CzarDrill - my first model for Cox

Thank you Czarobest   for sharing your plane CzarDrill project!

Some thoughts on the project:
You can yank n bank if the tail moment is reasonable which his is but the whole vertical stab/rudder looks
small compared to the elevator / horizontal stab. It will torque roll to the left on launch the CG will need
to favor forward to help it track through till there is enough airflow. Real weak spot noted at the wing saddle
that area needs to be beefed up on the inside.

The entire tank bay and radio bay wing saddle etc. needs to be fuel proofed / oil will weaken the plane fast.
Engine exhaust is going to blow back inside the fuselage with all that hatch work. Firewall thickness should be
more if wood screws are used. Oil seep is going to be a challenge, even at the wing servos that should have a
minimum opening iron on covering hatch with a slit for the servo arm will help slow down any oil seep there.
After every day of flying you will need to remove all that hatch work and clean out any oil seep.

Best wishes I hope you enjoy your efforts and flying the plane.

ian1954 wrote:
Is it going to have landing gear (undercarriage)?

No, this model will not have a undercarriage.

ticomareado wrote:I believe you can get a considerable amount of weight off by using a balloon tank. Also rudder control might not be necessary or even desirable.

I need to think about the use of the balloon, it is good idea. Maybe this way the center of gravity will be more at the back.

1/2A Nut wrote:
Real weak spot noted at the wing saddle that area needs to be beefed up on the inside.

This is where the shelf that reinforces the structure comes in.



But I'll see how it can be strengthened, although it seems very stiff in the hands.

1/2A Nut wrote:
The entire tank bay and radio bay wing saddle etc. needs to be fuel proofed / oil will weaken the plane fast.
Engine exhaust is going to blow back inside the fuselage with all that hatch work. Firewall thickness should be
more if wood screws are used. Oil seep is going to be a challenge, even at the wing servos that should have a
minimum opening iron on covering hatch with a slit for the servo arm will help slow down any oil seep there.
After every day of flying you will need to remove all that hatch work and clean out any oil seep.

Tank bay is laminated. Radio bay is protected with a car lacquer
Firewall is from 2.5mm playwood, I didn't use wood screws, I used Allen screws with nut secured with screw glue and spring washers. I'll also try to reduce the gaps in the wing. Each my model is of course cleaned after flights and this one will not be an exception.  


Thank you very much for all your advice and opinions  

I do not know what radio or receiver you had planned on using, but in teh past, I have actually removed the case from my receiver to save weight and have it smaller. This may also be an option for you, again, depending on what receiver you had planned on using.

So when's the maiden flight?

NEW222 wrote:I do not know what radio or receiver you had planned on using, but in teh past, I have actually removed the case from my receiver to save weight and have it smaller. This may also be an option for you, again, depending on what receiver you had planned on using.

I recently changed my radio to FrSky and I have only X8R receiver. This receiver is large even without a case. I could remove the pins and solder the servos straight to the PCB. But I use this receiver for other models and I can't do this.

dirk gently wrote:So when's the maiden flight?

It's hard to tell
Now I trying to create canopies for servos in wing, and I still waiting for send new receiver from Banggood. I might get upset and buy it at the local store. Although I don't like to pay 50% more

Guys, here is something presently for sale on ebay that you might be interested in.  I don't think they ship outside the US though.

https://www.ebay.com/itm/Sterling-C-Series-Polish-Fighter-Control-Line-Kit-Please-Read-Carfully/183953733928?_trkparms=aid%3D111001%26algo%3DREC.SEED%26ao%3D1%26asc%3D20160727114228%26meid%3D1477847a71614ba78c835f1d4daa5ab2%26pid%3D100290%26rk%3D1%26rkt%3D4%26sd%3D183953733928%26itm%3D183953733928%26pmt%3D0%26noa%3D1%26pg%3D2060778&_trksid=p2060778.c100290.m3507



Bob

It looks like the PZL P.1:
https://en.wikipedia.org/wiki/PZL_P.1

It was a very advanced design back in 1929, never entered production though. It could also be a P.8.

I find it hilarious how they coulnd't be bothered to print the name of the plane on the box, and just called it "the Polish fighter", as if there had only ever been one.

Note: the insignia on the box picture are wrong - red and white squares should be the other way around. Also, the wingtop insignia are way too large. The eagle logo seems to be just the kit designer fantasy.

