Episode 47 · Originally released December 12, 2020 · Hosts: Ron and Tom
Ron and Tom give short Duellist updates and work through a collection of questions submitted by RC Plane Lab listeners.
In this episode
Episode Topics
Connect with RC Plane Lab
Chapters
00:38 — Duellist progress report
08:16 — The first group of listener questions
16:31 — Building and workshop questions
24:47 — Radio, power, and equipment topics
33:03 — Flying advice and troubleshooting
41:18 — Final questions and closing
Episode Topics
Duellist progress report
The first group of listener questions
Building and workshop questions
Radio, power, and equipment topics
Flying advice and troubleshooting
Final questions and closing
Key Takeaways
The episode combines practical RC airplane experience with firsthand workshop discussion.
The hosts explain not only what they did, but the reasoning and lessons behind it.
Listeners can use the chapter list to jump directly to the subjects that interest them.
Episode 47 Transcript
This transcript has been lightly edited for readability. Timestamps are retained.
Read the full transcript
[0:00] Hello and welcome to RC Plane Lab, a podcast for anyone interested in RC airplanes. We'll share tips and tricks on how to build models and talk about successful flights, epic crashes, and everything in between. Visit us at rcplanelab.com to sign up for our email list and to ask us questions. You can also text us or leave us a voicemail at 818-351-9846. Please help us out by rating and reviewing us in your favorite podcast app. Thanks for spending time with us today.
[0:34] Now here are your hosts, Ron and Tom. Hello, everyone, and welcome to the RC Plane Lab Podcast. I'm Ron. And I'm Tom. Today, we're going to give some short updates about where we are with dualists yep i don't want to spend a lot of time on it because i feel like we're beating a dead horse already fair enough and then we also have some listener questions and comments to get to we actually have quite a few of those so yeah and funny story we've been meaning to cover
[0:59] them but i've been so long-winded on the Duelist updates that we've been unable to cover them up to this point. Right. So. Short. Short updates on Duelist, and then we'll move into them. Okay. You threw me off. Sorry. But no. And, that and I didn't get much down on mine, so there's not much for me to talk about. That's true. But first. Yeah, you didn't get much done at all. Enough for you to make fun of me.
[1:27] But anyway, first, before we get into that, our 50th episode is coming up. That's very exciting. And that's just crazy to think about it. I mean, really. Yeah, I can't believe we have sat down together 50 times almost already. This is 47. And done this. It's crazy. I know. Time flies. It does. But the funny thing, too, is the timing of it. 50th episode will be January 1st, 2021. How about that? How about that for timing? Right. Worked out great.
[1:55] So for that episode, I think our plan is to have the wives join us. Yep. Something really special. So it will be all four of us talking about it. And Lori is actually watching us now, and she's fisting the all four of us talking about it and and lori is actually watching us now and she's fisting the air because she's happy about it she's excited i think she enjoys it well i hope so she likes hearing yourself talk right oh man
[2:18] yes she does she's sitting right there so i'm not going to say much more about that yeah it's better when she's not here because then, you just act like she's never going to hear this. Exactly. She listens to every episode, though. Okay. More than I can say for my wife. Well, I think she listens to more of them than I do, actually. Well, that's not hard. Well, I listen to almost all of them. That's not a high bar to set. Anyway, so we're going to have the wives on.
[2:45] We don't really know what we're going to talk about yet. However, if you guys have any questions, you want to ask them anything at all. Yeah. Reach out to us. Send us an email. Let us know what it's going to be or whatever questions you have, and we will have them answer that on the episode. Yep, yep. Should be fun.
[3:01] Yeah, we need stuff to talk about, so let us know what you'd like to hear them talk about. Yeah, because it's— Or make fun of us about it, yep. Should be fun. Yeah, we need stuff to talk about, so let us know what you'd like to hear them talk about. Yeah, because it's— Or make fun of us about it, because we give them plenty of material. Yeah, we do. Especially you. Yeah, it's going to be all stuff on the hobby, though.
[3:15] So we're not going to spread off and talk about running or bicycling or any of that weird stuff you guys are on. We're not talking about politics either. We're not going to talk politics either, no. We don't do that here. This is the RC Plane Lab podcast. Exactly. Anyway. Yeah. So coming up, we've got some pretty cool stuff in the works for the podcast. As we've mentioned before, we're going to get into some video.
[3:41] So hopefully after the first of the year, we'll have some stuff ready for that. Hopefully. Coming soon, yeah, we're going more guests to the to the podcast again that was a good time so yeah lots of cool things coming up for the podcast yeah i'm excited me too doula's talk are you ready yes sir so i don't have much it's gonna be very quick i promise okay remember last week i said i was dreading making the nose i do remember that but i was hoping that it would be something
[4:05] that once I did, I would look back at it and laugh about how worried I was about how hard it was gonna be? Yeah, because it was silly. Well, I did it and I'm not laughing. And you're not, I am. It was the worst thing I think I have ever had to do on an RC airplane. And I'm not even finished yet, I just gave up. I mean, like it looks terrible. It does not look terrible. Then why did you laugh? I'm not laughing. The very first up. I mean, like, it looks terrible. It does not look terrible.
[4:25] Then why did you laugh? I'm not laughing. The very first thing, when you looked at it, you just started laughing when you saw it. Well, because I… -huh. Here we go. At first glance, the first impression is, what the heck did you do? And then after I realized what you did, what the heck did you do? And then after I realized what you did, I giggled to myself because that's about the absolute hardest way you could build up a balsa shape. It looked like you were gonna say worst way.
