I just have the hope that through projects like these, we might manage to make winch flying in the lowlands a bit more attractive again, and that we can give back the trust to pilots who might have had bad experiences with the winch, that winch towing can be a wonderful thing. And if we manage to get a few more people off the ground here in the lowlands as well, that would also be a nice thing.
-Glidz, the Lu-Glidz podcast.
Stories from the cosmos of paragliding.
Today with Andreas Hochscherf and Lucian Haas on the mic.
If you take the energy stored in a fully charged battery of a typical notebook, how high could you pull a paraglider up with a winch? Ten, a hundred, or a thousand meters? That's a completely relevant question if you want to build an electric winch that's battery-operated. And someone who can answer that is Andreas Hochscherf from Bonn. Years ago, Andreas had the idea to build an electric winch for his paragliding club DGC 7 Gebirge. Simply because he believed he could do it and because he was convinced that winches with an electric drive would allow for much better control of the pulling forces needed for a safe towing process. Even remote control would be easy to implement.
What had to be proven. But it then took more than seven years until the Elovin electric winch received approval from the DHV. Now it's in regular operation in Andreas' club. But it won't stop there. The paraglider manufacturer Nova plans to offer electric winches in series in the future based on the Elovin technology. As large double-drum or smaller reel winch models. For this podcast, I wasn't just interested in what technology is needed for an electric winch. I also asked Andreas what other, perhaps unexpected challenges are associated with such a project. And so he tells us about his motivation and the low points, the fear of potentially throwing thousands of euros of private assets down the drain, the draining feeling of responsibility, the idea of a community winch, why e-cars aren't simply suitable as e-winches, and how the search for materials led him as far as China.
Before we start, a quick note. Podz-Glidz is a listener-supported podcast. That means I don't fund this project, like the Gleitschirm-Blog Lu-Glidz, through advertising, but solely through voluntary donations. If you would also like to contribute so that Podz-Glidz can continue, please take a look at the Lu-Glidz website, specifically the support page.
Andreas, let's start the story with the Elovin from the end. You built an electric winch that is already in use by the club today. Mhm. And so, that's a success. But if you consider all the time, the effort, the setbacks, and so on that you had, if we were to play Monopoly and say, back to start, would you start running again and really launch this project?
I find it a shame to start a podcast with such a negative message, but I have to be honest, I don't think so. Why? Overall, it was very complex, very challenging. Very, very time-consuming. And I also didn't consider a few things beforehand that have nothing to do with pure technology or financial matters. For example, things like, well, what if you make a mistake somewhere and a buddy of yours falls because of it? Or a few other things. What if you get run over by a truck? You built your club an expensive winch, and they spent almost their entire club assets on it.
And you're not there to fix it, and no one else can do it. What happens then? Those are the kinds of things that make you start overthinking. In the evening or at night, when you wake up and think, what am I actually doing? And there are quite a few things like that—those are soft factors, completely independent of whether you can get the technology running.
That's the question of responsibility you're actually taking on. But you didn't even ask yourself that at the beginning. You only realized later on that it's actually a huge question.
Yeah, well, I did ask myself that at the beginning, of course. But if you don't get into the details, then, well, you might not really realize what it actually means in the end. I think everyone knows from their private lives that it's a different situation whether you just quickly imagine something or if you're actually facing the... concrete situation.
Well, that's how life is, you know—usually you start something and you have no idea what's actually involved with it. And you notice that you basically only grow with your tasks, which is probably what you're like too. Now, the whole thing took quite a while. If you put that into perspective, what timeframe are we actually talking about here? When did you start? When did this idea occur to you—that you want to build an electric winch?
That was almost ten years ago. Yeah, it must have been around 2011, 2012, when our club winches were starting to struggle a bit and were getting hard to repair. Almost impossible to repair anymore. At the same time, a flight instructor who's a friend was also struggling a bit with his training winch and always dreamed of a remote-controlled winch, and then a few other things came together, and then there was also the fact that I was quite far away from any concrete technology at work. Which is good too, but I also needed a technical challenge. And well, then it was somehow around 2011, 2012, when I thought, this actually fits. You have a nice, tangible project that you could tackle in your free time.
Why
did you feel qualified for that? I mean, which skills did you know you could bring to the table, that you could actually realize something like that? Well,
Yeah, well, I know a bit about many things. I'd call myself a bit of a jack-of-all-trades, and I'd dealt with enough electronics, software, mechanics, a bit of mechanical engineering, and so on, that I just felt I could do it. However, at the beginning, I also thought I'd get some help from other colleagues who might want to join in. But that didn't happen.
That's not the case. You basically pulled it off as a solo project in the end.
Yeah, in the end, that was unfortunately the case. I would have liked to do it in a team. But it's hard to find people who will stay persistent with something like this. I mean, many people get excited quickly. But when it gets really concrete and you say, "Look, we need to do this now" and "someone needs to take care of this," then it gets pretty thin pretty quickly. From the...
what you thought about at the beginning, what you said, I'm going to build an electric winch. What did you imagine would be the biggest difficulty at the start, or what did you expect to be the biggest difficulty during the realization? Oh. Were those the technical questions, like how do I get the motor running, or was it a software thing? No,
That was actually—and it turned out to be true later on—the day, the worry, the problems... you can solve those once you've thought them through well beforehand and don't see any fundamental issues.
