Sky Power GmbH introduced itself to the specialist public for the first time at this year’s AUVSI Xponential in Denver. Since then a series of new engines has been developed for a wide variety of Unmanned Aerial System applications (UAS). Now, with the newly developed 110 ccm engine, SP-110 FI TS, a completely new engine concept is presented, which focuses squarely on performance- and fuel optimization, ease of maintenance and space saving.
“Sky Power has dedicated itself to the development of high-performance engines based on 2-stroke and Wankel engine technology, that are used in demanding UAS applications. For this reason, we have optimized the existing SP-110 FI TS yet again, in order to make it even more efficient for the future tasks of our customers”, declared Karl Schudt, CEO of Sky Power GmbH. This not only includes the engine performance, but also the engine design.
The newly developed SP-110 FI TS has a system carrier, which is mounted above the two cylinders. Besides the two electronic systems of the HKZ215 ignition, the engine injection system is also mounted on this system carrier. Both the injection system as well as the system carrier are screwed firmly together with the engine. All data lines of the sensors, which gather engine data at a variety of measuring points and transmit these to the ECU030, are bundled on the system carrier. “The system carrier is fixed to the engine with screws. If faults occur, this can be completely dismantled together with the injection system. To do this, the screws and all plug connections are detached. A new system carrier with all modules and data cables can then be mounted and screwed together. As a result the engine is operational again after just a few minutes, since the ignition system is passive and is controlled by the ECU”, explained Schudt. Plug connectors from racing were chosen for the data cables. Plug connectors according to MIL specifications are also possible. “At the request of the customer, the system carrier can also be left out. In that case, all systems are positioned in the UAS body, whereby longer cables are required and the integration of the engine is more complex”, stated Schudt.
Engine, system carrier and all electronic modules thus form a compact unit, that can be installed in the UAS, thereby saving space. In addition, the engine performances and the smooth running were further optimized. The latter is important, especially for land survey or reconnaissance flights. The improved engine performances are dependent on the muffler and propellers and were determined on a dynamometer test rig. Particular attention was thereby given to a reduced fuel consumption, in order to make the operation of the UAS even more efficient. Due to the newly developed ECU030 and the new HKZ215 ignition, the development team already knew in advance, that fuel savings of 20% and more are possible. “This trend proved to be true. We were able to save a further 5%, dependent on the speed, as the dynamometer tests verified. Consequently, we will meet the current and future requirements of our customers, who are looking for efficient and fuel-saving drive solutions, in order to increase their range, the flying time or the payload”, stated Schudt happily.
The SP-110 FI TS is available as petrol engine. A Heavy Fuel (HF) variant will follow in the middle of 2019. “We are working on a new, lighter HF system, that besides the reduction in weight, also has a reduced fuel consumption of the HF engine as objective”, declared Schudt looking ahead.
Due to the growing number of inquiries concerning complete drive units for Unmanned Aerial Systems (UAS), the German manufacturer of 2-stroke and Wankel engines, Sky Power GmbH, has intensified its cooperation with Mejzlik Propeller from the Czech Republic. The objective is the development of propellers coordinated individually to the engine and the customer application.
“In past projects we were approached again and again by our customers for propeller recommendations. Since we develop complete drive units for our customers that are coordinated to the customer application, the requests on the part of the customers were understandable. Since we didn’t want to set up our own propeller development department, we looked around for a partner who had the same understanding of quality as us”, declared Karl Schudt, Managing Partner of Sky Power GmbH. Sky Power choses Mejzlik Propeller from the Czech Republic. “We had already worked well together in the past and were convinced of the quality of carbon fiber propellers”, elaborated Schudt.
In the world of unmanned aviation, Mejzlik Propeller is well known for its work. All propellers are manufactured from carbon fiber and can be adapted in a variety of features, forms and designs of the customer application and the outputs to be achieved. Besides the size and the pitch, the number of blades, the weight, the carbon fiber material as well as the surface can also be adapted. “The propeller must perfectly match the engine, as only this way can an efficient utilization of the entire drive unit be ensured”, explained Jan Hruška, Business Development Manager at Mejzlik Propeller.
Furthermore, at Mejzlik Propeller particular attention is paid to the quality. “Our customers sometimes move sums running into millions in the air, if one counts the UAS and the payload together. Apart from this, in future flying over groups of people will become routine. Flying must therefore be absolutely safe. For this reason, the quality of the propeller must be given special attention, in order to ensure safe flying”, stressed Hruška. That’s why various propeller tests are carried out before delivery. Besides a balance tests, an inner structure tests, an optional RPM tests and a visual quality inspection are performed.
Apart from that, for Sky Power there was a further incentive for the cooperation. Since every engine is coordinated to the customer specifications, so-called propeller curves are required. “Very few propeller manufacturers can provide these, as the tests are complex”, stated Schudt knowingly. The velocity, the flight altitude, the rotational speed as well as the environmental conditions influence the performance of a propeller and consequently also that of the entire propulsion unit. “Based on these details and the computation models, we can calculate and develop the right propeller for every application”. To design an appropriate propeller, we also consider the data that we already have from the propellers previously designed and measured. Based on these measurements and our experience, we can adapt the design to your requirements and give you a basic idea, how the respective propeller behaves”, confirmed Hruška. And Schudt added: “This experience is important for us, in order to provide our customers with a perfectly coordinated drive unit. Because this is what our customers expect”.