[4:53] No, no, no, not worse. Most difficult, probably. Well, I can attest that it's difficult. I don't know if it's the most difficult way of doing it. It was not fun. And like I said, I've given up on not at the time i gave up and that's why it's where it is because i don't want to deal with it anymore and that's unfortunate that it wasn't fun it was because because that will make you not want to do it again
[5:17] and that's certainly not not what we want to happen yeah so what ron did i'll i'll describe it Yeah. So what Ron did, I'll describe it. To build up the nose on his dualist fuselage, instead of assembling blocks and running the grain lengthwise with the fuselage to make them easier to carve, he chose to stack quarter-inch thick plates, essentially, of balsa to the front of the nose to build up the nose to
[5:44] the proper length, and then sand all of that down to the shape. I just to build up the nose to the proper length and then sand all of that down. I don't know how many layers together. There was a bunch of layers. So hard to use a razor plane, cross grain like that. Unable to use a razor plane, I found out. Right. So it's unfortunate, like I said, that it was not fun because now you won't ever really want to carve a block again, probably, for a while.
[6:08] Pretty much, you're right on there. I did not enjoy that. But if I did it wrong or in a difficult way, I am up to learning again and trying it the right way. And then hopefully it'll be better. And to be fair, I didn't offer a lot of advice because you didn't ask. I didn't. I never have to ask though. Usually you're just like, well, what I would do, right? True. Guilty as charged. I do offer advice even when it's not asked for.
[6:41] Which is not a bad thing. But in this case, I'm sorry that I didn't because I could have steered you away from a lot of aggravation. You have no idea how close I was. To sawing it off? To getting the chop saw and just chopping that off and starting from scratch. I mean, really, and I'm, yeah. Well, I mean, it can be salvaged. I mean, it can be sanded and you can salvage the shape out of what you have there.
[7:08] Well, and the hard thing for me, I think, is actually shaping it, like getting the shape to look right. Right. Because I can't – the way I did it might have been more difficult, but on a sander, you should still be able to sand it and make it look okay. Right. I mean, on a belt sander, right? Yes. I just – I cannot – I don't know if the airplane's too long too big too what but it's just so awkward to kind of hold it and cradle it and then
[7:32] try and get it to move in the right direction to get it sanded right i did even even doing the nose on mine the way i did mine running the blocks of the the grain the correct way sure i wouldn't say correct, but I didn't even use the belt sander on mine. I hand-sanded mine after the razor plane. Yeah. Because like you said, the shape of the thing, it's difficult to tell whether you're getting the one side exactly the same shape as the other side.
[7:58] And I'm sure mine's not perfect. No, it's not, but that's okay. But it's close enough for me. I didn't think you were finished yet. Are you finished with the nose? Pretty much. I mean, I had some final sanding to smooth it out. Well, that's what I mean. So there's a few lines and stuff. Yeah, yeah, yeah, the lines are, yeah. But I mean, as far as the overall shape of it, it's not perfect, I'm positive. That's a lot better than mine. But I didn't use the sander on my nose either.
[8:23] So anyway, that's how Ron assembled his nose, and he learned a lesson. The hard way. Pictures will be on the website, so you can get a laugh out of it too. I'll have them up on the build blog. It's good stuff. So the other thing, I got my covering in, but not the covering that I ordered before. So remember I told you i ordered some yeah and it was on like the 23rd i ordered it november 23rd it shipped on november 24th hadn't moved up
[8:52] until last week right same thing it still sits there and has not moved so that's crazy same place i'm pretty sure because it shipped from the same address one was an eBay store and one is an actual hobby store. So I bought a bunch of covering from their actual website store, that Value Hobby, and I ordered that last Thursday and it was delivered UPS Friday. So it's, I mean, I have covering. I just have a hard time wrapping my head around the same business. Granted, they're operating.
[9:28] Well, I don't know for sure that it's the same business. Maybe it's somebody working third party that's drop shipping. I don't know. That's not for me to worry about. The only thing that matters is they shipped it. They sent me the tracking number. It was shipped through the mail. And it showed that they accepted it. They have it. And it has not moved since november 24th and i even bought another like couple colors on the 30th same thing
[9:53] through the mail through the ebay warrants a phone call yeah i'm gonna have to get back in touch with them again like i figure it's gonna get here sometime yeah because i mean it's in the system and i really don't care that much because i can have extra covering it's going to get here sometime because, I mean, it's in the system, and I really don't care that much because I can have extra covering. It's not that big of a deal. Yeah, but still. True. You
[10:09] want to get what you paid for. Well, I will, but I would like to have it sooner rather than later. Yeah. Those are my updates. That's all I'm going to say. And yeah, we're good. So your turn, quick. Okay, quick. So my airplane is… That's all you have time for. Let's move on. Okay, there we go. No, mine is almost ready for covering. I got a lot of little details done that don't really warrant getting into depth talking about them. But basically, the construction is complete.
[10:38] I've got a few little things to do, some fuel proofing, final sanding, and I'm ready for covering. You are way ahead of me. So, yep. Well, I don't and I'm ready for covering. You are way ahead of me. So, yep. Well, I don't see, you keep saying that. I mean, construction, yeah, my construction is done, but I still have lots of these little things that just eat up the time. I mean, you don't have to worry about things like, I'm going to have to test the retracts.
