Ken-
Really neat project, especially since you made it on a short schedule. I started to make one, then lost interest due to the programming aspect, but the board you are using would work perfectly for mine.
Is there any chance of this making a guest appearance at UPENE?
@Cluso99: was too disgruntled to take photos of the wreck. What broke were the motor mounts - the body seems to absorb lots of abuse and the booms were not affected in three crashes. By the way, two of these crashes were from my kids - I let them fly without a buddy box. Started out really well but changed for the worse before we left. The younger one was really upset about his crash unfortunately.
@Adam: I think so! Today I decided to make enough 5/8" OD AL6061 booms for at least four quadcopters and I'll drop them off at the anodizer in the morning. One of them would go to UPENE if I get everything accomplished in time. All the other parts are made on a laser cutter so they'll be done tomorrow.
I have a small CNC milling machine in my home office. Since I wasn't at the Parallax home base today I played for at least half the afternoon and made some parts. Been working too much and this kind of therapy helps keep me in balance. Here's a video taken from my iPhone. Pardon the quality - it's difficult for me to work, talk, and run a video camera at the same time.
'Glad to see you taking time to enjoy yourself! Building stuff, even when it's just to repair something that broke, is the greatest tonic in the world for the realities of work. 'Beats booze, video games, and passive entertainment by a long shot!
Hobby drone flyers are fine as long as they stay under 400 feet. It's only the commercial or civil use of drones that is prohibited by the FAA right now...
From an air safety standpoint -- or whatever the FAA's concern is -- hobby vs. commercial seems to be, in legal jargon, a "distinction without a difference." Well, at least hobby fliers are exempt from official scrutiny. I hope it stays that way.
I just noticed the existence of this builders area, and this thread in particular. I can see I'm going to have to get off my duff and get mine flying again.
Congratulations on a great build, Ken - That thing looks very stable, which makes good advertising for the HoverFly guys. As soon as SIGGraph is over and our game is out the door, I'm going to have to cut myself a new frame with my machine. Yours looks very pretty - I really like the way you have the motors recessed.
Good grief! Is nothing beyond the government's reach?
-Phil
As a Cessna pilot, I definitely see the need for some type of control here. If any moron can buy a quadcopter and fly it anythere, bad things WILL happen. The Goodyear blimp airfield is just a few miles from my house, near a golf course. 20 years ago, some idiot flying a good-sized RC airplane on the golf course intentionally crashed his plane into the blimp, which caused a hole in the envelope and a controlled mild crash.
I guess I can see your point. After all, the FAA even regulates kite flying. Still, though, I don't see how commercial use of QCs presents a greater hazard to air traffic than hobby use.
Hi Al - I'd be happy to share the details of my little quad. It's "almost" ready for a test flight. It's completely together and everything is checked out and calibrated. All I have left to do is make another three prop adapters. I expected to do that today, but things got busy so I'll try again tomorrow.
I don't want to hijack Kens thread here so I'll start a new thread later this week and post more pictures and part details. It's pretty simple to build and VERY inexpensive. That was actually my goal and I'm pleased so far. I'll attach another picture here so you can see it completed. You can see I have it taped to the table so it wouldn't lift off with my one prop when I was doing the transmitter setup. :-) I'm pretty excited.
New thread to follow soon and link to it will be posted here. Thanks for your interest.
...Tiger
P.S. Let me answer two quick questions everyone seems to ask:
How big is it? It's 4-1/4" between motors (exactly 6" diagonal).
What's the controller: HobbyKing (Product ID: QUAD-CON) $29
Al, Tiger, you can post anything on this thread you desire - that's what I indicated in the first post. So, make yourself at home.
I can't wait to report on my latest quadcopter progress. I just came back from a couple of days "off" of Parallax, but I didn't go anywhere without a huge box of quadcopter parts I had made ahead of time. I spent the evenings building the third revision of my airframe and trying out some new Turnigy motors. The new airframe works fantastic [or should I say the Hoverfly board works fantastic!]! Better yet, the crew back at the office was sorting out an arrangement with Hoverfly that will tremendously benefit the quadcopter/Propeller enthusiasts - more on that this week.
