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Author Topic: Landing gear with rubber band shock absorbers  (Read 3946 times)

Offline Phil Goldberg

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Landing gear with rubber band shock absorbers
« on: July 02, 2015, 12:25:45 PM »
I remember long ago the wire landing gear, profile model, shaped and put through the fuselage with a dowel protruding about 1/2 in on both sides in front of the gear and rubber bands around the dowels and gear to absorb the shock.  Does anyone still think this is worth while.  I tend to land hard and bend gear and am thinking of going old school on a ringmaster I am building.   

Offline john e. holliday

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Re: Landing gear with rubber band shock absorbers
« Reply #1 on: July 02, 2015, 01:04:26 PM »
Yes the old Goldberg kits used this method for landing gear.  Some people still use it.
John E. "DOC" Holliday
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Offline Phil Goldberg

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Re: Landing gear with rubber band shock absorbers
« Reply #2 on: July 02, 2015, 01:12:12 PM »
Since my last name is Goldberg, it might be a nice tribute if I use this method.  Do you remember if there was also a peg behind the gear to limit the travel? 

Offline Avaiojet

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Re: Landing gear with rubber band shock absorbers
« Reply #3 on: July 02, 2015, 01:38:50 PM »
Since my last name is Goldberg, it might be a nice tribute if I use this method.  Do you remember if there was also a peg behind the gear to limit the travel? 

The travel would be determined by the number of wraps on the elastic bands.

Don't be surprised if you land after a number of flights and the rubber gives way.

Rubber bands have this thing with fuel.
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Offline Russell Shaffer

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Re: Landing gear with rubber band shock absorbers
« Reply #4 on: July 02, 2015, 02:10:58 PM »
Make sure the wheels do not hit the bottom wing spars. It happened to me.  Harder to fix than bent gear.
Russell Shaffer
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Just North of the California border

Offline Phil Goldberg

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Re: Landing gear with rubber band shock absorbers
« Reply #5 on: July 02, 2015, 02:39:03 PM »
I'll remember to keep a lot of rubber bands on hand. Also I now plan to insert a second dowel behind this gear to limit travel.  Might even soften the blow if I misjudge my altitude by a few inches.  Wishful thinking.

Online bill bischoff

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Re: Landing gear with rubber band shock absorbers
« Reply #6 on: July 02, 2015, 04:22:49 PM »
In answer to your actual question, yes there was a rear dowel and a front dowel. Seems like the gear had about 3/4" of movement between the dowels.

Offline jim gilmore

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Re: Landing gear with rubber band shock absorbers
« Reply #7 on: July 03, 2015, 12:23:34 AM »
If you want you could replace the read dowel with a bolt. it would be a lot tougher and a little bit heavier.

Offline De Hill

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Re: Landing gear with rubber band shock absorbers
« Reply #8 on: July 03, 2015, 10:46:14 AM »
It would help if you made the rear dowel 1/2" longer than the front dowel. (1/4" on either side) If you had a hard landing, the rubber bands would break, and the landing gear could jump over the stock rear dowel and the wheels would go up into the wing, damaging it. Lengthening the rear dowel prevents this from happening.

Been there, done that...
De Hill

Offline Randy Cuberly

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Re: Landing gear with rubber band shock absorbers
« Reply #9 on: July 03, 2015, 10:51:22 AM »
Of course, a better solution is:  Don't land so hard!!! <=  LL~ LL~ LL~

Randy Cuberly
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Offline Phil Goldberg

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Re: Landing gear with rubber band shock absorbers
« Reply #10 on: July 03, 2015, 10:25:25 PM »
Haven't flown in many years till recently and I guess I have to get me chops back.

Offline kenneth cook

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Re: Landing gear with rubber band shock absorbers
« Reply #11 on: July 05, 2015, 05:40:31 AM »
            I personally dislike the bungee gear. The rubber bands get oil soaked and turn to goo. They break usually when you don't want them to typically when you have none to replace them with. This was a horrible design on the Jumping Bean for 1/2A as the gear would be flopping all over the place and on the larger stuff they were just as problematic. Any of the Goldberg kits I had, I fixed conventionally with a landing gear strap. The shock absorbing design of the gear isn't going to save it in a hard landing. I planted one in from high atop of the circle on asphalt. While the plane literally exploded on impact, the gear took the majority of the shock. The crank still hit damaging the first few threads on the shaft but not enough to damage the entire engine. I strongly feel I wouldn't of been so lucky had I not attached the gear in the fashion I did. Just my opinion, Ken

Offline Phil Goldberg

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Re: Landing gear with rubber band shock absorbers
« Reply #12 on: July 06, 2015, 01:08:24 PM »
Thanks, I can see where the rubber bands might be a problem.  I am rethinking my plan.  I am considering drilling a hole in a 5/8 " dowel that is the length  of thickness of the fuselage, and then drilling a hole in the fuselage for the dowel.  Then bending the gear after installing.  I am trying to think of ways that I can add the gear last after finishing, also a way that the gear will not get in the way of a small fillet around the wing, which I see happening if I add the gear in front of the wing before installation of the wing.  If I did this I would first experiment to see if the gear is easily bendable once through a dowel.  UPDATE ...  dowel will break during bending.  Think I may use the dowel installed with hole drilled, divide gear in half, put one have on each side and secure to fuselage. 
« Last Edit: July 06, 2015, 01:27:14 PM by Phil Goldberg »

