In Make:V76, Mike Senese wrote an article, titled “Flight Trainer,” in our Made on Earth section. It was about the Kiddy Copter built by Charles Helmholdt of Grand Rapids, Michigan. Mike was not only impressed by the build but that Charles had created a 100 pages of documentation of his project.
A pilot, Charles had built his own plane, a float plane, which might have been the first thing outside of a deck that he had built. Then he built a series of Kiddy Cub planes in red, yellow and blue. They were rides that he brought to a Maker Faire in Grand Rapids one year. He started to wonder what it would take to build a Kiddy Copter. In this episode of Make:cast, I talk with Charles about the how the idea came to him, how he got started and what were the challenges of this project. What does stand out is that Charles likes to build things and he does it with and for his family.
In this video of our conversation, you’ll see images from the build process.
Kiddy Copter Documentation
Charles wrote over 100 pages of documentation with photos and illustrations. If you want to see the step-by-step process in more detail, check out how the Kiddy Copter evolved from a sketch as a series of smaller projects that were part of a big project.
Credits: Images and PDF provided by Charles Helmholdt.
Charles: The first thing I started with is these little Kiddy Cub airplanes. And my wife got me a set of plans for those. And they were basically a kit they’re like the wood parts that were routed out and some metal parts. And I made it my own. I went off the plans and I made a float plane and I made a ski plane. I made a Bush plane and they were like in red, yellow, and blue. And we took them to a Maker Faire here in Grand Rapids.
And we had a really great response. We have a little pushcart behind each airplane and the kids would jump in the airplane and we’d have a little engine sound. And as we would move along, the prop would turn and there was some switches and lights and the kids really had a ball and the parents took a usually a lot of pictures of their kids. So we saw, it was a lot of fun for the family.
I just was thinking one day why wasn’t there a helicopter and most likely because it’s very complicated. So I was struck by this little Chinese go-kart I found online.
Dale: Charles Helmholdt ordered the kids pedal cart from China for $300.
Before it arrived, he blew up a picture of the cart, pasted it on the wall and taped a piece of tracing paper over it. He started sketching out the Kiddy Copter. The picture he had in his head was a Bell 47 helicopter, the kind they had on the MASH TV series with a big bubble around the cockpit.
Charles Helmholdt’s Kiddy Copter is more like an amusement park ride than a real helicopter. It doesn’t fly, but it sure looks like it could. Building a Kiddy Copter involves welding a frame, including a tail boom, designing a cockpit inside an acrylic bubble, figuring out what kind of motor is needed for the rotors, and painting it along with many, many more details. It’s actually a big project. But as Charles has learned, a big project is really just a lot of small projects, done one after the other. But why go to all this trouble to build a Kiddy Copter? One answer is that Charles is always building things. He’s built an airplane, actually, a float plane. The Kiddy Copter was just the next thing he wanted to build. But the real answer to why Charles built this kitty copter has more to do with family.
Charles builds things with his family and for his family. And he shares them with a broader community. It’s why a Kiddy Copter seemed like a good idea to him. He could imagine how much enjoyment it would give to kids, sitting in the bubble cockpit with the rotors moving above their heads and the sound of the engine loud and real all around them.
Let’s learn how Charles got this big project off the ground. Tell me about your background.
Charles: In the early days when I was just graduated from high school, I was supposed to start in the family business, which my two older brothers were in and I was supposed to join them. And I decided that wasn’t quite what I wanted to do.
Dale: What kind of business was that?
Charles: It was a paint and wallpaper store. I decided to go to a design school here in Grand Rapids, which had also a really good reputation for creativity and so forth. So that’s where I started in the more creative aspects of my life and joined a company after graduating from the design school called Hayworth. Like Herman Miller, they are like a big furniture company here in west Michigan. And I was with them for years and then went out on my own. Then I met my wife who was also in the creative area. She’s in advertising and graphics and we got married.
We’ve been together both in marriage and business for almost 45 years now. That’s why, I’ve involved in creative projects because we both liked those things. But when I was a high school student, I did want to be a pilot and that was a big dream of mine.
And it was during the Vietnam war era. And I applied for a going into the military and then I found out my vision wasn’t good. So I put those plans aside. And then later when I got out of college, I got my pilot’s license. So I’ve been a pilot for almost 40 years now.
We moved to California for awhile. We worked for Disney. We lived in Glendale. It was a great experience. Most of our work was actually in Euro Disney, which was in Main Street and a beautiful experience.
