PZL 62 + Baby Bee

Thank you! This is very helpful. I was thinking of building wooden wings just for the fun of it, but since I expect this plane to be crashed very soon after first takeoff, I am strongly considering foam right now. I assume that it's possible to cover foam wings with film.

I built a handy foam cutter using a 10V, 2A transformer from a table lamp that my dog ate, and resistive wire from a hair dryer that my dog ate. Cutting a wing with it is basically 30 minutes of work, so it will probably be ok for the maiden (the wing doesn't even have to be covered) and I will start using a proper wooden wing once I'm comfortable flying the plane.

As for the servos, I didn't buy MGs, but similar ones - with metal gear and all, 11g servos. They were 3 timeas cheaper. It's true that it's not a good idea to save money on servos. Probably it's not a good idea to save money on *insert any plane part here*. I think, however, that this plane will be crashed before even the cheapest parts have a chance to fail

Let's just hope your dog doesn't eat the plane!
Indra

nitroairplane wrote:Let's just hope your dog doesn't eat the plane!
Indra

That's Ruff

complete fuselage (no covering yet) weighs 53g and looks something like this:

dirk gently wrote:complete fuselage (no covering yet) weighs 53g and looks something like this:

wow, looks really great!!! good luck with the rest of the build, cant wait to see more pics

Looking good Dirk
Don't forget you've got .25 gram of eleastic band as well

Thanks guys

It would be convenient for me to do the aileron steering/machanics at the bottom side of the wing. I would have a water cooler imitation that would be a servo protection and act as a "landing gear" at the same time. Is it a *VERY* bad idea to have the pushrods and horns on the bottom of the wing for a belly-lander, or just a plain bad idea?

In an attempt to save weight (and out of general boredom) I decided to do a hollow vertical stab, rather than solid balsa:

It looked good enough before I covered it with film. I did a pretty lousy job, there are small wrinkles on the stab. I seen a YT video where Oracover covering looked really easy. I learned my lesson: Internet lies. I am now concerned how on earth will I cover the wing, if I can't even get a flat stab right.

On a bright side, the stabilizer weighs 3g covered, did not warp and seems to be pretty strong. I will nevertheless do my horizontal stab out of solid balsa.

dirk gently wrote:Thanks guys

It would be convenient for me to do the aileron steering/machanics at the bottom side of the wing. I would have a water cooler imitation that would be a servo protection and act as a "landing gear" at the same time. Is it a *VERY* bad idea to have the pushrods and horns on the bottom of the wing for a belly-lander, or just a plain bad idea?

Put the aileron servo, pushrods and horns on the inside. It will be easier to do
because the wing will be sitting on the board, right side up, looking at you
saying put me here. Anyway it is a scale model and will look better for it.
Just remember you will have to position other servos to clear.
Oracover is an easy covering material but it takes a little practice before
you get it perfect. May not be on this model but you will get it perfect.
John

Actually, I did a pretty decent job with the horizontal stab/elevator. I made the hinges out of the film as well.
You are right - practice is the key. I already learned that I need to eleminate as many wrinkles as possible before ironing the whole surface, that kind of works.
It's still far from perfect, but I'm getting there
A huge advantage of film over tissue+dope is that it doesn't stink

Some very basic questions:
1. should I cover the wooden structure of the plane with something (dope?) to prevent it from warping in the presence of moisture?
2. what wire gauge would you use for torsion-driving the ailerons? I have 0.8mm and 1.5mm gauge wire, the former seems wobbly, while the latter is quite heavy. Do I need to get something in between?

dirk gently wrote:Some very basic questions:
1. should I cover the wooden structure of the plane with something (dope?) to prevent it from warping in the presence of moisture?
2. what wire gauge would you use for torsion-driving the ailerons? I have 0.8mm and 1.5mm gauge wire, the former seems wobbly, while the latter is quite heavy. Do I need to get something in between?

I have an unused set of commercially made aileron torque rods which are 14swg (Standard Wire Guage) which equals to 2.3mm in metric, but they are not Piano (Music) wire, but some lighter material, and, of course, are intended for models a lot bigger than your's, you aren't going to get enormous loadings on your ailerons, so I would think something around 1mm would be adequate.
I take your other question to mean whether you should seal the structure before covering it? In my (limited) experience with iron-on covering films this isn't usually necessary (I'm sure more film-experienced members will correct me on this if needed!)

Wilf

I was lately too lazy to take shots of my progress, but not too lazy to actually make progress!
I finally overcome my laziness, so here are the photos:
A mounted engine:

Using a large amount of epoxy and swearing I finally came up with something that with some imagination may remotely resemble a wing:

Some tail shots:



I also finished and flown my styrofoam trainer, but that one's too ugly to show here (also, not cox-powered).

Looking good!

Were your plans based on a 3 view of the original aircraft or scaled up/down from model plans?

Reason I ask is, for obscure aeronautical reasons I don't understand, I thought models scaled 100% proportioned wind up with undersized tail for flying. Vaguely recall that AMA scale competition (maybe just for RC?) back in the 60's gave you a 25% allowance in larger tail feathers without loss of points, just so things could be flown with some degree of control. So general rule of thumb was to add 25% area back there when working from original 3 views.

The sad story about this airplane is that no actual sources about it's shape exist other than a one side-view drawing (which has been made post-war and may feature some of the drawing's author's imagination). All the actual documentation has been lost during the war. There are no 3d views of the aircraft available.

The only materials I had available were plans for a 3ft wingspan RC model. I believe the tail size has been adjusted.
The horizontal stabilizer+rudder surface is 22% of the wing surface. The distance between the geometrical center of the wing and the stab is about 3.5 times the mean wing chord. Seems about right.

I totally gave up on oracover. I attempted to cover the fuselage today, and it came out to be basically a one great wrinkle. Ripped it off and threw it all out. What a waste of time and money. I fully intend not to touch the damn thing ever again in my life. I am going to stick with japanese tissue, which I am fairly familiar with.

In the mean time, I am building the right wing. I also made the aileron and the wingtip for the left wing, and it came out just fine.

That's more like it. The tissue is coming up nicely. I will post some pics later.

I still haven't decided what will I paint the tissue with. Do you have any suggestions? I'm not sure to what extent the paint needs to be fuel-proof, I sealed the engine cowling with epoxy, but how about the rest of the model?

Partially covered fuselage:


Still no idea what to paint it with.

dirk gently wrote:Partially covered fuselage:


Still no idea what to paint it with.

Paint it with an airbrush if you have one.

Yes, but what sort of paint do I use with the airbrush? I just test-painted an old, battered wing that I had lying around with spray paint, which, according to the label, is resin based, whatever that means. The tissue warped badly, but then started to tighten up again, we'll see how it comes out after it's dry.

dirk gently wrote:Yes, but what sort of paint do I use with the airbrush? I just test-painted an old, battered wing that I had lying around with spray paint, which, according to the label, is resin based, whatever that means. The tissue warped badly, but then started to tighten up again, we'll see how it comes out after it's dry.

Yes you just have to spray from a decent distance.

Good luck in this project!