P40-E 60 size ARF problems.
 

I just ordered and recieved a P40-E Warhawk 60 sized ARF. I am starting to build it and have encountered a few problems. After reading through the instruction maunal, It looks like there are a few steps in the instructions missing. Particularly page 2 where it talks abou tthe airleron servo hatches. I cut away the material from the bottom of the wing after matching the approximate placement of the servo hatch, not listed in the instructions. Also, the hatch is about 1/8" larger than the size of the opening for it between the ribs. Is there a problem with this kit or maybe the accessories packages were mis-matched to this 60 sized for a 90 or something like that? Also on page 7, there is nothing but a blank space where I guess the arrows to where the elevator and rudder and throttle servos should go in the fuse. I found a piece of ply that has a slot where a servo would go (I assume for hte throttle) in one of the accessory packages and it barely fits in the fuse. I was told by a friend to contact this forum on these questions, but should I instead contact the company directly about possibly sending this kit back for a replacement?
Thanks for any help you can provide either via this forum or to my direct email: [email protected]

Bryan Saldana

RE: P40-E 60 size ARF problems.
 

First, write down the C.G. and throws, then throw away the manual.

Yup it's that bad.


You selected one of the more complicated models to build, and as you've discovered the manual is of no help.

Given your description there doesn't seem to be anything wrong, but you are unfamiliar with this type of ARF.

See if you can get help from a more experienced builder.

Re: Hatch

This is typical. Simply file away material if needed and adjust. Try to avoid this whenever possible, but be away that you will have to do it from time to time.. Better that there be too much material ( which can be removed ) versus too little.

You'll also find that the servo holes may be a little small and you'll have to file away a bit of wood to make things fit.

RE: P40-E 60 size ARF problems.
 

Thsnks for the help. I have been taking my time and checking 5 times, measuring 3 times, checking again, then cutting. In checking things, I have had to figure out the proper sequence of gluying or cutting things in order for everything to fit. What do you think of using wood glue with wood sandings instead of epoxy?

Bryan

RE: P40-E 60 size ARF problems.
 

Some people here swear by wood glue but only if clamped and let dry all night.

I prefer the convenience of epoxy.

As you build more planes you'll be mixing up tons of epoxy in each step of the process. Wood glue doesn't need this, but you have to wait much longer for it to dry.

Epoxy also can be used as fuel proofing when mixed with denatured alchohol ( acetone is sometimes recommended but it's VERY hard on plastic and plastic covering ).

I like Tower/Hobbico's Epoxy packs. The GP stuff is awful and dries out very quickly even when adecuately stored.

RE: P40-E 60 size ARF problems.
 

My problem is mixing the epoxy correctly. It says 30 minutes, but I have found that especially if i mix more than a few ounces, it starts getting hot (curing) inside 15 minutes. It seems to hold well though because I pull on the pieces after a day or so of leaving it alone and it does not give at all with all the force I can muscle. I am just worried about mixing epoxy and joining the main wings together as well as the tail surfaces.

Bryan

RE: P40-E 60 size ARF problems.
 

Thanks for the input. Now I am having trouble with the wing joiner. I have epoxied the joiner into one side of the wing after I drew a line indicating the halfway point where the wings will meet. I am having trouble getting the other wing to set flat with the other wing. Now that I have sanded both sides of the exposed half of the joiner so much to try to get rid of the gap, the other wing fits loosely and STILL does not set flat with the other wing.

My concern is that even if I did get the gap closed or not (by using lots of epoxy to fill this gap), any mis-alignment when I do glue the wings together could result in a poor flying performance or the wing coming apart.

By the way, I did have to cut one of the airleron servo hatches down by approx. 1/8" in order for it to fit in the bay, the found the hatch would not set flat in the bay (rails crooked). And I had to sand quite a bit for the first of the retractable landing gear structure (plastic square where the gear pivots) to fit in the wing. I think parts of the wings are not built square.

The rest of the ARF seems to be okay as far as I can tell.

Taking this into consideration, Is it in this forum where I would talk with a representative with Nitro Models about getting a replacement set of main wings and joiner?

My direct email is [email protected]

Thanks,
Bryan

RE: P40-E 60 size ARF problems.
 

It sounds like you have a bottle of 30 minute resin mixed with a bottle of 15 minute hardener.

No matter the amount, I get 30 minutes almost to the second.

I prefer the Hobbico stuff, as the Great Planes Epoxy dries out VERY quickly once it's opened forming or looking like granuals.

RE: P40-E 60 size ARF problems.
 

Are you talking about the point at which the two wings meet together?

If you find that the leading and trailing edges meet but the mid points do, then sand the wing root material itself.

Typically only a little bit needs to be removed.

Right, I tape a sheet of sand paper down on a work surface and sand the wing roots flat.

I do this BEFORE putting the joiner in place to check the fit.

Most ARF's need a bit of sanding or adjustment, no matter the manufacturer to get things right.


PM John here ( Nitrostaff1 ).

RE: P40-E 60 size ARF problems.
 

The trailing edge is flat, but the gap is in the center and only in the top of the wing, the bottom meets okay. I can put a flat edge across the root rib where the wings meet and they seem level.

Bryan

RE: P40-E 60 size ARF problems.
 

Sounds to me like you might not be adding in the wing dihedral. The wings should not be flat.

RE: P40-E 60 size ARF problems.
 

I believe he is talking about the wing root junction points, where the two wing halves are epoxied together.

I just finished building another plane ( from a different manufacturer ) where I had to sand the wing root a bit to get the two halves to fit flat against each other... with proper dihedral.

On the other hand I don't know how much experience the OP has.

RE: P40-E 60 size ARF problems.
 

