Fournier RF4 RC Plane Build Part Five ... Let's Finish The Wings

Added: 2026-05-31

[00:00:04]Hi guys, and welcome back to part five of the Fornia build. Uh, we finished the last video of putting the wings together, and I haven't touched it for 5 days. [laughter] I've been busy doing other stuff. Um, but this is likely to be quite a short video uh because I haven't got time to record anything and and edit it and upload it and all that stuff. So, thanks for watching. That's the end of part five. [laughter] Only joking. Um, look, I've got um I'm wondering now, shall I start on the wings? do a little bit more on the wings cuz I'd like to get those joined and continue with the fuselage and servos and what have you uh later on. But I won't have time to look at the fuselage still here sitting on where we left it with the servos. So I think I'm going to continue with the wings. So I'll just get those in or move the camera out. Let's go and evaluate it actually.

[00:01:09]So, we left them popped up with the dihedral bracing and the center section made. I haven't finished sanding the lead and edge.

[00:01:22]Should really do that if I join them. It makes it quite a bulky thing otherwise, doesn't it?

[00:01:28]Um, so I've got the dihedral braces.

[00:01:31]There's this original one. So, I can glue those in.

[00:01:36]It's a very windy day today, by the way.

[00:01:39]Uh, I can glue these in. I think the first thing to do is going to be to get the wings finished sanding.

[00:01:46]Uh, I can cut the aons as well.

[00:01:50]Yeah. Let's get the leading edge sorted out and then we'll come back and we'll have a look at getting the wings glued together.

[00:02:00]I was inspired to get on with this this morning after chatting with Ian from Ian's RC exploits who um is unable [clears throat] to fly at the moment due to his recovery. But um we wish Ian speedy recovery as he must be climbing the wall. Can you imagine that? Not being able to touch your airplanes or go flying anyway uh because of your recovery and uh can take weeks. So, we wish Ian a speedier recovery. Let me go out and sand the wings and we'll come back to you in a little while. Can you see me?

[00:02:36]All right.

[00:02:38]It's such a beautiful week we've had in the UK this week. Um, but you don't feel you want to get out.

[00:02:45]You want to get outside and uh pursue other pursuits, don't you? Pursue other pursuits.

[00:02:51][laughter] Okay guys, see you in a minute.

[00:03:09]Right, that'll do for now, guys. I think it looks pretty good. I got a shadow.

[00:03:15]You can if you can get a shadow from the sun, you can see exactly if there's a a little little hard edge or something that needs slightly round in.

[00:03:27]But that's not bad. So, next job. Let's join them. Then I can sheet the bottom in. Cheers. Let's go in. Okay, it's 2 in under each wing tip.

[00:03:41]And now I've got it set up. These blocks of course are 1x 2x3, hence their name, one, two, three blocks, but they are 2 in. So, got a block under each tip. So, that, excuse me, uh, should be the perfect dihedral.

[00:04:01]So, what I'm going to do now, I've sanded the dihedral braces to give them a key. And what I plan to do is to epoxy them.

[00:04:10]Not [clears throat] that way. It's upside down. Epoxy them. Slide them in both sides. Put some epoxy on the main spars trailing edge. [snorts] And make sure there's plenty of epoxy around the inside of this rib to the main spar join. That's why I've left the bottom sheeting off here. And then I'll glue in this one which goes there like that. And it's exactly the same angle.

[00:04:42]She's got to go down a bit, isn't it? To there. Turn around for the sheeting.

[00:04:47]Like that.

[00:04:50]I might just put a little blob of CA on the end of the uh D brace to make sure it stays parallel to this cuz I want it to stay parallel. So, I'll probably do that.

[00:05:01]Could probably do that like this. It's good to have a dummy run, isn't it?

[00:05:06]Plenty of dummies around here.

[00:05:09]Let's move my split my glass.

[00:05:14]Um, so again, epoxy on the should slide in. Should slide in.

[00:05:26]Let's get the right technique. Really?

[00:05:32]Yeah. Slide that in. I'm wondering if I should use white glue actually.

[00:05:37]So, I think I might use white glue.

[00:05:43]It will stick to the plywood pretty well [snorts] and uh give me a little bit more working time, setup time cuz I don't want to mix epoxy with um can't add white glue to epoxy, but getting epoxy in there is difficult.

[00:05:59]Tell you what, I'm going to use white glue.

[00:06:02]The good thing about this is I've got to go out for a couple of hours. time will come back. It should be set nicely. Set enough anyway.

