Micro-H Quad

sparrow1717 shares his design in this RCG thread and provides these notes:

• 10mm SlowStick aluminum fuse for arms
• 5in props
• WMC FLIP FC
• 12 amp escs
• 2900 kv motors
• 2S 1000 mah batt
• 240 mm span
• 170mm motor to motor
• 7oz AUW

"I went with the H layout for ease of build and extra surface area for carrying cams or whatever. Try to build as light as you can. Weighing in at 7 ounces my quad flies quite spirited on 2S.  As far as the frame spacing . I decided something close to 250mm diag spacing as this seems to be a popular size for 5 in props. I finalized at 170 mm from motor to motor.

Two quad prop guards

From SDS Hobby.

From a 3D printed quadcopter. (img).

Quad EPS blade protection

The website is down now, but here's a quad with an eps blade guard.  The guard is sold separately as well.  It's four circular pieces with straight edged that attach together.

It would be great to be able to provision a homemade quad with something like this.

My Farm Fresh Quad Helmet

Here's how I attached a vegetable container from the supermarket to act as the cover for the Arcticopter 4.  I used these standoffs:

Nylon 6/6 Male-Female Standoff 4-40
1/2" Body Length,
3/16" Male and Female Thread Lengths,
White (Pack of 100)
http://www.amazon.com/gp/product/B00...ms_ohs_product

Even though the vegetable container is very thin, the standoffs keep the surface taut.  If you tap on the top it will reverberate like a drum head.

I attached the standoffs to the frame, and colored the tops with a Sharpie to align the holes. I handheld a drill bit to cut the holes in the plastic.

 4/40 bolts attach the stack of standoffs to the frame.  This stack is 1.5 inches, but I think you could double that and still be reasonably stable.

One nice feature of the nylon threads is that they will break before anything else.  If you break the threads off of a standoff, it becomes a perfect candidate for being the top screw.

I put a piece of blue tape on the back to block off the green LED, which I found to be too bright in the evening.  I added a 3-LED strip plugged into the balance port which works pretty well: visible without being blinding.

Article on PID tuning

Bookmarking this post for future reference; with a couple of videos.

Quad Dome from Electronic Goldmine

Looks like these might be nice for a quad hat; also available in red, if you like that HAL look.  Sales page says:

Green See-Thru Super Quality Acrylic Dome-The Electronic Goldmine:

"These domes make great additions to small robots. They are large enough to mount sensors, small circuit boards, LEDs, lamps, etc. underneath. Each dome is 2.83" in Dia. plus a .5" mounting lip. The highest part of the dome (at the center) is about 1" tall. These were made for large projection TVs and came in to us in sealed master cartons so they are in perfect condition. Green See-Thru.

Motor balancing in addition to prop balancing

Old Man Mike posts an interesting note regarding vibrations.  Not only is prop balancing critical, but blade orientation plays an important role as well.  He says:

This chart shows that even with balanced props, there is a sweet spot for mounting that will provide a minimum vibration level. Without testing, it is very unlikely that a low vibration will be achieved and most likely the number will be at least two times greater than the minimum. It could even be much worse. One of the five motor/prop combination had more than 6 times times the minimum vibration for some prop positions and more than 4 times as much even just 45 degrees away from the minimum position!

It typically takes about 10 mins per motor/prop to find the minimum so it adds a bit of time to my quad builds. Since I'm somewhat obsessed with getting low vibration performance with my quads, I think it is worth the effort.

Anti-vibration fasteners

FrozenCPU.com has a lot of grommets, etc, designed to reduce vibrations from hard drives.  Could these be useful for mounting quad controller boards?

A nice quad stand

Also, a pretty nice quad frame, the Dex.  It's the one that float on water.  From villagepilot on RCGroups.

Arcticopter II: test videos

Hooray, the Arcticopter II looks like it's going to be a fine flyer.  Powerful motors, it can probably shoot to a hundred feet in a couple of seconds.

More test results to come, but here's a couple of shots of the first test session.

 Here are the original flight tests.  We've substituted the wiffle ball landing gear... it's really nice if you can handle the weight.  As you can see from the videos, weight is not a problem for this model... it took all the control we had not to shoot it straight up into the trees and beyond.  One thing to investigate: using heli mode on the radio so as to set a throttle curve.  We fiddled with that a little bit, but then couldn't take the unit off of safety because we had displaced the zero setting off the power curve.

Here was our very first test.  Notice how the rightmost leg seems to stick to the ground?  That's the sure sign you've got a motor running backwards!  This also shows the original wire legs.

Before we did all of this of course we tested the electronics without blades.  It always sounds like an assembly line of dentists to my ears.

Arcticopter II: Build part 2

Picking up the build the next day.

We used an extra platter to keep the wiring together.   We used four extra standoffs (is that what these things are called?)  Here's some notes about how they're attached.

The tabs have been trimmed from two of the standoffs, so that they're acting as spacers but don't need to be attached to the platter.  this makes it easier to set up and remove.

Note that we cut off the tabs on two of the standoffs.  Originally we did this because they were two-tab standoffs lining up with three-tab holes, but it turned out to be a very nice setup.

We filed out the tab holes on the top platter so that it seats and unseats smoothly.  We'll use some thin bolts to hold things together.

We'll try putting another platter on top (or below?) to cover up the stabilization board.

The standoffs are placed in the holes that are offset from the arms, allowing unobstructed access for the wiring.

