Official FlightLine F4U-1A Corsair 1600mm (63") Wingspan

[Md_cobra]

[davegee]

I had a slight mishap flying my new Corsair today. Botched a landing in windy conditions, broke one of the steel pins that connect the servo to the landing gear strut. Looking at it closely, it looks to me that you can’’t Just replace the pin like on many other planes, but have to buy a whole new electronic retract. Do I understand that correctly?? I didn’t see a part offering on the website for that broken pin.
thanks
davegee

[Beeg]

I had a slight mishap flying my new Corsair today. Botched a landing in windy conditions, broke one of the steel pins that connect the servo to the landing gear strut. Looking at it closely, it looks to me that you can’’t Just replace the pin like on many other planes, but have to buy a whole new electronic retract. Do I understand that correctly?? I didn’t see a part offering on the website for that broken pin.
thanks
davegee

I don’t think Motion had ever sold those pins for landing gear. I’ve bent those pins more than a few times on other planes and either bent them back or find some stock of same diameter and cut my own. Either that or just buy a new gear. Nose gears on the EDFs are the most common bend for me when I overrun my runway.

[Ken Smith]

I had a slight mishap flying my new Corsair today. Botched a landing in windy conditions, broke one of the steel pins that connect the servo to the landing gear strut. Looking at it closely, it looks to me that you can’’t Just replace the pin like on many other planes, but have to buy a whole new electronic retract. Do I understand that correctly?? I didn’t see a part offering on the website for that broken pin.
thanks
davegee

I had to replace my pin in my P-40, I had to buy a 5/64” cheap drill bit to find the right size. A combination of press fit and CA. Had to remove the servo to get a good working space.

Ken

[davegee]

I had to replace my pin in my P-40, I had to buy a 5/64” cheap drill bit to find the right size. A combination of press fit and CA. Had to remove the servo to get a good working space.

Ken

I'm thinking that these are different than the P-40. The little steel pin that forces the gear to rotate 90 degrees goes through a hole in the center of the pin that attaches the main gear strut to the retract. I hadn't seen that before on rotating gear like FMS or Freewing. The problem is that pin is now compromised or weakened with the hole drilled through it, and easier to break. And sure enough, when I examined it in my shop last night, that is precisely where it broke. The landing wasn't great, but I didn't think it should have been enough to break that pin. Had it been solid instead of the hole through it, I bet it would have just bent some and would have been repairable. I wish they had come up with a better design than what they did. When I went online to try and purchase the entire servo with that pin attached, I saw that they are all backordered which tells me this is a common problem occurring. I'm very disappointed in the design of this part. It will probably be weeks now until I can get a replacement retract.

[xviper]

I had a slight mishap flying my new Corsair today. Botched a landing in windy conditions, broke one of the steel pins that connect the servo to the landing gear strut. Looking at it closely, it looks to me that you can’’t Just replace the pin like on many other planes, but have to buy a whole new electronic retract. Do I understand that correctly?? I didn’t see a part offering on the website for that broken pin.
thanks
davegee

If you're talking about that metal pin that goes into the strut on one end and the other end going into the trunion? (I think it's called that. It's the thing that is rotated by the worm drive to deploy and retract the gear.) If that's the case, I've seen these sold my Motion for planes like the A-10, which was known for breaking. I bought a couple in preparation for the next break. They brought one out made of stronger stuff. You can also find this pin for other planes (like the Avanti S maybe). Just measure the diameter you want and compare to the ones being offered as replacement on other planes. You may need to cut new flats and perhaps shorten the pin a bit to work.
The added problem with the Corsair is that the main gear is a rotating piece where a rotation pin has to be embedded into the main pin. This adds a level of complication that most people won't mess with. With my FMS 1700mm Corsair, I just bought a couple of spare retracts.

