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Old Nov 24, 2009, 02:06 PM
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Originally Posted by Dave Barrow View Post
I thought this was Bob's build log, not a design thread. Bob's Tricopter has been successfully used for AP also. He is now sharing it with all those of us wishing to build and fly one like his.
Bob, sorry for the intrusion, I will shut up about this and get back to my copy of your build.
Dave

If you had minded your own business in the first place, need of this would have been necessary. Enjoy your build and I am enjoying making my modifications to Bob's build.
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Old Nov 24, 2009, 02:44 PM
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Originally Posted by techspy View Post
Thanks. No, I am not that great of a pilot. It is just very stable. The thin/rounded body design helps fight the wind influence. You can see the flags/trees in that video showing a pretty strong wind.

I am using the 750kv motors from HC, 4 telebee HH gyros (in rate mode for the booms, HH for yaw) from HC, HC SS Series 25-30A ESC's and 11x4.7 props.

Using 120 swashplate mixing in the TX
All props rotating the same way. I have the front 2 motors tilted slightly to counteract the torque, which also keeps the craft level in hover as opposed to a slight tilt.

A couple lessons I learned while trying to get it right. Some esc's aren't fast enough to keep up with the gyro inputs. The 2 biggest issues I found however were that a motor with too high of a KV does not have the resolution to make the small rpm changes that are needed. Also, you need very light props with less pitch to be able to make quick/small changes in thrust.
Hey Tech

Do you have your telebees set in std or digital? My new small copter 12.5" radius is set to digital, but when I tried it on the DT750 motors I would get random shutdowns. Running in digital allows you to set the gyros even more sensitive. I'll try again on the large copter, see if I can get a good crash out of it!

Bob D
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Old Nov 24, 2009, 02:44 PM
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Quote:
Originally Posted by Dave Barrow View Post
I thought this was Bob's build log, not a design thread. Bob's Tricopter has been successfully used for AP also. He is now sharing it with all those of us wishing to build and fly one like his.
Bob, sorry for the intrusion, I will shut up about this and get back to my copy of your build.
Dave
Quote:
Originally Posted by reverendrichie View Post
If you had minded your own business in the first place, need of this would have been necessary. Enjoy your build and I am enjoying making my modifications to Bob's build.

Wow, down guys! Why don't we ask Bob to chime in here. No matter what our opinions are, it's his build thread.

- Jeff
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Old Nov 24, 2009, 02:46 PM
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Originally Posted by signguy View Post
Hey Tech

Do you have your telebees set in std or digital? My new small copter 12.5" radius is set to digital, but when I tried it on the DT750 motors I would get random shutdowns. Running in digital allows you to set the gyros even more sensitive. I'll try again on the large copter, see if I can get a good crash out of it!

Bob D
I had weird behavior when set to digital. They would "skip" at times. I could actually see the booms dip at random times like it was due to a quick loss of power. I have them all on standard. Can't remember about my yaw gyro though.
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Old Nov 24, 2009, 03:17 PM
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Originally Posted by techspy View Post
I had weird behavior when set to digital. They would "skip" at times. I could actually see the booms dip at random times like it was due to a quick loss of power. I have them all on standard. Can't remember about my yaw gyro though.
I just tried the telebees in digital on the DT750 copter. Its back to the same "skips" like Techspy says. I think it must be the SS30 amp speed controls. The small copter with the ss10 amp controls like digital. My last try at the digital setting ended up with the tri doing complete rolls only feet off the ground.I'll switch back .

Bob D
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Old Nov 24, 2009, 03:38 PM
Where'd The Wise Men Go?!?
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United States, NE, Bellevue
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Okay - I've gotta ask for a link All this talk about analog/digital settings, ESC compatability, Flipping on takeoff???? Gots me worried! LoL

I know what a gyro is, and what it is meant to do - working on USAF Avionics for 20+yrs I guess I should know.. But all this talk confuses the heck outa me. Anyone got a good thread going about gyros and what they're doing??? I wouldn't mind reading up on some of this before I get my stuff in the mail and ruin something..
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Old Nov 24, 2009, 03:45 PM
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Originally Posted by zirt57 View Post
Wow, down guys! Why don't we ask Bob to chime in here. No matter what our opinions are, it's his build thread.

