Muskoka dad

My Feedback: (5)

HEY GUYS  I GOT ALL THE SOLDERING DONE, LANDING GEAR AND THE CABANE STRUTS.

Zor

EWAN,

I am a bit confused from your posting.

Looks like you were using 24 ga wire for the landing gear and the cabane.
Then you changed to 20 ga.

The solder would not stick so you changed to copper wire.

I just cannot see that on this size of a model.

Clarification would be appreciated.

Annealed means reducing or removing its hardness.

Zor

senrak

Zor,
I think what Ewan is talking about is the size of wire he is using to wrap and tie the joints together. Soder will not stick to some metals, and 24 ga would be too fine in most instances on this model. I think I used 16ga on my landing gear.

Zor

Your thinking (guess) is probably correct.

The small copper wire to wrap around the bigger landing gear and cabane wires is better annealed so a figure 8 can be more easlily formed witht the copper wire around the steel wires.

Crimping the copper wire after circling around for a closer fit of the copper wire.

Thanks senrak.

Zor

Muskoka dad

My Feedback: (5)

HEY ZOR   YES THE WIRE WAS 24GA BLACK WIRE AND THE ROLL SAID IT WAS ANNELLED, THE SOLDER WOUNDT  STICK.  IT JUST 

Zor

These days I have been working on a Radian pro to improve its strength and appearance.

I also have a Spectra sailplane to continue working on.

I have done the kind of work you are doing soldering landing gears and so on many times over the years.

Sorry I got confused earlier trying to figure out what you were working on.

Glad to read about your good end results.

Zor

senrak

Here are some pictures of solder joints on my build.

foodstick

Its funny because I always sort of dread doing the soldering, but it is SO satisfying when its done and looks good.. Its always a huge step forward in the build...

It looks like you are making that big step forward and crossing things off the list..

Gulpster

Hey Guys, Ineed a little Soldering 101. My experience with soldering is very basic. Mostly electrical. So what kind of solder would Iuse for strength? Sorry for the lameness, but never needed to do it till now..lol.

KDBrown

My Feedback: (1)

I am at the same exact point as well. Have not done a lot of soldering and am just starting the landing gear. Do you guys recommend a soldering iron or a torch?

senrak

Okay, I'll tell what I have learned about soldering.
Cleanlyness is next to Godlyness. Sand all the parts with sandpaper. Wash them with solvent of some kind. Anything that removes the grease and dirt. I use a silver solder, it's stronger. Put on plenty of flux. Cover the joint. A paste flux that flowss into the joint seems to work best for me. For most joints I use an 80 watt iron. Sometimes a small pencil torch helps to get larger parts hot enough. A cold joint has no stregth. I always touch the solder to the iron where it touches the metal to so I get a good heat transfer. Then I back the solder away and touch it to the cold end and wait until the heat reaches it and flows it back to the joint. Hardest part is keeping the parts from moving when you are soldering. Do whatever you can to prevent this. Scrape off excess solder from where you don't want it to be and clean up with solvent.

Muskoka dad

My Feedback: (5)

HEY GUYS LOOKS LIKE ALOT OF US ARE AT THE SAME POINT IN THE BUILD, AS FOR KEEPING THINGS FROM MOVING , IN THE BUILD MANUAL IT SAYS TO USE CA TO TACK THINGS. I DID THAT AND IT WORKS GREAT, BETTER THAN CLAMPS. I JUST DID MY N STRUTS TODAY, I DEVIATED FROM THE MANUAL AND SOLDERED THE BOTTOM FITTINGS FIRST AND THEN I AM GOING TO TURN THE PLANE UPSIDE DOWN TO GET A BETTER FIT FOR THE X BRACES.

I TRIED TO POST SOME PICS, BUT THEY WONT LOAD. ANYONE HAVE A SECERT TO DO THIS?

LATER GUYS EWAN

jmatusic

My Feedback: (16)

I just picked up one of these at a local auction and have been making some repairs to strengthen the landing gear and to build in some shock absorbing. It has a G23 on it and looks to have been flown very little. Can someone provide the CG location as well as the suggested throws for the control surfaces. I also replaced the weak and frayed rudder thread pull-pull lines with twisted steel, extended the exhaust and fuel tank overflow line beyond the edge of the cowl.

Thanks and I'll post pics soon.

Joe

3136

Hi Joe, I had a look at my plans it shows 100mm from the leading edge of the top wing for balance.
Rudder 1,1/2 to 2 " both ways
Elevator 3/4 to 1' both ways
Ailerons 1'up and 3/4 down

Hey ALO111, I have the same dash kit from mick reeves you have, I'm about to start the fuse and it looks like a lot of the plywood crutch plate needs to be cut away to open up the area, did you strengthen it up to compensate for that?

Regards Mark

3136

Hi Zor,
there is a fellow on rc scale builder who made some lg that has a bungee system like the original had, he brased the parts together.



That looks quite good, however you mentioned not to allow to much heat in the metal as to not loose the temper.
I'm not familiar with brasing, how does this compare to mig welding?
I assume the mig will put in too much heat, is brasing any different?

Regards Mark

jmatusic

My Feedback: (16)

Thanks Mark!