[11:01] I'm going to have to install the engines. I'm going to have to install the tanks. I'm going to have to build the tank. You I'm going to have to install the engines. I'm going to have to install the tanks. I'm going to have to build the tank. what I'm saying? No, I get it. You're physically, I think, farther along than I am, but I still contend that I have less to do than you do overall. I would agree with that 100%. The finish line is the same, but the amount to get there is…
[11:22] Oh, and by the way, there was a nice little jab on the the forums there i posted a picture of my of my stork on its gear the dualist like i mentioned i made the gear legs longer to give myself some extra prop clearance and it does look a little weird in that photo just in that photo because that photo it looks it looks like some skinny legs holding that thing up and it doesn't look like it's going to be able to handle your hard landings. You keep, like, hard landings.
[11:49] I don't land hard. You're right. I'm sorry. Not usually. You float in like a… I grease them in every single time. Okay, we know that's not true. But, yeah, that's pretty much all I'm going to talk about for updates. That is, like I said, though, that's concerning on the spindly gear. You don't think so? No. Really? Like, once I had everything assembled, like, I had the gear only half bolted in. Like, I had two screws in each gear. And with it, granted, it's not full weight.
[12:21] the engines weren't in it and all that. It was not, like, springy, wobbly at all. Oh, good, because looking at the picture, I would have thought it would have been. Like, really. The picture is deceiving because it's a downward angle, and it makes it look. I'm not going to lie. It's tall. It is tall. But I've got room for 11-inch props if I ever decide to go that direction. So I'm happy with it. Good. And it's not going to be spending much time on the gear
[12:46] because I'm going to be flying it so much. Well, yeah, but every landing is going to beat it up. Because your bird is going to be heavy. It is going to be heavy. I no longer think I'm going to be three pounds lighter than you. I'm thinking it's going to be four plus. It's going to be more like four. Yeah, easily. It might be. I mean. It might be. Anyway. You've felt it. You've felt more like four yeah easily it might be i mean it might be anyway
[13:05] you've felt it you've felt it i've felt it and it is it's a it's a weighty girl yes okay all right so what we wanted to talk about tonight that's enough with the dualists we've got several questions and comments that we wanted to get to we have lots we have a book in front of us we have lots and lots of papers to go through that's right so was there anything else on this one We have lots and lots of papers to go through. That's right. So, was there anything else on this one? Nope.
[13:25] And as a reminder to our listeners, if you have anything you want to say to us, lots of ways to get ahold of us. Yep. And I just threw that paper away, so you go ahead and you say what it is. Yeah, so there's a contact us form on the website. There is. You can get us through email. That's ron at rcplanelab.com or tom at rcplanelab.com. You can also leave us a voicemail or a text at telephone number 818-351-9846. And if you send us a question, we'll most likely read it on the podcast.
[14:01] Well, of course. Because most likely somebody else is thinking the same thing or wondering the same thing, wondering the same thing. And they might not be, they might be a little too shy to ask. Yeah. So, yeah, send us questions and we'll go. First thing before we get into questions. So, the gentleman that texted us, that emailed us about the Fat Albert thing last week.
[14:26] Yes. So, he let us know that he got done listening to the new episode and that he said it was worth bringing up Fat Albert just to hear Tom do a hey, hey, hey. He said, man, I was laughing so hard I broke the rudder on my PT-17, a little glue, and she's all fixed up. Well, I'm not happy that he broke his rudder off his airplane because of something stupid I did, but I'm here to entertain. So I'm glad that he found enjoyment in my rendition of Fat Albert. It was quite embarrassing.
[14:48] I will not do it again. Good. Actually, no, do it again. Come on. No. Come on, one more time. No, I'm not doing it again. Okay. Hey, hey, hey. It's Fat Albert. There you go. If you didn't do it, I was just going to take one from last week and put it back in. Right, I figured you would. So I figured I'd There you go. If you didn't do it, I was just going to take one from last week and put it back in. I figured you would. So I figured I'd give you something. Oh, boy. All right.
[15:11] So we had another guy text us. And he said, hey, guys, sorry to bother you on a weekend, which it's no bother. No, it's really not. No, especially because it doesn't go to Tom. It goes to me. So it doesn't bother him at all. It doesn't bother me at all. I'm teasing. On the weekends, that's when I't go to Tom. It goes to me. So it doesn't bother him at all. It doesn't bother me at all. I'm teasing. On the weekends, that's when I do my RC stuff. Right, actually.
[15:29] So, like, that's usually the best time to talk about RC stuff is on the weekends. It is. I agree. And if we don't, like, respond right away, don't take it personally. Other things are happening at times. More than likely, we will get back to you. As quick as we can. But he said, but I just started listening to your 46th episode. So weird to hear 46. I know. How much difference in between the debonder and pure acetone? He said, I'm about to hinge some ailerons to wings,
[15:56] and I only have acetone for any spillage. That's actually a really good question. We covered it a little bit in previous episodes about how you could use acetone in place of debonder. It doesn't work as well as debonder. I'll just say that right out of the gate. But if you don't have debonder, acetone is a good substitute. I would strongly recommend testing it in a small area first to make sure it doesn't soften up your covering or mess with the… Or can it change the color of it even?