And I don't think I could really pinpoint one specific problem right now, except maybe whether I can get it done within the budget we set as a club. What was that budget, roughly? I mean, we never talked about specific figures, but it was practically a matter of sporting honor to say, okay, the thing can't get more expensive than a functionally identical gasoline winch. That means something between 15,000 and
Probably 20,000?
Yeah, I think it could be a bit higher, but let's say in the ballpark of 20,000 euros, including the cables and all that, ready to go. That was the target. Now...
you went into it, let's say, wide-eyed at the beginning because you didn't know at all what was in store for you. You only had an idea of it. Now there's this figure, let's say 20,000 again. How do you get a feel for that, to be able to say, I can do this? When you don't actually really know all the basic ingredients yet—what do I need? Where do I get it? What will it cost me? How much time do I have to invest? And can I just get it around the corner at Konrad Elektronik, or do I have to source it from some other super specialty shop? Right,
Well, I think it helped that I was able to estimate pretty quickly what the individual components would cost. Aside from one or two things—we might get to those later—but for the most part, it was clear to me that it would be another trade-off between hard work and buying something ready-made. Or let's say, okay, if the budget gets tight, then I'll just do it myself. And that's why I knew from the start that I had a certain amount of maneuvering room. And that I had a certain amount of weight on my side in this story.
Was was there from a technical perspective? You already mentioned the responsibility thing earlier. But was there something from a technical standpoint where you eventually realized, wow, this is the real sticking point of this project? Where you really had to grit your teeth and just push through?
Yeah, that actually happened in the end. Well, unfortunately not at the end, or thank God not at the end, but pretty quickly at the beginning. At a point where I wouldn't have expected it. And that was? It's the motor controller. It's not that easy to get an affordable motor controller that actually behaves the way you need for an electric winch. You can buy a very expensive industrial controller, but then you can forget about the budget. Or you can buy one of those—no offense intended—cheap Chinese knock-offs.
That isn't actually that big. It's actually optimized to somehow convert a motorcycle quickly. But then you find out—and this actually happened to me—that the thing isn't suitable for a winch tow. So, very specifically, I installed a controller, a power motor controller, in the hope that I could now switch it on. And it worked well at first. And then we did a test, just towing, and the pulled load—of course, everything happened on the ground at first. It has to be emphasized,
Safety comes first
before. Well, I don't think anyone would have been crazy enough to hook themselves directly onto it. No, no, we did a towing test with cars on a friend's airfield. And then, of course, there's such an interesting effect of what happens when the driver brakes while I'm pulling. And unfortunately, you could see that the controller's power immediately went up, because it was just pre-programmed to try to do what a picker does. And that's the big problem with gasoline winches—compensating for that extra power requirement by increasing its output. And at that moment, it also increased its power. And that's of course the very last thing you want to experience during a winch tow. That if you fly into a gust, you're suddenly being towed with double the force.
And then it was clear: you can't do that with the controller.
You couldn't reprogram that one either. It was programmed in one direction, and the other configuration wouldn't have been possible.
I tried. And the Chinese actually got back to me. But I think if I had ordered 2,000 pieces, they would have done it. But when I hinted at my quantity, namely quantity 1, the support ended pretty quickly.
Did you ever feel like throwing the whole project away at some point?
Actually, never really.
What kept you going despite all these difficulties?
Yes, the money I had already spent. Yes, the money I had already spent. And in order to get started at all, I already had to buy all the expensive components. So ultimately, it's four things. One is a trailer platform, so a vehicle platform. I could have sold that again, that wouldn't have been so bad. But I had to buy a big battery. I had to buy a big motor. And I had to buy this motor controller. And that makes, let's say, 70 percent of the total expenses. That means I had to invest so much so early on, without knowing if it would work. That I had put myself in a situation and said that giving up is actually not an option.
That means you would have just had to write off a really huge chunk of money and say, okay, I can't bill anyone for that anymore. That's not a problem now.
Exactly, that was also the agreement with the club. I get the money I spent back if I deliver a certified winch. And I was just very, very far from that. But I got to the point very quickly where I said, well, I've spent so much of my own money now that I want to see this through. And besides, it's a matter of honor. Honor is a stupid term, but it's actually a sporting challenge. So
I don't give up quickly. What you haven't done yet is deliver a finished electric winch. From your perspective, what is actually the advantage of an electric winch compared to the classic internal combustion winches that almost all clubs still use today?
I think you have to distinguish between things. So, the... the most important technical advantage, if you look at a purely classic towing operation,
it is quite beyond doubt that electric motors, at least the DC motors well-suited for this purpose, have a much, much better control characteristic than cars. I think the best way to compare this is, and everyone knows this, when you drive a car up a steep mountain. Then you have to give it quite a bit of gas and carefully dose the rest with the clutch to make the whole thing work. Because the problem is, I need a lot of torque to get the car moving. But a gasoline engine can't deliver much torque without producing a lot of power. And I then have to waste that power again with the clutch. And that's what happens permanently with gasoline winches through these torque converters. That's why they also get so incredibly hot during operation.
