Hi Bob, the pushpins are to simulate the knobs and handles found inside the cockpit - (throttle, flaps, gun arming,Landing gear wing folding etc.. ) . Just push them thru the abs plastic and have a small piece of balsa ca'd on the underside for durability. You can then just hit the underside of the pin where it came thru the balsa with a small drop of thin ca.
John

Hi John,

Thanks, yeah I kind of figured the push pins were for that but there is a pretty big number of other pins. I don't think there are that many levers in the cockpit are there?

Hey Guys,
I just purchased my CMP-Cat from AKModels. He also sells the "cheap" version of this CMP ARF. Asking Alex what the differences are other than the price he explained to me the difference is in quality. So I opted for the real CMP ARF for little under $200.00. Should receive it today. I am planning to power it with an FPE 1.3. A clubmember flies his with the new Zenoah 20 and it flies just great. I know this thread is huge and a lot of stuff has been discussed, but I am planning to upgrade the scale appearance with a better paint job and panel lines in addition. Problem is I can't find anything about the scale layout of the panel lines. Also, where did you guys get this nice cockpit kit from? I am going with Robart air retracts type 615. Any advise on what's the easiest and best way to drop those R/T in? Oh, one more thing: Is the suggested C/G right on where it's supposed to be? Thanks for your help.

Hey Virginian,
Do yourself a favor and skip the Robart 615's. Read through some of the other threads
about the problems with using them in a plane over 8 lbs. or so. You would be better
off getting a better set now than getting them later after they fail. They were never
designed for that heavy of a plane. Don't just take my word for it, ask a few other
what they think.

I appreciate your comments BigRetracts-RCU,
The reason I have those is, because one clubmember flies his with exactly the same R/T an dseem to have no problems at all. Besides I got this set with servo and everthing for little over a hundred bucks. I couldn't pass on that deal. If they fail I know how to strengthen them. No big deal for me. I have a small shop in my garage.

What I forgot to mention in my previous post may be interesting to anybody who thinks about purchasing a CMP ARF. I ordered my Hellcat from AKModels on Monday and today, when I got home, a huge box was already waiting for me. Atfer opening the package I could hear me say this: "Wow!!" Not only was the original box wraped with a bigger box for added protection, everything arrived in perfect condition. How many times do we receive stuff damaged and then have to go thru trouble to get replacements. The way this parcel was packed it would have been hard to be damaged by the carrier. Back to the actual ARF: I sure was impressed how everything was wrapes in foam and plastic and packed inside the box. Not even H9 or GP packs it like CMP does. After inspecting every part, I let go of another "wow". For less than $200.00 this is amazing. The fiberglass fuse is built solid. All plywood is glued in perfectly. I coudn't find anything wrong. The wings are flat and show no warp. The hardware is maybe not top notch but certainly no garbage, either. Overall my impression is nothing but positive. I devinitely will buy another CMP ARF and when I do I certainly call AKModels.

You should go ahead and use the Robart 615 retracts. 3 of my friends here in Denver, Co. have these retracts installed in 2 TF Corsairs and 1 TF P-40. These planes have been flying for the last 3 years and they haven't had problems with the retracts. All 3 have Robo-Struts and the gear rails were beefed-up in all 3 planes. The Corsairs weigh 12 pounds and 12 and a half pounds. The P-40 weights 11 pounds. These guy's are GOOD flyers. Any gear will cause problems if you are constantly slamming the plane into the ground on landing. I haven't read the forums on the 615 retracts, but I have seen them work just fine time after time in 3 planes with good flyers.

And yes I want one of these CMP hellcats.

Gotta say I agree with Big Retracts.
I've had the 615's for quite a few years and while they were great fairly new, after they wore I had to re-work them a few times to re-establish their reliability and they're still not too reliable. you'll be better off with a set of Robin-aire gear or Sierra which is manufactured by denny (Big Retracts). CJ are OK but not as good as the other 2.
Take it from someone who's dealt with 615's for a long time. BTW I'm still flying them but not near as frequently.

Well, I got them for such a great price, I have to use them. On a different note: I am looking for information about the Hellcat's panel lines. Any idea where I can find this info? Also, what is the approx. distance of the retracts studs measured from the lead edge of the wing. I guess the farther up front the better the ground handling.

If you look back in this thread there are at least 2 different places to get 3 view drawings of the Hellcat, that should help.