We got homesick. We moved back to Michigan and then we’ve just started things up again. And that’s when I got the urge to build an airplane.
Dale: What kind of plane is that?
Charles: It’s a plans-built airplane, which probably helped me do this Kiddy Copter later on, because it’s not a step-by-step approach. It’s more like you wander through the plans and build projects at a time.
Dale: You buy plans from someone who’s designed it and you have to figure out how to make it yourself.
Dale: So you’ve never done this before, right?
Charles: Never done it before. The only thing I had built before in my life was a deck on the back of the house. I don’t know what kind of territory I was getting into. I was getting into probably a lot of trouble is what I thought, but I found that if I just took my time and of course we were raising two young boys at the time, too, so I didn’t have unlimited funds.
It took me 13 years to complete this thing, which is about three times longer than most people take, but it got done and it flies and it does fine. But during that process, I learned how — it is the old story about how you eat an elephant, one, one bite at a time.
And so I divided the thing into a lot of, hundreds of projects and that’s what kind of works when, it’s delayed gratification, but each project had its own gratification. So when I got the ailerons done, I could move onto the flaps. If I got the flaps done, I could move on to the rudder or I could move on to the fabric work, that kind of thing.
So it did take a lot of time and every time we explored kind of new parts of that project, the kids, Diane and me would all get in the car. We actually went up to Canada. We actually started with a basic fuselage, which we’d gotten Canada and brought that back. And then we also bought a set of actually the parts for the wings.
And we also went to Canada to get that. And put that together. One season then we went down to Dallas and we actually built the engine. They would put all the components in front of you. And it’s a, a big four cylinder, 180 horsepower engine, and you build it in three days.
So my youngest son went with me on that project and he really has a knack for mechanical things. And so to this day, I rely on him for helping me look at certain things on the airplane when I need to. He attended a aviation extension course during high school and he learned all the techniques. He wanted to be an A and P technician but he changed this mind when he found out they don’t make very much money. So he got into the electric car industry and is doing quite well, but that’s how it started. It’s like just a project at a time.
Then Tony was going to Maker Faire, which was really cool. And he went down to Detroit to show off his electric motorcycle. And then we found out there was going to be a Mini Maker Faire in Grand Rapids, which I thought — can I go do it too, Tony? So I set up shop right next to him and gave kids rides and these little little airplanes and my gosh, we had a hundred, 200 kids over a weekend that we were giving these little rides to. So it was a ball. So I don’t know what really compelled me to do the helicopter other than I never saw one done before. There was no kit out there.
Dale: So you come up with the idea to do a helicopter. You can’t really buy plans for that. And so you’re starting from scratch.
Charles: Starting from scratch. And I didn’t know really what it was going to look like. I did a really crude little sketch and I asked myself a few difficult questions. Like, where am I going to get a big bubble that will look like a classic helicopter, right?
Dale: What was the model you were building it?
It was like the Bell 47, which is the classic MASH helicopter. Everybody recognizes that big bubble on it. And obviously there’s a lot more advanced looking helicopters today, but that was in the same vintage as my little Piper airplanes, the late 40, early 50 model aviation.
So I thought it would fit in great. And what is still had that problem? Like where am I going to get that bubble?
The thing that you bought first was a pedal cart from China?
Charles: That’s actually how it started too because I saw this little cart and I thought, my gosh, that’s like the same proportions that I’m using on these little Kiddy airplanes.
And I just imagined a little bubble around it and I thought, that could be a cool starting point for this helicopter. And we needed a lot of changes because it had to be modified completely there to do that. But I made a sketch and then I ordered the cart from China and it took like weeks to come in.
And then by the time I got it, I was a little ahead of the game, cause I knew the dimensions that the vendor actually put the dimensions on the site for me. So I was able to ascertain a few things while I was waiting for it to arrive. The bubble was a big thing and I actually found a company in California that makes big bubbles mostly for aquariums.
And of course I’m also familiar with acrylic fabricating because on my airplane, I fabricated on my own, bubble doors on my seaplane. And that was quite a job. I know what they do is they usually take sheets of plexiglass. They put it flat in a kind of like a pizza oven, warm it up and they put it over a tool and then they blow air from beneath, in diffused air until it reaches a certain height or shape they’re trying to achieve and then let it cool off. And then this shape is set. So I know that’s how they make it. And I talked to the company in California, said what size bubbles do you make? And they gave me the standard sizes, which none of them really worked.