And the worst thing that can happen to a gasoline winch is that it drags against strong wind. Then it produces 30, 40 kilowatts of engine power. And the torque converter transmission nullifies all of that again because actually no power is needed at all, only the force for the pilot to rise. So the holding force, because basically, it rises like a kite on a long string. Exactly. And I think every pilot who has ever experienced dragging knows how unpleasant it is when the force increases as you fly into a gust. And the wind pushes you, let's say, backwards and the winch tries to hold against it. Then you get this yo-yo effect. And all those things can be wonderfully compensated for automatically with an electric motor. You don't have to do much yourself; the electronics handle everything perfectly on its own because with an electric motor, you can basically adjust force and power separately.
Would you say that an electric winch with this electronic control you've built is ultimately even better than a really good, experienced winch operator? In principle, I mean.
Yes, exactly. We've already seen it in many towing tests in gusty conditions. A good, experienced winch operator simply cannot regulate that fast. If you look at the design of gasoline winches—what happens there—even if the winch operator reacts quickly, the system just needs a certain amount of time to regulate down because the entire winch is actually suspended from a boom, and when a few hundred kilograms suddenly start to move as the force increases, it takes time. An electric winch does that automatically in fractions of a second. And it does so multiple times if necessary.
Without going into too much technical detail right now, just for the sake of understanding: there's this motor spinning, and forces are being generated—you can probably measure how much current it needs right now to maintain that. How exactly do you measure that? Or in what timeframe do you measure it? How do you see it? Do you do about 10 measurements per second, or does it regulate 100 times per second? And how fast can the motor actually adjust accordingly? I mean, the...
Controller, we didn't quite finish that topic, the one we actually use now that provides exactly the behavior we need for the winch tow; it does that 200 times per second. Internally, I think it's even faster. The motor itself is of course a bit more sluggish. So, an electric motor with a certain mass obviously can't completely change its behavior within 5 or 10 milliseconds. So mass inertia still plays a role there. But it adjusts in a fraction of a second. And it does so automatically.
That means it's like a classic one—as far as you can even call it classic anymore—but an electric winch tow is, at least for the pilot, unless it's super stormy, probably going to be much, much smoother than it can ever be with any internal combustion winch.
So we've had tow pilots in heavy gusty conditions who said, "Oh, that was actually quite smooth." Because the winch itself regulated it so much. Exactly. Now, I don't want to rave about it in the highest tones, but we got a lot of positive feedback from pilots who had experienced that. And how do you experience it? Are you
have you ever even been towed by your electric winch, or do you just not trust your own technology?
For God's sake, I would never hang myself on that. No, I mean, that was a bit of a bitter pill to swallow. Unfortunately, we didn't have that many test dates anyway, because we aren't very active in winch towing due to the terrain and staffing situation. And on the few dates where I was actually there, I unfortunately had to stay on the ground to monitor the winch, take measurements, and collect data. And make sure everything was running. I didn't have the peace of mind to go up into the air myself. So effectively, I think I've only flown on the winch itself two or three times. And not even in conditions where I could test it out myself.
How was that then? Is it a particularly proud feeling when you say, wow, this is my baby, it's pulling me into the air now? Oh, that might come later.
You were probably still looking at it too much through a technical lens, trying to figure out what was actually going on. Exactly, exactly.
So that's more of an analytical look, like, oh, this is happening now, that's happening now, and this is happening now, yeah.
Now you've handed the winch over to the association. And you already touched on that earlier. There's still this question of responsibility, does it always play a role there? Basically, you'll probably never really get rid of that responsibility.
Are you actually still liable for the winch in any way, the way you have it there now? Also liable in some sense?
So I've always made sure that I don't end up with any personal, I mean private, liability. Except, of course, for the liability you can never escape from, like gross negligence or something like that. So I see myself primarily as morally obligated to see a project like this through to a good conclusion. I'm quite reassured now, though, because thank God we also have someone in the club who is taking very good care of the equipment now. And I was still relieved the first time the thing wasn't in front of my garage anymore, but somewhere else. And also when some towing took place elsewhere without my involvement, and they all ran smoothly. So now I'm definitely at a point where I say, okay, I trust the thing. And I mean, what can break, naturally, on a piece of equipment.
But it seems to have proven itself by now, so I can say, okay, I really don't need to worry about that anymore
...to worry about. But what about repairs? Can others actually perform them? Or is the... is the association, in a sense, at least when it comes to more targeted repairs or if it's about the electronics acting up or something like that, is the association basically still dependent on you for its survival?
That was one of the points—maybe I pushed it a bit too hard at the beginning, but it's actually one of the points that shouldn't be underestimated. I've developed a lot of specialized electronics and written a lot of software for it.
And the whole thing, of course, has to be documented. So if some board were to burn out now, even if I had given someone else the schematics or the software,
it would be a huge, huge amount of effort for someone to work their way into it and source a replacement. So for me, it's not a problem at the moment.
