Ruizmilton , I did get your email and responded to it requesting the other pictures you said you have and about pricing . Did you not get my email ?

Ruizmilton
another photo, the wing is finished. I have no interest with this story, I tell you what was done as modifications, if you are reassured it's good otherwise I don't care, on the other hand I understand the anger of those who bought the first version of the corsair.

https://cimg6.ibsrv.net/gimg/www.rcu...e37d0b2263.jpg

I don’t recall getting a response, still no worries, the complete explanation of what is the process to modify the wing is in the email, the pictures of the formers were included on it as well, there were a couple of pictures I did not have with me when I sent the email, they have already been posted on this thread. If there is something that is not clear let me know.

Thanks

Can any of the guys using a Saito FG 90 share the size of standoffs that you used? I’m done with the building if the airframe, servos and rigging, moving to engine installation next and need to know the size of the standoffs.

Thanks

im going a differant route with using expandable foam for the center section....may back the original spar with 4ply birch but i'm thinking consolidate all the air space and voids to act as 1 solid unit! not the entire center section just whats needed,i'll put tubes in for my wiring and block off where i dont want the foam to penetrate then put a few venting holes so excess has somewhere to go rather then blow the skins off the ribs and other structure, they sell high density 2 part foam for use in setting deck posts in the ground.

I think this will make the center section very heavy, and the foam will not add any strength to the stucture. For the skin yes but nog for a overall strength i think.

Geoff

I did that on my 85” ESM Corsair and it worked great! Still flying today. Heavier yes...but not enough to hurt flight characteristics. I doubt you will notice any difference. Bonds to the frame really well! Go for it!!!

well 12oz is 12oz regardless if its feathers or lead and all weight is at or infront of cg! and this thing calls for alot of ballast to balance,although its not upfront in the cowl its still forward of cg.... my opinion is filling a empty void that does nothing to consolidating the whole center section and tieing all formers and ribs as 1 solid unit definetly will spread the load, but i'm still researching at this point.

I have the TopRCModel Zero and Corsair, both I had to fix some kind of spar issues. I was hoping TopRCModel ARFs last longer than plastic covered ones but they do not IMHO. They make beautiful ARFs but I will never ever buy any more of them.

I have one as well and would be interested in seeing how that works, or the other fix. Also did anyone put a radial in this thing ? I seen the Moki's on youtube but those are hard to find.

i went away from the expanding foam and cut back 4 ribs to accept 2 sets of 4ply birch cut everthing out on the table saw a total of 6 pieces, they run from lower bend in gull to the entire center section with each butt joint or splice being covered with another full piece, used a combo of hysol and 45min epoxy,then i'm backing each side of ribs 1 cut with hardwood triangle stock then strips of CF cloth and resin to tie the skins into the spars along with the landing gear mounts......lotta work but rather do it now then later,i'll try and post pics, so i ended up with 12 ply birch spar

and yes im installing a ums 5 cylinder 100cc

pics

https://cimg9.ibsrv.net/gimg/www.rcu...0863505bd5.jpg

https://cimg3.ibsrv.net/gimg/www.rcu...23f76e85c5.jpg

Ouch !! Mine is very nice looking , still , but it has not and will not fly ..... ever .....

Claude sorry for the loss of your plane. Can you describe how your plane crashed?

Do not fly this plane new version or old version!
 

The spar system design is bad to begin with, they may have added carbon fiber in some places but it is not going to help unless they put a solid 1/4 aircraft ply spar without lightening holes. The shell surface is also very soft and it can be cut like butter. If you bounce this plane pretty good on landing, it will self destruct on its next flight and risk hurting people around you.

Lucky for me I broke the wing on its first landing and not on its second flight in the air.

Like I said before this wing design is for a 25lbs airplane, but this plane is over 40+ lbs

This is why none are flying. The wing design needs a serious re-design, True engineering not that looks about right. Most competent plane builders see the problems at hand and are not willing to risk what we have spent $2500 on. Like throwing $$ down the drain!!! Sad ,as many of their planes are decent.

This stopped me from buying the P-47 and I really wanted to.

