Multiplex Fun Cub

[dicks]

Hi. My newly built Fun Cub waddles down the run way during practice take offs. The wire undercarriage seem weak and the main wheels are hard to alaign so that the wheels don't drag along the runway. Has anyone found a away to straighten or strengthen the undercarriage to prevent this ugly movement. Thanks

Dick

[ctslacker]

I havent seen anyone upgradeing them yet but have read reviews that the plane doesnt like asphalt or concrete runways. those giant bush wheels prefer a rough surface. the rougher the better.

[dicks]

Thanks CTSLAKER for reply. I guess I need to look for some grass to taxi my funcub. One person suggested soldering a wire across the wire carriage near the big wheels for a little more stability. Might just try it after my maiden flight today.

Dick

[Turner]

If you solder a wire straight across, the gear will not be able to deflect to either side except together. Bend the wire to an inverted V to maintain some independent side to side flex while stiffening it up some. The deeper the V the more flex.

[dicks]

Thanks Turner. Good idea to use the inverted "V." I tried rubber bands on the undercarriage, but I think a wire with the V would be better. thanks again...

Dick

[Turner]

Be sure to post your results.

[xmech2k]

Maybe it's just the alignment? I think too much toe in will cause waddling.

[dicks]

Thanks xmech. I think you're right. Alaignment of those big wheels is very important. I soldered a piece of coat hanger wire midway up the under carriage, but haven't tried it yet. I think the fun cub is designed for dirt, not asphalt or concrete.

Dick

[Timewarp]

Originally Posted by dicks

Hi. My newly built Fun Cub waddles down the run way during practice take offs. The wire undercarriage seem weak and the main wheels are hard to alaign so that the wheels don't drag along the runway. Has anyone found a away to straighten or strengthen the undercarriage to prevent this ugly movement. Thanks

Dick

Hi, I just picked up a FunCub as well. Try using this recommended method, View picture below for exact setup. All you need are 4 wheel locks, 4 long screws and 2 hair bands. I have been reading a lot on the FunCub over the last few months and this system seems to be an easy fix and doesn't require any modifications to your stock system.

Anyone and everyone who says this is a brush plane is 100% correct she takes off like a dream in the grass and dirt, keep her away from the concrete if you can to avoid the bouncy effect.

On my plane I haven't installed the hairbands yet but I did go ahead and slip on the extra wheel locks, if you look closely you can see them in one of the pictures I posted. So basically all I have to do is throw on the hair bands later down the road. Here is the link to the other thread with pictures and a short clip of the dry test of my FunCub http://www.wattflyer.com/forums/showthread.php?t=65480

[dicks]

Thanks Timewarp for the neat fix for the undercarriage. Let me know how it works out after your 1st flight. For a temp fix, I installed a straight piece of coathanger wire brace (6-1/2") across the wire carriage assy about 2-1/2" below the bottom of the plane. I used epoxy to hold the wires together and may have to strengthen them later on. My test flight on a concrete runway proved successful. The wire carriage still has a little "give" on landing, sol I didn't have to form a "V" in the middle of the coathanger wire. I realize the Funcub is for grass, etc, but with our El Toro Marine airbase runway flying field, it lands pretty well on concrete with a straight rollout. Let me know how your 1st flight goes.

Dicks

[Van Leuven]

Originally Posted by ctslacker

I havent seen anyone upgradeing them yet but have read reviews that the plane doesnt like asphalt or concrete runways. those giant bush wheels prefer a rough surface. the rougher the better.

Hi ctslacker -

The bottom two pictures are without the black shrink tubing around the springs to show how everything goes together. I'm not sure if I will keep the shrink tubing on - the size I used seemed to constrict the spring movement a little. The rear bracket was made from a small piece of flat aluminum I had from another project. Dubro makes a nylon landing gear strap that would work fine. Both front and rear brackets are screwed to 4-40 blind nuts through 1/8" plywood backer for strength.

Hope this helps. Have a great day!

[scottdearinger]

Originally Posted by ctslacker

I havent seen anyone upgradeing them yet but have read reviews that the plane doesnt like asphalt or concrete runways. those giant bush wheels prefer a rough surface. the rougher the better.

too true

[dicks]

Thanks Van Leuven for the great idea on the Fun Cub's landing gear. It looks like a geat improvement over the original landing gear. I like the green color of your Cub. Cqan't loose that one in the bright sky.