[16:24] I've never seen it change the color of the covering, but it definitely can affect the adhesive on the backside. So if you're near an edge or a seam, you want to be really, really careful. And what I've done, I still use it. I just don't use a lot of it. I just get a little bit on the paper towel and give it a quick wipe, and that's usually enough Just get a little bit on the paper towel and give it a quick wipe,
[16:50] and that's usually enough to take off the CA or adhesive that might be on the covering. And you do have to be careful. Don't rub it too much. And this goes for debonder also because you'll rub the gloss right off of most covering films. Pretty easily. I did not know that. So when you spill or get any on your covering like CA, do you wait until it dries or do you try and get it off as fast as you can?
[17:07] I try to get it off as fast as I can because it's easier to get it off when it's not quite set up. Is it? But CA sets so fast that sometimes I don't even realize it until it's a days later. I'm like, oh, well, that's lovely. But debonder does work even on fully cured CA. Yeah, I've used it on my countertop before. And your phone. And my phone. But countertop was more recent, even though the phone was just last week. Anyway, moving on.
[17:37] So we also had a message from, actually, what? I don't know, do you think, because he didn't let us know how that worked out oh yeah so i don't know so it's one of three options okay so either he hinged his ailerons and everything went fantastic and he didn't need any debonder because he didn't have any spillage or acetone or acetone
[17:58] right and that's the one i'm hoping for me too or option two he hinged his ailerons and he had a little bit of spillage and he used the acetone carefully and it worked great. Which also would be okay. That would be acceptable. Or option three, he had some spillage, he used acetone and it totally messed up his covering job and he's so mad that he'll never listen to us again hopefully it's not that option well let us know how it went right if we
[18:29] don't hear from you then I'm gonna assume it was option number three oh gosh I'm going to stay positive and assume it was hopefully one or two I'm going for one but either way yeah you can use acetone in place of debonair just cautious just be cautious yeah especially on covering okay next william reached out and he said hi in the building podcast you suggested trying to find a coverite iron there are two that i found black baron and 21st century are they different and
[18:57] which one is better yes ours is 21st century yes that we use the irons that we are using is the 21st century and i should have i irons that we are using is the 21st century. And I should have clarified that Coverite's been in business a long time. Or they had been in business a long time. They were in business a long time before they were no longer in business. And they did actually make two different types of irons to coincide with their different types of covering.
[19:23] to coincide with their different types of covering. They had 21st century films and fabrics, and then they had coverite. It was just called coverite, covering. The iron that they sold to use with the coverite covering was just a standard old, just like a Hanger 9 iron with a rotary knob, heat control, not very accurate as you discovered. Like the analog control. Exactly. And then when they came out with their 21st century line of products, it was paint
[19:51] covering, a painted fabric covering, even if you remember those that made those, that was designed to work with their 21st century iron, which is the digitally controlled ones that we use. And that's like the top of the line version of the two. I mean, like when you're talking to the same company, you have your entry level, which is gonna be the Red Baron or the Black Baron one. And then the higher end is gonna be the 21st century. Exactly. And that's, yeah, the Cut-Right film,
[20:20] it was called Black Baron film. They had Black Baron and then there was the 21st century. Sorry. All right, yeah, that's fine. To add to the confusion there. Well, no, it kind of makes sense was called black baron film that black baron and then there was the 21st century sorry all right yeah to add to the confusion there well no i it kind of makes sense if everything sticks with this is the cheaper covering this is the cheaper iron and i don't know how the the black
[20:36] baron ones worked but if it is anything like the hangar nine ones exactly then set up exactly the same same the shoe shape was a little bit different. I believe they had the Teflon coating on them back then, but basically still the same old, analog control, just like the Hanger 9 or the Tile Hobbies or the MonoKote Iron. So possibly a larger swing in temperature. Yeah. I mean, like the Hanger 9 one that I have, like I said it before,
[21:06] it was a huge swing in temperature, like way too much. It doesn't have to be that much with analog. Like analog controls can get it much tighter control than that. And maybe it's just mine. Maybe some of them, some of the Hanger 9 ones are closer. I doubt it's just yours, because I noticed even, and that's why I always went to my 21st century arm, because it was, especially when using ultracode, it's very, very important to maintain a particular temperature, especially with ultracode.
[21:33] So that's why I never went to the standard ones, because they were all like that. I have one, a regular iron that's a monocode iron, same type of analog control, and the swings on it are crazy yeah but with MonoKote i just crank it up and use it what i'm saying but yeah well 40 degrees on mine i still remember that yeah and i'm not surprised and it was like three or six i think six degree total swing on the on the other one and here's some good ways yeah like i didn't realize
[22:02] this until i did a little bit of digging to to answer this question even though coverite they don't make this iron anymore and i'm not sure coverite is actually even a legitimate company anymore you can still buy digitally controlled irons out there and yeah you found them on on edge banding or something, wasn't it? Yeah, so for countertops, you put the iron on the edge. There's a company out there that makes an iron for that, and it is
[22:34] even better because it has a digital readout. You can actually select the tech. So, good news. They're pricey. But what tool isn't really for a good quality iron so there's there's hope so if you if you want a coverite 21st century iron and you can't find one there are alternatives out there just do a quick google search of digital temperature or digital sealing iron is that what you you look for? I believe that's what I
[23:05] look for. I brought up several different companies that make them. So good news. There you go. All right. Moving on. All right. So a while back, we talked about AMA here in the States. AMA is an insurance that kind of covers us. And I did get clarification from one of our listeners. Thank you, John. I'll just read what he writes. He says, so I'm a time traveler coming at you from way back in episode 34. Way back episode 34, that's funny. That is funny.
