LitterBug's RCExplorer BiCopter build thread

[LitterBug]

Results from testing the Oblique vs Standard were good. I still had slow pitch oscillations, but didn’t have to touch P/I on any of the Axis to get it there. I need to work on an oblique tilt with the Impossible tilt mount built in. Should be an easy add. That will make for an easy switch to oblique on EZbi#1 with the ducts too.

Cheers,
LitterBug

EDIT: Like this:

[jstremmler]

Did a preliminary test build to see how everything fits. Although my RX fits in perfectly I cant install it because the plug for the signal cable then does not allow to install the FC. Could take the case away from the RX and solder the signal wires directly, but I think, I will buy a smaller RX. Pls note that I did the maximum to soft mount my FC with the REALACC https://eu.banggood.com/Wholesale-Warehouse-4-PCS-Realacc-M376-Flight-Controller-Fixed-Screws-for-FPV-Racer-wp-Eu-1135527.html?rmmds=myorder and these ones https://www.aliexpress.com/item/HOT-SALE-20pcs-Anti-Vibration-Rubber-Balls-For-F4-F7-Flight-Controller-FPV-Quadcopter-M3-Shock/32853990689.html?spm=a2g0s.9042311.0.0.27424c4drIKaV0

Attachments:

1. 

   Bicopter-1.jpg
   

[Kevin_Erik]

Woot progress!

Let me know if you guys need anything modeled or remixed.

@jstremmler
There is something wrong with posting a link for “shock absorbing balls”… Just saying. 😛

[RCExplorer – David]

Can we start a new thread for the oblique control where we gather all the findings and designs? Would be great to have one place where we can explore this together.

Freaking awesome build @jihlein! Yours too @LitterBug.
I’m really interested in the oblique control. Makes the copter look really weird/cool 🙂

[jihlein]

“Can we start a new thread for the oblique control where we gather all the findings and designs?”

Certainly, will set this up tonight.

“Freaking awesome build”

It’s not so freaking awesome when you get it finished and during final setup the left servo decides to fry itself. Infant failure I guess, at least it didn’t happen in the air……

Bummer…..

[RCExplorer – David]

Ah man that sucks! Yeah better on the ground than in the air.
Was it the motor or the board that fried inside the servo?

[jihlein]

Pretty sure it’s the board. FC is still outputting the proper PWM signal (verified with logic analyzer). Servo will move in one direction okay, other way it move in fits and starts. Think the H bridge blew.

The bicopter is now in a dark drawer having a timeout until I get back from some business travel. That will teach it…..

[RCExplorer – David]

Yeah it sounds like the H-Bridge. I might have loose board laying around if you want to try and save the servo.

Hehe yeah show it who’s the boss

[RCExplorer – David]

Hows the progress going on this mr @LitterBug? Any more pictures?

[LitterBug]

@david, hoping to hit the field tonight. Been crazy busy lately with family, job, weather, dead wheel bearings, etc….

Cheers!
LitterBug

[RCExplorer – David]

I hear you. Have had a couple of those wheel bearing changes myself. Not as enjoyable as being out flying.

[LitterBug]

WOOT WOOT! Maybe not the best weather to be flying outdoors, but managed to fly for the first time in several months friday night. Packed the RCE Bicopter in and picked up where we left off with nasty oscillations hovering on default PIDs with dRonin. Took a cue from some emails a few months back that it is YAW oscillations, not pitch and dropped Yaw P/I to 15/15 and it hovered smooth as glass. My buddy did a slow motion vid of it hovering before I popped it in to autotune. I’m still running @jihlein’s dRonin branch for my firmware on the F3FC.

Ran out of time to do any more flying, but have another indoor fly coming up later this week.

Cheers!
LitterBug

[LitterBug]

Back to working on both my EZBicopter and RCExplorer Bicopters. Trying to use what I learn from both to make both fly better. Here’s some footage from the EZBi when I had @kevin_erik’s ducts on.


I’ve de-ducted it since then and it flew very well at another event but I did not have my gopro handy.

I’ve found that a combination of @Terje’s AKA @dkdarkness Impossible Tilt https://www.thingiverse.com/thing:1035497, and BabyTri Impossible Tilt https://www.thingiverse.com/thing:2869393 has worked best for the EZBi and am currently re-outfitting my RCExplorer Bicopter with the same hardware.

I’ve also found that the DALPROP T5044 props that @kevin_erik recommended for his ducts seem to fly better on the EZbi than the props I have been using even with the ducts removed. They are both light, and have a good profile which gives better clearance around the servo.

Working on updating the EZbi from an F3 based DTFc Flight controller to a Matek F405-STD and adding servo feedback before next week’s indoor fly. Should be interesting to see if there are any differences on either build.

I’ve got all of @jihlein’s latest firmware on the F3FC, DTFc, and F405STD too.

Cheers!
LitterBug

[Kevin_Erik]

Dam, that EZ copter flies like a F’n champ!

Just a heads up about the ITM (Imposible Tilt Mech), I had one break in half in my hands about a month ago while adding zipties. My prints are made from Kevlar reenforced Nylon so i was a bit surprised to see this. According to my print guy (Tobias) there’s something off about the print direction / pattern that made the ITM weak on one axis. This can be resolved by changing the print direction or making the thinner parts of the ITM slightly thicker. (area directly under the carbon arm where it meets the support)

As of late, I’ve been using “your” sOat design, which has proven to be both very strong and stiff. The stiffness of the mount is very important as I’ve discovered that too much flex can lead to oscillations. Maybe once the weather improves, I’ll swap back to the dihedral tilt mech and continue its developement

-K

[LitterBug]

BAM…. And then an explosion occurred:

Mid Re-FC-ification of the EZbi. Pulled The DTFc flight controller/PDB and replaced it with A Matek FCHUB-A5 PDB and F405-STD. Ribbon cable pinouts are different between the PDB/FC so had to manually solder Gnd, 5V, Curr, and VBat. Keeping my HV UBEC for the servos for faster response. Now if I could just find my nano Hex tools to get the @)#($ bolts out of the servos to add feedback…

I’m using the Impossitilts on everything. Baby Tris, Mini Tris, and Bicopters with no issues. I’m using PLA and have my settings tweaked to the point where these things are pretty much indestructible even when trying to break them. Different colors too! 😀 Using high heat for better layer adhesion, .1mm layer height, 100% infill, and fairly slow print rate. All these parts have been printed on a MonoPrice Select Mini V2. (the EZbi plates are only 20% infill)

Cheers!
LitterBug

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