We got lucky... the motor wiring, the ESC wiring, and the Wago connectors were the perfect size so that everything fit without having to add any extra wir

The KKBoard is being moved between the Arcticopters 1, 2, and (soon) 3 until some more boards arrive, so it's attached to a carrier board.

The KKBoard is sitting on a double layer of 3M doublesided foam tape, and attached to the carrier with zip ties.







For now we've got everything taped together, but we'll figure out how to attach it so that it's stable, firm, and easy to move.











HINT: don't mess up and mount your board at 90 degrees to what it should be.  As soon as you apply the smallest amount of power it will attempt to correct itself by instantly flipping upside down!










We didn't have a lot of luck with the music wire legs... Since the weight should not be an issue with the motors we've got, we tried zip-tying wiffle balls under the motors.  The motor mounts make a natural cradle that holds it in place.  Use some pliers to pull the zip tie tight and it's very stable.  This worked pretty well.  I'll get some numbers on the wiffle ball weight.

I'll try the music wire legs on Arcticopter III which will be much smaller and as light as I can get it.

A KFC bowl is the perfect size for covering the platter.  Thanks Colonel, this flight's for you!












Flight videos in the next post!

Arcticopter II: Build part 1

Here's the basic RadicalRC kit assembly.  It's really nice. We're using the carbon fiber arms.  Everything fit together nicely, and we glued it up with medium CA.  Hot glue seems to be just fine to center the arms.

 

Wago connectors for power distribution, as noted here.  These have been great on the Arcticopter I.  These motors are a lot bigger, so it will be interesting to see the power draw through the connector.  The motors max out at 375 watts each, but this thing will be at airliner altitudes if you keep that much power for too long.







Here's the basic frame with motors attached.  It's very light and solid.  I had originally been a bit skeptical about the 10mm arms but am now a big fan.

The motor had an extended shaft.  Drilling through the carbon fiber arm was a no-go, so Andreas tried every saw in his shop to cut off the motor shaft.  None of them even scratched the shaft, which is why every RC toolbox should include an angle grinder with cutoff wheel.

Cover it up with tape to keep crud out of the windings and bearings, and clamp onto the motor shaft.

Dont' forget safety goggles!  Next time I'm going to try it with a (much smaller) Dremel cutoff wheel.  If that doesn't work then I'll just borrow Andreas' big cutting wheel.

There's a little sliver left on the shaft.  You can trim it off if you're so minded, but it's not necessary.

A lovely fit!  This is a shot of the lower arm, where the shaft came close to fitting... it was a bit easier to get a good picture.











Here's how the motors are mounted.  The bolts have "blue" removable threadlock.

Say hello to our little 4S friend.  One goal of Arcticopter II is to measure the payload size that can be reasonably handled.  The final Arcticopter will need to carry Josh's full-sized Canon DSLR... we probably should find out the target weight.

As you'll see in the flight videos, there's no problem blasting into the air.  Andreas has told me it's pretty good with 3S as well.





For some unknown reason, the Hobby King shipment did not include the expected fasteners.  Fortunately the local Ace has a nice selection of metric fasteners.  Judging by the price, they're made from an allow of platinum, iridium and gold.








The build went really smoothly, and the Radical RC kit was nice to work with. Andreas had glued up the  pieces and attached the motors... Everything on this page we did in an evening.

Continued in next post...

Radical RC Quad Kit, part 1

Here's some notes on the new Radical RC Quad Kit kit being produced by Radical RC.  Here's the RCGroups Thread where Radical Dave made the announcement.

This is the first post of several; subsequent posts will show assembly, outfitting, and testing  and will be collected here.

Here's what arrived in the mail.  The basic kit contains everything necessary for the frame except for the arms.  There are a couple of size choices for the arms, and you can order them in aluminum or carbon fiber.  All arms are 10mm and compatible (the web site notes) with their Slow Stick hopups.  At the bottom of the picture are some of the extra accessory pieces that are available.

Feedback welcome, leave a comment!

Here's the basic kit as it's packaged.

The round center platform is on the lower right.  Other Pieces have been laser-cut on the left.  Hardware and battery strap are sitting on top of the instruction sheet.

Here's the 5 inch center platform, upside down with the boom mounts.  Note that one pair of mounts are higher than the other, and that there's a small mount in the middle that will keep the center platform from buckling or warping when the screw fasteners are tightened.

Here is the first aluminum boom in place.  One boom goes on top of the other, and the one closest to the board is sitting on the middle mount.  I'll be using the 600mm (24 inch) booms for real -- the short booms in this picture were easier to photograph.

The second boom goes on top of the first.  Tolerances are good... there's no slack between the booms.

If you want to mount the battery underneath, just attach the battery mount to the boom mount.

If you don't intend to hang the battery mount below, you can use the short mount.

There are a couple of auxilary boom mounts included.  Here's a 200mm CF tube attached to the main body.  Next to it are the other boom mounts included in the kit.

Here are the motor mounts, test fitted onto the short aluminum boom.  Note that there's two heights to match the two rods.

 

In part 2, we'll glue everything up and prep for the control and power systems.

Ardupilot Mega with Ardupirate-NG, software test

Hooray, we got the Ardupilot-NG load downloaded, built, installed, and configured.  Next step: hook it up to the Arcticopter.  Hint OTD:  the Arduplane and Arducopter loads need different inputs on the control inputs.  Channel 8 on both switch the APM into strict pass-through mode, definitely not what you want for multicopters!