[23:37] And he just wanted to clarify something about the AMA insurance coverage statements that I made on that episode. He says, AMA members do not need to be flying at a certified field to have the insurance coverage you just have to be following the ama safety code however ama member insurance is not primary over other liability insurance that you may already have
[23:58] so your own renters or homeowners insurance will pay out first, and then the AMA stuff kicks in, kind of like a secondary insurance. Yeah, almost exactly like a secondary insurance. Yep. So he says, so it's not so helpful for homeowners, but really handy for uninsured renters. So there you go. Thanks for that clarification. And then he also goes on to say, if you've already addressed this in a later podcast, feel free to ignore it. I'm not gonna ignore any of our listeners.
[24:24] Nope. And instead, enjoy this ignore any of our listeners. Nope. And instead, enjoy this lovely picture of my ace all-star biplane after a winning round of, he calls this, lobster combat. That's a first for me. I've never heard of that. Yeah, I've not heard of that either. By cutting off almost the entire streamer from a tow plane. Now, I am familiar with streamer cutting. That's a fun, could potentially be dangerous activity but
[24:46] basically if you're not familiar with what the streamer cutting is it's you have one plane out there that tows a streamer and then you have other airplanes out there trying to cut it off and see how short you can get it yep and luckily he was pointed right down the runway when he made the cut as it locked up his motor but the dead stick landing was perfect and he's got a picture of it and it does looks great that's a good looking biplane actually i like the like the color
[25:07] combination on there yeah you can see the streamer wrapped around the motor shaft that's fun we should try that sometime yeah yeah yeah so thanks john for the clarification on the ama appreciate that moving on you want to take this and you'll get to you i'll take you're being so quiet with your papers and I'm just flinging them. I mean… Well, you always yell at me for making noise over here. Well, it's usually with pens and stuff where you just kind of start fidgeting. I do.
[25:33] I do fidget a lot. Like I said, we've got a book to get through. We've got several more. All right, so I'll get into this one. Okay. Hey, y'all. It's from our friend Gary. Mm-hmm. I just got done listening to the episode on… It actually says y'all, by the way. It really does. Yeah. I mean, that… Okay. Y apostrophe A- by the way. It really does. We're not just… Yeah. I mean, okay. Y apostrophe A-L-L. Y'all. That's how it's spelled. Yeah, so that's why you got to say it that way.
[25:50] It says, you just got done listening to the episode on trimming your airplane for the first flight, and I learned some new things about trimming an airplane, like how to determine if you have enough right thrust. So for that, thank you. He says, but because you taught me something, now I have a question or more of a got to talk it through with someone. So, Tom, here we go. But Ron, you will have to convert millimeter to inches for Tom. LOL. Just use the calipers, right?
[26:19] And set it to what you want. Yeah, my calipers does both, so I don't have to do any converting. Something about 2.54, right? Yeah, I actually don't like those calipers. I don't like the do any converting yeah something about 2.54 right yeah i actually don't like those calipers i don't like the digital ones mine's not digital it's it's got a face but it has really yeah it has two has two gosh what's it markings two dials has two dials not
[26:39] two dials has one dial but it has two gosh darn it scales, scales on it. Oh, okay. Anyway. No, that's cool. It has a red one and a black one. Red one's metric and the black one's standard. I did not know that. Yeah, on mine. That's cool. It was a cheapy Harbor Freight one. Works perfect. Really? Yeah. Wow. So anyway, Gary goes on to say, I have an F4U that I finally got out to the field two weekends ago to fly it for the first time.
[27:02] The airplane's CG measures about 8 to 10 millimeters aft of the rearmost CG point listed on the instructions. So I'm going to stop right there. That tells me that he has a balanced aft of this recommended CG, which to me, that's already tail heavy. Okay. So he says, I was okay flying it with a slightly tail heavy condition. There we go. He says it's tail heavy. Of course, during takeoff, the nose wanted to climb as expected and at low speeds with an aft CG.
[27:34] But as the airplane gained speed, the nose wanted to dive. When the Corsair was trimmed for a level flight at a comfortable throttle setting, I noticed the airplane was extremely pitch sensitive. When I landed, I had three to five millimeters of up elevator dialed in for a tail heavy airplane. He says, this got me thinking about center of lift versus center of gravity. Oh boy. Yeah. So before I get into what happens next,
[28:02] I will say that there are some telltale indicators of a tail-heavy airplane. Pitch sensitivity is right up there, number, like, maybe not number one, but it's up there. If the airplane porpoises, you give it a little bit of up elevator and it climbs, and then you neutralize the elevator and it keeps climbing. So then you give it a little bit of down elevator, and then it goes down you go back to neutral and it keeps going down tail heavy
[28:29] right so that i call that porpoising and that's it looks like a porpoise that's basically what he's describing he says during takeoff nose one time but as the airplane gained speed the nose wanted to dive but he said in here that it was pitch sensitive. So that's the first indicator flight-wise that it's tail heavy, not to mention that it was tail heavy according to the instructions. Now, he mentions here in a minute that the instructions could be wrong,
[28:57] which that actually happens sometimes, unfortunately, that the manufacturers don't always get it right, which is unfortunate. That is unfortunate. But it does happen. Okay. And I'll go on to say, before we get into the center of lift and center of gravity discussion, that a warbird, like a Corsair or a Spitfire, anything that's short-coupled, and by short-coupled, I mean not a lot of airplane in front of the CG. They usually are sensitive to pitch. So you don't require as much travel
[29:34] on the elevator specifically. And usually Expo will help you out a great deal because they are so sensitive. The SOP with Camel project that I've been working on for years and years and years, it's going to be a very pitch-sensitive airplane, and I know that. So I know I'm not going to have a lot of elevator travel, and I'm going to have a lot of Expo, and I'm going to have a lot of nose weight because there's not a lot of nose in front of the CG because it's going to be tail heavy.