Mine is almost done, wing mod was completed (I won’t comment on it since it has been discussed to death) and last time I worked on it engine installation was completed, I still need to fabricate CNC parts for a servo actuated choke mechanism for the FG90, then it is taking CG, engine break in, radio program fine tune and maiden, this is exhausting…

https://cimg6.ibsrv.net/gimg/www.rcu...f9ca03d98.jpeg
https://cimg8.ibsrv.net/gimg/www.rcu...b9c93d204.jpeg
https://cimg8.ibsrv.net/gimg/www.rcu...c706a9d95.jpeg
https://cimg9.ibsrv.net/gimg/www.rcu...b17581958.jpeg
https://cimg4.ibsrv.net/gimg/www.rcu...bec36b514.jpeg
https://cimg3.ibsrv.net/gimg/www.rcu...a52d4390b.jpeg

hello Ruizmilton
did you put right thrust and down thrust or is your engine mounted straight ?

[QUOTE=claudebrifflot;12706194]hello Ruizmilton
saito 90R3 after the crash!
https://cimg6.ibsrv.net/gimg/www.rcu...27701d7853.jpg
https://cimg7.ibsrv.net/gimg/www.rcu...e23fe4ec2b.jpg

Oh man, that hurts my heart

Hi Ruiz,
Can you please post some information on what you did to modify the wing structure? Pics would be great too if you don't mind as I am interested.

Thanks in advance.

Craig:

There are some pics I posted on the previous pages of this thread, I’m posting under this new username as my original one can’t be accessed at this time (working the issue with RCU)

So in the hope that Robart finally comes through and gets my retracts to me in a couple weeks, I started on the Corsair. First step is to add some strength to the wing. There are two issues as I see it. One being the glue they used is a bit brittle, and if the glue joint to the skin fails the wing looses much of the structural strength. The glass combined with the ribs is fairly strong, as long as the glue doesn't crack. Along with that, I'll help it out by adding a spar across the weakest area, from the middle of the wing to the outer spars.

After opening up a couple of windows on the top of the wing, I used my dremmel tool to grind away some of the glue. The goal is to get wing and rib available for the Hysol 9462 to grab. Using the cutting bit, it's not too hard to grind it away. I had to be careful not to grind through the wing skin. Here's what it looked like after taking off some glue.
https://cimg3.ibsrv.net/gimg/www.rcu...9ddf4cc8b8.jpg

Once I had it ground away, I used the applicator tube on my Hysol to put a bead of good glue everywhere I could touch. It helps to have a longer nozzle, like 6". To build a spar, I used 3/8" aircraft ply. First I had to cut out an area along the existing "spar" so I could glue the new ply flush to it. I glued using 30 min. epoxy and used large screws to tie it into the outer spars.
https://cimg9.ibsrv.net/gimg/www.rcu...8c21af19a2.jpg

https://cimg5.ibsrv.net/gimg/www.rcu...710557f446.jpg
I also added a block of ply to help strengthen the area that I had cut away. Here you see the spar and block visible in the wheel well.
https://cimg4.ibsrv.net/gimg/www.rcu...e4b689cc98.jpg

Once the two spars were glued in place, I created a center piece that would tie them together at the center. Once again, I used 30 min. epoxy and large screws. It also glues to the center rib.
https://cimg7.ibsrv.net/gimg/www.rcu...e4a9978ddd.jpg

After gluing in the outer wing attachment spars, I made sure the screw went all the way through to tie my new spar together. Once again, everything was glued together using Zap 30 min. epoxy.
https://cimg3.ibsrv.net/gimg/www.rcu...59ecbe20ab.jpg

So that's about it for the wing strengthening. I think it will be strong, but is still susceptible to issues if there is a stressful landing (you can't access every glue joint to add Hysol). I plan to inspect it often to look for cracks. I also fly Warbirds gently. No stressful outside roll stresses, or snaps. In most cases the wing is compromised due to a ground incident, so frequent inspections are a must. I'm not sure my mods will be good enough, but I'm confident that I can fly the plane safely. I'll post some more information about the build as I make progress. I'm hopeful that I can squeeze the VVRC 120 twin in the cowl without too much trouble.

great job on the mod! You were even more aggressive on your approach than I was on mine, since you were already there, you should have gone all the way to each end of the center section, the other weak area is the thin support area for the outer wing spar where the retract motors get into the spar, that’s were most wings are breaking at. See what I did in mine below
https://cimg2.ibsrv.net/gimg/www.rcu...741d13104.jpeg

That's a weak spot on about every warbird. The retract body bridges it and usually adds some strength. I'm not sure that's where wings are breaking, post crash damage doesn't really tell you much.
In hind sight if I could have fed a longer spar through the wing to fill that area in I might have. Without the retracts in hand I didn't know what I'd need for clearance in that area.
I can always add some wood later, as long as it's not TOO late.

