Official Black Horse 2280mm F4U Corsair thread

[427jimmy]

Are these Corsairs still available in the US? Zigi seems to be out of business?
Thanks for any leads

[Katniss]

https://www.motionrc.com/products/black-horse-f4u-1d-corsair-2280mm-89-7-wingspan-arf-bhm1000-001

Motionrc

You might also consider the Seagull 87" Corsair
Legenghobby . com or gatorrc .com

[Rod Musgjerd]

Hi everyone! Going to maiden mine this weekend. Doesn’t sound like you guys are using any elevator comp on flaps, is that correct?
Thanks in advance.

[Zantero]

Hello all i have a question about engine sizes between the top rc 93'' corsair and the black horse 90'' corsair, i see a lot of people putting engines as large as the moki 180 in the top rc version while the largest i have seen on the you tube is saito fg90 in the black horse version, im not trying to start a why would you put that large of engine in that plane war just curious on thoughts as to why that is, i know it is a 60cc plane (the black horse version) and it will fly it, there's proof of it on you yube just want some thoughts as to is the toprc version more capable structurally of handling that much power and weight etc etc and the black horse is not, just want to hear some opinions on it, thanks.

[CorsairJock]

Thinking about ordering one of these, Motion RC has them in stock. I LOVE the weight, I like to fly light. I've read all the posts, would like to get better retracts but Robart is no longer in Business, so will like stay with stock retracts. Has anyone tried the Dubro 5" scale wheels for fit? That would be my choice if they fit.
Not looking to change much, but I like to hide control rods when I can, especially the rudder. Anybody tried? Ditto elevators.
Already have a 170kv Axi motor that should work, and ESC and a pair of 6S 6000 packs.

[CorsairJock]

Just received Black Horse Corsair from Motion RC, THANK YOU MOTION for FAST & FREE SHIPMENT!!!

I have read all the posts here 3 times, I wish I could install Robart 148s but Robart went out of business and they are no longer available (for now at least, but I understand another company has purchased everything and will soon be offering them again?). If anyone has a set they are willing to part with, let me know ASAP, I will pay fair price for the set.

My biggest concern before I begin building it is the flaps: I question having only one flap servo on each wing, actuating the outer most flap which then actuates the inner 2 flaps. It seems to me it would make more sense to have the servo drive the middle / curved flaps, that way there wouldn't be all that stress on the plate which actuates the inner flaps. So my question is: is this stock setup functioning / working well? Or should I consider a modification which has the servo driving the center flap instead?

I plan to build mostly stock for now in order to get her in the air very soon, but eventually want to add main landing gear doors and refinish her with a not so weathered scheme.

I have an Axi 5345/18HD (171KV), Castle Creations Talon 120HV ESC, a pair of 6S 6200 mAh packs, and 3 blade 22 x 10 scale prop for power.

I DO like building scale accurate Corsairs, and like I said it'll be mostly stock for now, but come this winter, ....

I also like to build light, and this looks like the best giant scale Corsair to achieve that.

[CorsairJock]

Retract Issue: Just trying to out the retracts with Stock wheels mounted, when retracted the wheels are against the wells and the retract unit has about 2 mm gap between it and the mounting plates. If I had bolted it down, it would have tried to push the wheel into the wing, NOT GOOD!
I have a dwindling supply of Ernst Thrust Plates, gonna cut a 2 degree one up and try shimming the retract units. I also may cut away the plastic wheel wells if needed.
Anyone else have this problem?

[Elbee]

[B]
I have a dwindling supply of Ernst Thrust Plates, gonna cut a 2 degree one up and try shimming the retract units.

Hey CJ, Could you post a picture with dimensions of your Ernst Thrust Plate(s)? Pretty easy to replicate in 3DP I would guess. I'll post the STL File back here. Best, LB

[CorsairJock]

Hey CJ, Could you post a picture with dimensions of your Ernst Thrust Plate(s)? Pretty easy to replicate in 3DP I would guess. I'll post the STL File back here. Best, LB

These were made by a company called Ernst (the spelling may not be correct), a company which made various accessories for radio control and controline model aircraft. These plates were designed to be sandwiched between a motor mount and the firewall, for the purpose of adding an offset to the thrust line. They came in 2 different sizes, one for larger motor mounts and the other for smaller. Each size came 3 plates to a package, one each 1 degree, 2 degree, and 3 degree.

The ones I have measure 2 1/2" x 2 1/2", and I believe they are the smaller size but not sure ( these were made decades ago, long before there was an abundance of giant scale models).

The one in the picture is a 2 degree plate, with "II" marked on it. I have only 2 degree and 1 degree plates left, my supply of 3 degree plates is gone.

I have used mine more often as plates to alter retract angles, such as I am doing with my Black Horse Corsair. Using them will move the retracted wheels away from the wells slightly, providing needed clearance. This will also result in adding 2 degree forward rake when gear is down, which I don't mind. To use for retracts, I cut a plate such as the one in the pics into 4 strips, then drill out for mounting screws and sandwich between retract and mounting plate in the aircraft.

[Elbee]

CorsairJock,

I remember both the company and the plates from my hobby shop days.

Could you give me the circle line depth or the remaining material height?

As i recall the edges could be cut or snapped off.

Also, if you want the corner and center depressions, what are those diameters and centers relative to the edges?

Here's my take on the 3 degree plate from 'eye-balling' your pictures. Look about right?

Best, LB

[CorsairJock]

CorsairJock,

I remember both the company and the plates from my hobby shop days.

Could you give me the circle line depth or the remaining material height?

As i recall the edges could be cut or snapped off.

Also, if you want the corner and center depressions, what are those diameters and centers relative to the edges?

Here's my take on the 3 degree plate from 'eye-balling' your pictures. Look about right?