Brief report on the Turnigy 2217 motor is that it's fantastic but without real scientific comparisons I'd say that it's nearly 95% as "good" as the expensive A20 Hacker motors from Germany. This is already obvious to the many quadcopter enthusiasts on the rcgroups.com forums, but I had to see it for myself. From a strict value perspective the Chinese might be delivering 300% more motor in my view. You've got to really want to "pay for it" for the extra 5% performance, if such performance gap really exists.
More on this later - I need to get settled before I share more on this thread.
Ken,
it would be great if you could publish the drawings of the QuandCopter (something like the MadeUSA Kit). You can help people to start their constructions and make their own proposals. Personally I would like to make a Sketchup 3d Model of the QuandCopter and suggest a XY-Base for the camera!
Of course I'll post the drawings. I have a bit of cleanup to do to make them presentable, so give me two weeks maximum (not because it will take me more than an hour, but because I'm booked solid right now).
And you can do whatever you want with the drawings: make your own, make a hundred and sell them, I don't care.
Today I finally had a few good crashes. The crashes were a result of faulty Turnigy ESCs and motor shafts that didn't grab the propeller's shaft and collet - nothing to do with my flying skill or the Hoverfly setup. I also managed to identify a couple of design improvements after breaking the motor mounts in the same place three times. The quadcopter even went upside down once before it buried into the ground.
Over the weekend I built a new airframe based on my prior version but with several improvements: a landing gear on the booms; a bit more "open" chassis for handling the wiring; and with a slightly improved motor mount. It flew very well at sea level on the California coast with lots of wind, but poorly at 7,000 feet above sea level (more on this below where I show the two motors I've been running).
Of course, I couldn't pass up the opportunity to make a tricopter frame from most of the same parts. Tomorrow we should have a few Hoverfly Sport boards at Parallax so I'll mount one up in the evening for a test flight with the office crew. How I wish I could get away with building these at my desk during the day. . .
I've been using two motors - the Chinese-made Turnigy 2217 ($14/HobbyKing) and the Hacker A20 ($49/Hacker). This is a relevant decision since you can multiple cost per part by four in a quadcopter. Lots of tests have been conducted across the internet on these motors, most notably http://www.rcgroups.com/forums/showthread.php?t=1006721. I wouldn't bother to repeat what's already been done, but there's one aspect that doesn't appear to have been tested: the effects of elevation on the performance of these motors. I really can't quantify what I've observed, so my findings are mostly based on direct observations.
First, a quick look at the two motors. Here's the Turnigy 2217:
Here's the Hacker A20:
The Hacker A20 works wonderfully everywhere, at my home at elevation 7,000 feet and at Parallax, elevation 50 feet. However, at higher elevation it clearly takes more RPM to get the quadcopter flying well. The Turnigy motors at the higher RPMs seem to get off balance a bit - any off-center mounting between the motor case and shaft amplifies, causing some physical oscillation at full throttle. Again, no problem at sea level with the Turnigy 2217s - in fact they're as nice as the Hacker A20s. And I think that quadcopters would really exacerbate any issue at high RPM - normally these motors are on an airplane that's slicing through the air instead of hanging vertically on a prop. I imagine that the motor stresses of a quadcopter are quite unique, especially when it descends and requires some throttle just to brake.
I've replaced ESCs, motors, balanced propellers, etc.
Anybody have any input on this observation? Would the same setup perform so differently at these two different elevations? Must be outside of the ideal power curve of the motors at high elevation.
And Nikos, you bet - all drawings will be posted. I just want to settle on an airframe design first. And I'm really close! The only way to get through this is to experiment.
