tommy s

My Feedback: (55)

When we flew the old AMA pattern no one thought twice about flying a .60 sized pattern
ship with retracts at 9 to 9.5 lbs, now it seems if the airframe is a couple of ounces over
what we think is ideal it goes in the scrap heap.
I haven't seen the .50 or the .90 size but the 1.40 Tojeiro is an excellent airplane no matter
what it weighs.

tommy s

Murdoc

You took the words out of my mouth! Couldn"t agree more.
Again to all of you who reads this thread, forgive my bad english

mr2mk1

Do you get your plane to balance at 3988 grm Wagen ? By the way great ideas on wheight reduction ,if i where to get it so light i woud be a happy man . Murdoc why isent it a good idea to discuss this problems with the weight when it is the biggest problem with the plane. Why do you think protec sets it at 3700 when it is imposibel to get so low unless you change parts in the kit ? 4,1kg is what mine ways ,this is almost as much as a modern 140size composit pattern ,look fore your self http://www.znline.com/produits.php?l...ata=1139435628 ..

wagen017

Unfortunately, all info I have about the weight sofar is simply putting all things together on a scale (with the small parts still in plastic bags). Still, it should give a pretty good estimate of final weight, since there won't go too much epoxy/glue into this plane. Anyway, all this discussion has now got me motivated to start working on the plane, and it will be a nice excersize to see how low we can go on weight. I just sent some emails to people who are selling a FA-100. Once I have got one, I know for sure I can go that route.

The only thing which worries me is to end up with a lighter airplane, which then needs lead to balance..... If I have the fuse in my hand, it does feel like the weight is a bit to the back.

Does anybody have a good CG? The manual states 140mm from the leading edge.

wagen017

I have been reading back in this thread, and the general opinion ventilated is that the Tojeiro-90 is a good flying airplane, capable of going thru its manouvres. Since I am still an average Joe in pattern, it will probably outfly me for the time being!

I checked the Tojeiro manual, and it recommends 2-stroke .61 - .91 size, or 4-stroke .70 - .91 size, with a flying weight of 3,7kg. Given all info, a flying weight with the smallest engine recommended (and even then you have to be picky, an OS-61 is too heavy!!) of 3,7-3,8kg should be possible (I don't think you can fly this airplane as intended with a 70 4-stroke IMHO).

The design of this plane has intentionally this small wingsurface, which then translates into a higher wingload. Like said before (and you can also find these comments here at RCU) the Tojeiro-140 is a great flying airplane, also with a gasser mounted, so I must assume the design itself is good. There should be no reason why the 90 is then not good as well!

I do get the impression the 90 is relatively heavier then the 140. Therefor I think it does make sense (I think this makes sense on any plane ) to see if it can be made lighter. Replacing the landing gear is an obvious start, since the original one seems to be really heavy, and not of such good quality.

wagen017

It would be nice if somebody who knows about pattern design can comment a bit on the effect of the relative small wings (or wingarea) on flying pattern.

mr2mk1

You will not get it under 4kg balanced ,if you youse the recomended cg frome protec it will be realy havey. It is normal that massproduction airplane has the cg to far in the front ,mine is a lot further back than recomended . I cant remember the masurment but i will masure and post it here ...Ok my cg is 17cm from the leading edge ,protech recomended is 14-15cm . I started with 14 and much lead in the nose ,terible elevator response and much down elevator when inverted . After many trim flights i have ended up at 17 cm from leading edge ,but this may not be the way you like it so test until you like .

Murdoc

wagen017: How is the building going? are you making progress?

wagen017

building, what building? Oh my god, I forgot about that box in my garage!!!

I had to rework another plane first, but that is done now. Now i can (and must!) start again. Will put some info on the site once I get going again!

Hope it doesn't get cold in between, I am working in my garage without much heating. So if it gets cold, my enthousiasm cools as well!

Murdoc

Hey! get you self together
Rc planes is your first priority, then you can think of the temperature in your garage!

wagen017

Spoken like a true Norwegian!!!