[00:06:15]So, here we go. If I put that in there is most of the epoxy I'm sorry, glue is going to get scraped off as I slide it in. But there's nothing to put on the inside anyway.

[00:06:28]the facing edge. It's not It's not gluing to anything there particularly other than the top and bottom sheeting which even then it doesn't particularly touch. So, let's just get on with it.

[00:06:43]As long as it's got white glue, I'm going to put Yeah, I'll leave a little bit off the edge there. As long as there's white glue on the surface, it should uh glue. Okay.

[00:06:56]Uh yeah, I'll leave that bit clear for the minute cuz I want to put Ca on that.

[00:07:04]What else I want to do is put some on the inside of there as well.

[00:07:10]It's all grain. Use that one.

[00:07:22]This is exactly why I left this so as I got access to it.

[00:07:33]Go the wrong side for that. I haven't. I put them upside down. Goodness me. Come on.

[00:07:40]Walk. Get your act together.

[00:07:46]That actually feels pretty good.

[00:07:50]Actually slowed right down as I pushed it in, which is good because it means that the glue is really uh touching where it needs to touch.

[00:08:03]It's I'm not going to use CA. I've decided so quickly, but doesn't need it.

[00:08:16]This is a big step guys today, isn't it?

[00:08:22]Certainly is good.

[00:08:25]And bit on there, best as I can.

[00:08:40]the end grain of the uh plywood box. Light ply box. Okay.

[00:08:47]Slide that in there.

[00:08:52]Oh, I tell you what I haven't done. I haven't put any glue on this, have I?

[00:09:08]I don't know how much of this is going to touch.

[00:09:11]Dripping down. Lucky I've got that plastic down.

[00:09:17]Last thing I want to do is get glue on the tablecloth.

[00:09:28]All right. Just wipe that there. Okay.

[00:09:31]Get that in. Good.

[00:09:35]Wipe the surplus off there.

[00:09:38]And the other thing I need to do now is to put that on there a moment.

[00:09:46]Push it together like that.

[00:09:50]Get the back spar in.

[00:10:07]Yeah, plans suggest that this be the only um the only main spot which I don't think was enough really, was it?

[00:10:27]How could I guarantee that stays there like that?

[00:10:33]Perhaps I should have caved that one. I don't know. Looks like it's got too much dihedral. Thing is, I can't keep an eye on it. I put that in place like that and get it down. I don't know what that main spar is doing.

[00:10:51]Wonder if I can put some CA on the on the top join. Might hold it. Oh yeah.

[00:11:00]Just put that on there like that for a second.

[00:11:05]The other thing I want to make sure is both wings are at the same uh angle to the uh [clears throat] obviously to the into each other.

[00:11:20]Don't know a good way to do that.

[00:11:22]Let's just turn this over. Hang on.

[00:11:29]Don't know if this is going to hold it sufficiently.

[00:11:34]Turn it gently over. Look at that spark.

[00:11:39]You see that's pretty good position.

[00:11:43]It's just a case of uh moving things around and making sure that things are where you want them before I leave it to set up.

[00:11:54]And a little bit on the end of there.

[00:11:59]Got to be a little bit lower to there.

[00:12:05]Good. Now I can pump some more white glue in there later when I come back. So we pop that back on there.

[00:12:14]Put the weight on there for good measure. And we'll let that set.

[00:12:20]And when that's set, say we'll put a bit more white glue in there and move on to the next stage, I think.

[00:12:35]Happy with that, guys. See you back soon.

[00:12:40]Okay, it's been a couple of hours.

[00:12:43]Couple of three, maybe four, actually.

[00:12:46]So, let's have a look.

[00:12:51]Okay, that's pretty good. It's below 16 of an inch just about below the uh main spot there. So, next step is to just going to look at the back end of it.

[00:13:11]Oh, that's pretty good for me.

[00:13:14]Pretty good for you, too.

[00:13:17]Oh, it just feels so light. I love the dihedral on this as well. It's lovely, isn't it?

[00:13:23]Right. Let's What I want to do is to It does. It's glued pretty well. Actually, what I wanted to do was just put a bit more adhesive in there and let it run against the main spar and and dihedral brace.

[00:13:44]So, I'll do that.

[00:13:46]And I need to drill a hole in the top of here for the circle wire to come up through.

[00:13:53]And I need to put a piece of plywood on the back here. Not on the back, on the back here for the take the pressure from the nylon bolt.

