Jet Gyro - Page 4 - RC Groups
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Feb 17, 2017, 04:45 PM
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orvie6's Avatar
Jimmy
Sent you an email with the info. Let me know when you get it.
Wayne
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Feb 17, 2017, 09:50 PM
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orvie6's Avatar

Balancing upside down


Anyone have any info on balancing a gyro upside down? I saw in one of the forums where they found the CG by balancing the aircraft inverted. Most agreed that the best CG was just forward of the mast or right at the mast. If that is the case, I need to add a little weight up front. Mine balances just behind the mast. Maybe that is why I am having trouble getting it to lift off. Any info will be greatly appreciated.
Wayne
Feb 17, 2017, 09:52 PM
PSALM 14:1
Sammy70's Avatar
What's it look like when you lift it by the mast? (Head/blades off and lipo in of course)
Feb 18, 2017, 12:43 AM
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Quote:
Originally Posted by orvie6
Jimmy
Sent you an email with the info. Let me know when you get it.
Wayne
I got the emails. A lot going on here right now. Not sure when I will get to start on it. Keep up the good work. I think you are getting close.
Feb 18, 2017, 05:11 PM
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orvie6's Avatar

I think it will fly!


Was able to get air under my wheels today! A good breeze, so was able to get enough rotor speed and I was able to rise a foot off the ground. I am testing on the street at my house, so not enough room to actually fly. I was able to do two takeoffs. As it lifted off it wanted to put its nose up. Not sure if this is normal. It may just be able to climb out and fly ok. Hope to find out this week. It did not show signs of unwanted roll. Lifted off level, except for the up condition. When I reduced power, it settled down and landed fine. No video, but hope to have some later in the week. Even if it is here on the street. Hope to show air under the wheels at least.
Wayne
Feb 18, 2017, 05:31 PM
PSALM 14:1
Sammy70's Avatar
Congrats
Feb 18, 2017, 11:30 PM
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Feb 19, 2017, 05:36 PM
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orvie6's Avatar

Temporary hold on testing


I have halted any further testing for a day or two. The reason is lack of proper hang angle. I have been using a small plastic protractor to determine my degrees. Not very accurate. It is ok for making my drawings and build measurments, but for " free hanging", not so good. So, I downloaded a protractor app for my tablet. I can tape the tablet to the horizontal datum of the gyro and get an accurate degree reading. That is when I found out that the hang angle was only 6 degrees! Needed to add about 8 ounces to the nose to get the 15 degrees. Since this is my "guiniepig" model, I will more than likely build another gyro along these lines to take to my fly in in June. So, made a note to make the nose longer on the next one to avoid adding dead weight! The model now weighs 7.75 pounds. With 21 square feet of disc area, I still have a disc loading of 6 ounces per square foot. Hopefully can try some more test tomorrow. With video. Here are the angles I now have...
Mast tilt back from horizontal datum.....8 degrees
Hang angle....16 degrees
Mast angle when gyros on the ground....21 degrees
Do those sound right?

Wayne
Feb 21, 2017, 12:40 PM
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video on youtube


I was able to get some very poor video yesterday. Unfortunately, I can seem to upload it here or get a url to YouTube. Just go on YouTube and search for "jetgyro". Make sure you get the one as one word. There are videos listed as " jet gyro" also. There are two videos. The one is labled as " eff gyro". If someone is able to get the video on here, go for it. Comments on what I am doing wrong are welcome. In the short video you will see that I lost the wheel collar holding the rotor on. But what caused the right turn?
Wayne
Feb 21, 2017, 12:44 PM
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Jockadopolus's Avatar
Wayne just copy the address and past in message
Joe


Jetgyro (0 min 4 sec)
Last edited by Jockadopolus; Feb 21, 2017 at 01:40 PM.
Feb 21, 2017, 03:22 PM
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orvie6's Avatar
Joe
Any idea what would cause the right turn on liftoff?
Feb 21, 2017, 04:08 PM
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Jockadopolus's Avatar
Quote:
Originally Posted by orvie6
Joe
Any idea what would cause the right turn on liftoff?
The only thing I can think is the front part of the body acted like a rudder
I had a similar problem with my Lightning model

https://www.rcgroups.com/forums/show...Bulgaria/page2
Post #26
Feb 21, 2017, 05:22 PM
It's all in the Blades!
SafeLandings's Avatar
Could it be lack of vertical fin area? Great effort so far😃

Rich
Feb 21, 2017, 05:49 PM
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orvie6's Avatar
Ok guys. I was thinking the same thing. In the process of doing a redesign. Mostly making the nose a little longer (adding 4 inches), and changing the tail group to a more conventional style. Center rudder with tip rudders on stab. May add an inch or two to mast height. Will be a couple of weeks before I can start the new build, but will continue to hack this one up and try some of the new things. At least it is showing promise. And since it technically was "flying", does this mean that I have the only "jet" gyro in the world? Probably not, but sounds good anyway. I do know that my edf unit will have enough power to fly this. I can point the nose up vertically and with full power it will try to lift out of my hands.
I am going to make sure my combined vertical tail area is larger then the body area.
Wayne
Feb 22, 2017, 08:42 AM
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106flyer's Avatar
Great Job Wayne, looks great but the flight aspect seems a challenge:

My thoughts - based on my Profile AC20 models which were horrible to start and now fly great..

1. Hang angle at 16 could be too low - maybe 18 to 20 deg ?? My AC20 was poor so added 8oz nose weight .. hang ok but carrying far too much weight. To solve i changed the mast and moved head point 50mm back . then hang was ok but with all additional weight removed.
2. Side area could be an issue . My Ac20 was horrible to start and we discovered the side area INFRONT of the mast seemed to be steering the model . Increasing rear tail area did not help. Solution, cut the top off the model and turn into an open top version - perfect. now my two models and Graham L model fly great.

Have a look at the Ac20 thread on here - "skunkworks" It might no be relevant to yours but just a thought.

Good luck and most important .. KEPP GOING

Steve