More Flippin Practice with the Twitchity Acro Quad

Not much to say here, just having some more fun until parts arrive for my projects!

Practicing my flips with the Twitchity Acro Quad

I had some time to fly this weekend, so I decided to practice my flips with the Carbon Fiber Twitchity Acro Quad. It is super durable, and it was designed by the guy (Twitchity) who also happens to cut all of my frame plates.

Idle hands do the Devil's work.......so I designed a new tricopter!

Waiting on parts and hitting setbacks with the Gimbal Quad, I decided to design something new instead of just twiddling my thumbs.

I present the Manta Ray Mini Tricopter:

My first serious multirotor was a Fortis Airframes Titan tricopter, and I still fly it especially when I want to film something because I installed a 2-axis gimbal on it. It's hard to describe, but tricopters just have a different flight feel and envelope than quads, the yaw/tail movement is just so fluid like. It makes these frames very fun to fly even though they add a layer of mechanical complexity compared to a quadcopter.

This design/build is inspired by others on the web. Starting with inspiration from Twitchity's take on the mini-tri, I began looking at other designs, and even found a frame that was fully printed. For my interpretation, I also took inspiration from the web-series Rotor DR-1, which is based around a post apocalyptic future where drones were used to deliver medicine to help treat a viral outbreak.

I decided to give this tricopter a sleek body shell which is comprised of three main 3D printed parts: the main frame plate, upper shell, and lower shell. The arms are direct carryover from my quad designs, and since I have spares of these parts, that will make things easier. The frame is designed around the KISS ESC's and a Naze32 size flight controller. For FPV gear, the frame is also designed to carry a Fat Shark Pilot HD V2 camera. This is the newer low latency version. I have a micro 200mW VTX which was purchased from Range Video. On the bottom side of the frame plate there is a provision for mounting a Multirotor Superstore power distribution/regulator board. With the exception of the motors and servo, all electronics will mount inside the shell. 

As of this post, all the printed parts have been submitted and ordered through Shapeways. They will probably be here around Christmas time. In the meantime I need to order some motors, an extra Naze32, and a FHSS Futaba receiver to complete this build over the holidays.

If it flies well and works out, I am considering redesigning the arms to be 3D printed as well. I anticipate in the next 6-8 months that I will probably purchase my own 3D printer, so being able to print out a full mini tricopter frame on demand will be great.

Gimbal Quad Videos!

Here are a couple videos I had made of progress on the Gimbal Quad. Things are currently on hold as I mentioned in a previous post. Once the new ESC's get here, hopefully I will have more videos to share.






PS- I am aware I spelled "compete" instead on "complete" in the opening title. I am too lazy to upload the corrected version but I did fix it in iMovie.

Gimbal Quad Woes?

I've been pretty quiet in regards to development of the Gimbal Quad lately, and that is because there are some issues to iron out. Due to the shorter daylight hours since last month, I haven't had a whole lot of time to fly during the week. Consequently it took me a while to realize a major issue with the setup of the Gimbal Quad. Thankfully it appears to be a hardware issue and not a fundamental design issue with the frame.

It all started with the maiden flights of the quad. Since I am running the Tau Labs Sparky, I was hoping to use the autotune feature to dial in the PID settings. I set everything up in the GUI so that I could enable autotune from my transmitter, took the quad outside, got it into a hover, and flipped the mode toggle switch to autotune. It began to oscillate like it was supposed to in autotune mode, but shortly after one motor/arm took a dip, almost in an insta-flip fashion, and the quad landed on the pavement.

That was very disappointing, but after picking up the frame and inspecting the damage, it was just a couple cosmetic scratches to one of the arms and a broken prop. Unfortunately I was out of props so I had to place an order and wait until I could fly it again. I also figured that since autotune was technically in beta, that maybe it was a bug which caused the crash, since everything seemed to still work ok, and it hovered fine in self level mode.

Once I got the props replaced, I went to maiden flight the quad again assuming this time I was going to end up manually tuning the PIDs myself. It was during this flight that I believe I found the real issue. It seems that one of the ESC's, and I am not sure if it is the same or just a random one, is de-syncing from the motor under higher throttle! This time I was hovering around in auto level, and I decided to give it a little punch of throttle to see how it responded. Just like the first flight in autotune mode, one of the motors/arms dipped and the quad nearly flipped and crashed to the ground. This definitely leads me to believe there is a sync issues with the ESC/motor combo.

I had read about people having issues with this on the forums, and it seems to just depend on the motor/ESC combo. It seems the mini motors of higher kv values are more prone to having issues with different ESCs and firmwares. I currently have a set of Multirotor Superstore branded SimonK 20A ESCs installed. I have ordered another set of KISS 18A ESC's like the ones I am running on my other Mini GoPro Quad to replace these. I am hoping this will solve the issue and also hopefully I can actually try out the autotune mode on the Sparky flight controller.

In the meantime I just have to sit and wait on the parts, but that hasn't stopped me from working on a new project.........more on that in another post though.