But the problem actually hasn't been solved yet. I mean, I hope we'll solve it. We might get to that later.
What made me very happy is that we've now found a way to perhaps produce this in small series and put it on slightly more solid ground. And then, of course, we have the possibility to also supply things like electronics or software as spare parts.
to be able to. So, basically as standard spare parts, where you'd say the control board fried for some reason, here's a new one, you just plug it in. Exactly. Plug it in and it just works somehow. And then what happens next. Originally you wanted something like that too, I think, if I remember correctly, you had the idea of building something like a "people's winch," where you'd say, okay, I'll make a kit or at least release the construction instructions. And then any club that wants something like that can simply rebuild it based on my experience and what I provide them. What became of that idea?
Yes, that's a good point. There have been some projects with that ambition. That's also very nice, by the way, because there are other electric winches as well, and actually, all the ones I've met are quite generous with their ideas and are happy to say, yeah, you're welcome to build one yourself, I'll tell you everything.
The fact is, just because you know how such a thing works or how it's built, it doesn't mean you're anywhere near the point of being able to replicate it. There are so many individual steps involved. And so many different trades. I mean, with a gasoline winch, it's relatively simple; if you can weld, so if you know a bit of metalwork and know how a gasoline engine works, then you can somehow manage it. But with an electric winch, besides all the mechanics, which have to work, you also need electronics knowledge, you have to be able to handle high-voltage technology, and you have to be able to handle software, because ultimately you need software to get these machines running. That is definitely something interdisciplinary.
And it turned out, unfortunately, that this was an unrealistic path. I had once thought of something like a component—or modular—system, where perhaps different clubs with an interest, and with different qualifications, would manufacture individual components that you would then assemble together, for example, once a year as part of wind power workshops to assemble finished winches. But all of that ultimately failed.
confronted by reality. It would be like an electric winch corporation, where one person says, I'll supply the motors, the next says, I'll always assemble the electronics, and then we'll put it all together at the end somehow. That was the idea? That was
the idea. That was one of the ideas. The original idea was, I'll just document everything very nicely and then anyone can build it themselves. But it became pretty clear quite quickly that that wouldn't work.
And the next step would have been, okay, you also organize it so that several parties manufacture individual components and then assemble them. For example, one club builds five cable drums, another builds five frames, and a third builds five circuit boards, and then you help each other out and get...
get the whole thing up and running. Nova actually announced at the Thermik trade fair that they want to bring the Elovin—so, this model you developed as the Elovin—to production readiness and onto the market, at least in a small series. How did this cooperation with Nova actually come about for you?
That was now a good three years ago. The DHV had founded an electric winch forum where all interested developers or friends and family who were interested in the topic could register and exchange ideas. And I found out about it relatively, relatively soon in 2017 from two flight colleagues from Nuremberg in this way, who wanted to realize a very interesting project, namely a trailer hitch winch. One or the other of you might know them, Skinch, in principle, so just a motor with a drum mounted on a trailer hitch, kept relatively simple mechanically, at least at first glance.
And they were looking for support. And at that point, I could already contribute quite a lot. And then we got in touch. And we made a deal: I provide you with all the electronics and the software, and in return, I get a cable drum from you.
And then we just started developing it together. And at some point, it turned out that one of them is at Nova and could also imagine producing something like that in small series. Although more like these reel winches or these trailer hitches, but he then also increasingly—or the two of them then also increasingly—were able to request the larger frame version. And ultimately, over the years, where the projects were successfully completed,
decided that we would now try to produce both models in small series.
When will this first Elovin from Nova be available? Is that already foreseeable?
I don't want to step on the company's toes regarding their communication strategy. So, we're hoping that, unfortunately due to Corona, we can get started with a prototype in July with a three-month delay. It will be very similar to the Elovin we have here at our club. And then we'll see how well it holds up in practice. And hopefully, we'll be able to launch a small series with it relatively quickly. You're saying now...
very similar. What is different, though, because maybe from the experience with your first one, the first prototype, you'd say, okay, I would basically solve that differently today? Actually
it is
just the motor.
To be honest, I'm surprised that we're actually going to reuse almost everything, whether it's the clamping device or the electronics, especially the controller principle. The motor was actually a problem. Maybe I'll mention that briefly later. In the end, it was one of the major sticking points, along with the controller. I needed a very specific motor. It's a direct drive, which is quite expensive in that power range if you try to get it in Europe. And I have it—direct drive, just for clarity, meaning no gearbox, but... No gearbox, exactly. It delivers all... Exactly, it should be quite simple and anyone should be able to build it.
That was always the goal. That's why, as far as possible, no gearbox, no gearing, but a direct drive, like you know from bicycle hub motors, just on a larger scale. And for that, you naturally need very, very strong magnets in these motors. And they are very, very expensive, unless you have access to rare earths like China does, which allows you to build them relatively cheaply. And actually, I managed to get a company in China—one that didn't do any business with Europe at all, I think they don't do any business outside of China at all—to somehow build me a motor exactly as I needed it through a rather adventurous route. That worked too, but it became pretty clear very quickly that this isn't the way to set up a small series.
