R/C Art

My Feedback: (38)

rotorboy

Google the Hoosier Dawn Patrol, then go to the pictures, then click 2011 pictures - then click on my N-11 build thread pictures. There are several sections which deal with the landing gear.The pictures show how I made a functional gear for my third scale N-11. I also made the same type of gear for a 1/3 Sopwith Pup.

It is simple, durable and functional!

Cheers,
Art

Steve Percifield

My Feedback: (14)

or go direct
http://www.hoosierdawnpatrol.com/201...res/n-11build/

rotorboy2.4gh

My Feedback: (2)

Thank you guys SOOOO VERY MUCH!!!FranK!

Eindecker_pilot

Rotorboy,

I can vouch for Art's landing gear method. After seeing how well his held up & not wanting a more complex landing gear that required heavy-duty welding; I built the landing gear for my 1/3 scale Pup the same way Art's is done. Check out the photo on the web link Art has sent. You'll see a photo of the gear. In the middle of the axle is a piece of brass tube that captures a generous solder joint between the axle & the fixed cross piece. You'll want to make axle guide slots at the outer landing gear legs. Put your bungees around the ends & you're good to go.

The big solder joint in the middle of the axle takes all the side load & bending loads, so you do want to make it a good one. I used this same method on a retro-fit of the gear on my 1/4 scale pup as well.

best regards,
Greg

wphilb

My Feedback: (10)

I'm sorry, where do you wrap the bungies? I'm used to seeing little tabs sticking out that the bungies wrap around and the axle.

R/C Art

My Feedback: (38)

http://www.hoosierdawnpatrol.com/201...target183.html

wrap the bungee around the axel - pass the bungee under the bottom of the gear and over the spreader bar - and then back and forth until you have enough bungee to tension the system .....maybe 5 or 6 wraps....depends on the size of the bungee cord.

the bungee should not be strectched while wrapping, but rather just made snug as it is wrapped.

R/C Art

My Feedback: (38)

Whit

There is a slight difference that I built into my last pup - I don't have a good picture of it, so I will try to explain it.

The spreader piece of music wire that is soldered onto the bottom of the landing gear........instead of cutting the wire even with the landing gear.......let the ends extend outward approximately 1/2 inch or so and bend 90 degrees down......then the bungee can attach there.

wphilb

My Feedback: (10)

OK,

valleyk

My balsa usa 1/3 pup needed a landing gear overhaul. I chose to buy aluminum struts from GTM models and JB weld them together. I can’t weld or braze anyway and this method works just a good and is a lot less messy. I used piano wire routed in wood as shown. Nails were used to hold bungee cord around axial. Believe me this setup works great form past expense with my 38lb GTM dr1which I stalled at five feet and came crashing down on the gear with no damage.

abufletcher

Do you feel that the JB "Weld" is really as strong (or almost) as welding/brazing? I use JB Weld a lot, but I think of it more as "workable epoxy" and wouldn't rely on it for any strength application. As I understand the way that GTM uses it on the DrI undercarriage is that music wire is wrapped in cotton and then stuff into the ends of the tubing with JB Weld. As such, the strength comes from "gap filling" which holes the wires in place.

valleyk

Bond joints are good in shear and bad in peel. A lap shear joint would not be good design for this gear application. So yes your right you want to insert aluminum fittings inside the strut tubes and fill with JB weld to stabalize and provide good tension compression strength. In my case I slotted the strut with a saw and press fit in shaped aluminum plate for bending strength. Its not too hard if your good wifth a file. This gear is strong trust me.

Canuck1

I used the JB we'd on my DR1, attaching the music wire into the aluminum struts.
The cotton is used to provide a stop for the JB weld so it does not run down inside of the aluminum tube. This allows the JB weld to remain in place so there is a complete bond with no airspaces. Notching the wire prior too, also allows for a solid joint and something for the JB weld to adhere too.
Seems to have worked pretty good, no issues that I know of.

Craig

rotorboy2.4gh

My Feedback: (2)

WOW!!! Thanks GuysGreat info. Im trying to put up some pics,I hope it works!

rotorboy2.4gh

My Feedback: (2)

GUYS-On the functional gear,do I use the stock landing gear wire and build on that????Frank-PS. You can tell im single by where im workin on the planeLIVEING ROOM!! Sure is nice-ALSOIm useing GOOD polyester for coveringIve done this and silk beforethis is MUCH cheaper.Question-CRAIG, or anyoneI was hoping the caps will help the covering stay put on the undercamber with the stix it ADVICE!!-Do you just iron down after stix-itthen nitrate downthen follow up with complete coats of nitrate and talcum to fill the weaveTHEN Automotive paint-I was reading where someone stuck the covering down, then just painted to fill the weave for a final finish-I was thinkingstix-it-nitrate down-nitrate,talcum fill coats-then paint!! Am on on the rite path??????