So I had to actually have custom tooling made because I wanted it precisely at a 31 and a quarter inch diameter because that would work with my openings that I had determined for the doors and for the feet to go through. So that was one big obstacle to get out of the way.
Dale: A lot of the initial challenges is actually just figuring out the dimensions, isn’t it?
Charles: Absolutely. What made this difficult is that, you’re not a kid, I’m an adult, so I can’t figure out how to fit in it. You have to think about kids sizes. And one of the things like sitting in the helicopter — the cart was great because it was already set up for a kid, but the seat was just the right distance from the pedals.
So I knew that part would be a good starting point, but then I had to make sure that the kid’s legs would fit through the opening and the bottom of the bubble and not interfere with anything. I had no test kids that it could bring over to actually tell me that. So I relied on some of my design books.
I actually have some ergonomic books that show a lot of children dimensions. Body frames. Actually pedaling. And I use that as a reference point. They actually determine what size opening is I needed to make that bubble wins. So luckily I never really had to start over at any point in that project because something was the wrong size.
That, that was a good thing. Another big obstacle that were question marks about whether this was gonna work or not was, how to simulate the rotor assembly, how authentic can I make it? How is it just going to be a crude little motor with a little prop spinning above, it would look cartoonish.
I wanted to go for a much more realistic look. And so a lot of it was like research, finding out rotor head assemblies, how big, or how small they were that were available off the shelf. And I particularly found a rotor head that was actually made for these massive RC helicopters.
And it would just really be perfect for this particular design. And while the blades articulate and I can make the cyclic in the swash plate work on it’s still a crude representation. It’s not a, it’s not a direct simulation of the kit, but it sure looks like it. So that’s what I was going for.
Dale: So talk about the frame itself. This is a big welding project.
Charles: That was the good thing because when I was doing my airplane project, there was a lot of welding. It was very little woodworking. I did a lot of metal work. I learned how to weld 41 30 Chrome-Moly steel and use gas welding for it.
So I was familiar with that. And Tony was very good at it. I’m more good at fabricating and tacking it together. And I had Tony do a lot of the finished welding but it was laying things out. Once we had the cart chopped down to how it attached to the skids, that was a project in itself.
And we set that aside and then I laid out the tail boom section. We still have big drawing boards from our design business when Diane and I — we worked out of our house. So I have great big design boards down in our office. So I laid out the tail boom drawing on mylar. And the reason we do that is that paper shrinks.
And I wanted to use the mylar as a pattern for actually setting the sealed parts on it and basically making sure it all stayed where it was supposed to stay during welding. We laid that tail boom assembly out in stages. And it was tedious though. It was that took a long time because there’s just a whole lot of very complicated joinery, where you have to fish mouth out that steel on the ends to fit as precisely as you can before you weld it. So I had a lot of mistakes. I made a lot of wrong size tubes during that, but I made enough right- size tubes to make it work. So we got it put together. And then as we went on Tony came over in the evening and he would finish-weld my joints until it was all ready to go. And then the assembly of the tailbone to the front cab part and the problem there was just keeping everything straight and true and square.
I’ve found during the fabrication of my airplane, never rely on anything sitting on a garage floor because garage floors aren’t always even. So you had to make a lot of extra measurements and you’d have to shim things up certain ways, until it was just right. And then you could tack it together.
So then we had the tail boom merged with a cab section and we’re really excited at that point, cause we’re good to go on doing that, that finish assembly then. But like I said, it was done in stages, one bite at a time until we got it.
Dale: Going back to the bubble for a minute, you found a supplier for it. You got to exactly the size you needed and perhaps the cutouts and other things. And you order it, it takes a while to get there, but what happened when it arrived?
Charles: Of course, the minute I opened the box, it looks like it looks like the box fell off a truck and sure enough it’s split. What they did is they made bubble in two parts and they actually use, I dunno if the glue or heat to fuse the thing together. And they assured me that would never break.
So when I got the box and I had to show them the photos of it, they were just astounded. And they quickly put in a replacement but I decided to actually use that broken bubble anyway. It broke right at the seam. Right at the bottom. Just where it was supposed to be fused together, it came apart.
I’ve got a lot of experience from my airplane experience with acrylic. And I know that acrylic when you’re trying to attach it to something, you have to make sure that no metal comes in contact with the edges.