Offline Avaiojet

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Re: Landing gear with rubber band shock absorbers
« Reply #13 on: July 06, 2015, 03:01:01 PM »
Of course, a better solution is:  Don't land so hard!!! <=  LL~ LL~ LL~

Randy Cuberly

Phil,

All kidding asside, I believe Randy nailed it!  LL~

R/C nose wheels and some R'C wing gear have coil bent wire. Might be an option?

I see you are in northern FL. I would like to be up that way, there are hills there.  ;D

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Offline George Albo

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Re: Landing gear with rubber band shock absorbers
« Reply #14 on: July 08, 2015, 06:02:43 PM »
My .35 powered Shoestring stunter by Carl Goldberg had a dowel and rubber band shock absorber. I would use clips today.

Rubber bands get chewed up from the fuel. I remember using screw hooks with rubber bands to hold the gas tank back then as well. Wouldn't do that either today. Live and learn.

Good luck with your project whatever you decide to do. Post pictures!

George Albo
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Offline jim gilmore

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Re: Landing gear with rubber band shock absorbers
« Reply #15 on: February 15, 2018, 03:22:02 PM »
You might consider having the landing gear angle forward more and put the dowel behind  the landing gear. Not real sure on the difference in strength of a 1/4 hardwood dowel as opposed to a piece of solid carbon fiber. I would consider the stronger one since I have seen dowels get broke off.

Offline Peter Nevai

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Re: Landing gear with rubber band shock absorbers
« Reply #16 on: February 15, 2018, 08:46:58 PM »
Take a sharp scissor, cut them into two or three equal loops, tough as nails and fuel proof.

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Offline Larry Renger

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Re: Landing gear with rubber band shock absorbers
« Reply #17 on: February 15, 2018, 10:06:10 PM »
The Knights of the Round Circle ET-1 trainers have both nose and main gear sprung with rubber bands. I highly recommend it!

However, we are flying electric, so fuel degradation is not an issue. Crashes are the issue for us.

We do need replacement bands frequently. Would you rather replace a band or a fuselage? When you are trying to train as many as 100 kids in a day, bands are cheap and easy! We also go through a lot of prop retainer O-rings.

I think we average about 200 kids on one model before needing to replace itl. We always have 4 models on hand for a training session. It is usually a race between getting blown out and running out of flyable models.

Some venues have kids who listen better than others, and have a clue about what Flying is about. At the AMA Expo and the local STEAM Expo we suffer way less damage than the other two events we fly where the general public is in majority.
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Offline Gary Dowler

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Re: Landing gear with rubber band shock absorbers
« Reply #18 on: February 15, 2018, 10:55:42 PM »
I remember long ago the wire landing gear, profile model, shaped and put through the fuselage with a dowel protruding about 1/2 in on both sides in front of the gear and rubber bands around the dowels and gear to absorb the shock.  Does anyone still think this is worth while.  I tend to land hard and bend gear and am thinking of going old school on a ringmaster I am building.   
My Shoestring Stunter has exactly this setup. So does my 1/2A Wizard. Used to be a pretty common method.
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Offline Tim Wescott

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Re: Landing gear with rubber band shock absorbers
« Reply #19 on: February 17, 2018, 10:07:06 AM »
It kinda depends on how hard you crash.  If you start with good music wire then LG will last a good long while just bending it back into shape after every hard landing (or just every once in a while).

Bicycle inner tubes make rubber bands that last better than office rubber bands.  O-rings are better yet, but aren't as stretchy.  There's a lot of different materials to choose from, so if you do some research you can find a good compromise between fuel resistance and stretch.  I think I use Viton to hold nylon mesh onto my venturis, and fuel tanks to my fuselages.
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Offline FLOYD CARTER

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Re: Landing gear with rubber band shock absorbers
« Reply #20 on: February 17, 2018, 01:33:31 PM »
Myriads of successful trainers have survived hard landings simply using the conventional music wire 2-wheel landing gear.  Making the gear a bit longer, and with the proper size wire will absorb most landings. 

Usually, the simple solution is the correct one.
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Offline Larry Renger

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Re: Landing gear with rubber band shock absorbers
« Reply #21 on: February 17, 2018, 11:04:36 PM »
When you are training dozens of kids in the course of a day, there are going to be some really hard landings, and depending on bending the wire back is NOT going to be adequate.

Other than blowing out rubber bands, and expanding the hole for the retaining dowel, we have had a darn reliable system.

I would not consider a non sprung gear system for our trainers.
Think S.M.A.L.L. y'all and, it's all good, CL, FF and RC!

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