WILDCRASHWILLY

Zor,

Yes, I'm running dual switches and dual bats. I'm feeding the power in at each end of the rx bus. Where I normally run about seven channels 1 through 7, I just reprogram my sticks and channels to use 2 through 8 on the Optima 9 channel rx. I use channel one and nine for power.


Dand@oz,

Man, you are a fast builder. Your build looks great. I have been very slow. I travel a lot in my job and have had quite a bit of extra activities on the days I've been at home the last year. I do have a few pics to update but not much. I'll post them this weekend.

Zor

WILDCRASHWILLY,

So from what I see and understand I really wonder what you are accomplishing with two batteries, two switches and their wiring.

You have this extra not negligeable weight.
The extra battery is as I understand supposedly for reliability in case a single battery fails (like a cell becomes opened (no voltage from that battey) or shorted (lower voltage) ) .

Now if one battery fail there is no way in flight to open the switch and disconnect the failed battery.
If the failed battery is opened and no voltage is present that is fine but if a cell is shorted then this failed battery becomes a severe load on the still good battery.

Batteies are much more likely to have a shorted cell than a fully open one.

Any comments (from anyone) ?

Zor

beepee

Zor,

I have done the same and have remained concerned about a cell shorting out, but it is the simplest system. It also provides switch redundancy, which is a known mode of failure.

Bedford

Kolbboer

Hi Wildcrashwilly,

I have beenused the same system andfeeding the power in at each end of the rx bus. between the switches and rx i have added a batschare from "Smart fly" price~ 30$

Smart-Fly BatShare, you can tolerate a single failure (open-circuit, short-circuit, low voltage) in either battery pack, or switch, or battery wiring, without losing radio control.
The Smart-Fly BatShare continually monitors both battery packs and switches for the one with the higher voltage, and routes that to your Rx and servos. You may combine different size packs. In practice, with two good packs, the BatShare draws power equally from both packs, adding their individual capacities. I.e., if Battery #1 is a 6V/1350mAH pack, and Battery #2 is a 6V/2700mAH pack, you will have 4050mAH power supply onboard, with at least 1350mAH to fly on, in case of a failure.

3 yearsin my Yak 54, andno problem (im going to use the same setup in my Dynaflite Decathlon)

Jan B

Zor

Now this makes sense.

Any idea of the insertion losses in voltage?

Zor

[email protected]

Yes, I've gone fast with this plane, probably faster than I should have because there are some things that I could have done better. But I'm trying to meet a model contest date of 31 March. I won't be able to fly it until later in April due to unfavorable weather, but I can do the dog an pony show Still have windows, trim scheme, and finalizing details, but it looks like a plane now.

WILDCRASHWILLY

Jan,

I've heard about the bat share over on a ******giants thread but I have never used one. Definitely worth checking out.

Zor,
I agree that this will not help for a shorted cell, but it will cover me for a bad switch or bad connector. Although, I have heard of cell shorting, I have not seen this. At some of the clubs I've flown at, I have seen a switch failure and a few battery failures due to poor solder joints. Fortunately I have never had a bat failure. I only use Nobs batteries from Hangtimes Hobbies. His quality is excellent. Also, I have been told that wrongwayrc has great quality as well. I'm mainly doing this for redundancy on the connectors, wiring, and switches. Also, I'm increasing flight time with dual 2300 a123's. I like the idea of having 4600 Mah reserve to work with. With the engine I'm running the additional weight of 6.3 oz for the extra bat. and the extra half ounce for the switch really is not an issue for me. I will admit however, I have not completely decided to go with the dual set up as I'm only running metal gear analog servos. I do run duals in the 3d plane with digitals though as they can draw pretty heavy. The A123's will give up their energy rapidly if the demand is there. The down side, is if something shorts, it will be like an arc welder in the fuse... (It will all be toast[:@] )

dand@oz,

From what I can see your workmanship is great. Looking forward to seeing the finished model.

WILDCRASHWILLY

Here are a few pics. I may have a duplicate if so, I'm sorry. had a couple out of sequence on my computer. Spent a little time documenting the LG mod today. On some previous post here somewhere, Zor spoke about floating the collars if fastened to the LG at the fuse and locking the wire to the collars if the LG was not fastened to the fuse. I originally planned to have it all float but the more I thought about it what he said made sense, so I locked the music wire to the collars. Also, I used 5/32 wire and wheel collars. I used 6-32 allen head socket screws from RTL Fasteners to lock the collars. My screws were a little too long so I cut them off with a little cutter that I have. I cut them to 7.5mm in length, (give or take .1mm either way. Hope the pics are self explanatory.

WILDCRASHWILLY

Some more pics. Also, in the previous post, you'll see where I was making some servo trays for the choke and throttle servos. Forgot to mention that earlier.

minkiehuoise

      i need some help!!!!!!!! i have a dynaflite super decathalon kit i am trying to build.i have the tail feathers done ,now i am at the wings and need help. i would like to know how the four basswood spar .doublers go with the taper, up or down just on the main spar or back spar too
                                                                                                                                                         i need help waynw

minkiehuoise

      i need some help!!!!!!!! i have a dynaflite super decathalon kit i am trying to build.i have the tail feathers done ,now i am at the wings and need help. i would like to know how the four basswood spar .doublers go with the taper, up or down just on the main spar or back spar too
                                                                                                                                                         i need help waynw

Zor

WILDCRASHWILLY

Just to mention that something is bothering me about your landing gear.