Thankfully, we've now found a company that is also represented in Europe and can deliver in series.
Even those
Good motors of the corresponding power you need. Exactly, that was the problem. The company, they already existed before, they had smaller motors, which are somewhat sufficient for a solo tow, but for a zero-wind tow or for a tandem tow, you simply needed stronger motors.
Just a quick word on China, I'm interested in that now. You say you found someone in China who builds something like this for you. You're sitting here in Bonn now—so I'm sitting here in Bonn with you too. How do you find someone in China who builds a custom motor for you, where you then write, "Hey, I need something for an electric winch," and maybe the Chinese guy says, "What's that?" Good.
Point. I think I spent about two or three months hanging out on the internet just researching, researching everything possible. Getting parts is tedious. Whether the springs are for capping devices or what, and you have to calculate everything, you have to see where you can get it. And the electric motor was a huge problem. I first looked around here in Germany, of course, then in Europe. But then it turned out, no, it doesn't help, you have to look at China. And in the end, there were only two or three companies you could find via Alibaba... As a platform, that's like a trade platform, right? Exactly, the Chinese one, actually an industrial trade platform, at least at that time, I found a company,
that was at least reachable in English. And a Chinese guy got in touch—they all kindly give themselves some English names so you don't have to struggle too much. And that was Chris. And Chris was very helpful, took down my requirements, and then said something like, yeah, we can build something like that or do something like that. And it got pretty into the nitty-gritty, like really with RPMs and Newton meters and so on and so forth. Then eventually the email came back, yeah, okay, we need an order now, but we can't process that through the normal company account. You would have to somehow transfer it to our development head's account.
And now, we're sending a proforma invoice. And that's the... account number, and then please 2,000 euros. Yeah, that was the first time I really had to swallow my pride. How many sleepless nights did you have before you made the transfer?
None, I did it immediately because I knew it was make or break. So, that was one of those tipping points, as they say. So, if I jump over the shadows here... So, without the motor, would the project have stopped? Without the motor, the project would have become pretty boring. So, a winch without a motor is... Yeah, sure. Not an exciting thing. And I didn't have a proper plan B. So, I would have had to start thinking from scratch. Then maybe with a gearbox and a standard electric motor. I thought to myself, come on, you're this far. Now you take the path. And it all worked out wonderfully. But it was exciting.
But was the motor then custom-built for you there, wound, or whatever, and shipped? How long did it take from the time the order was placed until you actually had it in your hands?
So, eight to twelve weeks, I think. Or eight to twelve weeks, I don't know exactly anymore. Oh wait, not that long. No, no, no. Yes, what do you mean by specially built? They obviously have their motor platforms and just have to adjust certain things. And I think they are... I mean, these types of motors aren't built in huge quantities anyway, they're just delivered customized relatively frequently.
What is something like this normally used for? In this... I mean, even with this kind of power? You say you normally find it in bicycles, but now, this is obviously something bigger. Yes, that was also quite
interesting. Of course, I would have liked to have some kind of reference that this motor actually works, so that it's not just some pipe dream. And then they just sent me a few pictures from their workshop where they converted taxis. They actually just stoically took the rear wheels off the taxis, put their welding sleeves in there, screwed in their motors, put the wheels back on, and then these taxis set off. And they said, "Well, our taxis are already..." Or let's say, the customer who operates these taxis has been driving them for three years now in...
flawlessly and without any issues around. So, they were actually already being used as electric drives for Chinese taxis. At a time when people in Europe weren't even thinking about it yet.
You mentioned earlier that the controller was also a problem. Couldn't you have gotten the controller directly from them, if you say the taxis are already running on them? There must be the corresponding electronics available directly. That's a completely different issue.
So, just because someone builds motors doesn't mean they can build a controller for a long time. And they bought their controllers from the relevant suppliers too. They recommended a controller to me, which I had already tried and that worked well with the motor, but just not for winch towing operation. Because it was programmed incorrectly and you didn't know how to perhaps reprogram it. Yeah, even if I had known, I wouldn't have been able to do it. That's already etched into the chips. You can't get to that.
This controller you're using now—that's a bit of a specific technical question. Why can it do what you need for the winch, when you say that for normal driving, I don't actually need this behavior at all?
That's a bit annoying, because what the controllers need to be able to do for winch towing, basically any controller can do. This Chinese controller could have done it too. It just couldn't, so to speak, output it. It just didn't expose it externally. To parameterize it in such a way that it actually works. And the controller I'm using now can be parameterized very, very extensively. So, it can be adjusted very, very heavily. However, that was also a major hurdle. I think I ended up taking over a year to set the thing up so that it works. Just to understand how it works in the first place. It was an incredibly complex piece of equipment.
And it cost me many, many sleepless nights. But in the end, it was the key to success. The fact that it revealed the parameters you need for winch towing. And I also know of other electric wind projects that failed because of this problem.
