully tweaked I expect to get more rpm doing passes in front
of the camera the NV was left rich as the engine has hardly any run time but also to handle the
huge fuel demand when on the pipe.

Static at launch 27,816 rpm / 119 mph prop speed
Unloaded 37,710 rpm / 161 mph prop speed (PS)

+960 rpm increase do to less drag and weight, this will also  
improve the doppler reading to be closer in sync with prop calc.
Warm partly sunny 78F with the heat index. 5 to 8 mph winds.
Perfect day thwarted by a fuel tank clunk!

DART - Fuji .05 / 148 mph doppler / 156 (PS) / 4x4.5 / 36.75K
NANO- Sportswerks .05 / doppler? / 161 (PS) / 4x4.5 / 37.71K

A 4x5 will be tried after I lay down some good 4x4.5 passes in front of the camera expect about 155 per doppler.
The 4x5 should bust 160+





The rains and warm weather have the bugs out playing in the sky:



At 2 mins 10 seconds into the vid I see the plane is finally in good trim and set up to bang the throttle wide open.
The glide is still good with the extra 1.15oz of weight of the new engine pipe combo 10.15oz  RTF
1440p HD

Wow that’s some serious rpm!
Unloading an extra 10k seems like a lot

Some of those bugs look bigger than the nano lol

I’ve seen you build a header for the tee dee .049 do you think it’s possible for the .020?
I suppose the best way to make a pipe would be a wax plug on a lathe then wind on  carbon tow with some high heat resin.

Also have you tried enlarging the Venturi what affect would this have?

And what about bladder tanks for the .020?

Just as well I waited for your reply, getting the drive plate on with the crank inside the case had me stumped.

I think I’ll send the carb body and NV assembly back and re order some oem parts, Coxengines looks to have the carb body already milled flat on to to accept the Venturi assembly.
I also brought a rod resetting tool as I noticed a tiny bit of play on one of my pistons.

I’ll keep that spinner for one of my pee wees I’ll probably build a vintage free flight for


.

1/2A Nut wrote:...

When I tighten down the soft metal bolts I found them shifting causing notable wobble and
the spinner too robs top rpm. the solution is a quality hard bolt that will not flex when torqued
down. Less chance of a prop flying off loosing the spinner assembly in the grass. Major power
robbing issue if not addressed. I hate spinner wobble wears out the crank case over time.

For the same reason I replaced the TD020 stock prop screw with the 049 engine mount socket head screw sold by COX Int'l, and it was really worth it:

https://coxengines.ca/cox-049-engine-mounting-3-48-x-1-2-socket-head-screws-3-4.html

Yes loud and fast with just a taste at the end of the vid a quick shot across the sky
was enough data to calc out the possibilities with the next flights. The bugs are having
a party no doubt in Texas we are getting into the rainy stormy time of the year, grass
is growing and the bug count is picking up and thriving. The car engines on pipes can
really turn up and let loose in the air.


I would not bore out the venturi too much fuel draw issues, steady runs etc. If you have
a spare one opening it up a 10% and bench testing vs stock. Should be a safe bet for
a bit more rpm and even more in the air. Smooth and polished intake after drilling it out
a hair bit will help speed up influx. Pressure works till the pressure is down and
then you have a section of the run time at the end that won't be as stellar. A good latex
tube will keep the flow going 90% of the run. I would learn the TD .020 in stock form
first less trouble more flying.

Tune pipes have been made using carbon sock, wax form and high temp epoxy.
Scroll through the conversation / pics / data / articles.
https://www.rcgroups.com/forums/showthread.php?2684743-1-2A-Speed-010-to-15-Size/page5#post36993976

https://www.rcgroups.com/forums/showthread.php?2684743-1-2A-Speed-010-to-15-Size/page3#post35409217

https://www.rcgroups.com/forums/showthread.php?2684743-1-2A-Speed-010-to-15-Size/page9#post37321755

Here is the only engine I have with the arched top on the carb body a careful effort with
the flat file as previously described only a small area need be flat, was enough to get 118 mph
prop speed with the engine. You should be brave and just fix it save some time, everything you
have will work fine. If you keep using Cox engines times like these tend to happen.



I have some of the carbon sock material in rolls can stretch it over a form here is a rendering for the TD .020

Contouring Gauge helps to copy actual shape.

That was some good reading material there, I’ve saved the articles for later reference.
I’ll make sure I’ve got everything running reliably before I start messing around with big modifications, I’ll try enlarge my spare Venturi and polish it to see how it goes.

I have noticed when you use an exhaust collector you use a piston and cylinder that doesn’t have SPI, all of the .020s do, will that counter the gain of putting a pipe on it?

I had to get a new needle valve body because it was stripped out so I ended up throwing in a new carb body in the same order as well as a piston reset tool.

You’ll have to tell me how to use them too

There are many high performance engines that have SPI and use tuned pipes,
my take is mixed on the subject but the bottom line is the engine can function
with the pipe from 140 degs timing and up, the higher the timing the more
gate time you have to shove in more boost of course. The pipe adds enough
benefits to use them. Sound and goo control is a plus. They add to the fun
of it all and look cool on the plane. I have mentioned header pipes for the
.020 and .049 so folks can use mufflers and in my case I want to try a
tuned pipe on the .020. I hope he releases them backplates soon. Turbo
plug adapter for the .020 is another item on the menu, lastly a RC carb
for the .020, a good engine size for park flying with modern micro gear
this displacement has much to offer now. I plane on making another
.020 plane made for the new backplate motor and if all goes the additional
add on's. Yes reset tool is good to have I have one for all the cox engines
less the .15 TD. I plane on making a 21" span NANO IV a 4th generation
design with some new changes made for 3.7g metal gear servos.