Both companies will in future work more closely together on customer projects.
“In individual projects, we will fall back on the experience of our Czech colleagues very early on, if our customers also want to adopt this approach”, stated Schudt. In this case the customer can expect a complete solution from a single source.
If you need more information or more propeller details, please contact the sales team.
3W-International’s performance partner, Sky Power GmbH, has introduced its engine and product concept at just the right time before the leading trade fair, Xponential 2018, in Denver. Karl Schudt, managing director of Sky Power GmbH, explains the company’s goals.
You introduced a whole series of new products in April. Can you explain Sky Power’s product and service concept?
Karl Schudt (KS): Sky Power sees itself as a service provider for 3W-International GmbH. We develop technical designs on contract in order to optimize existing 3W-International engines to customers’ wishes. In the process, we generate solutions such as the ECU030 or the high-performance HKZ 215 ignition, which can also be used for other engines from 3W-International. Furthermore, we’re the production service provider for 3W-International GmbH. We’re located in the greater Frankfurt area.
Besides the hardware, you’ve also developed an engine construction kit, which is also being introduced at the fair.
KS: That’s right. The engine kit contains all of the components needed for an engine in order to adapt it to the most varied applications. Thanks the construction-kit principle, we can quickly and graphically illustrate to the customer the components of which his future engine will consist. An adaptation of the engine to the application area can thus be quickly visualized. We’re convinced that an efficient, sustainable engine application can only come through application-specific engine designs. 3W-International’s basic engine always stands at the centre here. We illustrate the overall principle on the new SP-110 FI TS engine.
Can you identify the differences to 3W-Intentional’s basic engine?
KS: The Sky Power engines are all equipped with twin sparks as well as with the ECU030 or the high-performance HKZ 215 ignition. Moreover, the SP-110 FI TS possesses a newly developed injection. For these, we need a lot of data to adapt the engine to the environment. This happens via the ECU. Furthermore, we achieve better fuel combustion with the HKZ 2015. All in all, it’s possible to say that we’re achieving a massive reduction in fuel consumption through these measures.
Will further engines follow this development?
KS: Of course. We’re introducing the SP-55 TS and the SP-210 HF FI TS at the Xponential trade fair. The latter will be the first re-engineered Heavy Fuel engine that Sky Power offers. A development pipeline is already available for the post-fair period, and the first customer projects are also scheduled into the development. Furthermore, we’re also continuing to expanding the Wankel-engine portfolio together with 3W-International. So we’re showing a prototype of the 2-disc hybrid Wankel engine SP-480 SRE, which with 70 HP will become the most power engine in the 3W-International/Sky Power product range.
The 2-disc hybrid Wankel engine SP-480 SRE hybrid is being introduced for the first time to the professional public at Xponential 2018. 3W-International and Sky Power thus continue the tradition of presenting a new Wankel engine at the leading international trade fair. The SP-480 SRE involves a prototype.
Following the very positive resonance to the 3W-180 SRE, which 3W-International introduced in 2017, the company decided to further expand this engine portfolio. “The customer resonance surprised us at that time. We’ve launched a large number of projects since then with our customers. These projects often revolve purely around the generation of electricity. That’s why we’re now introducing the SP-480 SRE, which can also be used as a hybrid drive”, explains Karsten Schudt, managing director of 3W-International GmbH.
The engine was developed at performance partner Sky Power GmbH, which was also active in other forms in the background during the 3W-180 SRE hybrid’s development. The SP-180 SRE hybrid is a 480 ccm, 2-disc Wankel engine. At 6000 rpm, the engine achieves 70 hp with a basic weight of 14 kg. As with the single-disc engine, the housing and the trochoid are water cooled. An active oil circuit cools the piston. “Both cooling systems are very effective. They don’t need a pump, so they’re virtually maintenance free”, continues Schudt. The engine can be driven with both gasoline and with Heavy Fuel.
The engine is being introduced as a prototype at Xponential 2018 in Denver. “As in 2017, we want to test the market with the presentation of the new engine. We know about the performance level and also the customers for which it makes sense. Now it’s about supporting these assumptions through customer reactions. The customers have confidence in our 1-disc Wankel engine. The reactions show that. That’s why we’re assuming similar reactions for the SP-480 SRE hybrid”, according to Schudt.
3W-International and Sky Power are exhibiting together at booth 2210.
3W-International GmbH’s performance partner, Sky Power GmbH, will introduce the first advanced engine to the professional public at Xponential 2018 in Denver. It involves 110 ccm, 2-stroke power plant that has been provided with a new injection and ignition. The basic engine originates from the firm of 3W-International.
Sky Power’s R&D department further developed the engine SP-110 FI TS based upon the successful 3W-110i B2 TS FI engine. “Many of our customers inquired about a consumption-optimized version of the engine”, according to Karsten Schudt, managing partner of 3W-International GmbH. That’s why the Hessian engine builder granted the contract to further develop the engine to Sky Power with the goal of reducing consumption and thus increasing the range and take-off weight.