Todd, before you fly, I'd follow his post, the only thing I would do different, instead of using ply, use some preformed CF plate and laminate that to the spar going well past the thinned area in both directions. The cf will be easier to slot in and will be as strong as the ply. Get it in with a good 30 minute epoxy bond to the spar, backed by screws as he did. The plane hitting the gear, repeatedly' right under that thinned area of the spar will stress crack the spar unless you can land on an eggshell all the time. A few not so soft landings and you'll have small stress cracks that you won't see untill its too late. The cf plate doublers would take the brunt of the abuse.

I'm putting Robart AIr retracts on mine, so I need to get those to make sure I know what I can do in that area. A have some thick carbon fiber that I will laminate in there.

Aloft has some 1/16th yhixk cf plate that wouldactually be better. One plate would give you enough to laminate both sides of the spar in both wings. You wouldn't have to worry about inyerference issues either. I used it on the firewall of my current build, to yest strength I dat the engine (6 lbs) on yhe plate and suspended the plate a couple inches in the air and started adding weight..at 15 lbs of weight there was mabe a 1/16 inch of flex in the plate. Aloft gurantees 30 percent stronger than an equivelent thickness of aluminum.
https://cimg1.ibsrv.net/gimg/www.rcu...2ec165dac1.jpg

I laminated both sides of the firewall with it. My engine is mounted with a 1/16th mild dteel plate to that that pretty much covers the whole frontof the firewall. (Zenoah mounting plate) Had to do it to create the notch you see. Its to clear the carb which is on a vogelsang aeroscale 90 degree intake Notch is not fully finished yet as it will be laminated in a cf matte material when I get the needed hole(s) in for air, and linkages.

added weight...maybe 2 oz of cf. Firewall is also dowel pinned with cf dowels.

The plate is what came from aloft. Just be careful after you cut it...stuff gets knife sharp.

Hot Rod Todd...I really like what you are doing. I also opened up the center top of the wing. I have come to realize that the Chinese ply can be separated using your fingernails. Of course this has been true for many years. To that end I have been lightly thinning epoxy to paint all of the balsa and ply in the fuselage and wings. In this plane I was able to reach 90%+ of the wood. The remainder I was able to reach through 2 holes cut and filled in the bottom section of the center wing. This keeps the ply from splitting under normal loads, provides additional and thorough glue to the bonded surfaces and in many areas enhances the strength of the composite covering.

Just an idea that I have been using on my Chinese arf's for the last 15 years.

Is there a gear readily available that will work for this plane? My friend bought one awhile back and will not buy the top rc gear, Sierra is on long term backorder. He's been waiting almost 2 years

Readily available, I'd say no. I ordered Robart gear as a package deal with mine last march. Still haven't seen them. Robart says they're starting to fill the backorders and getting them shipped out (last Friday) but it could be a while if you ordered a set from them.

https://cimg2.ibsrv.net/gimg/www.rcu...ac884a836.jpeg
Finally finished. Got Robart main gear last week. Sierra tailgear. All up weight is 37 3/4 lbs.
https://cimg9.ibsrv.net/gimg/www.rcu...d2a84b518.jpeg

Still waiting for my Robart gear (pneumatic). I ordered it last March and paid in full. I wouldn't think there are a lot of people ahead of me on the list.
Texans55, When did you order your Robart gear? Air or Electric? Thanks.

I picked my plane up at Robart on December 3, 2020. I ordered these pneumatic retracts while I was there.

Ok, that makes sense. Robart responded that they expect my gear to ship next week. Mine were on order from the end of Feb. last year.
The plane is coming along, I should be able to finish it up quickly once I get the gear.
Graphics are on. Getting ready to detail, weather, all that fun stuff.
https://cimg9.ibsrv.net/gimg/www.rcu...ffc1c0aa99.jpg

I got to speak with Tommy Blackburn before he passed several years ago and have pictures somewhere with him of my Top Flight Gold corsair in his scheme, he got such a kick out of the fact someone wanted to make a model of his plane instead of Kepford. He had some great stories. Nice job on Big Hog