Murdoc

yeah man we norwegians get used to the crazy temperatures, you know!

mr2mk1

Ok i wrote a email some time ago to protech regarding the weight of it ... this is the what answer i got back :Hello,
The model that we tested was 3.7 kg.
Oure supplier added some extra's, that is the additional weight.
Whe have changed that info now in the manual and catalog.
My father fly's with a tojeiro 90, with a 91 four stroke and the model weight is
4.5kg
It fly's good.

Regards

Luc Van Tricht

4,5kg[X(]

wagen017

Maybe it flies great at 5 kgs as well........sure it does!

You know, I think it will fly good at 4 kgs as well, but 4,5kg to my opinion is too much!

wagen017

Anyway, spurted on by Murdoc, I finally got some work done. Finished the wings. The location of the servo's is such, that the connector just barely comes out of the wing. Therefor I lengthened the wires. I never like to use the extension wires (with extra connectors) so I soldered them.

wagen017

Some bright person might have thought that servo's have no wires attached to them, so there is no place for where the wire exits the servo. I just pressed the servo in there, breaking the balsa, so I made the space. Here a picture of the servo and the supplied hardware for the aileron.

The finished weight of the wing is 389 grams.

Murdoc

Great to see you are making some progress on the build!
I also agree that 4,5 kilos is way to much.. on their website it still says 3,7...

wagen017

Here's a picture of a test fit of the wings on the tube. The second picture is with the canopy hatch on. I like this concept, gives great access.

On some other threads there were complaints of a too loose fit of the wings on the tube. With this one, it is good. The tube is sitting quite loose inside the tube in the fuse, but this is no issue, since the wings are secured well onto the wing.

wagen017

The elevator halves are joined on the fuse by a aluminum tube (which I plan to replace with a carbon one). The manual states very clearly you should only fix them onto the fuse with epoxy once the whole model is finished. Anybody any idea why?

The design seems to be a direct copy of the 140 version, on which I assume you can take off the elevator halves.

wagen017

Epoxied the hinges in the elevators and stabilizer. Then continued on mounting the rudder. After epoxi-ing the hinges I mounted the supplied pull-pull. I shortened the threads on which the pull-pull wires mount on the rudder on the same length as the arm on the servo, so I have about a 45 degree throw on the rudder.

I always have dual rate on the rudder, activated by the throttle (>30% throttle 70% throw, 50% expo; <30% throttle 120% throw, 100% expo)

For the elevators I mounted the supplied bell-crank. I really like this solution, first time I use it! On my pattern ship I use pull-pull for rudder and elevators.

lodomjr

My Feedback: (6)

Wagen017,

Sorry for no replys, I've been out of town for a week. I will gets some photos of my modifications and post them Sunday 1-14 in Florida. As for the weights of my Tojeiro 90 I'm not sure, but my 91 AC pulls it very well. It does not have unlimited vertical, but it's pretty good. My wing tube was loose in the fuse. but it was tight in the wing. I took a piece of masking tape and wrapped the tube near the fuse. exits. That took up the slop there. I also cut down the 4mm bolt for the hard point out on each wing so they would tighten down on the tube and be flush with wing.

lodomjr

My Feedback: (6)

Here are a few pics of the modifications I did to the radio compartment and the pipe tunnel. The pipe is a home made from 4 oz. spray cans that were brazed together. The pipe works extremely well. I made my own servo trays and I know you can't see it the photo, but the battery and receiver are under the elevator servo.

Murdoc

That looks sweet!
But is that the stock wheelpants?

wagen017

Lodomjr: I like the solution for the pipe/muffler. I have been thinking about this, in particular how to get the muffler to fit into the fuselage. Your solution is better, just leave it open!

Do I see it correctly that you installed wing incidence adjusters?

volkert

wagen017

although I am tempted to go for a Saito FA 100, I am totally put off by the price they ask for this motor (325€ here in the Netherlands, that is 420 US$!!!!). I have not been able to find any other second hand for a reasonable price.

Also, I liked really the performance of my OS-91FX with perry and pipe. So, although it is tempting to see how low you can go on weight, I am still thinking about mounting the OS. With a carbon landing gear and tubes, the weight should still come out at 3,8 kg, which isn't light, but will be fine for the flying I do.

Now first I need to get parts to finish the plane. With the last flight with my infinity, I lost both my header and the needle valve. Also I first have to get my hands on the carbon parts.