The SP-110 FI TS was equipped with the new ECU030 injection and the new HKZ215 ignition. “Thanks to the two new systems, the engine can be tuned exactly to environmental conditions as well as to the customer’s wishes”, explains Karl Schudt, managing director of Sky Power GmbH. The ECU030 injection system is usable for both gasoline mixtures and HF applications. The system has four ignition channels with two separately settable injection nozzles. Pump pressure is regulated electronically. A cold-start function of the engine is possible without further ado. The automatic controller adjusts the fuel mixture to the current cylinder temperature, air pressure, and exterior temperature. All of the engine’s data can be monitored via a PC and can be readout by a CAN-BUS-interface. The user interface is intuitively constructed so that all of the engine’s settings can be easily carried out.
The high-performance HKZ system was developed for significantly greater ignition powers. The engine’s overall fuel efficiency is thereby enhanced and the exhaust values improved. All of the add-on components, such as connector plugs and spark plug connectors, are designed and shielded for challenging application areas. “With the new ignition and injection system, we achieve better power performance in 3W engines”, explains Karl Schudt. Fuel reductions at constant power proved achievable during test runs with the 3W-110i B2 TS FI. Thus a fuel reduction by more than 20% was achieved at 5500 rpm. “The results aloft also surprised us, but they clearly show what is possible in the area of efficient fuel and engine management”, according to Karl Schudt. Sky Power is also offering to convert propulsion systems already in use on the market. For this purpose, the engine has to be sent in to the new service centre in Germany.
3W-International and Sky Power are exhibiting together at booth 2210.
3W-International GmbH’s performance partner is introducing a novel engine construction kit in order to enable still more efficient and performance-optimized engines in future. Using this construction kit, propulsion units can be ideally tuned to the customer’s desired performance parameters and application area.
“We’re seeing ever stronger demand for application-oriented solutions”, explains Karl Schudt, managing director of Sky Power GmbH. “That’s why we considered how we could best serve this demand, since each customer favours his own solution. In the past, UAS manufacturers were just interested in getting their flight systems into the air. That’s why propulsion units were often relegated to a subordinate role. This has changed permanently in recent years. Today, UASs have got to fly efficiently and be tuned exactly to their application area”, explains Schudt further. Out of this came the first engine construction kit for UAS systems from Sky Power and 3W-International with which customer- and application-specific propulsion solutions can be quickly visualized and implemented.
The engine construction kit consists of widely different components. At the centre is the basic engine, which can be equipped with both a carburettor and the new injection from Sky Power. To this is added as desired exhaust, silencer, and the new ECU and ignition. The engine can furthermore be provided with an e-drive or generator, which uses a converter to generate electrical energy for batteries and super capacitors — so-called supercaps.
Super capacitors can be charged and discharged very much faster. Besides, they withstand a lot more switching cycles than rechargeables, so they lend themselves as substitutes for the latter whenever severe switching stress is required. Super capacitors’ application area stretches from provision of the weakest currents for data retention in static memories (SRAM) up into the power-electronics range, thus for instance, as the store of electrical energy in the KERS system in Formula-1 racing cars. This is also exactly the property required in UAS propulsion units when they’re used as a hybrid system or to feed in energy to enhance the engine’s short-term performance.
All 3W-International engines can be equipped with this e-drive supercap system. The engine can therefore be used as a pure power generator for electrical motors, but also as a combined system in which electrical and combustion energy can be used in combination. Pure usage from combustion energy is likewise possible. The customer’s performance parameters and application area determine the engine’s usage type. “At the trade fair, we’ll show visitors which modular components are necessary for an electrical emergency system, for direct engine use, for a range extender, and for hybrid applications”, explains Schudt. The hybrid application is being accorded a lot of attention at Sky Power because the demand for such propulsion solutions continues to intensify. “Hybrid drive units are going to be the propulsion source for unmanned systems in future”, continues Schudt.
The engine construction kit necessitates the propulsion manufacturer’s early involvement in the customer’s project. Here not only the right components are sought out, but they’ve also got to be tuned to one another. Thus for instance, the silencer must be orientated towards the basic engine’s cylinder volume in order to prevent a performance-diminishing backing up of exhaust gases. The e-drive must be selected based upon the desired electrical power and the ECU must be calibrated to the propeller used, the desired flight performance, and the flight surroundings. The same applies to the use of carburettors or injection. In addition, the customer requirement decides about the use. For instance, cost-optimized carburettors make sense for target drones, whereas a carburettor must be discouraged in the case of performance-optimized engines.
“Many details must be clarified with the customer before initial engine assembly. So we’ve got to maintain tight information exchange with the customer. After all, he’s getting an individualized product that has to conform with defined parameters. That’s why we’ve invested in additional in-house test systems in order to demonstrate the engine performance that the customer wants”, Schudt continues.
The engine construction kit is being introduced in 3W-International GmbH’s booth 2210 at Xponential 2018.