BackyardRC

A practical approach to RC planes

Tag Archives: BackyardRC

I am a backyard engineer

odds & ends

odds & ends

Engineering allows me to take something conceptual, transform to visuals, print to tangibles, and finally build into useful objects. I often find myself mid build, mentally piecing together things and realize the standard options just don’t meet my level of individualism and dare I say it: flare. I look and look for bits and pieces to fit the build but I’m left designing the ideal solution in my head. And that is where my engineering process begins. With a little necessity, a bunch of function, and a bit of personal touch I find myself creating one off custom DIY parts.

Quad mount v 2.0

Quad mount v 2.0

The tools of my trade have been gathered and refined over many builds, years, and failures. They include everything from the pen/paper and hand tools to the complex like CAD programs, 3D printers, and laser cutters. I am a jack of many trades but a master of none. Constantly increasing the tool set at hand. I have little formal training but a deep love for hands on learning and the confidence to try until I break it. Then I have the patience to fix it.

Laser cut wing set

Laser cut wing set

In short I love to create something useful and cool from nothing. For this I am a backyard engineer at heart.

If you have a desire to design, create, and build, I encourage you too to become a backyard engineer. Soak in as many skills as you can. Acquire, borrow, or build and engineers tool set. And have fun learning as you build.

Advertisements

Anti-vibration to the rescue

Solid mounted ardupilot

Solid mounted ardupilot

Saturday I took some time to modify the top plate for the 3D printed BackyardRC Quadcopter. In the original design the ardupilot was mounted solidly. With this setup the motor vibrations almost made the ardupilot useless.

Super high tech anti-vibration apparatus

Super high tech anti-vibration apparatus

So it was time to modify the build with anti-vibration in mind. So I looked for the most high tech solution I could think of. Ear plugs.

All mounted up!

All mounted up!

I had to drill out the stock holes to fit the compressed plugs. The finial product looks pretty good but will need some testing. More to come on that soon.

Checkout the rest of the build here:

3D Printed Quad Build

And all of the parts are free to download on thingiverse:

A wise man designs twice and prints once

3D Printed Quad Build

-Miles

TwinStar II EDF Rebuild – Part 1

Today Austin and I started the rebuild of my old EDF TwinStar II. Back in 2011 Todd’s Frankenplane and the TwinStar EDF had a mid air collision on it’s first full day of flight. The only damage was from a direct prop slice on the left aileron. You can see the collision here (1:20 into the video).

aileron carnage

aileron carnage

Even with the direct hit I had no problem bringing her in for a safe landing. SInce then I’ve had it a handful more times with a horrific looking field repair including ripped cardboard and tape.

pre-repair damage

pre-repair damage

Here you can see the prop slices in what remains of the aileron. A good inch and a half is missing and another 5 inches torn. The hinge is completely pulled away for about 7 inches.

measure twice cut once

measure twice cut once

First the section of damaged aileron was cut off and a matching section cut from a spare TwinStar wing.

repairs are looking good!

repairs are looking good!

From here we hot glued the new section in. A super thin line of glue along the hinge edge and a glob on the end. After paint the hinge will be reenforced with packing tape.

old coast guard TwinStar II

old coast guard TwinStar II

In the spirit of salvaging and rebuilding we dug out the old Coast Guard TwinStar that crashed after the elevator servo stripped while inverted. This old plane had a ton of flight hours on it. Amazingly the landing gear held up even thou it was just held on by sandwiching the foam belly between the gear and a section of balsa.

rear gear removal

rear gear removal

messy front gear removed

messy front gear removed

So we pulled out the poor man’s landing gear leaving plenty of cleanup. (In a future build I return to the landing gear mod for the TwinStar II with fully laser cut balsa subframe. But more to come on that on another day)

painter's tape is a painter's best friend

painter’s tape is a painter’s best friend

Then we decided to paint the wings to match the fuselage with matching red and blue stripes.

painting complete!

right side painting

We finished up the day with matching stripes on the right wing. Next up is to reinstall the electronics, patch up the holes in the belly, and head out for some test flights! As soon as we have this bird back in the air we’ll be sure to post about it.

-Miles

The night before first-flight and all through the shop…

Late night at the lab

Late night at the workshop

Tonight was spent printing the last of the parts for the new quad. I still have a few hours of assembly and testing before a scheduled test flight at old Delps Airfield tomorrow. So for now it’s just a quick post and back to work. I can’t wait to write up the full build and share the first flights!