R/C Art

My Feedback: (38)

If you use my method (N-11 & Pup examples), you can use the stock landing gear (it is 3/16" music wire) for the down legs and the spreader wire and then use a 1/4" piece of music wire for the new axel.

My first gear on the N-11 used 3/16" as the axel, but by the third time out flying I had bent it - so I replaced it with quarter inch. I have had no problems with the axel after a year of flying. The N-ll wieghs about 28 lbs.

On my Pup, it was quarter inch all the way for the axel. I worked flawlessly. Pup weight was about 36 lbs.

Eindecker_pilot

Another tip that worked for me was to use silver solder, not the regular stuff. Also; with music wire pieces this thick & the brass tube sections; a propane torch was critical to getting the right amount of heat on the parts. My electric solder gun was not sufficient, but a propane torch gives you plenty of heat. You just have to be mindful to not overheat & oxidize the metal. The key was moving the torch around to raise the temperature evenly. I keep a piece of solder against the metal as I'm heating it so that I know exactly when the metal is at the right temp to avoid over-heating it.

-Greg

rotorboy2.4gh

My Feedback: (2)

Great stuff guys. I was starting to cover with dopeTHEN,did some research and got some good advice from Craig,and went with minwax PolyC. Works awesomePlus my 3 dogs are not chasing butterflies that arent here anymore. It does NOT get as tight as dope,but not by much and is VERY goodI am a CONVERT!!!-I found that after all is dryI could VERY carefully use my heat gun and draw it up pretty good!!

R/C Art

My Feedback: (38)

Hi rotoboy

Your are making good progress with your pup. TMoth is a big supporter of the waterbased poly stuff - I'm going to have to give it a try some day.

I see you are using Robart hinge points - I use those a lot, too. I couldn't help but notice how they are installed (visible through the covering). I know that you are a long time modeler and please don't be offended when I tell you this. Remember, it just my opinion (and like armpits we all have them and all of them smell!).........that being said, when I use that kind of hinge I add extra wood in front of and behind the hinge line, so that the barbs on the hinges have something to be glued to. The more glue area the more secure the hinge is. Just my opinion.....
Art

Canuck1

Rotoboy
Looks good. I cannot take credit for the Polycrylic method, Tmoth was the one who started me on with it. I don't think I will ever go back to using dope again.

Keep up the good work, looks like you are well on your way.

Craig

Tmoth4

My Feedback: (1)

Hi rotorboy,

I agree with Art that there should have been balsa blocks glued to the spars for the Robart hinges to grip onto.

But don't despair!

At this point, instead of tearing the old hinges out and tearing up the covering and structure too much, you could cut small sq. holes in the covering (on the bottom side) where the hingepoints are, and work some thickened epoxy around the barbs and up against the spar. Then you would put patches over the holes. This would all be done from the bottom side, so it won't be seen.

Jim

Eindecker_pilot

Rotorboy,
You could also retro-fit balsa blocks to the extra free length of those hinge points. For each block, just drill the hole that would have been there fill it with glue & slip it over the free end of the hinge point, gluing it to the existing frame. I'll admit I actually did the same thing you did the first time I used hinge points & this is how I fixed it. I felt a lot better after beefing that up. That much extra wood isn't needed with regular hing tabs, which is what I was used to.

-Greg

rotorboy2.4gh

My Feedback: (2)

No offenseI have extra wood on EVERTHING else but this was a late night brain fart!!They are not epoxied in yet because I realised what i did. SOnow the big questionDo you really think it needs it being a floater-I know it sounds like a dumb questionjust dont want to hack if I dont have to..I put macho blocks on all the other hinges!!Trust me, I usually,and never have done that beforeBut be honestDo you really think it needs it?Oh coarse,I dont want to lose a plane-Frank!

rotorboy2.4gh

My Feedback: (2)

OKI thought about it and here is what i am going to do cause I dont feel comfortable. I will take a pin vise with a small bit and drill through the wood and hinge,and pin it-I think that will work-Opinions??Frank!I am not hard headed and will listen-Oh yea,and NEVER OFFENDED!!!!!

Eindecker_pilot

Hi Frank,
I think it would be difficult for me to run a pin through the leg of the hinge point. Running a pin through the flat part of a regular hinge is easy, but you're aiming for something much thinner with a hinge point. I would just open up the covering as Jim suggested & either slather it in epoxy as he indicated or retrofit the extra wood blocks. You won't notice the patch on the covering.

Greg

R/C Art

My Feedback: (38)

Yep, Frank, it needs it. There is a lot of shakin' going on back there on the tail end. It probably doesn't need it for the flight loads.........just needs it for longevity!

My 2 cents worth.
Art