[30:03] So just wanted to get that out there before we start talking about center of lift versus center of gravity. I'll read the rest of his email and then we'll get to that. So typically, he says, typically in an airplane, the center of lift is aft of the CG, which we agree. Okay, I agree with that. is aft of the CG, which we agree. I agree with that. Moving the CG to its aftmost limit decreases the moment arm between the center of gravity and center of lift,
[30:32] so you're shortening the distance between the two, and allows the tail more authority, making the airplane pitch sensitive. Okay. This would also cause the plane to dive at higher speeds and climb at low speeds as the lift increases and decreases. He says he made a brass spinner to bring the CG back into limits. He says he's hesitant to fly a second flight because he might be way wrong on this.
[30:56] He's bounced the idea off the guys he flies with, and they looked at him like he had three heads. So what do you think? So my initial reaction was it's a tail heavy airplane it's displaying classic tail heavy tendencies in flight yeah it's tail heavy according to the instructions and we have to believe the instruction because it's the manufacturer even though they do get it wrong occasionally so my advice to him was to add nose weight, which he did, and go fly it and have fun,
[31:28] which he did. And he contacted us later, and I'm not sure if we're… Yeah, I don't even know if I have that one. And it was terrible, he said. But getting back to the center of lift versus the center of gravity. So if you can picture it, so let's say your center of gravity on your airplane is right on the main wingspar. The center of lift is usually going to be someplace aft of that. And that makes sense to me. Yeah. Because if your center of lift is in front,
[32:04] then, hold on, now I've got to try and think how I want to say this. If your center of lift is in front, then… Hold on, now I've got to try and think how I want to say this. If your center of lift is in front of the center of gravity, when you stall, you lose the lift. Hold on, how's it going to be? So when you stall, you're going to stall backwards, so the tail will fall. Am I saying that right? Yeah, so your lift is trying to pull up ahead of your CG,
[32:28] never allowing the nose to drop to recover from the stall. Right. Is what you're trying to say. So it's just going to kind of fall backwards out of the sky. I mean, tail first. I don't know how else to say it really well. Having the center of lift behind the center of gravity facilitates recovery from high alpha or stalls or anything like that and makes an airplane dynamically stable. And this is RC airplane. RC airplane. Right.
[32:55] Well, I think the same sort of principles apply to aviation in general. Principles, yes, but when you get into the fighters and all that kind of stuff that throws everything out the window yeah so those rules don't necessarily apply i mean they sorry they apply but they they do different things like some of those actually have center lift in front of center gravity and yada yada yeah they have computers to overcome the dynamic instability
[33:19] that happens right yeah so yeah like you were saying, when you stall with a CG that is four of the center of lift, then you're going to fall forward as opposed to dropping that tail. Exactly. Which brings up the whole other discussion that you and I were talking about when we were first discussing this as well. Lifting stabs. Yeah, I still haven't wrapped my mind around that one yet. I don't know. But anyway, yeah, so this, it's definitely beyond my pay grade. Like, I'm not an engineer.
[33:54] I'm not an aerodynamicist. Is that it? Anyway, all I know is it's weird, but his airplane, according to his description, was displaying, in my mind, classic tail heavy symptoms. He added nose weight, and it got worse, according to his follow-up with us. Yeah. So, Gary, sorry about that. Gave you bad information, it sounds like. Hopefully, the airplane's flying well now. Hopefully we figured it out. And makes me curious as to whether the CG recommendation
[34:32] and the manufacturer's instructions on that airplane are right or not. He never says what brand it is. He says it's just an F4U, which is a Corsair. Yeah. Which is a short couple. Yeah. And most of the time kind of instable or in in state yes it's not stay my goodness i'm having a problem with that one it's not a stable airplane like it just the design of it low wing with the gold shape going all that weird things going on with
[35:00] the corsair but yeah whistling death they were were known, I think, as whistling death. Oh, was that that one? I thought that was the Mustang for some reason. Was I wrong? I don't think it's the Mustang. I thought it was the Corsair because the shape of the airplane made a weird whistle when it was… Yeah. I know the… I don't even know what it's called, but there's a term for that whistle, and I know people
[35:19] are listening and they're yelling right now at the speaker because of what it's called. Probably. Yeah. Because I have no idea what you're talking about. Oh, really? Hey, look at me making noise with my paper. Well, I can do it too. All right. Next. Okay, so this is from Jonathan. He says, In the last episode I listened to, you were discussing the struggles of bending and forming eighth-inch balsa sheeting for the Duelist
[35:39] and how you might need to wet and form it a couple times to get the shape right. He said, I found it easier in situations like this to use two layers of 16th-inch balsa sheeting. As individual sheets, they are more flexible, and after they dry into the correct shape, a little aliphatic glue. You got somebody else to say it. There you go. A little aliphatic glue will lock the layers together, creating a composite structure stronger than the single eighth-inch sheet.