[paladin]

idk, IF THESE ARE THE SAME, BUT:

https://www.motionrc.com/products/fms-designed-rotating-e-retract-set-for-1700mm-corsair

I ASSUME YOU HAVE TO PULL THE TILER arm to remove the rotating pin. I would be very interested to see if the rotating pin is metric or English. metric and your done without a lath. English I would be tempted to replace it with music wire, in fact replace both with music wire. i'm sure they are untampered as purchased. which means they won't take a lot to bend.

might be worth it to talk to these guys about making both pins in a kit:

http://smallpartscnc.com/index.php?route=product/product&filter_name=Sk3&product_id=129

joe

[Aros]

One thing I found when replacing my retracts (and is the case on most) is the way the servo wire is channeled would be next to impossible to switch out a new retract and run the wires along the same nice hidden - but tiny - channels. So I ended up having to re-route the wires unceremoniously through the wheel bay. Not a huge deal since with some tape and paint it won't be too bad but what I would love is if the connector is close to the retract itself so all you have to do is unplug the old retract by the base and plug in the new retract at the base and simply screw it down. Using the same servo lead as the original. Would make switching out retracts SO much easier.

[xviper]

idk, IF THESE ARE THE SAME, BUT:

https://www.motionrc.com/products/fm...1700mm-corsair

I ASSUME YOU HAVE TO PULL THE TILER arm to remove the rotating pin. I would be very interested to see if the rotating pin is metric or English. metric and your done without a lath. English I would be tempted to replace it with music wire, in fact replace both with music wire. i'm sure they are untampered as purchased. which means they won't take a lot to bend.

might be worth it to talk to these guys about making both pins in a kit:

http://smallpartscnc.com/index.php?r...product_id=129

joe

Those FMS parts are pretty pricey and we don't know if the holes will line up. For $17.00, you can buy just one of the FL Corsair retracts. If you had to buy 2, it's still cheaper by more than a factor of 2. True, Motion is currently out of stock but they shouldn't be that way for too long.
Pulling pins and lathing this and that, to me, is too much hassle when you can wait just a bit and get a whole new retract.

[Ken Smith]

Read the above and learned a good deal, thanks, great thread, great info. While on landing gear, what is the size of the set screw on the main landing gear sturt? I think it is 2mm. The stock ones are soft and strip out, want to order some extras or may have them in stock.

Ken

[davegee]

idk, IF THESE ARE THE SAME, BUT:

https://www.motionrc.com/products/fms-designed-rotating-e-retract-set-for-1700mm-corsair

I ASSUME YOU HAVE TO PULL THE TILER arm to remove the rotating pin. I would be very interested to see if the rotating pin is metric or English. metric and your done without a lath. English I would be tempted to replace it with music wire, in fact replace both with music wire. i'm sure they are untampered as purchased. which means they won't take a lot to bend.

might be worth it to talk to these guys about making both pins in a kit:

http://smallpartscnc.com/index.php?route=product/product&filter_name=Sk3&product_id=129

joe

Thanks, Paladin. I am very conversant with the larger retracts for the 1700 mm Corsair. I did go through a few of those over the years, but they were much more robust, and that little pin at 90 degrees to the main pin was off to the side, not through the actual pin like the new Corsair is. Plus, the main pin was pretty large steel that although might get bent, usually did not break under loads like bad landings and stress. And they did sell inexpensive replacements. I'm really upset about what I think is a very poor design on this newest Corsair for the main retracts, the fact that since the main connecting pin between the gear strut and the retract, has a large hole in it for the smaller pin that rotates the gear to pass through and is much weaker because of that. Very poor headwork in making this design, in my opinion!

[davegee]

Read the above and learned a good deal, thanks, great thread, great info. While on landing gear, what is the size of the set screw on the main landing gear sturt? I think it is 2mm. The stock ones are soft and strip out, want to order some extras or may have them in stock.

Ken

Hi Ken: not certain, but I think the set screw is a standard 2 mm size like most of the other gear parts on these foamie airplanes. The price doesn't necessarily bother me as much as the fact that I think it was poorly designed, making it much weaker with that hole through the pin and with any force at all, it is going to break. Then you have another $16 charge each time this happens, not to mention damage to things like the prop and other parts that scrape into the runway when the gear snaps off. It really seems to me that they could have engineered this better, without this problem, based on other previous designs like the A-6 for instance. Stuff like this really pisses me off, and if they keep doing it, I'm out of this hobby!