They did print it on the plans though. I find those gull wings interesting. I may make a bid if it doesn't go to high.

Looks like most of it is there or at least the main stuff !! No hardware i can see

getback wrote:Looks like most of it is there or at least the main stuff !! No hardware i can see

Seems to be an engine spinner tucked away far right.  Printed ribs can be a challenge for me, but at least they don't appear to be die crushed.

This is the one that I'm biding on that he has. I have built two and have two more complete kits plus a partial. Love the things.

https://www.ebay.com/itm/NIB-Vintage-Sterling-C-Series-Nieuport-28-Captain-Eddie-Rickenbackers-No-Less/183953776629?hash=item2ad47fdff5:g:JR8AAOSwZc5de9R4&autorefresh=true

Thank you Bob for the link. Nice model, but I don't think I'm going to bid. For now I have other expenses and the delivery would be problematic.

I'm slowly creating servo canopies. I made them from PET bottle. In the evening I will apply a clear coat on them.

rsv1cox wrote:

getback wrote:Looks like most of it is there or at least the main stuff !! No hardware i can see

Seems to be an engine spinner tucked away far right.  Printed ribs can be a challenge for me, but at least they don't appear to be die crushed.

This is the one that I'm biding on that he has.  I have built two and have two more complete kits plus a partial. Love the things.

https://www.ebay.com/itm/NIB-Vintage-Sterling-C-Series-Nieuport-28-Captain-Eddie-Rickenbackers-No-Less/183953776629?hash=item2ad47fdff5:g:JR8AAOSwZc5de9R4&autorefresh=true

Sweet !! that engine
cowel will look good

Man those servo canopies look really nice , you do a good job at making them !!

Today I finally made an attempt to maiden flight .
Unfortunately it didn't work out completely. The front canopy wasn't holding well so I used the rubber to hold it, also the cabin fell off. But these weren't big problems.  

The model after the cast ascended into the air, but it was flying nervously and reacted strangely to the elevator. Eventually it dragged out and forfeiture and I couldn't save it. Surprisingly, practically nothing happened to it, only the hinges of the elevator were damaged. I also had to dismantle the engine and wash it out of the sand.

Perhaps the center of gravity was too much at the back, I will make further attempts soon.

And, of course, a film:

Wow, your motor is an easy starter and a great runner! I find it easiest to start them at full throttle.
To my untrained eye, the issue with the model is the lack of dihedral. It actually looks like it has a trace of anhedral. I would consider cutting the wing in half and glueing it back together with 6-7 degrees of dihedral.

But today the engine wasn't working good and I couldn't try again .Yeah, I usually start it at full throttle .
You're probably right, however I'm gonna try to fly the model again. If it doesn't work out, I'll have to add a dihedral.

It is tail heavy need to move up the CG
Ailerons need some left trim
Rudder needs some left trim
Dial down the elevator throws they are too much.

Success! It's very stable in flight but it's very fast (I like it) .
I installed the GPS inside, but forgot to turn on the logging so I don't know the exact speed. Next time, I'll turn on the logging .

Unfortunately, I crashed in the end (I'm a lame pilot) but the losses are small and I'll fix it quickly.

And most importantly, the video


I'm very pleased that the model of its own design is flying quite well . And Cox on the fly sounds brilliant .

THAT was fun thanks

Pretty darn good for a "lame pilot." Flight looked great to me. Thanks for sharing.

Bob

Hello, I congratulate you on the flight, I would like to give you some points of view so that you can adjust your model and enjoy it relaxed, but even at full speed.
You have a lot of elevator movement.
You have a lot of flap movement. (ailerons) - (Alerones)
Regulate in a flight position (quiet) less movement on those surfaces and place 30% of exponential, you will notice a total smoothness in the flight, without shocks or sudden changes.
Remember that you have an accelerator, fly with less accelerator until you know your model and then you can better enjoy the passes and trajectories.
At minute 2:35 You can notice the excess movement of the elevator that acts as a brake and a relative loss. (as I said before, put less elevator) ... I hope it is useful.

Thanks guys . I think the flight looks good because the model is really stable   .

I had the epxo set up here, but I preferred a larger range because I didn't know how the model would behave. I also had an additional phase of flight set up with smaller angles. But out of stress I forgot to test it . I wasn't using full throttle, but I was afraid to go low due to the possibility of the engine stalling. I'll try to take advices, thanks Mauricio .