Those look nice. I really like the aluminium/Delrin mechanical combination. Those aluminum arms are about the right size for a 2-meter crossed dipole antenna, aren't they? I'm envisioning an emergency airborne repeater station.
I've always wondered if a tricopter was possible, but couldn't envision how yaw control would work without an even number of counter-rotating props. 'Anxious to see how that works out!
Phil - The crossed dipole is a cool idea. I'm not sure how's you keep the controller from crashing with all the RF, but if you could, you'd have a really cool aprs or voice repeater to use for emergencies up in the mountains. Now if you could just make it solar powered... :-)
UPDATE 2-1-2012: THESE RESOURCES ARE OUTDATED- USE THE PRODUCT WEB PAGE FOR DRAWINGS, BILL OF MATERIALS AND TECHNICAL INFORMATION
For those interested in drawings I have attached them as a DXF at the bottom of this post. This isn't the final set, though, as some more changes lie ahead. I've provided a JPG so you can see that the DXF imports correctly.
Ken,
Is it possible that the Props are slipping at high RPM with the Turnigy motors? The prop mounts looked different. I have this problem with my setup using the 3 blade props on a motor that has the same prop mount as I see on the turnigy motor. With the 3 blade props I have to run at really high rpm to get enough lift at all, and they start slipping and I can't get it to be stable at all. I've switched up to larger 2 blade props that get good lift at lower RPMs.
They are both under $14 a piece, and are "hacker style" motors. That second one is rated rank 1 in that chart on the forum you linked above. You can also get them here in the USA for $20 each: http://montorc.com/KDA2022L.aspx
Ken,
Is it possible that the Props are slipping at high RPM with the Turnigy motors? The prop mounts looked different. I have this problem with my setup using the 3 blade props on a motor that has the same prop mount as I see on the turnigy motor. With the 3 blade props I have to run at really high rpm to get enough lift at all, and they start slipping and I can't get it to be stable at all. I've switched up to larger 2 blade props that get good lift at lower RPMs.
They are both under $14 a piece, and are "hacker style" motors. That second one is rated rank 1 in that chart on the forum you linked above. You can also get them here in the USA for $20 each: http://montorc.com/KDA2022L.aspx
Hey Roy - thanks for checking in. I had prop/shaft slippage on the Hacker A20, which is the authentic version of the clone you showed on the second link (we have some of these at Parallax but I haven't flown them yet). With the Turnigy motors I'm not having this problem - there's no collet but four screws that attach the propeller shaft to the outrunner's body.
But your point is valid - I need to use a larger propeller at high elevation. At Parallax I should be able to get by with the 10" APC propellers.
I tell ya, you really need to plan ahead when building quadcopters. The hobby stores don't normally stock pusher-props.
I saw the tricopter video, and it made me a believer, but I still don't understand how it works. Can someone explain this: For hovering, to maintain pitch and roll stability, you need equal lift from all three rotors. But two are rotating in one direction, the other, opposed. That's a 2:1 torque component in the yaw axis. How do you keep it from spinning while hovering?
Adjustable in flight. A friend of mine built his tri this way. A tri with that configuration can be controlled with 3 gyros and Radio Mixing no u-Controller.
Comments
Really neat project, especially since you made it on a short schedule. I started to make one, then lost interest due to the programming aspect, but the board you are using would work perfectly for mine.
Is there any chance of this making a guest appearance at UPENE?
@Adam: I think so! Today I decided to make enough 5/8" OD AL6061 booms for at least four quadcopters and I'll drop them off at the anodizer in the morning. One of them would go to UPENE if I get everything accomplished in time. All the other parts are made on a laser cutter so they'll be done tomorrow.
I have a small CNC milling machine in my home office. Since I wasn't at the Parallax home base today I played for at least half the afternoon and made some parts. Been working too much and this kind of therapy helps keep me in balance. Here's a video taken from my iPhone. Pardon the quality - it's difficult for me to work, talk, and run a video camera at the same time.
