Bob Pastorello

My Feedback: (198)

I've read the different threads, and haven't seen issues reported with the 50cc gear? I have one completed, ready to maiden, and noted that the gear reinforcement seems to include two fore-aft 1/8" CF rods that go through the firewall, then through the ply landing gear plate, and into the bulkhead behind. Seems like that addition would add quite a bit in tension / shear, but of course don't know, 'cause I've not flown it.

Pondering just changing to CF gear from a 50cc Sbach - gets rid of that rearward sweep, which also must reduce the pullout forces exerted?
Looking at the two smaller Revolvers, the LG plate seems to be attached differently, and isn't recessed into the bottom of the fuse, but hard to tell from pics in manuals.

Anyone with specific info about the 50cc version and this issue?

eddieC

My Feedback: (2)

I'm on my 2nd H9 Ultra Stick and they have the same problem. I fixed it by fitting a thicker ply plate up into the fuse sides, doweled it in, then used triangle balsa gussets all around the perimeter. Small nylon bolts hold the stock gear. This bird also has a weak rear attach for the wing! That's also been fixed.

I agree, they won't fix the cheezy design until customers use their wallets as a weapon. Just don't buy it!

pmerritt

My Feedback: (118)

Mine has never come off...but then again I land upside down all the time.

Granpooba

My Feedback: (5)

See how simple it was to come up with a fix. Now, why can't Great Planes think of that ?

opjose

Why does everyone ONLY re-inforce landing gear by shoring up the attachment plates/area?

The problem is the TORSIONAL force ( e.g. front to back ) and the lever moment around the attachment area.

A simple easy to implement solution is to add a re-inforcement wire or strut attached to the gear leg mid point, that in turn also attaches further back on the fuselage.

That forms a supplemental re-inforcement that prevents the gear from being pushed back and up.

You can do this easily with piano wire and the Bennett Built re-inforcement standoffs used in a more "creative" manner.

http://www.bennettbuilt.com/shop/Whe...doffs_316.html

I've done this with club trainers and it works very well even for those rough landings.

ahicks

My Feedback: (2)

opjose, nothing is going to work if the front of the landing gear plate won't hold. Torsional loads are exactly what I was talking about, with the front of the plate twisting to the rear, away from the firewall.

Once that joint is secured with the mod, I've hit hard enough to see the gear completely flattened - without failure - on numerous occasions! Wheel pants take a terrible beating, but the gear stays put....

raptureboy

Would some one post a link to the mods as we have a couple of guys with these going through the same issue. Thanks.

eddieC

My Feedback: (2)

If the above fixes don't work, check for gear fixes for the H9 Ultra Stick series. Very similar problem/repair.
I wound up beefing mine and other ARFs by replacing the plate with a thicker one of marine ply, but 'keying' it into the fuselage (making the plate the width of the fuse and notching the fuse sides for it).

Bob Pastorello

My Feedback: (198)

No pictures, but easy to describe/do. This will work on MANY different "weak gear plate" designs, minimum of fuss/expense, and results in an exceptionally strong vertical connection to resist shearing and downward movement of the front edge of the LG plate. By far, that is the most significant rearward leverage concentration point on the fuse, barring whatever bolt system is holding the gear to the plate in the first place. Here's the mod:
1. Remove landing gear from plate.
2. Carefully inspect interior of fuse at rear of firewall/landing gear plate attachment area. Make sure no plumbing, wiring, or hardware will interfere with next steps.
3. Obtain some bamboo skewers ( the ones at Wally world work just fine; 1/8" for 60-size stuff, the larger ones for bigger.
4. Obtain a long drill bit, slightly larger than the bamboo skewers (a slip fit, not a SLOP-fit).
5. Carefully mark about 5 holes ( four probably works fine on smaller birds) about 3/8" AFT of the front edge of the gear plate.
6. Viewing from the fuse SIDE, eyeball the angle you'll need to have the drill bit exit the fuse about 1 and 1/2" or so up from the bottom edge of the firewall. This looks to be about 70 - 80* eyeballing it.
7. CAREFULLY drill all five holes through the gear plate from the BOTTOM exterior toward the FIREWALL at the angle you decided on.
8. Slip fit some of the bamboo skewer pieces through the plate, and up into the firewall, extending out the FRONT of the firewall just a skosh.
9. Using either your favorite medium-cure epoxy, or the expanding foam polyurethane glue, Install all five wood pieces so that they extend beyond the firewall face, and the gear plate.
10. When everything is cured, clean/trim excess on the gear plate. Saturate the skewer ends with thin CA, let cure, then be sure they are sanded smooth.
11. Reinstall landing gear.

This whole thing ties the front of the landing gear plate to the firewall well above any triangle stock or doublers of junk ply, and really beefs it up.
CAUTION : If you land hard enough to shear the landing gear from front to back, peeling them off the landing gear plate, you will significantly (irreparably) destroy the integrity of the firewall forever. Unfortunately, I have tested this in practice, and it is the truth. ((

Granpooba

My Feedback: (5)

I have also opted for the triangle stock between the firewall and landing gear plate. Never had a problem after that. But I do understand and like your fix.

Skinny Bob

My Feedback: (12)

Here is how I fixed the problem on mine.

ameyam

Well, I will share my experience with the LG Block on my Reactor 46. The first reactor I had lost the engine at 20ft in a hover. Though it was level by the time it hit the ground, the fuse shattered. Had a similar issue on the second one. The problem on the reactor is that the LG plate is in the centre of the fuse in front of the wing LE. So when the LG plate breaks off in a hard landing, it rotates and shatters the fuse. Also, since the LG is two piece, the block also breaks in the centre and that also has the same effect. I did reinforce and fly my second reactor a couple of seasons until the plate broke off so bad, I couldnt install the gear. So on my third fuse, I used several CF doublers plus tristock on the inside of the fuse. The tristock takes care of some torsion. So far this has held up.

LG block problems are common to GP airplanes in the size. GP expects that these are flown off tarmac. So those who fly off grass fields need to reinforce.

Ameyam

Granpooba

My Feedback: (5)

Tarmac or grass, its going to come apart. I fly off of both ! Simply boils down to a damn poor design.