How many current electric wind projects are there where you're saying they weren't even ones where one was built and then just sits there but doesn't go any further? But rather ones where you say there's really still development potential in them. Or they could maybe even hit the market or whatever. Or are you, with Elovin and Nova, basically going to be unrivaled there at first? Oh,
I think many projects have development potential in terms of electric. That's not the issue. Some projects were designed from the start to, let's say, go all out and not care about costs, but simply wanted to reach a goal. They did reach it, but at a cost point where it was clear to them at all times that no one would replicate it. Yes, that's illusory. So you quickly end up at 50,000 euros or more for such a winch. There are one or two projects I know that I believe would fundamentally be suitable for commercialization. But you have to find someone who will actually do that. And I haven't seen that so far.
So the only electric winch I know of that is also available in a small series is the Molivinch, which, however, cannot be operated with batteries, but runs on mains power or, well, a
...diesel generator. Speaking of batteries, we haven't actually discussed that at all yet. One special feature of your winch is that everything you need for it is on the trailer, so the power supply. You're mentioning batteries now. What kind of batteries do you have installed in the one that's finished for the club?
Yes, after a lot of research, I decided on forklift batteries. They have the advantage of being able to deliver high currents, which is important. And they're relatively robust and, above all, not that expensive. I mean, lithium batteries already existed at that time. We're talking about the period around 2012. But they were still three times as expensive as lead-acid batteries back then. And I didn't want to do that to the club right away. I thought, let's go with lead-acid batteries for now, and eventually, when these lithium batteries get cheaper, we can switch again. However, they haven't actually become cheaper to this day.
But what you're saying now, if you're planning with Nova, does that also have those lead-acid batteries? Or are you actually planning it with lithium batteries, because you say basically that's the way to go, that they're lighter, the energy density is at least just as good, or something like that?
Well, the idea is actually that the interested party decides for themselves. So, unlike with a gasoline conversion where you say, "I need to put in a 20-liter tank and then everyone's happy," it's different here. There are small towing communities that are happy if they can still do five tows in the evening. They get by with a small battery, and then there's a large club that says, "Well, we have to manage 100 tows." And they obviously need a completely different battery. That's why the whole thing is designed so that you can actually choose the battery type independently of the winch.
You know a bit about electric data, don't you? Just for comparison, if I were to take a typical notebook battery and ask, how many winches are in such a notebook battery? I mean, how many pilots do I get under normal conditions, or let's just say zero-wind conditions? I need a lot of power from the winch. How many do I get hauled up with a notebook battery?
So I'd say a 50-kilo pilot would maybe reach a release altitude of 150 meters, then it's empty. A notebook battery? A notebook battery. That means if I say,
I want to manage 100 tows per day, which shouldn't just go up to 150 meters, but ideally provide me with a release altitude of maybe 400 meters, so I'd need 1,000 of those. Right? Did I calculate that wrong?
So, let me just say, a laptop battery has around 100 watt-hours to stick to the technical specs. And for a normal launch, you need something between 150 and 250 watt-hours, depending on the situation. So with a lot of wind, you could also manage with 100 watt-hours, meaning with a laptop battery. So if you want to do 100 launches, so one launch, one
Notebook batteries? Let's put it this way,
one trailer, two notebook batteries, then you're reasonably on the safe side. So for 100 trailers, you need 200 notebook batteries. Yes,
That's just to give you an idea of what you're actually getting in terms of weight. If you really want to carry all that energy with you, then you've got a significant load on your trailer in the back. How much do the batteries you have on there weigh? Those lead-acid batteries are probably even heavier than those lithium ones.
-Things? They're three times as heavy. So, lithium batteries are about three times as expensive as lead-acid batteries, but lead-acid batteries are three times as heavy. And... I think they weigh about 600 kilograms here. So they definitely make up more than half of the total weight.
That's quite a lot already. Yes. Let's jump around the topic a bit. One special feature you also built into this Elovin is the possibility of remote control via radio. How safe is that actually? Radio links can drop out or something, and someone is hanging on the rope. What happens then? So, how did you realize that? And why do you even know about radio...
...right? Can I take a small detour? Because that brings me back to the point I wanted to finish just now. You asked what the advantages of the electric winch are at all. One was this advantage of mechanical control. That's the bare comparison when you compare it to a gasoline winch. However, if you design such a winch accordingly and also control it with modern computer technology, you get a whole range of possibilities that can also bring many advantages beyond the normal towing benefits. And one of those is simply that you can design a remote control relatively easily. That's what I did. So, on one hand, I've always been somehow interested in radio controls, and on the other, my professional background is a bit in that direction and I was somehow quite happy to apply my radio technology knowledge again.
to be able to. Let me give you a bit of a spoiler. You worked for a mobile network provider and co-developed a lot of things in radio development and such. So, okay, you know a lot about radio technology.
Although the development part was purely paperwork. I mean, I wasn't an electronics developer or anything like that, but more of a conceptual developer, or I worked on specifications. But in reality, it's like this: you just asked about the safety of the radio control—some safety mechanisms from mobile communications that I was simply able to reuse for Elovin as well. For example, I built in certain mechanisms that, following a specific procedure also used in mobile communications, automatically reduce the power if the radio connection gets worse. And I think that's also the decisive feature of a radio control. You can execute it more or less safely, but you can of course never achieve the level of safety you have with a wired connection.
