Profile Landing Gear

I'm retro fitting some profile planes with new landing gear setups.
I've drilled a 1/2" dia hole thru the fuse and plugged with 1/2"dia hardwood dowel and have drilled a 5/32" hole in the center of the dowel. I'm wondering if I should use brass or aluminum tube to place in the landing gear hole? Or does it really matter?

Wish I had done this little trick when I was building them.

Doesn't matter. Aluminum is lighter if that counts.

Thank you

Well the Twister comes with brass. I found that after a rough landing the brass tube would bend and the gear would not be in the same position. I think aluminum would be even worse. I prefer to use stainless steel tubing or I've heard other use a steel roll pin.

Mike

Mike,

By putting the dowel rod through the fuselage to support the tubing, Rick will prevent the problem of which you write.

Another solution (I don't know if others have mentioned it) is to put two tubes one in front of the other and extend the legs (arms) of the gear so each passes all the way through. That way you don't have a pressure point in the middle of the tube and the gear is much less apt to twist (Don't want the gear twisting on a Twister, now, do we?)

>Another solution (I don't know if others have mentioned it)
>is to put two tubes one in front of the other and extend the
>legs (arms) of the gear so each passes all the way through.
>That way you don't have a pressure point in the middle of
>the tube and the gear is much less apt to twist (Don't want
>the gear twisting on a Twister, now, do we?)

Wouldn't this make it hard to line up the plastic landing gear straps?
I like the idea of no pressure point though.

>>Another solution (I don't know if others have mentioned it)
>>is to put two tubes one in front of the other and extend the
>>legs (arms) of the gear so each passes all the way through.
>>That way you don't have a pressure point in the middle of
>>the tube and the gear is much less apt to twist (Don't want
>>the gear twisting on a Twister, now, do we?)
>
>Wouldn't this make it hard to line up the plastic landing
>gear straps?
>I like the idea of no pressure point though.
>
>regards,
>Rick "catdaddy" Blankenship

If you use bolts where the straps are mounted with one set of bolts all the way through, if you mount them at the bottom and angle the wire accordingly, things line up just fine. If you want a second set up on top (not needed) just stagger them slightly and use wood screws to hold them in.

Note: Even though the top of the gear wires are staggered under this arrangement, the bear itself is bent just lightly different so it is located straight at the bottom of the fuselage. You can do the same thing, also, by making one gear just slightly longer than the other and use two tubes one above the other.

I did almost exact same thing with my Super Clown. I did not put the metal tube through the dowel though and several rough lands later (well ok lots of them) the gear have started wearing loose again. Definately put the metal liner it will help.

Finch

What is a unladen Finches flying speed?

African or European?

You have to know these things when your King.

The landing gear on my TwistMaster is held with a brass tube through the bottom motor mount which runs all the way back to the wing. One set of plastic landing gear straps with 4-40 screws all the way through the fuselage.

3 years of grass landings and it is as solid as it was the day I built it.

I couldn't find any tubing I liked, 'til I replaced a Power Antenna in a BMW for a customer. I thought all antenna masts were chrome brass until I took a closer look. This one was Stainless, and a L.G. wire telescoped nicely. Cut it with a Snap-On tubing cutter, finished the I.D. with a mini file, and it was great. One thing about the 'stubs' that plug into the fuse sides: They were too short butted up like that, so I offset them (1 fwd, 1 behind) and left each one with 5/8" into the fuse, at the doublers.The inside gear is at the front, to discourage excessive 'turn-in' whilst taxiing.

When you're talking about profile landing gears, being "as solid as the day I built it" is nothing to brag about. Just means it's still really wobbly.

>When you're talking about profile landing gears, being "as
>solid as the day I built it" is nothing to brag about. Just
>means it's still really wobbly.

Is that why you never build profiles...because you can't mount the landing gear properly?
regards,
Rick "catdaddy" Blankenship

Well, you'll have plenty of time. When you're standing in the unemployment line or food line, with all the playing on this site you do while at work!

For what its worth, I use an entirely different method which I started for GY Scale Racing back in the late 60's. Either bend a complete "U" from 1/8th piano wire or wrap and solder two legs of the lg at the top about 1.25in long. This part will be incerted in the bottom edge of the fuse in a 3/8" hole drilled at a angle to approximate that of the legs to the plane. Fill the hole with slow cure epoxy to weld the unit fast. The legs will have been bent to the desired length with an axel portion necessary for the wheels to be used. If this assembly ever breaks it may be removed by heating the wire closest to the fuse and de-bonded thereby! Pull out, clean up hole and install new assembly! I've had these things last for many years. If the gear splays out from too many less than perfect landings, wrap and solder a doubler to the original as in a modified "V" to tighten up the terger. Phil Spillman

Hi Rick,
I would use the hard brass. I have used aluminium and had it *compress* when tightened real hard. The brass will resist this. My $.02 worth.
Bill <><

I've tried al lot of different approaches but one that I heard recently made alot of sense and sounds a lot stronger. Dan Banjock said to use two pieces of brass tubing not just one, this doubles the wall that the LG have to break through.

Has anyone tried Carbon Fibre tubes in lieu of Brass?

I also if I'm bending a new landing gear will sometimes bend the whole gear ala ringmaster and shoestring style then it doesn't really matter if there is a tube or not. You still need the hardwood dowel though to give you a big enough whole to pass the bends through the fuse. It also limits your choices as far switching from grass to paved etc. but it is alot tougher than the two leg landing gear.

Mc,

I have several profile planes with many flights that use the inserted dowel feature, so I know that the split landing gear is plenty strong, even for flying off rough grass fields, when it is installed in a brass tube inserted through a 5/8" or larger dowel installed through the fuselage flush with the outside of the doublers. This removes the two hard support points (each doubler) and the one soft support point (the balsa interior) that cause the tubing to bend inside the fuselage, thereby causing the gear to be misaligned. For my next profile with fuselage mounted gear, I believe that I'll try Bob Reeves' solution of a lengthened motor mount into which to insert the tubing. It seems that this would make for a "cleaner" landing gear installation as well as a stronger nose, killing two birds with one stone. Both methods will allow for a split gear, enabling one to use different gear depending on flying field conditions.

Sourdough has a point, and a 'solid' one. The mount beam is ideal, as the bore for the L.G. bushing is merely wall thickness squared.
If Doubler Crush is feared, a hard dowel can be inserted flush with the doublers, and screws run into the dowel. Fast drillpress op.

I've been using stainless steel aircraft hydralic tubing. It is suprising light and strong. A tight fit is needed around the wire so I fill the gap between the gear wire and tube with metalic tape. Works good and holds gear firm. Nice to see so many other good ideas.