I just bought a hands free radar gun that will wifi (150ft range) to a 20" LED screen shows the
top speed and current speed.  Comes with a tripod for the radar gun nice setup.

- Bushnell Speedster III  / range of 1,500 feet and an accuracy of +/- 1
- LED Radar Gun Display
- Tripod
- $247 delivered.
https://www.opticsplanet.com/bushnell-speedscreen-radar-speed-display-101922-wireless-radar-gun-screen-w-tripod-ca.html?_iv_code=BU-GA-101922-KIT1&image=a33fe854e7

Free shipping  bundle deal you save some cash. I will buy a shoulder strap bag to haul the
setup out to the flying spot at my field, leaves me free to carry the plane and field box.
The radar is good for up to 200 mph with IC engines. I wanted the screen so I could glance down
at the latest speed pass. I have been eyeballing this for a while the price has gone down after
a couple of years on the market. It will hold the last reading till it picks up a new reading so
each pass can be evaluated as I glance at the screen while filming. After landing I can do a final
check of the fastest pass per the smaller display in the bottom right corner. Easy enough and
no more calculating mph. Will still want to know the rpm. This will be good for my outrigger hydro's
too big plus to have real time data flowing in for swapping / testing props.

That’s a sweet set up with the radar gun, especially with that massive screen!
One of our members is a cop so I’ll get him to bring one out from work hahaha

Will your next nano design have internal push rods?

I’m also going to design a new fuselage for the tee dee.020, there is too much drag from the engine and fire wall and push rods for my liking, I may do something similar to this with a Cowell for the cylinder  



Possibly even a wooden speed pan to give a good solid mount for the engine.
I’ll probably decrease the wing span a little too, it glides too well I thing, just a waste of area  

Hello all! 1/2A Nut was asking about some backplates a while back over at RCG and I had a design I was ready to make. He's posted about them here. I have these ready now for Tee Dee .010 and .020.

Greg

Greg,

Welcom to the forum. Thanks for designing and making these back plates for these little gems.

Jason

gkamysz wrote:Hello all! 1/2A Nut was asking about some backplates a while back over at RCG and I had a design I was ready to make. He's posted about them here. I have these ready now for Tee Dee .010 and .020.

Greg

very good your work Sir !, congratulations and welcome to the forum!

1/2A Nut wrote:I just bought a hands free radar gun that will wifi (150ft range) to a 20" LED screen shows the
top speed and current speed.  Comes with a tripod for the radar gun nice setup.

- Bushnell Speedster III  / range of 1,500 feet and an accuracy of +/- 1
- LED Radar Gun Display
- Tripod
- $247 delivered.
https://www.opticsplanet.com/bushnell-speedscreen-radar-speed-display-101922-wireless-radar-gun-screen-w-tripod-ca.html?_iv_code=BU-GA-101922-KIT1&image=a33fe854e7

Free shipping  bundle deal you save some cash. I will buy a shoulder strap bag to haul the
setup out to the flying spot at my field, leaves me free to carry the plane and field box.
The radar is good for up to 200 mph with IC engines. I wanted the screen so I could glance down
at the latest speed pass. I have been eyeballing this for a while the price has gone down after
a couple of years on the market. It will hold the last reading till it picks up a new reading so
each pass can be evaluated as I glance at the screen while filming. After landing I can do a final
check of the fastest pass per the smaller display in the bottom right corner. Easy enough and
no more calculating mph. Will still want to know the rpm. This will be good for my outrigger hydro's
too big plus to have real time data flowing in for swapping / testing props.

Brad, do you think the gun can take the model given its small size?
That is to say, I do not know the capacity of that team, I was wondering if the model is not very small so that the gun can read it ...?! ?!

I already own the Bushnell Velocity radar gun is good to 200 mph it has had no problems
reading airplanes and boats.

The new tech is the Bushnell Speedster III
I will have the radar gun in front of me to insure I get accurate readings and when the plane
passes in front of me going down wind the gun will be to safe by my right side out of the way.
As the plane accelerates towards the radar gun the mph readings will increase to it's maximum
for that pass. The 20" LED wifi monitor will be positioned as shown in the foreground as shown
in the photo to capture on video the speed of each pass with the current top speed in the
bottom left hand corner.

This will save me time calculating speeds at home and from defending the reported speeds.
Beyond that it just makes for a better video when you can have real time speed results.
The Speedster III is on K band 18 to 24 ghz. so the radio frequency will be sent out up to
24 billion hrz as far as 1,500 ft with accuracy and bounce back off the plane to the radar gun
which will receive the difference in the compressed frequency wave and calculate the speed.
As you know my passion has been to maximize for speed without going exotic with materials
to achieve good results with the Cox engines.

Jordan, I like your approach to improve on the simple design look forward to your next build!
Internal torque rods for the ailerons requires a bit bigger fuselage and more weight but
would be nice to run a clean setup. A cowled engine would be cool, it gets very hot here in
Texas in the summer, I would have to have a intake vent for the crank case and for the cylinder
with good size exits to keep airflow positive. I like the open firewall to make engine changing
easy the Sportswerks engine was fast to set up.