So you have to account for failures. But if you design the winch so that in, let's take the worst-case scenario, it's poorly built,
the radio fails and the motor stops, then for a pilot, that's like a cable snap. And that's a situation he has to be able to handle. In that sense, you could say, okay, it's not all that dramatic. With the Elovin, it's like this: in such a case, within five seconds, the power ramps down linearly to zero. And that's a relatively smooth process, basically, just like during a normal power-down. So you don't have to worry about that. So
not where it's at, but what is the actual advantage of this radio control in normal operation? I mean, why did you design it this way? What's so great about it? Well, that brings us back to
the opening statement on motivation. The flight instructor who says, "Good grief, especially when I'm training my beginners, depending on who I have sitting on the winch, it's terrible for them,"
then I'd rather sit on the winch myself, but then I can't train them. And then, of course, it's clear that the solution would be a remote control, so that the flight instructor can operate the winch themselves from the launch site. And that was the goal. In the meantime, we're doing even more. We're also pursuing concepts where a pilot can tow themselves into the air using such a remote control. That
means that, ultimately, I could get myself into the air alone with such a winch—one that I put on a trailer hitch on the back of my car or something like that, with the corresponding electronics connected to it—I could say, I drive out to the field, spool out the line, and then tow myself up. That is
possible, yes.
And that will all be electronic, including rewinding the rope or whatever. The car stays parked there. I fly around up there, I still have the remote somehow, I'll probably have to plug it in somewhere. But then it would really work as a solo operation in this form. Yes.
It would work as a solo operation. I don't know if it's practical, though. I know of projects in Germany that have built it this way and are already using it or have used it. It's not exactly covered by the current operating regulations, of course. But I believe the DRV is working on getting that approved as well. And whether it turns out to be an interesting option in practice, we'll have to see.
You also got your winch approved by the DRV. Was that hard? Or was it actually relatively easy because it worked so wonderfully technically? And how did the DRV actually react? Did they say, "Great, this is the awesome technology we need now"? Or were they like, "Another nut with a weird idea"? That might have been what we...
...thought at first. But no, the DRV was very supportive and very positive and actually helped wherever they could. And that was from the very beginning. Even back when Horst Barthelmes was still the tractor commissioner, he was very motivating. And his successor now, Andreas Schöpke, has also supported it very, very strongly. In the end, passing the tests was very easy. That wasn't really a problem. What was a bit difficult was finding a procedure to even define the tests. Because the normal winch test procedure is designed for gasoline winches. A lot of things just don't fit there. They test things that are completely irrelevant for electric operation.
And conversely, important things that would be relevant for electric operation aren't taken into account at all.
And how does that work then? Do you negotiate that with Horst Barthelmes or whoever, so to speak? Do you say, I think it's important that we should perhaps test this? Or who defines the test procedure then?
We actually agreed on that. I think I was able to show through good arguments and good documentation that I take this very seriously and that I've given it some thought. And then we found a procedure relatively quickly after we were able to approve them.
Will the future standardized models—let's call them Elo-Viens for now—that come to market under the Nova name, will they also be approved using the same procedure? Or maybe the prototype will be approved first and then the others accordingly? I assume...
At the moment, I assume that in the medium term, further regulations will have to be adjusted and things will develop. I don't think the approval regulations for gasoline winches were created overnight back then either. So, that will certainly develop over the years, and perhaps based on new findings, one or two additional test points will be added. But at the moment, I assume that it can be done this way.
If an electric winch marketed by Nova comes onto the market as a standard, do you think they will prevail in the market? That people will say, electric winches are so great, we don't want any more gasoline winches? Gasoline winches still perform pretty well.
And electric winches aren't exactly cheap either. So I believe, ultimately, it depends on the price. If we somehow manage to make these winches available at a price point where many clubs say, "Yeah, then my next winch will be an electric winch," then they will prevail in the medium term. Because they offer a whole range of advantages. It's not just this safety aspect and the fact that you can definitely let an inexperienced winch operator stay on the stick during heavy conditions.
Or it's simply much more pleasant. Anyone who's operated a gasoline winch for a few hours usually has ringing in their ears; they had all those gasoline fumes in the air. And that was never the main motivation for an electric winch. But with an electric winch, you can say you can still chat with your buddy next to you while towing. And there's no smell, unless you happen to cause a short circuit.
But these electric winches, at least in this solution with battery operation, can only really become cheaper if you say the batteries become significantly cheaper. So, for example, if these lithium-ion batteries drop significantly in price accordingly. That would then affect the price—I mean, if we're talking about an electric winch like the one that's finished now, and you say you'd equip it with lithium-ion batteries, what percentage of the price would that battery alone account for? Would it make up 60 percent of the total price?
