the Wasp

My Feedback: (1)

Guys, I know little about wood,, and, I have a World Models .50 size P-40 Warhawk for zipping around, I feel I better reinforce the Plywood that the Retracts mount to, should I use more Plywood or a Hardwood ??

I have both woods, if you say Hardwood will Cherry be good to use ??

note that the retracts are held in with Wood Screws.

thank you Guy !!

Jim

raptureboy

Any pictures of the current mounts? Depending on how they are mounted may determine the best approach. I have used maple for those mounts that are rails and also plywood for others. Don't see any downside to cherry if that is what your have.

F4 Phantom blue angles

It could be possible to get some fiberglass cloth, fold it a few times,flatten it and soak it with thin CA. and make your own reinforcement. It should be lighter than wood,and will definitly be strong and take a screw. I did this before in differant applications and works great. But this is only what I do,

j.duncker

My Feedback: (2)

Think hard before making this sort of reinforcement.

You will add weight which is BAAAAAD.

in the event of a hard landing it is better that a plywood plate breaks or the screws tear out than YOU TEAR OUT LARGE PARTS OF THE WING STRUCTURE.

the Wasp

My Feedback: (1)

good replies guys, thank you,,

sorry, i didn't think to post photos and I will not be able to until late tomorrow..

j.duncker,, I thought about both those things a lot, so I posted and asked, as for the weight the strips only need to be 2&1/8 long and 12mm wide.. the plane is rather nice over all but World Models did no good here with these Plywood Mounts, you know the wood is cheap, and one screw hole was stripped straight from the factory and as for the other holes their threads look bad but do hold, but how well will they hold is the question there,, World Models told me just to soak the holes/threads with Thin CA,, I didn't think that would hold ???

from the factory the Plywood is 5 Ply, 3 rather thin pieces and 2 thicker pieces,the thick pieces are maybe 3x as think as the thin pieces, the Plywood is 6mm thick..

to add, the Plywood I have is 7mm thick Aircraft quality and each Ply is the same thickness, I sure would replace the Chinese wood with my wood if it was easy to do errr..

thanks again !!!
Jim

scale only 4 me

My Feedback: (158)

Defiantly add something, the cheap china ply is a joke

My preferred method is to go with AC grade ply and soak with thin CA, Then use a tap to create threads for a 4-40 or 6-32 bolt, it's a process, you tap the threads add more ca, tap a again, might have to do this 2-3 times to get a nice solid threaded ply piece, but once done you have a good strong attach point.

p.s.
Chucking the tap in a cordless drill speeds the process considerably..

good luck

the Wasp

My Feedback: (1)

see photos
you can see I added CA,, and in the last photo you can see that there is no wall inside the wing to support the front of the Mount

scale only 4 me

My Feedback: (158)

Looks like it's all cut out of one piece into a U shaped piece,, shouldn't really need more up front, once you bolt the gear down, it holds itself all together,,,

Way I see it, option one, add that 7mm AC ply and tap the wood for some 6-32 screws
or option two,, just add some blind nuts, with epoxy,,, access looks pretty easy

good luck

the Wasp

My Feedback: (1)

I forgot to add,, there are 2 wedges under each side to help support the plywood, these wedges come out from the Ribs and stop just before they reach the holes,, the Plywood looks really cheap, if they used more Plies it would be much stronger,

adding Blind Nuts, I was thinking about that, I'm sure they will work, but I'm worried about making the holes larger

Jim

scale only 4 me

My Feedback: (158)

Huum,,

The larger hole doesn't worry me, but the wedge or triangle stock support close to the hole will make seating blind nuts flat more of a challenge, you'd somehow have to cut that away,, A new ply piece can be cut at the angle to fit tight

Probably not,,the wood they use in that china ply (lack of a better name) is too soft to hold threads, even thick or more layers would eventually fail

the Wasp

My Feedback: (1)

what I did,,

so what I ended up doing is cutting small blocks of my AQ 7mm Ply to glue under each corner of the retract mount so I can use blind nuts, I cut each block larger than the Blind nut and filed a slot on a angle to form around the Wedges that support the mount, then I used thickened epoxy for glue,,
I wanted to use just one piece of wood for each side but I could not hold it in tight (I didn't have a small enough C-clamp, I have to hold the pieces in with my fingers till the epoxy gets hard), so I cut the pieces of wood smaller, and on one side 2 pieces are also glued to the Spar, it will work,,

as for the epoxy I use 2 Ton Devcon, I have used it for years and years and it works much-much better than 5 minute or 15 minute or even the 1/2 hour stuff,, I used West Systems 403 Micro Fiber to thicken the epoxy, I have been uses it since 1997 and it has never failed me.

Jim

Steve Collins

My Feedback: (8)

You could have saved some effort and just used the threaded brass inserts and bolts. These inserts are superior in my opinion to blind nuts.

TowerHobbies.com | Dubro Threaded Insert 4-40 (4)

the Wasp

My Feedback: (1)

I did think about that, but the Chinese wood is so dry and cheap I didn't want to trust them

thanks !!

Jim