[36:07] And if strength is really important, you can cross the grains in the sheeting or use more layers and even thinner sheeting, creating your own formed plywood parts. Yeah. Happy building. Yeah, that's a great idea. Yeah. That's a very good tip. Sixteenth-inch sheeting is much easier to work with and form than 8-inch. And it is, a laminated structure. It is definitely stronger than a single, thickness of, especially if you cross the grain. So, yeah, it's a great tip.
[36:38] It was a little bit too late when I did my fuselage, but you can see how I did mine on our build log on the website. Forums? No, oh gosh. It's on the website. I won't say it again. The Duelist build logs. You're right. But yeah, it worked out pretty well for what I did, but certainly his tip is a very useful one and will definitely make for a strong structure. Yeah, one I will probably take up one day yeah i do this again well i mean not this one again we do have a much larger
[37:15] project on the horizon that we'll probably use that very technique that john recommends really for what part to it yeah there's gonna to be some roundish parts around the engine cowlings that I can foresee. Yeah, I didn't know how we were going to do that. This is for the tri-motor? Mm-hmm. Yeah. Yep. So, yeah. Cool. Easy peasy.
[37:36] But yeah, thanks, John. That's a great tip. Hopefully, we'll be able to use that in the future and maybe some of our other listeners. Yeah. So for the tri-motor, the way I foresee this happening, since you're the builder and you do such a great job, and I'm just like the behind-the-scenes kind of guy, I will do all of the tracing. I will do all the cutting and give you the parts, and you can build it. At least some of the pieces. They don't want to have a hand in any of the building.
[38:09] Well, I'm so unsure of myself now, after you look at what I've done on the do list that I don't know if I want to or not. Your do list looks fine. You laugh at it every time you look at it. I don't laugh at it. I die inside a little bit, just a little bit. I don't laugh at it every time. I actually think it looks really good i really do and i say that a lot yeah it doesn't count when you ask for the compliments tom oh okay
[38:34] no but i mean it's i'm only laughing at your techniques the finished product looks fantastic that makes it even better i think i don't know't know. But, I mean, like, honestly, though, I think a lot of the things that, like, the tri-motor is going to take a lot of time to do. Yes. And it's going to be a lot of, we don't get together that often. We don't have that much time together to work on it completely,. No, you're right. As a team.
[39:02] So, I think it's going to be something where we're going to have to kind of split it up to actually make it happen. Well, in my head, I envisioned a lot of the construction going on at my house, to be honest. That's how I sort of envisioned it. Yeah. Well, me too then, so that's fine. Yeah, I don't mind. When it comes time, like the bigger parts and pieces, if you need somewhere else to work on it, we can do it here and all that stuff too.
[39:24] Or hands. Or hands, yeah. Yeah. But, yeah but yeah so yeah that's how that okay i can't wait to start on that one well we've got other things to finish first i'm sorry we have a Telemaster we still need to fly oh that won't take long well we hope that shouldn't take long but we'll see all right all right so what's next last thing Emilio reached out and long story short he says honestly you guys are doing a great job
[39:57] all the woodworking tips help if you haven't talked about a tip on how to cut wing ribs out. I would appreciate that. So, and he says on my recent plans build profile hots, that was my least favorite part. Oh, and he continues. He says, keep up the great work. Oh, yes. I love that. I mean, I love it when they, I mean, he starts out doing a great job and then keep up the great work. I love that, by the way. You just love to have your ego stroked. Well, I mean, doesn't everyone?
[40:30] I mean, really. No, not really. It makes me uncomfortable. Oh, does it? Mm-hmm. You can't take a compliment? Not very well. Oh. Which is why I'm friends with you because they don't come very often. That's true. So Emilio asks about cutting out wing ribs, or he wants a good tip on that. So my tip would be buy a laser. No, I'm just teasing. Yeah, I would hope you're just
[40:55] teasing. Of course, I'm just kidding. Okay. The way I have done it in the past and the way I've always kind of done it until recently is basically I make a paper tracing of each rib on a HOTS. Great thing about a HOTS is they're all the same. I don't know what that means. What's a HOTS? Oh, a HOTS. So a HOTS is an airplane, a blast from the 80s. It was a fun fly type airplane.
[41:24] So it had a very, very thick cord. I'm sorry, a very thick the 80s. It was a fun fly type airplane. So I had a very, very thick cord. I'm sorry, a very thick airfoil, straight wing, same, a Hershey bar wing, if you will. And a kind of a cool looking triangular shaped fuselage and a very basic sheet balsa tail. They were super easy to build. They flew flew awesome they were great at funfly events
[41:46] candy drops and spot landings and most loops in the mid that sort of thing we've talked about before kind of a stick if you want to think of it that way not as much wingspan much longer cord and the fuselage the moments were shorter for aerobatics. So that's a hot. Okay, so it makes it a little bit quicker to move and responding better. And it was a kind of a mid-wing design so that the wing actually kind of mounted down into the fuselage, like about halfway down.
