700 T-Rex 700E build

coolgabsi

coolgabsi

Super Mod & DEAL KING!
I had a conversation with the owner and designer of kde. He told me that a tight straps will hold the battery on the battery rail very well. I have a whole email chain I can send you. I was iffy too. Lol

But he said he threw 3D on that and the batteries hold up :D

Fly safe!! :) have fun!
 
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pvolcko

Well-Known Member
I cinch them down pretty good. Since the batteries are relatively close and spread out on either side of the to the main shaft and not too far from elevator or ail roll axis I would expect that g-forces attempting to eject them fore or aft wouldn't be too bad on them. If I ever got to the point that it is an issue I'd either drill and tap a thumb screw through the rail and into the holder to pin it in place, or, more likely, upgrade to a goblin or whatever is the hot 3D machine at the time. :) Could also load up the front battery with something gummy for the straps to grip. Or put a couple of pieces of velcro on the back of the strap and on the battery to hold it better during shearing forces.

- - - Updated - - -

Lot of options. I had a pretty wild method of strapping them in on the front and back side going. Back side was going to require putting a foam block or something in there to fill the space between the battery back and the back velcro strap. Would have been a pain to use as a securing method. Glad I did some digging for the "proper" strapping method.
 
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coolgabsi

coolgabsi

Super Mod & DEAL KING!
Yeah that pin method is taken from compass 6hv. You can do that mod. That's awesome!

Fly safe!! :) have fun!
 
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pvolcko

Well-Known Member
Well, for some reason YouTube is taking forever to process the first vid.

Second one is up though:

[video=youtube_share;1-u7oW9U0zU]http://youtu.be/1-u7oW9U0zU[/video]
 
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pvolcko

Well-Known Member
Gaba, what kind of gain were you running on this when you had it? I started at 57.5% (0-100 range on the hh mode). I got some flutter from the tail on mild pitch changes. Thinking I was on the edge of gain induced oscillation I tried bumping down to as low as 40, but it seemed to get worse. Not wider, exactly, but louder it started to happen more prominently even when holding it still or doing piros. I tried 65% on the last attempt before my battery ran down and that seemed to improve things. Just wondering what you found you needed when you had the brain on it.
 
coolgabsi

coolgabsi

Super Mod & DEAL KING!
My radio was set to match 45 percent on ikon for tail gain.

Make sure in your setup, you don't have "tail gain in software " checked

I think I was at that value or a bit lower .

Keep going up till it starts to wag like a puppy .. FAST! Then back off ...

Check that tail gain thing in software for sure. My warp assumed it was, and the tail was not holding right... Just because transmitter wasn't talking to the right channel on ikon for it

Fly safe!! :) have fun!
 
coolgabsi

coolgabsi

Super Mod & DEAL KING!
Also .. Just watched the video (second flight)


What headspeed you running? Your motor stalled there for a second.. That's pretty low.. I would run 1900 atleast and then tune the tail. That'll make a big difference

Fly safe!! :) have fun!
 
Tony

Tony

Staff member
I have to agree with the head speed, needs to go up. And seems like your GOV is just a little too high causing the shudder that you hear. But I will leave that determination to others that have run them on electrics.
 
coolgabsi

coolgabsi

Super Mod & DEAL KING!
Also realize that I was running edge 115 on my tail. That's quite bigger than the stock align . So mechanically I had more gain to start with

Fly safe!! :) have fun!
 
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xokia

Active Member
Good job I am envious looks like you can fly in your back yard.

I cant tell but did you heat shrink your batteries together? It makes it so much easier if you buy large heat shrink and make those 2 batteries into 1. The heatshrink itself is pretty cheap $5 for 4 pieces. Then you will also need a balance cable extension.
 
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pvolcko

Well-Known Member
No on the heat shrink batteries together. I've been looking for a source for shrink wrap large enough. Just found it. I have the extensions and all that and have them secured to the trays well so that's all good for now.

I'll try backing the gov gain down a bit. That's a good thought, Tony. Wouldn't have considered it until exhausting the tail gain. I can see the tail suddering which is what led me to that train of thought.

And will up the normal headspeed to 1900. I was tuning the tail gyro while in idle up (2000).
 
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xokia

Active Member
pvolcko said:
No on the heat shrink batteries together. I've been looking for a source for shrink wrap large enough. Just found it. I have the extensions and all that and have them secured to the trays well so that's all good for now.
Click to expand...
They make heatshrink specifically for doing this its sold at the hobby shops. If you cant find it it's readily available at the hobby shop near me. I could pick it up and ship it to you if you cant find it locally. Just pay for it and shipping.

$5 gives you 4 pieces large enough to heat shrink 4 sets of batteries. It makes loading and unloading the batteries so much easier.
 
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pvolcko

Well-Known Member
For auto-rotation bail out on the CC ESC... Let me check...

DX7s
Throttle travel: -131% to 129% to get -100 and +100 in the ikon setup on throttle
Throttle hold: flat 9% (0-100 range)
Throttle cut: -30% (which puts it even lower than the -131% on the travel extent)

If I remember right I found that the threshold between auto-rotation bailout and reset/full-off was around 3-5% throttle. And the threshold before the ESC kicked into running mode was around 15-17% (again 0-100 range).

BTW, Tony, you were right on with the gov gain suggestion. Moved it back to low setting in the ESC and flutter is gone. Video coming tonight.
 
Tony

Tony

Staff member
Sweet deal on the gain. I knew it wasn't the tail, definitely the motor making that shudder. Can't wait for the video. Love these big birds.
 
coolgabsi

coolgabsi

Super Mod & DEAL KING!
Ohh you are using castle bail out... Sorry I thought you were on ikon bailout.

Fly safe!! :) have fun!
 
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