[00:14:04]I need to sheet in these areas. I need to drill the hole on this side, which I haven't done yet. And generally oh and make the a which will take 2 minutes. So yeah I'm quite happy with that.

[00:14:23]Just to make uh life a little bit more complicated guys I've decided you know on the or perhaps you don't know on the full size formula there's a outer little outer wheel out here just to keep the wing tips off the ground which stay permanently fixed. They're only very small. I was thinking I would like something like that, but I think just a single wheel is going to be a little bit delicate.

[00:14:51]So, I was thinking how about putting a couple of like little skids like that sits in a tube. The the full size one about here. So that sit in a tube and being sort of spring loaded, they would just hold themselves in and I could remove them if I wanted to. So I'm thinking a bit of brass tube uh either in this corner and down here.

[00:15:22]And I could put another gusset on to strengthen that up even more because this is going to put it under a bit of spring tension.

[00:15:37]and be they'd be virtually unnoticeable, cause very little in the way of drag, but because they're spring loaded, they would keep themselves in. That's my idea.

[00:15:50]I suppose you could, if you wanted, put a little bit of a a sort of a dummy wheel on it to make it look realistic.

[00:15:58]Anyway, that's a detail. So, the question is, shall I put it I like the idea. So, shall I put them here or shall I put them there? The full size are out here. If I put them there, they'll they'll still do their job.

[00:16:14]They're not going to be long enough to touch the ground.

[00:16:17]Uh because the other wheels going to be there. Probably won't be far off, but it's just if it should rock, it just stops the wing tip from touching and then turning in.

[00:16:30]It also uh serves to keep the control horn on the aon out of mischief if it can't go down too far. So yeah, I got a bit of tube. Okay. And I'm thinking if I put it there, I just don't like that corner being under tension.

[00:16:51]So I'm wondering if I could maybe, as I say, put another gusset in there, which would work. could make it put an even bigger one in to spread it even further up the rib. And the Yeah. The only other thing I've got to think about is the control run for the uh aon horn comes out the bottom diagonally across and to here. So, this diagonal portion of the control arm is going to be moving down here. But I'm I'm well clear. In fact, I think I was initially thinking just there, but if I put it there, it's going to be well out of trouble and put the other one there through the plywood against the main spot. That's a really solid, really solid for fixing. This one here, not quite so solid.

[00:17:45]So, yeah, I'm thinking definitely a bigger gusset here. Could always put a plywood gusset in actually. Just here, look, I've got the plywood servo, man.

[00:17:57]If I put a gusset here, in fact, it could just be a straight piece of wood just there like that.

[00:18:09]And that would connect the brass tube to the plywood servo mount. And the plywood servo mount would take the strain of it pushing apart sideways.

[00:18:22]Excellent. That's what we do. Then there is one thing I've got to do. I can't have that going up too far cuz it'll punch it right through the covering. So perhaps I'll need to Oh, I know. I can just I can just crimp the end of this.

[00:18:37]Just crimp it and it it'll stop it going up too far. The rear tube isn't going to be very long. That's something to think about. It's only going to be about five mil six maybe.

[00:18:52]Should still be okay if it's in the ply.

[00:18:55]Yeah. So, that's what I'm going to do. I think I'm going to put a hole through there.

[00:19:02]So, let me go and gather the bits and uh make a hole and cut the tubes cuz I've got to fit them in, of course, before I cover it.

[00:19:14]And then there'll just be a little hole in the bottom of covering for the tip skids to go in. cuz I've got a I've got a wheel. The original kit didn't have a wheel, so I've got the wheel retracted in as well.

[00:19:28]And now I've got tips, kids. Lovely. Let me get some ply and do all that and then I'll come back to you. I've gone for a decent size plywood gusset. I'm going to put that right in there like that. And I'm going to epoxy it in. And it's going to be very strong indeed.

[00:19:52]Some on that edge.

[00:19:56]And maybe a little bit until I've mixed up too much. Some on that edge there.

[00:20:07]That will strengthen that up beautifully. It give me plenty of compressive strength.

[00:20:14]Right, let that set. We'll come back.

[00:20:16]I'll drill some holes and we'll cut some vast tube.

[00:20:20]Well, this isn't working out very well, guys. So, I've cut some tube because the back tube is quite short.

[00:20:28]The front tube is a bit longer. And I've just pushed them in. And I've bent up a bit of it's not actual piano wire. It's a welding rod, I think. Little bit softer. Uh, and and just putting it in there. It's This is the idea.