As I said, it depends on what needs the club has. So if I want to do over 100 tows a day and want to have a lithium battery, it's quite possible that I have to account for 40 or 50 percent of the price for the battery alone. But if I have a small project, then it can be significantly less. Or if I say, well, I don't have a weight problem, I'll take a lead-acid battery, then it's not that expensive at all. The problem is, overall, the components are relatively expensive. We need this expensive direct-drive motor, which isn't easy to get. We need this expensive electronics controller, we need an expensive battery. And those are all, I'd say, price disadvantages compared to a gasoline winch, of course.
For a gasoline winch, I go somewhere, get an old Golf engine, build it in there, and the rest is mostly metal and an old car seat, and then I'm done. It's different with an electric winch. You just have to get over it and say, okay, I have to shell out a bit more money because these are all new, expensive parts and not some used parts from leftover cars.
If these batteries are such a central component, wouldn't a modular solution be possible where you say, okay, in the future there will be many more classic electric cars that already have great batteries built in? They might even have their tow bar. Couldn't you just put a device like that directly on an e-car and hook it up to the car's battery system and say, wonderful, I'm just pulling the energy I need directly out of the car and can do my towing with it perfectly, and then I basically have a dual-purpose vehicle?
Nice idea, yeah.
It would theoretically be conceivable, and I don't want to rule it out in the long term, but at the moment, I believe electric cars aren't designed for that—meaning, as far as I know, they aren't designed to deliver high currents to external systems. Then there's the fact that electric cars operate at much higher voltages. That means you'd have to switch in some pretty expensive power electronics again to be able to work with the winch. But in the medium term, it's certainly an option one could consider. Although, to be honest, I'm more assuming that used battery markets will emerge from all these electric cars. You can already see that today. I mean, even today you can get a Tesla battery that's no longer good enough for a Tesla, but would still be enough for a winch tow three times over.
bought for a reasonable amount of money. That
means that a new energy market for winches could simply emerge. Or for winch batteries, yeah. If another pilot came to you now, had listened to this podcast, and was somehow still hooked on the idea and said, I want to build something like that too,
because in the end, you actually pulled it off. I mean, something came out of it and it might even hit the market soon. So it's possible. Yeah. He's asking you now, like, what do you think, should I maybe take this on too? Would you tell him, after everything you went through, to climb that mountain and really go over the high peak until you realize it works? Would you advise him to do it, or would you say, look, it's great, I learned a lot or whatever, but you'd better not.
Yeah, you asked me at the beginning, would you do it again? And I said straight out, no, I wouldn't.
And I think everyone has to decide for themselves whether they want to do it or if they think they can handle it. I wouldn't want to talk anyone out of it, but I can only strongly recommend that everyone really thinks the whole thing through completely to the very end. And I've already met people who thought I just had an electric motor and a controller here and that the whole thing turns, so there's not much left to do. And that's just the beginning of the beginning once you've achieved that. I can't in good conscience recommend it to anyone who isn't already relatively sure of what they're doing.
Are you proud that you made it? Yes.
Yes. I mean, I've had to overcome so many hurdles and stood at so many points where I was really at my wits' end, like, "That's it, I'm just going to give up, stomp on all this stuff and shove it into a corner." But I kept pulling myself back up, and in the end, it dragged on for over seven years, and yet, I have to say, I feel a certain pride that I
that I managed to do. Andreas, thank you for these explanations. It gives us a bit of insight into the development of an electric winch. Flying didn't come up much in this podcast, but it's an area that will really help us to perhaps get into the air even better and more in the future, especially in the lowlands. Thank you for this development, thank you for your stories, and yeah, I'm curious to see what the next project is and when the Nova winch is ready so that we can eventually have something that is actually available on the market. I
I just hope that through projects like these, we might manage to make winch flying in the lowlands a bit more attractive again, and also for pilots who might have had bad experiences with the winch—I know a few who say, "Hey, I'm not getting into that"—so that we can give them back the confidence that winch towing can be a wonderful thing. And if we manage to get a few more people off the ground here in the lowlands in that way, that would be a great thing too.
That was Andreas Hochschärf in conversation with Lucian Haas. Anyone who wants to learn a bit more about the Elo -Wien and electric winch towing should check the show notes for this podcast episode in the Lu-Glidz blog. I've put together several links regarding the topic of electric winches there.
By the way, I've launched from the Elo -Wien cable myself several times. At times, there were quite nasty, gusty conditions with shear winds. A classic internal combustion engine winch would quickly reach the limits of its control mechanics, which can result in a rocking ride for the pilot. In contrast, the control electronics of the Elo -Wien showed impressively what they can do. They essentially smooth out the turbulence, which results in noticeably better release altitudes. So all I can say is, lowland pilots, look forward to the future with an electrified ascent.
If you want to help Podz-Glidz and the associated Gleitschirm-Blog Lu-Glidz reach new heights, then why not become a supporter? How much you want to give as a contribution is entirely up to you. If you're unsure, I recommend one euro per podcast episode and two euros per reading month on Lu-Glidz as a non-binding guideline. Payments are easily possible via PayPal or bank transfer. You can find the relevant details on the Lu-Glidz website, specifically on the Support page. I'd like to say thank you in advance and see you soon. Ciao.