Question to the glue experts

[Bobmic]

Unfortunately I broke the landing gear plate on the Revolver the second time - made about 10 touch and goes and landing before I had one in which I was already rolling on the ground for quite while and was pushing the rudder to align the plane with the middle of the runway as it was going on a bit of an angle. Anyhow in the previous repair I glued the landing plate back using Gorilla glue - the results can be seen in Photo2 and the landing gear plate is in Photo3. I am planing to add two pieces of quarter round oak on both sides of the walls holding the landing gear (one seen in Photo 5 will add a second on the left side of the picture).
I cut a new plate which will be larger than the original and will have more surface for glue I will also add another thin plate on top of the one cut as done in the original one to match the overall thickness.
Now the question - which glue will hold the strongest - Carpenter glue, Epoxy or Gorilla glue (the last option will not work on the flat surfaces but can be added as before.

Thank you
Bobby

[battlestu]

I'm not expert but I would pick epoxy

[Frank v B]

Bobby,

The experts are out so I will attempt an answer.
I have repaired 3 planes with a similar problem.  In my opinion it is not a glue issue, it is a design issue. 

The long landing gear acts as a huge lever against the landing gear plate (fore and aft, not sideways).  I extend the plate to the first ply bulkhead aft (left of the photo).  The ideal is to have the plate on top (outside) of the ply bulkhead.  If it needs to be flush with the bulkhead, butt it up to the front side of the bulkhead and add tri stock balsa on the front side of the bulkhead on the inside of the airplane.  You now will have 3 times the resistance against the leverage of the landing gear.  I would always use 5 minute epoxy.  It is the strongest and fills gaps.

Frank

[michaely]

The epoxy will be stronger than the carpenter's glue and will stick better to wood "contaminated" by previous glue residue.  I would first glue in the widened plate you made, then after it is cured, glue in the oak reinforcements you made (but balsa triangles would provide almost the same strength at less weight.  The 15 minute epoxy in the last photo has more strength than the 5 minute stuff I'm familiar with.

I wonder about the landing gear plate ripping out twice already... was its anchoring so poorly done that a fairly routine landing/taxi shock would dislodge it.... if this is the case then firmly locking in the landing gear plate is fine and shouldn't rip out the reinforced anchoring...... but if the landing gear is going to be subjected to big shocks, strongly bolting in the landing gear legs (aluminum?) might rip out not just the landing gear plate - again - but the lower bulkheads to which it is now more strongly glued... you might want the landing gear leg to break away from the plate by using nylon bolts than might shear off before ripping out the reinforced plate.  Just a thought, not a firm recommendation.

good luck

Michael

[Wingnutz]

Bobby,
Both my GP ARFs, Revolver and Escapade suffered torn out landing gear plates. The nylon bolts suggestion makes sense to me as the GP design doesn't seem up to grass fields. I'm going to scope out some nylon bolts for my Revolver and hope they don't fail on take-off with the prop close to the ground and the motor at full throttle...been there, done that, ...not pretty!
As much as possible, I'm avoiding wheels on grass and hand, bungee or float launching...
How about some floats for the Revolver? (Tongue in cheek) Then you could join the float flys! (No tongue in cheek)
Good luck with the repair! Keep us posted.

[Bobmic]

Thank you guys,

Frank - per attached photo, is this what you meant? It will require quite a large plate...

Michael - Do you mean just a regular balsa triangles? I was planning to glue the triangles (or quarter rounds) after the main plate is mounted but this can only be done with the current setup. If I extend the plate I will not be able to do that.
When building this plane I read about the landing gear issue and did one of the modes - I think that Ben went with the stronger option that apparently was better .
I've done the nylon bolts on a small 48 FuntanaX but I can do the same with this one as I think I used 4mm blind nuts which should be strong enough. The only problem is that the wings will get damaged if the landing gear rips due to the large wheel pants.

Bill - I hope you don't want me to hand launch the revolver .. I can not even handle this with my Spitfire:)

[michaely]

hi Bobby

Regarding the suggestion of balsa triangles.... it was just a way of lightening the reinforcement (instead of oak) and, they would be located in the green shaded area in the photo you posted in your reply.

Between a reinforced landing gear mounting block and  'breakaway' landing gear legs is the option of building more shock absorption/deformation into the landing gear legs, so the legs take a good portion of the greater than normal shocks before passing on even bigger shock force to landing gear mounting system.
Landing gear made of music wire - which is still be sold in some local hobby shops in a wide range of diameters - would provide this 'built in' shock absorption and even when they deformed, can easily bent back into shape.
Just now when I googled "pictures of music wire landing gear" some options come up.... the one that was most commonly used is shown in the underside of the blue model: a larger diameter main leg up front and a slighter smaller diameter reinforcing rear legs at the rear, both attached to the landing gear mounting plate with plastic or tin straps and screws.  You could use your plan to add an overlay of plywood (to build up the surface to the landing gear plate to match the fuselage sides) by installing it in three pieces, providing two built in grooves for the horizontal sections of the music wire to lay in.  You could still retain the option of bolted in aluminum gear legs (rigidly attached or with nylon bolts for breakaway) in the same landing gear plate.  The music wire could be 'dressed up' with filler covering or balsa between the front and rear legs.

good luck

Michael

[Papa]

A glue works best when it has time to move into the pores of the wood on both surfaces. If you can remove old adhesive that will make the joint more secure. Use a small drum sander remove as much old glue as possible and expose as much fresh wood. old glue will sometimes contaminate and weaken fresh glue.

jack.

[Frank v B]

Bobby,

re: your mock-up photo.  It is exactly what I meant.  The tri-stock gets glued where the blue tape is at the left of the photo.  I repaired Keith Barrow's* Revolver that way 2 years ago and it has not broken since.  I re-used the metal bolts and did not even think about nylon ones.  It may be wise to increase the wheel diameter one size so that it can act as a better shock absorber and does not dig into the grass as a smaller wheel would.  If the repair holds, you can then keep the larger wheels or try the smaller ones again.

Frank

* Bramalea- it was wildly overpowered... as a good plane should be.

[Bobmic]

Thank you all.

... the glue residue was removed with a metal brush using a Dremel and it all looks clean now.
By the way I bought the Dremel compact scroll saw a while ago and this was it's first use ....It's quite nice and I like it