[42:19] So it was midway down the fuselage. So that made it great for rolling because it rolled axially. No dihedral, it was a straight wing. Super, super easy airplane to build. And the best part about it, all the ribs were the same shape. So in this particular case, Emilio, what I would do is I would make one plywood template, basically do a tracing from the plans, cut that rib out of a piece of
[42:47] eighth inch light ply or something maybe a little durable like that. And then stack that on a sheet of, I think the ribs were probably eighth inch for the 40 size hots. I made them in different sizes. Stack that on a sheet of eighth inch balsa and go hit it with your with your bandsaw using that that plywood template on the top and cut it really slowly cut it away from the lines and then make your stack of ribs not so wide that you can't hit them all with a block sander
[43:17] block send them all together that's how i would do it oh okay yep so just stack it all together together cut them sand them cut the spar notches do it all like one one time or maybe a couple of groups of a few ribs each whatever will fit underneath your sanding block to make them nice and square and and go to town that's how i would build that wing and how i'd cut them out would you do a single like a single piece
[43:41] of plywood on one side or double it up so you can double it up but I I soft balsa usually my band saw doesn't wander too much especially if I keep the stack not real real thick like maybe an inch or two max and don't cut real close to the line because sometimes the saw does want to undercut or whatever but yeah one one plywood template on the top cut around that template and then hit it
[44:06] with a block sander to take it down to the final shape and that's yeah that sounds pretty easy i've built several basic constant cord wings that way and it works you'd be surprised how quickly you can knock knock the ribs out that way the ribs seem like they would be the most difficult part on an airplane like if you're building without any extra help i guess i would say like with laser cutter or tools like that they seem like
[44:31] they would be the most time consuming yep is that is that that's an accurate statement yep on a on a on a tapered wing or a wing that the the cord tapers out at the tip where you have basically two ribs that might be the tip, where you have, basically two ribs that might be the same shape, the left one and the right one of number one or number 10 or whatever.
[44:51] Yeah, it gets a little more tedious. And then I resort to the old sharp X-Acto knife with a paper template of each rib. And then I'll stack the two together and, make two identical ribs, one for the left panel and one for the right. And so when you do that, then do you cut it out as close as you can or do you kind of leave enough room to sand it down again? If I'm cutting out one at a time with an X-Acto knife, I'll cut right to my line. Really? Yep.
[45:18] And so how do you do that with an X-Acto knife without tearing out the back of the balsa? Because if i'm trying to don't do it in one pass well even if i don't do it in one pass like i always with even a sharp knife like when i go cross grain i will rip out the back on it so most ribs are not going to be run with the grain vertically right most ribs are going to be laid out. Eventually, you're going to get some across grain. Leaning edge and your trailing edge will be cross grain.
[45:49] Well, for the leading edge, okay, where you're making your cut for where the leading edge goes and the trailing edge stock and so on, those cuts, yeah, I'm not going to cut those right on the line. Okay. Usually, I'll cut those to length either with my razor plane, or not my razor plane, my razor saw, or I'll cut way far away and then i'll sand down but the the profile shape of the rib oh yeah that's all exactly right to the
[46:10] line for me really it goes goes slow there's no hurry you're you're building an airplane because you enjoy the time spent doing it so spend the time doing it and enjoy the time you're doing it yeah yeah okay yeah that's how i that's how i've done it i think that's how most folks who cut out their own ribs that's how they how they do it but lucky for him he's building a hots and they're all the same all right cool
[46:38] hey that's the last piece of paper i have that's it anything else you want to talk about today no like i said earlier some cool stuff coming down the pipe for us like i said after the first of the year we're gonna we're gonna get into video hopefully your camera gets here in time you keep saying that i i hope so you're putting me on the spot now well you're gonna make it happen i have every bit of confidence in you making that happen well that, that's… With my help. That's fair.
[47:06] I'll help. Okay, yeah. If I can. I can't wait to see what you do. I just do what you tell me to do. Okay. And then keep an eye out. We, other stuff hopefully here pretty soon. Maybe another guest. And then we have our wives episode coming up too. So don't forget, if you have any questions for our wives, email them to us, and we'll be sure to ask it. Yep. And if you have questions for us, hit us up on the various different ways to do that,
[47:34] and just like this episode, we'll eventually, hopefully, get to them right here on the podcast. There we go. And also, if I've given bad information, please let me know. Yeah, please call him out, because those are my favorite messages. He really does love it when you guys call me out. I glow so much when that happens. He does. I shine. But I do admit I'm no expert. And the center of Gary's question with the center of lift and the center of gravity, that's a really good question.
[48:04] And to be honest, it's over my head without me diving into the internet and getting the answers. And I just don't have time right now. Right. You're building a do list. So if somebody out there has the answer and can make it clear as mud, let us know. Yeah. Knowledge is power. Oh, gosh. Okay. Knowledge is power. Okay. You don't agree? I guess I've never thought about it. Isn't that something from the 80s? I think you've said it before. I don't know.
[48:30] Remember, I was like a toddler in the 80s. That's true. Sometimes I forget how young you are. Well, your wife is giving me the finger, by the way, because I said I was a toddler in the 80s. Sorry. That wasn't very nice at all. I don't think it was. See, I have to say that because she's sitting there yeah otherwise you'd be doing it too what is that oh that's supposed to be a heart weird anyway okay well that's what you get to look forward to when she's
[48:57] on anyway what are you doing i was reading my i was reading my list to make sure we got everything. Did we? Yep. Okay, cool. Until next time, I'm Ron. I'm Tom. Good night. Good night. We hope you enjoyed this episode of the RC Plane Lab Podcast. For topic suggestions, to ask questions, or to give any feedback, connect with us at rcplanelab.com, or email us direct at either ron at rcplanelab.com or tom at rcplanelab.com. You can also text us or leave us a voicemail at 818-351-9846.
[49:30] Please subscribe, rate, and review us on your favorite podcast app. Until next time, may your landings be gentle.