-Miles

Grounded but not out

Quadcopter Motor Mount Sneak Peek

Quadcopter Motor Mount Sneak Peek

Well today I broke a lead off one of the motors on the new quadcopter build. I’m not too happy to say the least. Often I’d just pull apart the motor and try to solder the lead back on. But with a quad if a motor goes so does the flight capabilities. At least with a plane you can dead stick it back down. So while I wait for a new motor to arrive this build is grounded.

But the silver limning is I’ve been secretly designing my own set of 3D printed quadcopter parts. With the recent CD flyer grounding I’ll be shifting gears and posting about my new parts. Stay tuned and I hope you like the sneak peek!

One man’s junk is another man’s treasure. – Quadcopter build continued

Finished Quardcopter Airframe

Finished Quardcopter Airframe

Late last week (before the F22 CAD craziness) I continued the build of the new quad. It went fairly straight forward and smoothly. I used an old CD case as a base of the build. Scavenging old hardware and spare parts I added no cost the build. The airframe build time came in just under 2 hours.

CD Case to house all the electronics and Ardupilot

Discarded CD case to house all the electronics and Ardupilot

First round of bolts and everything is rock solid.

A motor mount made a great lower brace

A motor mount made a great lower brace

A big part of the DIY ethnology is reusing old stuff in new and innovative ways. It much like the old saying: One man’s junk is another man’s treasure. 

The power distribution board on the lower level

The power distribution board on the lower level

With the board centrally mounted there is still a ton of room to run the motor, ESC, and battery leads. But this if going to require a bit of cutting through the deck of the CD case.

Ardupilot and RX on the upper level

Ardupilot and RX on the upper level

I am really happy with the outcome. The CD case turned out to be a great clean compact base to build upon. I still need to come up with an anti-vibration solution for the Ardupilot. Please post any ideas in the comments below.

Everything fits under the CD case lid

Everything fits under the CD case lid

Looking good!

Looking good!

Next up is all the wiring of motors and ESCs. With any luck the first flight will be only a week or two away 🙂 The real question will be will it lift my GoPro?!?

Follow the full build process from the beginning:

Rebuild F22 CAD files underway

Last night I continued some of the work on the fully customized F22 CAD files. All the easy parts are completed. Now to build out the sides and motor mount. Who knows I might even get creative and build in the servos and linkage.

A hard lesson in CG

A few weeks ago a 747 cargo plane crashed just after takeoff at Bagram Airfield in Afghanistan. The cause has been determined to be shifting cargo.

Shortly after takeoff the cargo broke free, shifting to the rear of the plane. The sudden shift in weight drastically changed the flight characteristics.

But there is a lesson we can directly apply to RC flight. Knowing and checking your Center of Gravity (or CG) can drastically change the behavior of your model.

A tail heavy plane will want to pitch up, causing lost lift and stalls. Depending on the stall characteristics of your plane there might not be a way to catch it.

In the video you can see this very thing happen. The weight shifts to the rear, the plane slows, pitches up, looses lift, and then stalls completely. Wing tipping hard to the right, the pilot tries to level her out but all forward momentum is lost.

A great rule of thumb when in doubt fly with a slightly nose heavy plane. This will cause the nose to want to drop and speed the plane up. The increased speed will cause increased lift counteracting the nose down motion. An easy method of balancing RC airplanes is to place the tips of your index or middle fingers under each wing, exactly on the line of the CG. A correctly balancing rc airplane, sitting on your fingertips, will either be level or have the nose pointing slightly downwards.

Remember to always check the plane in its flight ready configuration. Loaded with all batteries, RX, camera, and cargo

Remember to always check the plane in its flight ready configuration. Loaded with all batteries, RX, camera, and cargo

Remember to always check your CG before flight. After each flight process the planes behavior and adjust the CG for the next flight. An iterative adjustment process will lead the to best flight experience.

Good luck and wheels up!

Shark Attack!!

SHARK FINS!

SHARK FINS!

Today brought more rain and more time indoors.  It also brought and opportunity to add some artistic touches to my original F22 Foamie.

My girlfiend’s son received a Crayola marker airbrush kit for his birthday this year. So while we had it out we took the time to stencil my nearby plane. We started with a test run on a scrap of paper. Then onto the plane. The results look fierce!

theFLEET

The past few days have been rain filled here in the City. So what better to do but watch old flight footage.

Checkout a this short video I put together this week.

Leave a comment. Let me know what you think.