Okay, thanks for the input. I took it to a friend's house who has more experience building. We put the wing together and he noticed that the TE and LE were touching before the middle was able to. So we rubber-banded the wings together and used a women's nail file to sand the TE and LE high spots. after a little sanding, everything fit fine. We used wood glue that contains wood fibers and it went together perfectly with clamps and rubber-bands holding tension on it while it dries.

I'm a happy-camper now.

Now on to gluing the tail feathers to the fuse and the adventure continues....

Thanks again for the input,
Bryan

RE: P40-E 60 size ARF problems.
 

Great!

Yeah this is quite common.

Good luck on your assembly.

Take it slow.

RE: P40-E 60 size ARF problems.
 

I'm happy to see you have your wing figured out. I was not trying to question your
building skills. I work part time at a LHS and it seems like its the simple things people
forget or miss when building ARF's. Good Luck !!!

RE: P40-E 60 size ARF problems.
 

Well, you know how it is. At the time, you can't see the painfully obvious until either you take a break away from it for awhile or get another pair of eyes (especially more experienced) looking at the problem. Then when looking back, you hit your forehead like those "could have had a V-8" commercials!

Well, now I have learned something new and that's what this hobby is all about!

Bryan

RE: P40-E 60 size ARF problems.
 

Hello, i'm baaaack! I tried to start last night, where I would have to put the wing on the plane to start aligning the tailfeathers for epoxying in and discovered that the dihederal (sp?) we glued the main wings together at is WAAAAAY to much! When the wing sits in the saddle of the fuse, the TE pokes up off the surface of the fuse. I discovered that when I was epoxying the main wings together, I should have had that hardwood piece to verify the dihederal (sp?) that glues on the underside of the wing at the TE because it was at the correct dihederal. Since they are permanently joined together, I guess I will need to order a new set of wings!

DARNIT!! (I want to use stronger language here...)

Anyway, please advise on how I go about ordering a new set of wings.
Bryan

RE: P40-E 60 size ARF problems.
 

Wait before you do...

You have nothing to loose by doing this...

You could CAREFULLY cut the wings apart on the epoxy line.

You will have to either use a fine coping saw or similiar saw, or something like a band saw, that is capable of making a clean cut through the material. The finer the better, but it will take longer to cut.

Do NOT pry the wings apart.

Once you've done this you can then sand until you get the right dihedral, then drill out any dowls and insert new ones, and re-glue everything... Consider also adding a couple of CF rod pieces too.

I've done this with a wing I once screwed up, and I've had no problems.

It's cheaper than ordering a new wing set.

RE: P40-E 60 size ARF problems.
 

i'd rather have a new wing with an in-tact joiner that has not been cut into than "fix" this one and the wing fold on me in a hard turn.

Someone from NitroModels please contact me: [email protected]

Thanks,
Bryan

RE: P40-E 60 size ARF problems.
 

Eh, not quite the way to do it..

PM John here and ask for a new wing set.

RE: P40-E 60 size ARF problems.
 

whatever happened here?

RE: P40-E 60 size ARF problems.
 

Well, sorry about taking so long to update. After searching on the internet for pictures of real P-40's and seeing how much dihederal they have. Comparing these pictures to what I had, I decided to leave the present wing alone. During this time, I took a break and built a website for the R/C club I belong to. www.jetero.com A month ago, I began working on the p-40 again and finally got it ready. After waiting for a perfect sunny, non-windy day (procrastinating), which hardly happens in Texas during May, I decided that if I try to wait for someone else to maiden flight this plane and it crashed without me doing it, I would never have had the satisfaction of flying something that took me so long to get ready for flight. I had an experienced person check it out for me about a week before and when I tried taxiing, it would nose-over. I was advised to bend the landing gear forward a little, but I tried and upon bending them, it made the wire loose in the mylon gear (that screws into the wing). I was advised to put a little thin CA in there and be careful not to get it in the part the moves. It worked. I was told I could put maximum throw on the elevator and put dual rates to switch when in flight as well as throttling up a little faster and smother than slow and deliberate. A week later, I decided to try to maiden. There was about a 45 degree crosswind to the runway at about 10 mph. I should have waited, but i figured I had enough experience with sport tail-dragger planes in crosswinds to be able to compensate. Well, with a quicker throttle-up, and full up elevator lessening as it gained speed, the plane did not bounce as it sped up. Being nervous, I guess I was over-controlling the elevator (with high-rates on) and the p-40 was teeter-totting on its mains as it gained speed. I guess I over-compensated with up (on high rates) and all of a sudden, the p-40 lept into the air straight up and began to roll right!! I immediately inputted in some left aileron as well as too much elevator (high rates). The p-40 immediately flattened out and since it lost all its forward speed, belly-flopped into the ground at about a 15 degree downward angle. I didn't have to cowl on, so the pitts style muffler (2 pipes straight down) were broken off, but the engine and prop was okay! The chin wood structure that is just before the wing was broken backward and the plastic middle piece tha goes in the center bottom of the wing was broken up. The landing gears were torn off the plane broken at the nylon main piece that screwed into the wood structure of the wing and tore into the bottom covering and broke some ribs. The ailerons were even torn off and luckily only the control arms to the servos were borken. Everything else looks okay. If I didn't roll left, it could have rolled and crashed on the wing or upside down and really totalled the airplane, so it could have been worse. Way back, I had requested another set of wings from Nitro. I'm putting things together again and will be ready soon for its second maiden flight. Next time, less wind (or no crosswind), maybe get used to switching to low rates elevator during takeoff, practicing control during takeoff roll with my club 40 taildragger, and put some exponential on the right stick.

Well, this ended up being longer than I thought, but I figured I owed this forum an update. Nitro Models, I"ll soon be ordering some parts from you.

Thanks for reading,
Bryan