[paladin]

every form of refuge has its price. now where did I hear that?

this is where I would go for good screws:

https://www.mcmaster.com/set-screws

[davegee]

If you're talking about that metal pin that goes into the strut on one end and the other end going into the trunion? (I think it's called that. It's the thing that is rotated by the worm drive to deploy and retract the gear.) If that's the case, I've seen these sold my Motion for planes like the A-10, which was known for breaking. I bought a couple in preparation for the next break. They brought one out made of stronger stuff. You can also find this pin for other planes (like the Avanti S maybe). Just measure the diameter you want and compare to the ones being offered as replacement on other planes. You may need to cut new flats and perhaps shorten the pin a bit to work.
The added problem with the Corsair is that the main gear is a rotating piece where a rotation pin has to be embedded into the main pin. This adds a level of complication that most people won't mess with. With my FMS 1700mm Corsair, I just bought a couple of spare retracts.

Hi XViper. It looks to me that this is a slightly different animal. I have lots of experience with the 1700 mm Corsair, A-6, other rotating main gear on foamies. This one has the 90 degree pin actually through the center of the main pin connecting the gear strut to the retract. That leaves very much smaller area to absorb the shock of landing, and as I said in a different post, that is precisely where it fractured. That's where it had to break, at the weakest point.
I don't suppose that they will fix this issue. I'll buy the full retract replacements for $16 each, and hope they don't break as often. It is also a pain in the drain to pull the old retract wire out of the wing, and then thread it back in again to the connecting bus. I see that Motion is totally backordered on these replacement parts, so I suspect many others are now experiencing the same problems that I am talking about. My point is if they had just engineered it better, this brain damage wouldn't have been necessary.

[downwindleg]

every form of refuge has its price. now where did I hear that?

this is where I would go for good screws:

https://www.mcmaster.com/set-screws

Lyin' Eyes....The Eagles:Cool:

[theoldALFER]

every form of refuge has its price. now where did I hear that?

Eagles, Lyin Eyes (Henley and Frye). :Cool:

[theoldALFER]

Before I got sidetracked, I was going to write this ...I, like the rest of us, really appreciate this Corsair. The fact that there are almost to 2000 posts is a testament to that. It also took that many posts to discover a weak point on this aircraft. THE LANDING GEAR “PIN.” The last airplane that I remember that generated this much of a “buzz”was the Starmax/HSD Skyraider. It to had 90° rotating re-tracks. And, as I well remember, a problem with the LANDING GEAR “PIN.” As Yogi Berra once said, “Deja’ vu all over again.”
SmallParts CNC might be a solution.
The pins for the A10 or the Avanti might be a solution.

MOTION RC SHOULD COME UP WITH A SOLUTION...SHOUlD BE THE SOLUTION! FOR AN INVESTMENT OF $459.00, A LOUSY $3.00 “PIN” SHOULD NOT BE THE CAUSE FOR GROUNDING THIS PLANE :Whew:DUE TO POOR ENGINEERING (AS EXPRESSED IN PRIOR POSTS). MOTION, YOU ARE TOO GOOD TO LET THIS SLIDE.
AT LEAST STOCK REPLACEMENT PINS!

JUST MY HUMBLE OPINION

theoldALFER

[TiredIronGRB]

It's not the pin...it's the retract housing.

[xviper]

It is also a pain in the drain to pull the old retract wire out of the wing, and then thread it back in again to the connecting bus.

I know it well from my FMS Corsair. I've changed retracts at least twice and repaired each one at least once. I still have a couple of spare new retracts. If and when I break my FL Corsair's retract(s), I may see how much it would take to swap in the ones from the FMS and use the struts and wheels from the FL. It may just turn out to be wishful thinking.

[Ole-Timer]

How about some pictures of where your gear are failing...?
I cannot figure out why all Rc components come with preinstalled wiring harnesses. Why aren’t they all made with a plug at the component, just like real aircraft are made. Would make component changes a snap, right :Silly: