BackyardRC
A practical approach to RC planes
Category Archives: BackyardRC
TwinStar II EDF Rebuild – Part 1
Posted by on August 17, 2013
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
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
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
First the section of damaged aileron was cut off and a matching section cut from a spare TwinStar wing.
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
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
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
Then we decided to paint the wings to match the fuselage with matching red and blue stripes.
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
3D Printed Quad Build
Posted by on August 13, 2013
BackyardRC’s 3D Printed Quad Kit
Most of last week’s evening were spent finalizing the Solidworks design for our new BackyardRC Quad Kit. On August 3rd’s post I shared the first revision of the new 3D printed motor mount. Quickly followed with the second version early last week and by Thursday the legs, center hub, and Ardupilot mount were fully designed and mocked up in Solidworks.
Fist printed quad leg
Thursday afternoon the printing started in ernest. Each motor mount took just under two hours. While each leg took about two hours and fourty five minutes on the Cube.
Mock up version one – where mount met leg
I could not be more happy with the results. The parts fit so well together. The beveled edges of the motor mount alighted perfectly with the raised edges of the leg. The mounting holes and hardware guides worked perfectly.
building booms
After about 16 hours of printing the four booms were finally assembled. Motors attached, ESCs fixed, and wires tied down.
center hub v1.0
Friday evening brought forth the marathon print of the center hub. With dowel mounts, bolt holds, power distribution board mounts, and a battery lead guide this print took just over six and a half hours.
nearly done…
top view
The finished product turned out to be a bit thicker and heavier than planned but nothing we can’t manage with. I have tentative plans to redesign the center hub someday… guess we’ll see but this one being so bullet proof I may never need another one.
test fitting the booms
I quickly mounted the power distro board and mocked up the booms. Everything aligns well and is rock solid.
oooo white, how fancy
While mocking up everything I started the custom top plate. Running low on black I switched over to white filament.
BackyardRC’s Aurdopilot TopPlate
I was not disappointed. The top plate looks awesome! With ardupilot raised mounting, BackyardRC logo, and in white this part looks show room ready!
The finished build
Saturday was the fist scheduled test flight. And in all the excitement to get the new quad off the ground I didn’t even setup the GoPro… what a mistake. After some initial bench testing without the props I raced to see her fly. And rushing is not a good thing. The first flight lasted about .00005 of a second. I powered up to about 25% throttle and the unbalanced prop hubs must have thrown the ardupilot into chaos because it instantly wanted to bank hard forward. Powering up two motors to 100% and whipping the quad hard into the ground inverted.
The first casualty
The result was a broken boom dowel and motor mount. Luckily nothing else. But being far from the shop this meant quick reprints and repairs were out of the question. She was grounded before she even had a change.
printing a replacement motor mount
Sunday back at the shop I had the opportunity to print a replacement part. And for me this is where the power of DIY and home 3D printing comes into full effect. Within 20 minutes of printing the quad was fully put back together. No long lead times for shipment of replacement parts. Or even worst your model is no longer manufactured and parts can’t be sourced. WIth Backyard DIY designs you always have the means to rebuild!
All patched up
With the quad back together I did the wise thing and put here back on the shelf. Before she flys I’ll have to come up with a vibration isolation system. My first thoughts are to use earplugs as shock absorbers. So it’s back to the workbench.
Shortly I’ll post ll the STL files for these prints up on Thingiverse. Stay Tuned!
On another note with the quad grounded I did get in some sweet flight time on the foam board F22 with plenty of air and ground footage curtsy of QSOPC. I’m deep in the editing room now and should have a the footage up by the end of the week!
-Miles
Mama said there would be days like this…
Posted by on August 10, 2013
And this is how Frankenplane got his name
If there is anything I have leaned while flying RC planes it is that you will crash. You will go nose down in a spiral of death and distraction. And you will want to curse this hobby, kick your plane , then set it all on fire. But as soon as I had learned this lesson I quickly learned my second. It’s always satisfying to rebuild it stronger, better, and faster.
When a day like this hits you. Remember it can always be fixed. No matter how hard of an impact. Fall back to your DIY roots and backyard engineering skills and you’ll be back up in the air in no time!
Rebuilt Frankenplane is on the left and he is still flight worthy to this day!
The night before first-flight and all through the shop…
Posted by on August 9, 2013
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
A wise man designs twice and prints once
Posted by on August 5, 2013
Quadcopter Motor Mount v1.2
Late this weekend I completed the cleanup of the quadcopter motor mount. The focus was to cleaning up the edges, raising the motor above the plane of the boom and overall lighten the mount. On all accounts version 1.2 is an outstanding success. And if I was truly the wise man I would have simply skipped the functional test print and go direct to v1.2.
My my that is a fine looking mount
Along with cleaning up the design I also rotated the position in which I printed the part. In this iteration the mount was printed standing upright as shown above. This change made for a near perfect print. Not spaghetti mess in the boom opening, nice neat bolt holes, and it even printing a bit quicker (a full 4 minutes). The very top arch was a bit sloppy and if I expand this design to fit larger sized motors I’ll have to make some adjustments. The slimmed down version of the mount is still super strong and rotating the print grain really increases the strength along the axis of stress.
print grain makes all the difference!
In the version 1.0 print the grain ran along the boom and even with the additional wall thickness it still cracked.
If you are interested here is the thingiverse listing for the part files they are located here: http://www.thingiverse.com/thing:128477
New version of the BackyardRC Quadcopter is under development!
And here is another little sneak peek into the fully redesigned BackyardRC Quad CAD work. Stay tuned because it is no longer just a CAD drawing! I’ve been printing like crazy. I’ve also started the building, joining the mount and legs! More on this to come soon!!!
Other quadcopter posts:
Follow the CD Flyer build process from the beginning:
- Part One: Quadcopter Crazy
- Part Two: Motors, Mounts, and Arms
- Part Three: One man’s junk is another man’s treasure
- Part Four: Quadcopter Build Goes 3D
3D Printing with Austin
Posted by on August 3, 2013
Quad Mounts!
Well the day at the shop is over and it was a super productive one. Austin and I printed both version 1.0 and 1.1 of the quadcopter motor mounts. We also finished re-building one of my Twinstar 2 planes with a set of freshly printed motor mounts (more to come on this in a later post). And finally we we snuck in a quick cad design lesson and 3D print of a hammer loop for Austin.
a hammer loop for any pants!
First up was version 1.0 was printed face down in black PLA. The cubify software was set to build it solid but in reality this means supported cavities on inner dimensions.
Quadmount version 1.0
After printing I found an interesting oversight. A 3D printer prints layer after layer building from the bottom up. When a ‘ceiling’ is reached the printer attempts to print in open space. I hadn’t tried this before with my new printer and didn’t know how wide of an unsupported ceiling could be created. But the 1/2 inch dowel opening proved to be too wide for unsupported printing.
Curly Q’s block the dowel hole
A cobweb of plastic nest like curly q’s blocked the opening not allowing the dowel to fit. After a ton of cutting with the hobby knife and sanding on a dowel, I aligned the motor and bolted it up.
A freshly printed mount mated to it’s motor
The 4-40 bolts I had we a bit too long for the job. Out came the dremel but beware: Motors are magnetic and mettle shavings will easily embed in the windings and bearings sucking the life out of your motor. So before you dremel, tape all the opening.
An ounce of prevention is worth a pound of repair
Version 1.0 DONE!
With the bolts all cleaned up and the dowel test fitted this mount passes. It’s functional but a bit blocky and unsightly…. time for revisions and the next version.
Quadcopter Motor Mount Sneak Peek
In the next post will we’ll walk through the improvements and enhancements of version 1.1.
Rainy Saturday
Posted by on August 3, 2013
This morning Austin and I are off to the shop to print the first two versions of the quadcopter motor mount.
I’ve been using HobbyPartz Exceed RC Rocket 2220 series for a ton of my builds. I’m a big fan of these little motors. For its small size they packs a ton of power and takes a beating. I’ve used their 1500 kv on my scratch build foam fighters numerous times. With a 6×4 prop and a four cell battery they rocket!
So with this motor line in mind I started designing motor mounts for the next iteration of my quadcopter. With the CD Case Flyer build still underway I have quietly been planning version 2.0. With custom 3D printed motor mounts, center hub, camera mount, and legs. I’m still up in the air if I’ll build a tricopter first or another quad. Time will tell.
But for today I’ve finished my first CAD designs of the Exceed RC 2200 Series fixed motor mounts. The mount is fairly straight forward with function in mind. Using the X shaped motor mount included in the Exceed box I’ve designed the 16mm bolt pattern with center hub around a 44mm cylinder.
8 mm Motor bolt pattern off center (approx: 0.63 inch)
The booms or arms of my copters are all based off 1/2 by 1/2 inch square dowels. They are cheap, easy to find, and hold up well. Therefore my mount design incorporates a direct fit for the dowels with a #6 pan head bolt pattern.
Square Dowel Mounting Point
In the no frills first version (v1.0) the dowel mount is 2 inches deep with a solid back wall, no rounded edges or raised motor cylinder.
Later today we’ll share the finished product. Stay tuned!!
Grounded but not out
Posted by on August 2, 2013
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!
Quadcopter Build Goes 3D
Posted by on July 23, 2013
3d Printed ESC Mounts
A few weeks ago I picked up a Cube 3D printer. A relatively cheap low end 3D printer stocked by Staples.com. After a few days of testing and setup I printed my first set of functional objects.
Solidworks File
Using Solidworks 2013 I designed a simple but effective mount with two connecting rectangles. One for the quad’s arm and one for the ESC. Then on the perpendicular plain a mounting hole was added.
3D printed ESC Mounts
The Solidworks file was saved as an .stl, loaded into the Cubify software, configured, and finally a file was print ready. Each part took about 32 minutes to print and they came out identical! The parts are super light, weighing in at about 15 grams each. If you are interested in the stl file I have uploaded it to Thingiverse.
Power tools are FUN!
Next up the mount was placed on the arm with the ECS firmly in place. A quick measurement from center, the mounting hole drilled, a bold threaded in for safe keeping and the mount was on!
Wiring up the power distribution board
I then drilled small holes for the ESC power and servo leads. The power leads were the perfect length, aligning with the distribution board without excess slack.
All four mounted up!
Now with all of the frame build, RotorBones attached, motors and electronics mounted all that is left is a little wiring and Ardupilot programming. Then test flights! With any luck this little guy will be up in the air next weekend!
Follow the full build process from the beginning:
- Part One: Quadcopter Crazy
- Part Two: Motors, Mounts, and Arms
- Part Three: One man’s junk is another man’s treasure
- Part Four: Quadcopter Build Goes 3D
Sunday Afternoon Flight
Posted by on July 16, 2013
This weekend Anne and I found ourselves at the Grand Canyon of PA in Tioga County Pennsylvania. We met up with Craig Musser at Grand Canyon Airport for a flight in his 1981 Cessna 172P.
Anne and I before takeoff
We met Craig at 11AM as the overnight showers gave way to bright blue sky and sunshine. Craig introduced himself as he walked us out to his beloved Cessna. He popped a few pictures for us and then we all jumped in.
Grand Canyon of PA
Quickly we were up in the air and over the Grand Canyon. The views were breathtaking as we traveled south along the eastern edge and then back north along the western edge of the canyon.
Pine Creek
Throughout the flight Craig chatted as he pointed out key landmarks. He was super helpful and willing to explain the controls of the plane. As a pilot instructor he answered all my questions with ease.
Out the back!
After we landed Craig spent another 45 minutes with us but I really think he would have spent all day with us if he could. Walking us through a nearby hanger, showing us some of the nearby planes, answering any questions, and encouraging us to learn to fly. His love of flight and the airport was plainly evident.
Grand Canyon Airport – Wellsboro, PA
Overall Craig was a great host, an excellent pilot, and an all around wealth of aviation knowledge. I would highly recommend him to anyone in the Tioga County area looking for an awesome way to view the the Grand Canyon of PA. Make your way over to the airport and look him up!
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