'Glad to see you taking time to enjoy yourself! Building stuff, even when it's just to repair something that broke, is the greatest tonic in the world for the realities of work. 'Beats booze, video games, and passive entertainment by a long shot!
-Phil
Good grief! Is nothing beyond the government's reach?
-Phil
-Phil
Congratulations on a great build, Ken - That thing looks very stable, which makes good advertising for the HoverFly guys. As soon as SIGGraph is over and our game is out the door, I'm going to have to cut myself a new frame with my machine. Yours looks very pretty - I really like the way you have the motors recessed.
As a Cessna pilot, I definitely see the need for some type of control here. If any moron can buy a quadcopter and fly it anythere, bad things WILL happen. The Goodyear blimp airfield is just a few miles from my house, near a golf course. 20 years ago, some idiot flying a good-sized RC airplane on the golf course intentionally crashed his plane into the blimp, which caused a hole in the envelope and a controlled mild crash.
-Phil
Gee, I need to get out more...
Pretty cool stuff.
Very nice project. Would be willing to provide a list of the parts you used - motors, ESC's, props, and control board?
Thanks, Al
I don't want to hijack Kens thread here so I'll start a new thread later this week and post more pictures and part details. It's pretty simple to build and VERY inexpensive. That was actually my goal and I'm pleased so far. I'll attach another picture here so you can see it completed. You can see I have it taped to the table so it wouldn't lift off with my one prop when I was doing the transmitter setup. :-) I'm pretty excited.
New thread to follow soon and link to it will be posted here. Thanks for your interest.
...Tiger
P.S. Let me answer two quick questions everyone seems to ask:
How big is it? It's 4-1/4" between motors (exactly 6" diagonal).
What's the controller: HobbyKing (Product ID: QUAD-CON) $29
Al
I can't wait to report on my latest quadcopter progress. I just came back from a couple of days "off" of Parallax, but I didn't go anywhere without a huge box of quadcopter parts I had made ahead of time. I spent the evenings building the third revision of my airframe and trying out some new Turnigy motors. The new airframe works fantastic [or should I say the Hoverfly board works fantastic!]! Better yet, the crew back at the office was sorting out an arrangement with Hoverfly that will tremendously benefit the quadcopter/Propeller enthusiasts - more on that this week.
Brief report on the Turnigy 2217 motor is that it's fantastic but without real scientific comparisons I'd say that it's nearly 95% as "good" as the expensive A20 Hacker motors from Germany. This is already obvious to the many quadcopter enthusiasts on the rcgroups.com forums, but I had to see it for myself. From a strict value perspective the Chinese might be delivering 300% more motor in my view. You've got to really want to "pay for it" for the extra 5% performance, if such performance gap really exists.
More on this later - I need to get settled before I share more on this thread.
Ken Gracey
it would be great if you could publish the drawings of the QuandCopter (something like the MadeUSA Kit). You can help people to start their constructions and make their own proposals. Personally I would like to make a Sketchup 3d Model of the QuandCopter and suggest a XY-Base for the camera!
Of course, I couldn't pass up the opportunity to make a tricopter frame from most of the same parts. Tomorrow we should have a few Hoverfly Sport boards at Parallax so I'll mount one up in the evening for a test flight with the office crew. How I wish I could get away with building these at my desk during the day. . .
I've been using two motors - the Chinese-made Turnigy 2217 ($14/HobbyKing) and the Hacker A20 ($49/Hacker). This is a relevant decision since you can multiple cost per part by four in a quadcopter. Lots of tests have been conducted across the internet on these motors, most notably http://www.rcgroups.com/forums/showthread.php?t=1006721. I wouldn't bother to repeat what's already been done, but there's one aspect that doesn't appear to have been tested: the effects of elevation on the performance of these motors. I really can't quantify what I've observed, so my findings are mostly based on direct observations.