- Jeff
Wow! I'm not going to take sides on this one. I am one of those guys that will almost always modify something in a design, then have to revert back to original to make it work.
I don't mind anyone changing anything, just don't ask me about it, because I probably have not tried what you are going to do.
I posted this in the AP forum as a build. The design was worked out on the multi rotor forum long ago ( Thanks Sebastian )
The point was to show what WORKS, every time, as long as you setup yours the same way I setup mine.
That being said, I don't mind seeing mods to the design, just post pics and vids because we all want to see
Bob D
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Old Nov 24, 2009, 04:17 PM
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Originally Posted by reverendrichie View Post
If you had minded your own business in the first place, need of this would have been necessary. Enjoy your build and I am enjoying making my modifications to Bob's build.
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Old Nov 24, 2009, 04:25 PM
Begin with end in mind...
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Eagle Lake, Minnesota
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Originally Posted by nocontrol1 View Post
I decided to start on what I thought would be the most difficult part first. This is what I came up with for the yaw motor mount using the golf shafts. Its a Raptor 60 blade grip cut down. Ball bearing supported- smooth as silk! The best part is it already has a ball link for the pivot arm. Next thing is to mount a servo...

Rob D.
Great job Rob, I like it!!

Now... since I know nothing about Heli parts. Can you tell me where I might find the part/parts you modified to make that mount.

Man, I have been busy lately, lots of new posts here. I will have to get rolling on this thing



Mike
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Old Nov 24, 2009, 04:43 PM
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Originally Posted by Dave Barrow View Post
I will start my own Thread from this point forward but I would like to share my first modifications. I made this from junk around the house. The booms are old curtain rods. It weights in a little on the heavy side at 380 grams however, I still have room to drill lightening holds without weakening the structure.
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Old Nov 24, 2009, 04:43 PM
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Wow this tread is really growing - Techspy nice video and great flying - I must just be a little slow when it comes to flying mine - Yours and Bobs are so smooth and mine makes me sea sick to watch - great going - Gonna try leaning the two outer motors and see what happens - Easy enough to make a boom with a slight angle to it - Any idea how much you have angled it- Bob - What do you have the gain and atv pots set to on your telebees?

Mike
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Old Nov 24, 2009, 05:31 PM
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Quote:
Originally Posted by reverendrichie View Post
I will start my own Thread from this point forward but I would like to share my first modifications. I made this from junk around the house. The booms are old curtain rods. It weights in a little on the heavy side at 380 grams however, I still have room to drill lightening holds without weakening the structure.
You may not be happy with the curtain rods..... I expect they will kink, bend, twist and in general not last very long.
On the other hand if you get it working it would be a really cool sight to see it flying with some nice curtains trailing in the breeze. Lace curtains would be a weight saving option.
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Old Nov 24, 2009, 05:38 PM
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Originally Posted by techspy View Post
No prob. I can't remember which way, just experiment. With all props spinning the same way, the yaw motor can counteract it with a bit of tilt. The problem is that with a constant tilt in hover, it causes the whole craft to tilt a bit. Tilting the front motors just a tad counteracts this.
Helis tilt in a hover as well, most people don't notice it. I had it pointed out to me years ago when learning to fly Heli's. Left and right rotation tilt oposite.
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Old Nov 24, 2009, 05:49 PM
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It is a very slight tilt. I am using carbon fiber tubes so I was able to just twist them slightly without loosening anything.

Yeah helis tilt as well. Mainly from not being perfectly balanced and from the tail rotor not being exactly in line with the main rotor. With the tri-copter I only noticed tilt after using props that weren't counter-rotating and thus having to use yaw to counteract the torque.

As for the atv setting, I power up with the atv as high as possible. Be sure to have your throttle on 0, or more technically at -100, all the way down. This will prevent the esc's from initiating. I then turn the atv down slowly until the esc's initiate. This way you have as much resolution in the esc throttle curve while still allowing them to initiate.
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Old Nov 24, 2009, 05:54 PM
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Here is my contribution to the "mod" part of this thread. I'm thinking about making the tabs like the below picture's, lower right tab. This way I can easily attach an elastic to go around the arms.
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