DIY Super Class "Sinister 770" Quad

Derek

Well-Known Member
Here is a pic of my Sinister 770 quad. No, it won't be the fastest quad at the field but I'm just hoping to have a functional "eye catcher." Featured in the picture is my 3 year old daughter, Makayla. She is a very helpful Crew Chief. She has helped by sanding parts and tightening screws, as well as losing a few, lol. Makayla asked to be in the picture.....as if I could tell her no, lol.

I did try a hover test, the other day. I plugged in the first battery and one of the esc's went up in flames. All my wiring looks to be soldered in the proper places, so "who knows" what caused the fire. No damage to the frame, only a bit of a burn mark.

New esc's have been ordered an should be here Monday. If anyone is interested in the specs, I can share them.

Sinister 770.jpeg
 

D.O.G.

Goblin 380 Supporter
Good luck on your next attempt Derek. I'm routing for you to get that beast airborne. I bet you and your pit crew staff can't either :)
 

Derek

Well-Known Member
Thanks man! I'm learning something new about "this size" quad, every day. The setup and protocols are so different from our beloved mini's, lol. I'll post more info as I go.

What does Linda think about the 770 beast?
 

D.O.G.

Goblin 380 Supporter
She loves it and wants to know when it will be available for rides Lol. She also would like to know how did you come up with the name "Sinister" ?
 

Derek

Well-Known Member
lol...i'm not sure that version 1 will be rideable....perhaps version 4 or 5, lol.

As for the name....I actually didn't name it until it was all built. I put the 15" props on it and the first thing that came to my mind was that this quad just looked sinister.....and it stuck.
 

Tony

Staff member
Bro, she is getting so big! Hows the wife?

The quad is looking great as well. Keep the pictures, and better yet, the video, coming!
 

Derek

Well-Known Member
Dude! Makayla is very big, and what's worse....she knows it, lol. She's 3 1/2 now and she's Daddy's lil helper, no doubt! Jordan is doing quite well, too, and beautiful as always....and she still has yet to tell me "NO" or "STOP" when it comes to my rc stuff.....hence the reason I now have the Sinister 770 Super Class quad, lol. Nothing on this build was "cheap" but the wifey lets me play, lol. She may shake her head, in disbelief, at times...but she never stops me. From time to time, I even get an "at a boy" from her, lol.

As for the quad...I did have an esc catch fire the other day when I tried to hover it. Thankfully, I was able to get the battery unplugged before any REAL damage was done, but the esc was "toast", lol. I did order 3 new esc's. One esc to replace the burnt one, and the other two are spares....just in case, lol. I have a KISS FC on the 770 right now but I'm not happy with the KISS FC because it doesn't like Windows 10, which is what's on my laptop. The FC won't communicate at all with my laptop. I can configure the FC with my Windows 7 PC but the purpose of getting a new laptop was to be able to program quads and heli's "at the field".....not in my living room. So, I'm going to take the KISS FC off and put on one of my "old reliable" Flip32 FC's. That way I can make adjustments "at the field."

My new esc's will be here Monday, so I'll be working on the 770 again on Wednesday (my next day off). When the esc's get here, I'll get one of them installed and get the Flip32 installed and programmed. Hopefully we can get a hover test (without fire) on Thursday.
 

Tony

Staff member
Try running the program for the ESC's in compatibility mode on your laptop. W10 is really good at fooling the programs that it is actually running on an earlier version. Worth a shot anyway.
 

Derek

Well-Known Member
I have a friend that is much more knowledgeable about PID tuning that I am. I've never had to tune a quad, lol. My Sinister 770, on the other hand....well.....lol.

My friend met up with me at my usual field today to test hover and tune the 770. We plugged in both 6S packs and stepped WAY BACK, lol. Lets face it...this machine is more than any of us had seen before and now it's got voltage running through it, lol. Armed the board and raised the throttle slowly....it does manage to get off the ground a bit with TERRIBLE oscillations and before I can set it down, the quad flips over and slams into the ground. Nothing broken, so we try again. After about 30 minutes of hovering and tuning...the 770 now is able to be flown around but still has some oscillation. We are going to meet up again this weekend for more tuning. But....the Sinister 770 Super Class quad did fly and it did go home in one piece. I'm stoked!

Dad was on hand with a video camera. I'll share some the videos as soon as I get them.

Sinister 770b.jpg
 

D.O.G.

Goblin 380 Supporter
Good going Derek. You put alot of hard work and time on this quad. It's just a matter of time, minor adjustments and you will have another quad to your collection :).
 

EyeStation

Well-Known Member
Good going Derek. Looking at the two photos you have uploaded, I wonder if the amount of arm surface that is under each prop is causing some of your problems. To me it seems like there is quite a bit of lift air being blasted down on each arm. In the smaller versions we fly, the surface width of the arm is nearly the width of the blade above it. And the motor mount area does not extend out much further than the can of the motor.
It looks like your arms are deflecting quite a bit of lift and may actually be causing the oscillations due to trying to correct that downward force on each arm.
Anybody have any thoughts on my perspective?
 

Derek

Well-Known Member
Thanks man! I have to agree with you. Im just a "builder" not an engineer lol. I do have plans to eliminate some of the arm material to allow the downward air to actually go down and not get deflected by the arms.
 

Derek

Well-Known Member
I found a guy on Facebook that does custom graphics and decals. I spoke with him about my 770 quad and told him what I'd like to see. After about 15 minutes of talking with him, he already had one cut out. He got the second decal cut and shipped them to me for $4 each and $5 for shipping....totaling $13.....I sent him $30 because I was so impressed with his work. Check this out!!!

Sinister Decal.jpg Sinister Decal2.jpg
 
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