[00:20:43]Um, the idea was that they'd be under tension to be under tension. It It's a They don't Well, they don't go straight in. I might have played with some piano wire in a minute, but um it's and it's also a little bit wobbly. So, I've crushed the tube a bit to make it uh oval.

[00:21:04]And I'm thinking that I might end up gluing these in.

[00:21:10]If they're glued in, then it won't be a problem. But if they're glued in, then they can't drop out. And I think they look okay. I think that's all right.

[00:21:19]Then just keep the wing off of the ground.

[00:21:23]I've also just pinched over the end of the tube and it just prevents it going any further. So that's not a problem. So I think the idea is sound. So, I'm going to keep working on this and playing with it and see where it takes me. So, that was my attempt number one.

[00:21:46]Then my attempt number two with uh piano wire. Really hard to work.

[00:21:53]Attempt number three. Perfect.

[00:21:56]Uh I think it's some sort of aluminum.

[00:22:00]So, I've just made a couple more unsquashed brass receivers.

[00:22:13]And go in there.

[00:22:17]It's an original one, wasn't it? Yeah.

[00:22:20]That go in there.

[00:22:23]I will glue it in.

[00:22:27]As you can see, I've turned the lights on because the sun has set.

[00:22:33]So, that go in there. That can go in there. And there's not a lot of tension on that either. And it's actually squeezing out, which is what I wanted.

[00:22:42]So, as long as this brass tube here is below the surface, which at the moment I think it's above, we don't want any of that going on, matey.

[00:22:57]Might need to cut it down.

[00:23:00]No, no, it's perfect length. This one here might need to be trimmed down slightly.

[00:23:11]I want it as long as possible, of course, but at the same time, I don't want it to um get too close to the surface. They're they're absolutely perfect.

[00:23:22]And if necessary, well, I'll probably glue these in after the event, but there's one. I'm happy with that. I've glued them in with CA.

[00:23:31]And if necessary, I can put a little ply gusset at the top to stop it flexing.

[00:23:38]This one's pretty good cuz it's in the 16 and 1/8 volts of gusset. But they'll put a little ply gusset at this top and that means it's going through the plywood on the servo tray. So, that can't move. So, That will be a nice secure little fixing. Actually, I think that's worked really nicely. I'm happy with that. You won't particularly see it either. And then when the model's finished, I can all the underc carriage is down. I can see how it's sitting. And if necessary, I can trim this down a little bit. For the minute, I'll leave it at that length.

[00:24:14]So, yeah, happy with that.

[00:24:18]There we go. Okay. So there we are.

[00:24:21]They're both in.

[00:24:25]There it is sitting on its underc carriage as I think they work really well actually.

[00:24:31]I'm quite quite pleased with those. I really am.

[00:24:37]Slowly cut it way through a very neat hole.

[00:24:44]All right.

[00:24:49]They presto one lovely neat hole. You do the same on this side.

[00:25:03]There we go. So that's the center section holes cut.

[00:25:08]It's where the cable comes up through on the server wire. I can now sheet this and that will be done. So, I'm going to go and find some shoes.

[00:25:21]The bulsa is cut and ready to glue on there.

[00:25:40]This one is a tight fit. It's such a tight perfect fit. I reckon with the glue on it's not going to go in. So, I'm just going to make it less than perfect.

[00:26:21]Okay, next piece.

[00:26:24]It's going to go in there. Lovely.

[00:26:34]I always like to try and get um something glued up so as it's drying overnight and then from the morning you've got a lovely solid item you glued.

[00:27:05]What I want to do is get this um gets glued up. Then I can put a weight on it.

[00:27:15]Right, there we are. That's the bottom sheetated in. Now we got to do is to find something just to on the bottom there. And I can There's my weights.

[00:27:27]There they are.

[00:27:29]What I think I'll do is put one at the back here. And I'll put the plastic on cuz I've got some glue seeping out.

[00:27:37]We'll let that dry. Come back to it in the morning. And I think that's pretty good progress actually. Just leaves the aons to cut to length.

[00:27:47]No building involved.

[00:27:50]We'll continue for part five. Six. This is part five. Yeah. We'll continue in part six next week uh when hopefully I'll have done a little bit more. Thanks guys.

[00:28:03]Take care. Night.

[00:28:06]Cheers. And if you want to look at channel memberships, the links just down below under the description. And be sure to give the video a thumbs up. [music] Thank you. Bye-bye.

[00:28:21]>> [music] [music]