That is not a true statement. The further forward the main gear are positioned ahead of the CG the greater the tendency the aircraft has to ground loop. To far forward and it can be almost impossible to take off. As you move the gear closer to the CG the more stable the aircraft becomes, but it will have a greater tendency to nose over. You'll notice that models that come in for a landing that have the gear to far forward, the pilot cranking in lots of rudder to keep the plane heading straight, it does not take much movement either forward or aft to greatly affect the ground handling either way. It's up to the designer to find the sweet spot, that provides good take off and landing directional control with a reduced tendency to nose over.

BlackSheep-1 is so correct about too forward or rearward of gear placement. A good starting place is to have your axles as close to even with the leading edge of your wing when looking down on the plane as it sits on the groung from above. You need to have the tail elevated so that your center line of the fuse is parallel to the ground. This works very well with a C/G that is about 25% of the cord of your wing. It can be a real close measurement in some cases. On gear that fold either inboard or outboard this has worked very well for me. I really don't know about rotating rearward folding gear. This may not apply. This may or maynot help.

The 3-view pics I've seen of the real thing show the axle just slightly behind the leading edge with the fuse elevated to level. With the tail wheel on the ground, it in front of the leading edge.

Bob

When the tail wheel is on the ground and you can apply some up elevator you have positive control. It's when the speed increases and especially when the tail comes up that the problems start. I think he was using the reference to the leading edge as if the tail was up, not in a 3 point attitude. I would follow the factory drawings for landing gear placement.

Yeah, that's what I meant by the Fuse elevated to level. Poor way of saying it I guess. Hey Pappy, I've caught up with the cockpit instructions and posted pics a while back. Would love to see more (did you see the question on the pins) I can put together a pdf file for you when they're done if you want. Keep up the GREAT work.

Bob

Thanks guys,
I think I am not too far off from the correct location if you look at my pix. I made myself custom wheel wells and fitted them in this morning. Came out alright, I guess. Used a Tupperware jar slightly larger than the 3.5" wheels I am using. Fiberglassed on the outside and trimmed it acc. to the airfoil.

Looks pretty good, I like the tupperware idea. When the retracts are extended where are the axles in relation to the leading edge of the wing?

Bob

Hey bigbird,
I have attached a pix that should give you a pretty good idea of the location. I have no way of measuring the exact location of the axles since I have not installed the wing yet. But to give you some numbers here is what I measured: The struds are 2.25" behind the lead edge of the wing when extended.

Looks good to me! I guess I'll start on my retracts. I'm stripping the wing, tail feathers and control surfaces and fiberglassing and painting. I have one wing stripped and was not impressed at all with the joint at the dihedral. It appears to be filled quite a bit at the trailing edge, fitting better toward the leading edge. From what I could tell you didn't have to cut into the ribs on either side of the wheel well, is that right? I'm using 4" wheels so I'll have to.

Looking good so far, thanks for the pics

Bob

Hey, bigbird
I did cut into both ribs. As you can see in picture #2 fro my first post, I had the bigger wheel well outlined. But I am using "only" 3.5" wheels. As a matter of fact I am using the H9 wheel from my big P-47 (80" wing). I stiffened the sheeting around the bigger well with balsa and epoxied the new fiberglass wells in place using micro balloon. That way it helped to strengthen the area around the retracts. I feel pretty comfortable regarding structurel strength of the wings.

I got a rude surprise today, I started digging in the box (F6F Hellcat from NitroPlane) for retract mounting blocks and found they forgot to include the belly pan! I unwrapped everything hoping it was inside the fuse but, nope. I emailed them but from what I've read here I don't have much hope. This must be the knock off as it doesn't have CMP any where on it, not the box or instructions. The order did say CMP Hellcat though.[:@] Bummer!

Bob

That kind of sucks....I almost bit when NitroPlanes had that $139.00 special on the Hellcat. They also said that it was a CMP, everyone I know that did the deal got the knock off kit. Hope you can get your missing part.

Yeah it does that. I don't have a lot of hope they'll make it good, going by what's been said here. It was the $139 that got me. I'm going to fiberglass the wing and tail feathers and after I stripped the wing I noticed a pretty big gap (filled) where the dihedral starts. No problem if you fiberglass it or reinforce that spot but could be trouble if you don't.

We'll see.

Bob

I guess if it comes down to it you can always make some formers and glue them to wing and then sheet them for the belly pan. You sound like you are handy enough to do that.

Good luck and enjoy the build.

If I have to I'll shape some foam and fiberglass it, it would be a first but then life is full of them!

Bob