Where it is mounted to the fuselage it is so narrow front to back.

I imagine that on a landing the planemay be coming at what would be a wheel landing and the wheels hit a bump or a crevisse in the ground. There is little front to back distance to prevent the gears from tearing backward and pulling out of the fuselage or damaging it.

Just a thought.. Any comments ?

Zor

WILDCRASHWILLY

Minkie,

Spar doublers go on the root side of the wing. Doubler with taper is on top of bottom spar and below on upper spar. The spar slots on the inner ribs are deeper to accomodate the wider section of spar. Look back on page 50 of this thread post 1247 left pic and page 51 post number 1259 at the right pic. You'll need to blow the pictures up to see better. Look next to the tube just out of the ply webs and you can see them. Sorry, I should have taken better pictures of that stage of the wing but, in all honesty, I didn't think to get a detailed picture.

Zor,

I agree, the landing gear should be a little wider but, it is built to plan at that point. No doubt, the narrow gear is why everyone is having to modify with the music wire to keep it from bending. Look at the picture in post 1334. The inner ply plate is wider than the footprint under the plane. Hopefully this will be strong enough to hold it. So far I've not heard of anyone having issues with that part of the fuse, so I guess it is working okay.

Zor

Looks like we have a misunderstnding here.

The "music wire" help to reduce the bending upward toward the top of the model.
I does nothing for what I am talking about.

I am referring to movement backward toward the tail. The wheels hitting a bump or falling in a groove in the ground resulting in a backward impact on the wheels.

There is much longer moment arm from fuselage to ground than there is in the longitudinal (prop to tail) dimension (width if you like) of that narrow landing gear.

I was just commenting. There would be no problem in any normal landing.
I noticed that you are using four blind nuts holding this landing gear.
I see that the piece of ply is fairly long in the front to rear dimension .
I am concerned that the blind nuts can crush into that plywood.

The main thing is that you are not concerned as I am and of course it is your plane.

If it was mine I would modify this mounting.

Cheers from Zor.

minkiehuoise

thanks for the help because it was driving nuts. it all make sence when you think about it. just had a mental block for a while thanks agine
minkiehuoise

do335a

FWIW, that was never a problem on my Super Dud. The issue was the cheap, weak LG itself. That would allow it to splay with the slightest load.

Even with that music wire brace, there will be a tendency for the gear to bend at the unsupported curve in the leg just above the wheels. I found that out very early on.

do335a

Don't trouble yourself with that.

The taper is only between two ribs and amounts to nothing. You will not compromise the plane in any way if you don't bother to taper the spar doublers. You would save maybe a fraction of an ounce of weight in what is already a very porky airframe. Won't amount to a pinch and not worth the effort.

Just cut the doublers to the appropriate lentgth and laminate them to the spars.

There are many other places where you can save much more weight than that without hurting anything and with a lot less effort than cutting a taper.

83scamp

I don't know that I agree with that statement. By not tapering the end of the spar doubler, you create a potential stress riser right where the doubler ends. The whole point of tapering the end of the doubler is to gradually transition the load to the thinner section of spar. The struts on this plane are for looks only, by not tapering the doubler, you significantly increase the load at that spot, and if the wing ever fails, it will fail there. I personally will follow the directions on this step. I don't want to accidentally end up with a folded wing. It works on a Corsair, not a Super Decathlon.

Pitts532M

My Feedback: (1)

Zor

FYI ___The struts can be easily made "working effective struts" by using the snap mehod.
No tools needed for removal or assembly.

Zor

do335a

A stress riser is the last thing that you need to concern yourself with at that point. You've got bigger problems, such as where parts don't fit because of the size supplied yet they are shown to be in contact with one another on the plan and glued together. The designer's solution was to draw the lines thicker on the plans to fill the gap. Not so great engineering there.

You will also notice that my spar doubler buts against the rib at its end. It's also attached along its length to a shear wb. It ain't goin' nowhere, my friend.

Just to be certain, I also junked those flimsy plastic strut attachments and the wood screws to hold them on. My struts became fully functional, attached to the plane with 6-32 socket head cap screws througn metal tangs into blind nuts, installed in well reinforced hard points.

Look at the sketch below and you'll see what the book shows and how I did the spars. Does it work? You bet! My plane flew through a tree and the only damage was to the tree. This plane is built like the proverbial brick XXXXhouse.

beepee

532M,

Don't shorten the nose, whether scale or not. It would only make the tail-heavy problem worse.

Bedford

Nothrottle

I see the music wire as unnecessary weight as my Decath has experienced a few hard landings. No splaying here but.... the 6" DuBro under-inflated tires do provide an ample cushion... with a 55cc DLE spinning a 22x10 composite prop. This setup provides ample additional weight and power! By moving the rudder and elevator servos under the rear hatch plus the 5-cell battery pack just behind the CG. The 16oz. fuel tank is centered on the cg, perfect balance was obtained.

minkiehuoise

hi crashwilly:
when i built my taylorcraft and i wanted make the gear stronger i used coat hangers hope this helps minkiehuoise

Guitarman52

My Feedback: (2)

I finished my decathalon kit about a week ago and got to maiden it Saturday. I put an RCGF 26 gasser on it with a 16x10 prop. I was very disappointed, it was a real hand full. Very under powered. I tore the landing gear off , but other than that it was in pretty good shape. What do most of you guys use for a motor.