Determining how to fasten the plexiglass bubble to the frame was a concern. And so I came up with these two hoops, which determined the best way for that bubble to set into was a hoop on the bottom and hoop on the back. In Grand Rapids, we have a lot of great metal working people, but for the life of me, I could not find anybody to give me a bend of metal in the precise dimensions I needed it.
So I had to go all the way to Houston and have somebody. I think I made up about five or six of these hoops and those were welded into the frame. And those would be the support structure for the bubble. I couldn’t let the bubble sit directly on the hoop because the abrasion of the bubble on the hoop would more or less make it fail later, especially like in, Take a kid for a ride, it would just be too much.
I have found basically a little fish mouth standoff that attaches on the rail of that hoop on both the bottom and the backside. And that stands the bubble off from the rail. And then we used fasteners that actually attached to the standoffs and we drilled oversize holes and put bolts through that have actually rubber, in this case, plastic piping around the threads.
So the threads don’t even come in contact with the edge of the bubble. That makes sure that no metal actually touches that bubble whatsoever. And then to actually go through the other process we riveted gussets in a strap over the bubble to actually make it even stronger than it was. It looks more like a real helicopter anyway.
So we really beef that bubble up and it seems to be working fine. We also noticed that with the kids are crazy animals, when they’re going to jump into that thing, there’s gonna climb in it any way they want. There was a failure point if they stepped on the edge of that bubble then it’s going to crack again. So we actually engineered a little step that cantilevers over the edge of the bubble so that would hopefully prevent that from happening.
And then of course, then it got even you got even more difficult because then I wanted more authenticity in the cockpit.
And we wanted to put a cyclic in there, a stick. So it would feel like you’re steering it or you are steering it, just like a real helicopter. And we wanted to put the collective lever in there to actually demonstrate to the kids how the collective brings up the swash plate and changes the tilt of the rotors.
So now we’ve got two controls on each side of the seat. One is the collective; the other one’s the brake lever and in between their legs is the stick. So we had to make sure that their legs would fit in all these things. And then if they wanted to use those controls, that their legs would not be in the way of it.
Dale: To make it real, you build out instrumentation and some other things inside the cockpit.
Charles: Another part of the authentic look was that control panel. That was a project in itself. I think what, and again, as I made this into little projects. When I do a project like that, I actually set everything else aside and I just concentrated on the control panel of the helicopter.
And so the starting point there was, how do I get a similar look? And what I did is I did a little research on other helicopters with a Bell 47 has a center console. I don’t know if you ever watch MASH, but that helicopter has got a big, heavy console on it. That would have been too cumbersome, wouldn’t work.
So then I did more research and I found on eBay, there was a nice little panel, very similar in shape, but much smaller and they use it for ultralights.
So I sent away for that. But when I got it and I was expecting it still to be problematic, size-wise. It was too deep. So we had to first find out a way of how were you going to float this panel in front of the bubble and then how we would chop it and follow the curve of the bubble from the inside and then how we are going to build out the instrumentation. So that was a lot of fiberglass work and I had actually done some fiberglass work in my other airplanes. So that was another skill that I acquired from the first major project that I wasn’t too afraid of. So I got the console started and then the idea there was instruments that look like the Bell or the R 22 Robinson helicopter in the gauge work, but the gauges are actually quite fake.
They’re just really bezels with glass lenses and they look real, but they don’t, there’s no gauges that work. They’re very convincing though. But the other switches that we have are lights in and basically on off switches.
There was lights everywhere. There’s a light right on the nose wheel of the helicopter. And what’s fun about that one is that is connected to the stick. And so when the child like pulls back on the stick or he turns it left or right, the light actually turns with them. It’s like that old Tucker automobile so that they can actually swing the light around like a spot light.
But we’ve got nav lights on it. The red on the left, the green on the right. We’ve got strobe lights on it. And when the kid puts the switches on, there’s also a feedback light that when they are throwing that switch on, they can see what it’s turning on the panel. So that was a lot of fun for them.
And then additionally and this is the funnest part. We got a sound card and I put an amplifier in the thing. So when they flip the switch. It sounds just like a helicopter, just like the rotors. So it’s very authentic and I pop that in with an amp, so it’s quite loud too. It sounds like a real helicopter.
Dale: You had actuators to raise the helicopter a bit?