WacoNut

Once you heat the metal to where it is red hot it will lose it's temper.

What I would do is after all the brazing or welding is complete I would reheat the area until it is red then quench it is oil. This will put the strength back in the metal. I have also heard of quenching in sugar.

I have found that with silver soldering I did not have to get the metal too hot. I woudl try to silver solder before welding.
Later!!
Anthony
BTW: I will be starting a BUSA 1/4 Fokker DR-1 before long.

senrak

Hey Guys,
Link to Balsa USA 1/4 scale Sopwith Pup specs
http://shop.balsausa.com/product_p/420.htm

senrak

WacoNut is correct. Unless you are skilled in those area's, brassing and welding can be risky methods because of the high temperture and lose of temper. The silver solder done correctly is plenty strong and with practice, easy to do.

Zor

Hello Mark,

There is a lot of fine information nearby from many contributors to this thread.
However when addressed directly I believe a response is in order.

I should first mention what credentials do I have to talk about the subject being discussed namely "joining steel wires in the construction of landing gears or cabanes.

I first learned how to solder while at technical school during world war II . Four years of technical school from September 1942 to June 1946. Following which numerous building of home brew radio control (Tx, Rx and servo modifications). Home built ham (short wave radio operaters) transmitters up to (1) one kilowatt output, short wave receiver (10 tubes superheterodyne), High fidelity stereo audio amplifiers and pre-amplifiers and many other items. .

Later on while with RCA (Radio Corporation of America) I spent some time giving seminars and training radio service technicians. All RCA dealers had to have a service department with qualiied technician(s).

Later on while not flying the corporate aircraft (turbo-prop Aero Grand Commander) I was in engineering and designed a method of feeding two mig welding heads from a single supply. i was also responsible for setting up all welding machines, tig and mig.

So here follows my thinkng.

In model building i do not see any need further than the simplest ordinary soldering using a 100 watts iron or smaller depending on the job. A 100 watts iron properly used will easily handle steel wires up to1/8" dia including soldering three (3) wires together using 40/60, 37/63 and even 5/95 soldering alloy.

For the bigger wires a propane torch can be used if you really know what you are doing.
The risks with a propane torch is overheating and softening the wires (lost of hardness and strength).
It is not necessary to get the steel wire red to loose some of its hardness.

If it gets red at any location the hardness at that place is alllost and the wire willbend easily and remainbent.
Straightening it out will not give it any strength and it will bend again at that spot.

The wirecan be tempered againbut then some "revenue" (as it is called) must be performed.
Fully tempered wire will be too hard and may break before bending and thus provide littleshock absorption.
The hardness of full tempered depends on the alloy of the material being joined.

Brazing and silver soldering has much similarity but is done at a higher temperature using a higher temperature and harder melting alloy.

Tig and mig welding is fine if you know how and have the equipment. These welding techniques heat and melt the metal locally nearly instantly (do not spread the heat in time) and do not heat up the adjacent areas sufficiently to soften them. Do not expect however to separate the wires to relocate them if not intheir proper position to start with. Bending is not likely at the welded area due to multiple wires together.

The best solution for all this is to use spring wire and solder it the simplest way with a soldering iron.
You then have a shockabsorbing landing gear that neverremain bent.
Keep in mind thatsuch a landing gear also springs back and with a tail dragger may increase the angle of attack and force the model to lift again and stall just above the runway. There is less tendency to do that with tricycle because theangle of attack is then reduced.

Have fun soldering andif relativelynew to you, learn the proper soldering method.

Enjoy dropping your model to the floor from 4 to 6 feet and see if the landing gear is bent or if the structure is strong enough. Following such a testI had to reinforce the landing gear on my Skybolt. That landing gear that came with the kit is made of bent flat aluminum and easily bend and remain bent on a hard landing.

Zor

Some edtting to correct spelling or typing errors.

senrak

Well said!

jmatusic

My Feedback: (16)

Pics of my Pup and her gear setup.

3136

Thank you Zor and every one else for your help, I'm no expert but actually pretty good with my mig but I'll stick to solder and see how it works out.

Jmatusic, does your one have any give in the landing gear? Are those black threads elastic?
It doesn't look like there is a slot for the axle to travel.

Hey Senrak, I had a look at the link you posted, you Yanks are lucky, kits are so cheap over there, it's $269.95 in the USA .
That kit here in Australia is around $495+

Regards Mark

Zor

Mark,

Are you comparing based on the same dollars?
Amercan or Australian ?

Things over here are also much more expensive and our Canadian dollar is not much different than the United States dollar on the exhange rates.

We cannot compare unless the exchange rate is nearly the same.

Zor

3136

Hi Zor, Australian dollar is $1.02 at the moment, it has been as high as $1.10 recently.
Sadly some importers here whack a huge mark up on  some kits.
The esm line is frightfully dearer here as well compared to the USA
Strangely though Black horse are about the same $ in AU and US, clearly the BH importer isn't as greedy here
I think manufacturers should be careful that their dealers don't mark their items up too much, otherwise they just don't sell a lot of them.
The esm is a prime example, there are tons of them in the states and rarely seen here in AU.

Regards Mark

PS how much is a 1/4 pup in Canada?