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I got the fan with the big 1400 inrunner all assembled,balanced and clocked. Runs nice and smooth. I ran it up on my old 12s 25c lipos. they are only holding 42v at 90a which is almost 3.8kw. I`m using a CC 120hv to control it.
The motor is very happy hanging out in that nice 300mph breeze. Can`t wait to run it up on my new Dinogy 65c cells. I`m be over 4kw I`m sure. When I get another YEP 120hv, I will run it up on 13s and maybe even 14s. I need to get my thrust stand working better and measure the thrust. My ET airspeed sensor quit working, but it`s useless on this fan anyway, because it pegs the meter at 300mph. |
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Here`s a picture........... I ran it last night at a full 4kw with a Haoye 7blade rotor. 12s (Full 44.4v) and 90a....motor/fan/esc (cc120) were all very happy. Yes 12s is a lot for a 70mm, but at 90a and with today`s lipos, I can see 12s 2500 cells for speed dedicated applications.
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Last edited by Knife Liddle; Dec 13, 2013 at 06:22 AM.
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35mm bolts, but I also reinforce the motor tube with hardwood and soak it with thin CA. It`s very strong. It adds a great deal of strength to the fan shroud and eliminates most of the shrouds ability to twist.
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Yes you`re right. It get a little warm at 4kw, but it`s only rated at 3kw. I think it will handle speed runs at 5kw without problems. Can`t wait to get it in the air.
I have this that will easily carry 12-14s 3700. It`s pretty draggy, but I wouldn`t be surprised to see 180+ with it at 4.5kw or so. |
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[QUOTE=Erik v. Schaik;
Roughly the new version should be about 26"wingspan, close to 1200W and 40-43mm thrusttube diameter and 2.5-3minutes full throttle flight time. I'm building a reversed trike at this moment but I'd like to start on the new speeder within 6 months or so.[/QUOTE] Hi Eric, in the past I experimented with chocking down thrust tubes to generate more efflux. I've had a few disastrous results. but I know it does work. So I must've been doing something wrong. and/or doing it in the wrong jets. In your opinion, is there a ratio for long or short a thrust tube should be based on the diameter of the exit tube? |
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Hi Johnny.
Rule of physics show thrust tube cone should be 4 degrees maximum. You can find some info on the Stumax sm110-52 manual. 4 degrees is pretty steep and if possible I'd recommend less if the construction permits. airflow is best when laminair in and out. reducing the exhaust diameter too much will stall the rotor blades but this is noticed in static conditions and may not occur at dynamic conditions. High blade count rotors do not cope with small thrusttube diameters too well. My theory is they do fight rotor wash sooner as low bladed rotors. The old shubie fans (3 bladed) were known for high efficiency at high speeds. The downside is they are pretty loud. I was able to scoot around with 44mm exit diameter. The new multiblades cannot get lower as 80%FSA. Because of this I wasn't able to proceed much more forward. Do note the 44mm outlet is similar to 80%fsa of 60mm fan with 28mm motor and there isn't really an advantage for me to cut down a multiblade to 60mm. Similar like props, the best efficiency is at the rotor tips. reducing fan diameter may not get good results as well. increasing motor diameter might make more sense but turbulence behind the motor can might cancell out any gain here as well. So now you may understand why it takes much effort to raise the bar for high speed and why i am having trouble finding a good combination of hardware br, Erik |
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I picked up a Castle Link last weekend and I`m learning how to use it. Just about have it figured out. Here`s a graph of a short bench run of the HET-1400 powered fan in the pictures above.
After I downloaded the graph I opened it in paint and drew lines from the basic readings over to the scales at the sides to make it easier to read. Note.... 1).on the amps, the CC is showing about 100A and my clamp meter is showing about 91 or 91A. Not sure which is correct, but all of my other data has been based on my clamp meter, so that`s just a heads up. If my clamp meter is correct, that would bring the watts down to 4kw instead of 4.5kw shown on the graph 2) RPMs shown on the graph seem a little high to me also, with some bright daylight I`ll see if I can get a reading with my optical tach to see how they compare. |
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Say Lee, The operating features readings on the bottom of the graph show the maximum, average and, when you mouse over a specific area it shows the reading where you hover in the display. Much easier than striking lines! And yes the CC info seems inflated to me also.
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From memory, the Jeti Spin controllers have 15% tolerance on current readings. I think the temperature of the controller may cause the measurements to drift.
still 4kW input power in a 70mm fan is amazing! br, Erik |
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Quote:
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I like to put the mouse around 10 seconds of WOT to get a settled number. Then do a Print Screen and paste it into Word in a landscape template. Now I have a file I can share or print out with data for maximums and settled.
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