First, a quick look at the two motors. Here's the Turnigy 2217:
Here's the Hacker A20:
The Hacker A20 works wonderfully everywhere, at my home at elevation 7,000 feet and at Parallax, elevation 50 feet. However, at higher elevation it clearly takes more RPM to get the quadcopter flying well. The Turnigy motors at the higher RPMs seem to get off balance a bit - any off-center mounting between the motor case and shaft amplifies, causing some physical oscillation at full throttle. Again, no problem at sea level with the Turnigy 2217s - in fact they're as nice as the Hacker A20s. And I think that quadcopters would really exacerbate any issue at high RPM - normally these motors are on an airplane that's slicing through the air instead of hanging vertically on a prop. I imagine that the motor stresses of a quadcopter are quite unique, especially when it descends and requires some throttle just to brake.
I've replaced ESCs, motors, balanced propellers, etc.
Anybody have any input on this observation? Would the same setup perform so differently at these two different elevations? Must be outside of the ideal power curve of the motors at high elevation.
And Nikos, you bet - all drawings will be posted. I just want to settle on an airframe design first. And I'm really close! The only way to get through this is to experiment.
Ken Gracey
Those look nice. I really like the aluminium/Delrin mechanical combination. Those aluminum arms are about the right size for a 2-meter crossed dipole antenna, aren't they? I'm envisioning an emergency airborne repeater station.
I've always wondered if a tricopter was possible, but couldn't envision how yaw control would work without an even number of counter-rotating props. 'Anxious to see how that works out!
-Phil
...Tiger
For those interested in drawings I have attached them as a DXF at the bottom of this post. This isn't the final set, though, as some more changes lie ahead. I've provided a JPG so you can see that the DXF imports correctly.
Ken Gracey
Is it possible that the Props are slipping at high RPM with the Turnigy motors? The prop mounts looked different. I have this problem with my setup using the 3 blade props on a motor that has the same prop mount as I see on the turnigy motor. With the 3 blade props I have to run at really high rpm to get enough lift at all, and they start slipping and I can't get it to be stable at all. I've switched up to larger 2 blade props that get good lift at lower RPMs.
These are the motors that I have: http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=2049
And these are the ones I am probably going to switch to: http://www.hobbyking.com/hobbyking/store/__4700__hacker_Style_Brushless_Outrunner_20_22L.html
They are both under $14 a piece, and are "hacker style" motors. That second one is rated rank 1 in that chart on the forum you linked above. You can also get them here in the USA for $20 each: http://montorc.com/KDA2022L.aspx
Hey Roy - thanks for checking in. I had prop/shaft slippage on the Hacker A20, which is the authentic version of the clone you showed on the second link (we have some of these at Parallax but I haven't flown them yet). With the Turnigy motors I'm not having this problem - there's no collet but four screws that attach the propeller shaft to the outrunner's body.
But your point is valid - I need to use a larger propeller at high elevation. At Parallax I should be able to get by with the 10" APC propellers.
I tell ya, you really need to plan ahead when building quadcopters. The hobby stores don't normally stock pusher-props.
Ken Gracey
Phil: Here is a link to a fantastic TriCopter video - flips and all (bottom of the page) http://www.multiwii.com/
For anybody interested, I've posted a new Bill of Materials on the second link. It doesn't have a complete screw/nut listing at this time.
I saw the tricopter video, and it made me a believer, but I still don't understand how it works. Can someone explain this: For hovering, to maintain pitch and roll stability, you need equal lift from all three rotors. But two are rotating in one direction, the other, opposed. That's a 2:1 torque component in the yaw axis. How do you keep it from spinning while hovering?
-Phil
-Phil
Adjustable in flight. A friend of mine built his tri this way. A tri with that configuration can be controlled with 3 gyros and Radio Mixing no u-Controller.
-Ron
You've got to be kidding, Rich. That's really a bit wonky, isn't it?
I don't buy it. . .but I don't know much about this, either. It just doesn't seem practical.
Ken Gracey