DickS

[Van Leuven]

Originally Posted by dicks

Thanks Van Leuven for the great idea on the Fun Cub's landing gear. It looks like a geat improvement over the original landing gear. I like the green color of your Cub. Cqan't loose that one in the bright sky.

DickS

I hope that helps. All joints are wrapped with very small wire and then silver soldered and the screws are attached with blind nuts through 1/8" plywood . Also you can cover the springs with a large piece of black shrink tubing to look more authentic and to keep grass from catching.

[dicks]

Thanks Van for the mechanical details for the landing gear. Where did the green color come from? Did you buy it that way or did you modify the colors yourself? It really looks great.........Advise

Dick

[bnick2k11]

I did my gear similar but without the springs which look very cool I have to say...

I'm 4 oz over stock weight with the new Flycam 45G HD Pen sized Camcorder I bought at xheli for $45 and a full 14oz over stock when carrying my Aiptek Camcorder with it's above-wing mount yet she flies as if she's not carrying hardly anything extra at all...

This is simply an amazing plane and so light and strong to begin with... Got mine mainly for the 2 grandsons to fly but I seem to fly it the most, ha...

I'm also flying the FunCub with the new Feytech FY30A Aircraft Stabilizer for my HD Video recordings... It has to be one of the finest RC devices I've ever bought bar none... This planes a kick...

Happy Flyin...
bnick

[yeager1ab]

This might be blasphemy but here are some other gear designs using what looks like fglass gear. I would think that if you use soft foam wheels you will still get the same cushion on landing.

http://microrczone.com/content/fun_cub.htm

I much prefer grass over asphalt. Ever try smoking asphalt?

[planedog]

Hi All,
I have been looking to buy a Fun Cub. Not having the Fun Cub yet,I was wondering if some body could furnish a couple landing gear deminsions of the stock landing gear. I am sure there are other options for after market aluminum landing gear for the Fun Cub. Or maybe bend up some of my own out of Aluminum sheet. Thanks in advance
~planedog

[yeager1ab]

Near as I can measure after a couple dozen flights and rebending... 10 cm x 23 cm

[HobbyJumper]

Personally, I am a fan of the stock gear, and just avoid things like long takeoffs or taxiing. Even without the flaps down, the FC easily gets airborne before the wobble is an issue, and I'll bet the designers would tell you it's meant to do that. I would rather leave the springy, shock-absorbing (i.e. not "weak") gear as-is, for those exciting off-airport, tundra landings (and my cub has done some "beauties"). Where I fly, even grass is a luxury. They don't call it a Fun Cub for nothing.

Originally Posted by dicks

Hi. My newly built Fun Cub waddles down the run way during practice take offs. The wire undercarriage seem weak and the main wheels are hard to alaign so that the wheels don't drag along the runway. Has anyone found a away to straighten or strengthen the undercarriage to prevent this ugly movement. Thanks

Dick

[planedog]

For those who might be interested in some Aluminum Landing gear, I have found these by Hyperon one or two just might work.
http://www.allerc.com/airplane-kits-...2&sort=model-a
Go down the list about half way to find the Aluminum Gear.
Just my 2 cents. I have used wire landing gear in the past on other planes and as a personal preferrence I like something just a little more solid.
I found this too.
http://www.rcgroups.com/forums/showthread.php?t=1209004

[aerotony]

Originally Posted by dicks

Thanks Van for the mechanical details for the landing gear. Where did the green color come from? Did you buy it that way or did you modify the colors yourself? It really looks great.........Advise

Dick

Hey Van,
How about sharing the details of your brilliant colour scheme?
Tony

[garycrump]

I too have purchased a Multiplex Fun Cub. I am currently eagerly awaiting delivery. The thread on the landing gear is facinating to me. What other modifications have you fella's made to your model, in addition to color and landing gear? I will be using the EMAX GT2815/07.

[flyingmonkey87]

I glued a spring I purchased from Lowes between the undercarriage. It was a pain to do but it works pretty well. I might try some of the ideas posted here as they look a bit more elegant.

[flyingmonkey87]

My FunCub:
-used all the servos from my PZ Stinson, plus one extra for the flaps
-Stock/recommended power pack
-some control surface modifications (because I lost some screws from the original package)
-is painted rather than used decals

there now I can post a picture.