Charles: Yeah. That was to give the kids a little flight experience. If we could give them an idea of what it would be like to hover. So there’s two actuators that lift the helicopter six inches above the ground.
Now the only person that really is allowed to do that is the adult. And that controls on the tail boom control trays.
But I also found that to be very useful in loading the helicopter onto the trailer now. So that is both a kind of a lifesaving device too, because that thing is heavy. So that helps me get it up onto a ramp.
Dale: You paint it yellow, you connect everything up.
Charles: First of all, I thought like on the motor, I had some original motors that was trying to do direct drive, so that motor was centered right below the rotor shaft.
And what happened was and I learned this I guess it’s a typical helicopter problem. Anything that is direct drive, you’ll get wobble on that shaft. And mine did the same thing and it looked awful and the shaft was going everywhere. It was only when I went to a right angle drive, all the wobble disappeared. So if you look at the Huey 500 helicopter, for example, that sits down like on a 45 degree angle to the shaft of that Huey. And that’s one of the things that actually with the gearing that stops any wobble from happening. So I had to ditch a couple early attempt motors and then end up with a right-angle drive motor which finally ended up working quite well.
That is operated back on that operator control where I have a rheostat and I can actually start it. And then I can gradually increase the speed. It only will go up to a 100 RPMs. One of the things that’s always a concern is we gotta be careful with other kids in the area cause it could come around and hit them.
But there’s enough like breakaway points like in the rotor that that wouldn’t really probably any harm anyone. So we had to think safety constantly. And one of the things like on the bubble too, is because the bubble goes envelops the child, there’s no chance that they’re hair could ever get caught in the rotor assembly behind them, which was a concern. So that bubble protects them from that that probable accident.
Dale: So how long start to finish was this project?
Charles: It probably took over a year. I didn’t set any deadline.
Dale: Was this a project you started before COVID?
Charles: I started before that and we squeezed in one event before COVID hit, which was ironic.
What I did is I had it completed for the 100th anniversary of the Grand Rapids Santa Claus parade. We had our friends. They had actually two twin boys. So we took our little yellow Cub airplane and the new Kiddy Copter. And we all set up dressed up as elves. We called ourselves the Elf force and we went on a parade through Grand Rapids with it.
Which was the one and last time we’ve actually had it in the public and it got rave reviews. Everybody loved it. It was a lot of fun, but we’re really, we’d love to bring it to another Maker Faire so we hope we have another Maker Faire in Grand Rapids again in the future.
Dale: Not only are through the plane, did you learn how to do things and through your design business, you learned how to do certain things. You bring everything to bear on a project like this. But it was also, it struck me as a family project, and there were probably apart from you and Tony, there are others involved in it throughout. there’s something they’re able to share. And the first pilot was your grandson.
Charles: He was just old enough to fit in there. He wasn’t scared of it, which amazed me. I thought he’d be frightened. And we turned all the thing on and the lights and flashing and in the sound he just sat in there having a good old time.
So that was encouraging. But no, it’s always been a family thing. My wife and I have operated our design business side of our house for the last 30 years. So we raised our kids. We were always at home for them. We have a pole barn behind our house that I built the airplane in. So it’s not hard to quit a little early and go out and work on something.
Oftentimes Diane would come out and help me on things especially in need an extra hand or another idea that, putting the graphics on the airplane, even doing the fabric on the airplane, but, just basically she’s been very supportive of helping me get it done. And, you’ve got to remember, it’s kind of a money pit, it’s not designed to actually make any money.
It’s designed to have fun with. And she’s been very good about allowing me to do that.
Dale: That’s good.
Dale: You could have done probably half the work and not done the fit and finish. It still look looked like a helicopter, but this looks like something that just came off a production line . It’s really beautiful.
Charles: That’s somewhat evolved. We didn’t have a drawing from the very beginning of that it was gonna look like that. As we got further along, we did create a sketch that we want to track toward. It had to have some nice design lines to it. So I guess that might be our graphic design business showing through there.
Dale: Thank you for sharing with me this great project of the Kiddy Copter, and I hope I hope you find a Maker Faire soon to share with other people.
Charles: We hope so. And that’s where we got to start. We love to make things and that’s what it’s all about.
Dale: Another amazing thing Charles did on this project is he produced complete documentation on his build, over a hundred pages with photographs and illustrations of the step-by-step process. He said it was a practice he learned from building his plane, apparently a requirement to document that you built the aircraft yourself.