Test with Polini Thor engine

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Polini Thor 250. This engine is what I need! I finally tried it out today. The propeller that I ordered a month ago came and this morning I tied the ekranoplan to the boxes at the entrance to the hangar where I work and started the engine. On the model, I already tested the method of binding the ekranoplan, so I knew how and in what places to bind it so that it could stand symmetrically in the air stream. In short, everything worked out for me. The boat flew up and stayed in the air while I held full throttle. I think that on the water I will give full throttle and immediately jump out of the water, and as the speed increases, I will slow down the throttle and get the right flight. I would very much like the rear wing to work correctly and the flight would turn out to be horizontally even, and not with a raised nose. The model flew smoothly and so far everything worked out just like on the model, so there is no reason to worry about the fact that the full-size device will carry itself any differently. It remains to wait for the weather and go to the water. Video from the tests below.

Airboat. The second test on the water

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So, briefly about the last test of the ekranoplan. The alteration turned out to be correct and the engine began to blow at the correct angle under the wing, which resulted in sufficient lift. In reality, if there were a dozen more horsepower in stock, or better, twenty, then the boat, like the model, would take off like a bullet and fly forward ten centimetres from the water. It’s amazing how a large boat, modeled after a small model, behaves the same way. We need more motor. There was a desire to put back the little motor I had left to add power, but I don’t know yet. The motor is very unreliable, and coming to the test is a whole test. You need to adjust the weather, you need to come to an agreement with a Friend who has a house on the shore of the lake within the city of Riga so easy to drive up to the water. You need to beg for a minibus at work and so that on a working day, because on weekends the lake is full of fishermen and in our business it is a hindrance and you need to have the time and energy to carry and assemble the boat from parts. And when things go wrong, it’s incredibly demoralizing. This summer I made only 4 trips to the water and was so exhausted with all the hassle that I decided to take a break before the time. As for the ekranoplan, a lot became clear to me, I know what work needs to be done. Silence about boats. We need a new propeller for the motor to accelerate the boat faster. I also think to put an ordinary 6 horsepower outboard motor on one of the boats and try to overclock it. And in the off-season, in addition to the modifications of the ekranoplan, I decided to build a new boat. Just taking a ride on the airboat with a motor in front, I experienced the unforgettable sensation of feeling like a fighter pilot and decided to make a more elegant boat based on this model. I have an old book from 1961 called boating. and there is a drawing of a sharp-nosed light planing boat and taking it as a basis as a base so as not to invent anything I will build an aero boat with a motor in front with a beautiful closed cockpit like on seaplanes of the Schneider trophy era. I use the engine that is on the ekranoplan and for the ekranoplan I hope to get hold of something more powerful. Photos and video of ekranoplan tests below and preliminary drawings of the next boat are also in the bargain.

 

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New engine for the ekranoplan

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Everything is ready for the third test of the ekranoplan. True, autumn has come and the weather has deteriorated a lot, but still there is hope to go out on the water in September. In the meantime, I’ll tell you about what I managed to do. After the second test on the water, I realized that there was not enough power and for full satisfaction this season I need to drive the car again, but with more power. I figured out where I can get the engine. There were few options. The first is to sell what I have, to save up a little and buy the engine I need. And I need a Polini Thor 250 with a capacity of 36 horsepower and a thrust of one hundred kilograms. The weight of the engine is small, only 18 kg, but it is already liquid-cooled. In general, I will not be able to sell anything quickly, especially in a crisis that unexpectedly hit us with this virus, so I remembered who had such an engine and friends of paragliders. And I remembered that my old friend Alexander bought such an engine 3 years ago to build a trike. I turned to him with a request to provide me with the engine for testing. He calmly said – take it, test it but don’t drown it! If anything, you will have to reimburse the cost of the motor, which is 2500 euros. I understand that I am taking a risk, but still I took the motor because I want to find out how the ekranoplan will behave when the power increases to the calculated one. In general, with this engine, I am already approaching the border at which the boat may begin to “levitate”. He brought the engine to the workshop and, having remade the engine mount, installed it. Everything became as it should. He handed the jammer button and the engine crank rope into the cockpit. The only thing I don’t have yet is the propeller. I need a pulling one and I have already ordered it from the Skyruner company from Pskov. They sent it to me a couple of weeks ago, but it hasn’t arrived yet. The Russian Post prepared the goods for shipment and took them to the border, and this is already 10 days ago. No more news yet. I hope it will come before the cold weather. At least test it on concrete in the hangar, I want to fix the boat and drive the motor. I also redid the front tail – I increased its area and screwed rubber along the sides so that you could crawl ashore and test on the asphalt without fear of erasing the bottom to the plywood. Here is the news. Photo as usual below.

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First tests of ekranoplan

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The first tests of ekranoplan made. For the first time, fine, I think. The steering is working. The boat is not leaking. The motor has little power for this boat. The rear wing has a large lifting force and therefore presses the nose and does not allow the boat to accelerate. Perhaps if there was more power it would be pulled. I don’t know, I need to try different options. While I calmed down. I don’t have a powerful motor, which means that you can do airboats. I will rearrange the engine to a new aero boat and arrange races. now I have two airliners and two motors for my small boats will be just right, and the winged aircraft needs to be improved and a new engine. And in general, to come with him to the lake is a very big problem. Three bulky parts need to be assembled and taken by bus and then collected and adjusted for two hours. Very hard. For such tests, you need a base near the water and some free funds, then things will go faster. Yes, and I forgot to say, I was flooded with water from spray from head to toe. And the propeller hit the water. I don’t know when the next time I will take this green monster to the test, but so far I’m satisfied.

Special thanks to my friends Karlis, Tom and Roland for their help at an important moment.

The boat is assembled

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I put together all the details of the boat. Without a pilot, the boat weighs 125 kg, with me – 200 kg. Connected and started an engine. Engine jams, can not give full throttle. Engine fills. I tried to adjust the carburetor, but there are no changes, we need to look further. But the fact that the motor made it clear was enough to understand that the rear wing rises, and the front does not move. On the model there was also a rear wing always the first to come off, but there the power-to-weight ratio was huge, but here it is not enough. According to the plan, it should be so. When the boat accelerates and the front wing starts to take off from the stream of air tending under it, the rear wing will have to push it down, balance it. But still too sluggish the engine blows under the front wing. I digested the engine mount. I lowered the motor 10 cm lower. Now the tip of the propeller is 30 cm from the ground and from the water it will be about 20-25 cm. Started up again, again tormented with an engine that stalled all the time, but still managed to understand that the lifting force under the front wing not enough to pick it up on the spot. The fact is that my wing is made of PVC fabric and it is soft, which was made for weight. And it turns out like a pocket. So I’m thinking, either redo the wing and make it flat below so that the wing plane is closer to the surface of the water and thereby increase the pressure under it, or not get hot and wait for spring to do sea trials. Then I understand firstly how the boat behaves on the water, how the wings work, maybe everything will be fine at speed. And then, based on water tests, you can continue to improve the boat, or leave everything as it is. I do not know what to do. So much effort has been invested and now wait until spring to understand whether I was right or not. Okay, if someone reads this blog, someone who has experience in such matters and some comments would love to hear any constructive criticism. As usual below the photo and video report.

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