Best, LB

I Can give you precise measurements as measured with my calipers on the 2 degree ones: 0.0400" on the low end, 0.1180 on the thick side. As for the breakaway edges: they serve no purpose for the way I use them as shims for my retracts, and were meant for round motor mounts. It's easy material to work with, yet strong enough to support compression loads that would be imposed on it.

Pics are of the 2 shims for the left wing (ones on right wing already installed), as well as the left wing minus most of the wheel well. With the wheel well partially removed as shown, the wheels still bottomed out/ would not turn, until I added the 2 degree shims. Now it's perfect, just the right amount of clearance, but I'm gonna paint the wheel wells before I install the retract unit.

[Elbee]

I Can give you precise measurements as measured with my calipers on the 2 degree ones: 0.0400" on the low end, 0.1180 on the thick side. As for the breakaway edges: they serve no purpose for the way I use them as shims for my retracts, and were meant for round motor mounts. It's easy material to work with, yet strong enough to support compression loads that would be imposed on it.

Pics are of the 2 shims for the left wing (ones on right wing already installed), as well as the left wing minus most of the wheel well. With the wheel well partially removed as shown, the wheels still bottomed out/ would not turn, until I added the 2 degree shims. Now it's perfect, just the right amount of clearance, but I'm gonna paint the wheel wells before I install the retract unit.

Offset Plates 1 2 3 Degree STL Files.zip

CJ,

I have attached a zipfile of the design.

This includes 1 each: 1^o, 2^o, and 3^o plates designed in the style of your Ernst Plates.

Dimensions should be accurate outside of 3D printing shrinkage (00.2mm+/-)

It is just as simple to design the STL file for the part the way you will use.

If you don't need the circle or would like to have these rectangles or squares or whatever, let me know.

I was just using your Ernst Shim as a start.

I can do these any way you need the finished shim plate for future work.

Best, LB

[CorsairJock]

Just spent a week fabricating a transport frame for it, will also be used to hold fuselage while I build/ complete it. Frame is made from 3/4" PVC, and a lot of fittings ("Furniture Grade" when possible).
The fuselage cradle will hold it upside down when transporting in my Ram with Lear cover, and hold it upright so I can assemble at the field. Wings are removed from openings on the sides.

[CorsairJock]

Last 2 pics are in the back of the Ram

[Iraiam]

I just received mine last week, looks like a well built model, it came in with good packaging and no damage. I have multiple engine choices, I have a 3w 60i or DA50 available.
I'm leaning towards the 3W right now. but depending on the final weight and balance, I might use the DA?

[CorsairJock]

Wings are done/ ready for flight, now working on the fuselage. One of the few changes I am making is to make the horizontal stab removeable. I completed that today, added about .4 oz doing it, but the tail cone AND the stab are now held in place by nylon allen bolt: (2) Dubro 10-32 for the tail cone, and a single 1/4-20 with about 3/4" shoulder for the stab.

First pic is the plate which the allen bolt is inserted into, it is glued ate the rear of the tail on the underside of the stab saddle. I made it from sawing apart the DLE motor mount.

Second pic is 5/16" thick piece of ply that I cut to fit on the top of the stab cradle. It has a 1/4-20 blind nut on the top side of it.

Third pic is the stab, with a little bit of extra wood added near the hole location.

Fourth pic is everything put together/ stab bolted in.

I started by drilling out the lower piece, added CA to the inside of the hole, redrilled it and made sure the bolt went in and was snug, then glued it into place.

Once the glue was cured, I temporarily installed the upper plate, holding it in place with 3 servo screws, then the stab, then drilled thru the existing hole in the lower plate and all the way thru the stab and upper plate.

Then removed the stab and upper plate, CA the hole in the stab and redrill for fit, drilled out the upper plate so the blind nut could be installed, then used 30 minute epoxy to attach to the fuselage, reusing the screws that help it temporarily to make sure it had the same alignment, then done / mission accomplished

[CorsairJock]

BEWARE!!! ELEVATOR & RUDDER CONTROL HORN INSTRUCTIONS ARE WRONG!!!

First pic is screen shot of how to attach control arm to the rudder. The diagram shows a M3 x 30 bolt being inserted into the control arm, and screwed into the rudder. Nothing more, thats it.

SO, that's what I did, screwed into the rudder until it protruded out the other side, it wasn't getting any tighter and the control horn had obvious slop.

Looking back at the instructions, I see a nylock nut mentioned, and altho it didn't mention the square piece with a hole in it: I assumed it should go on the other side where the bolt was sticking out, then the nut should be added.

NO WAY that nut was going to fit into that hole in the square piece, and even if it did there would be no way to tighten it.

SO, I reasoned the screw must go into the square piece, then thread into the control horn, THEN somehow thread the nut on.

Well, that did the trick, only because I could not see the sides of the rudder, I didn't realize until too late that I was crushing and distorting the balsa. UHHHG! Now I am bummed, I figured the rudder was ruined, and being less that a week from completion and the weather up here turning colder, I need a new rudder NOW!

Instead, I stripped the covering off, repaired and reinforced the damaged area, covered in some old flat gray MonoKote that I had, put everything back together the RIGHT way, and now ready to install after I throw a cote of paint on it. The paint doesn't match, but I eventually want to paint the whole thing anyway so that'll do for now.

SO, in summary: the M3 x 30 bolt goes thru the square piece, then the rudder, then the control horn. Good luck adding a nut, I just added a regular M3 nut and put CA all over and around it, but the bolt threads nicely into the control horn anyway.

[CorsairJock]

Since I had to re-cover the rudder, decided to re-cover the fin also, AFTER re-shaping it to a more accurate scale profile.
Painted both with rattle can Rust-Oleum Ultra Matte Nantucket Blue.