DIY Tiny QuadCopter - Advice

HopWorks

HopWorks

Member
Hey Everyone! Greets!!

In case I post this before I have performed my search, my apologies!!

I need advice. All I need is a point in the right direction for a frame and advice on the proper motors and ESC's.

I want to build a tiny quadcopter. Something in the range of 50-150 mm, or even smaller. I have an autonomous in-door task in mind, and I will either buy or build a smd-based flight controller for it. I might even build the ESC's myself, although would prefer to buy pre-built equipment because of the reliability and ease of troubleshooting. I'm looking for direct-drive for the motors, and weight and power is certainly an issue. So is cost since I'm not funded by big company with endless resources for a thousand dollar prototype. It's for home use anyway.

I am looking to build a platform that will perform tasks based on code, a scripting language of sorts that I have developed myself. I plan to have on this platform, a few 2.4GHz transmitter/receiver pairs for telemetry, interactive control, and a camera feed from a small CMOS camera module. A 9 axis accelerometer, and (based on R&D) several IR RX/TX pods for object detection. I haven't used simple camera feeds for object detection or identification lower than a beaglebone black platform so that's not in the works for now.

All I really need to get started though is a tiny lightweight frame and some tiny motors and tiny propellers. I have googled this somewhat, but I figured I would find the best sources here, which is the reason for my post.

It's an idea from a guy (myself) who envisions such ideas but doesn't have the product knowledge in this area. This is a reach out so I can certainly get started!

I fly my little palm-sized quadcopter all the time in the hopes I'll get good enough to try something larger. This idea is based on that, but certainly not forwarding that area of interest for me. I write scripts and conditional code better than I react at the flight stick. lol.

Hope I didn't bore you with my post, and certainly appreciate your time! Thank you for taking the time to read about my reach-out idea!!

Sincerely,
Gary Rubin
HopWorks - Embedded Imagination
 
mm said:
This looks like it fits the bill & everything is integrated, which is almost necessary at this size:

http://www.hobbyking.com/hobbyking/...atible_with_FTDI_Tool_MWC_Multi_WII_BNF_.html

And I believe the MWC is open source.
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Yep! Thank you sir!! That is exactly what I am looking for!! I work with the 328p all the time via the Arduino Pro Mini (5v, 16MHz) so this is awesome! I was actually feeling guilty posting like I did. So many have started from scratch and after reading my post, I felt like I was trying to leap-frog over all that, using other people's hard work to launch myself forward. As it turns out, it was a good idea because of where you pointed me to. I'm sure I have a lot of trial and error to experience still, but your answer puts me right where I want to be with this project!! Again, thank you!!!

I have no idea how I missed this item. I searched all over their site too. What isn't listed in the 'features' is the motor type or options for other motors. No biggy, this is a huge start. =)
 
No problem! Never a bad question. Also, the whole point of the forum is to save people time and to point them in the right direction!

Yeah, their site is a pain to search. I honestly don't even know how I came across that. I just remembered it when I read your question. I didn't have the link, but I just searched "micro mwc" on HK and it popped up. I just searched "micro quad" and didn't see it in the first couple of pages, so I probably wouldn't have found it if I didn't remember it had MW controller integrated.

I have no clue what the motors are and they don't look like they have any markings on there. I've never tried it, but it's possible that if you contacted Hobby King, they could answer. Also, you could always pose your question on the product page and someone might know.
 
mm said:
I think these are the same motors:

http://www.hobbyking.com/hobbyking/...cro_Hexa_copter_Replacement_Motors_3pcs_.html
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Or these...
http://www.hobbyking.com/hobbyking/...bbyKing_Pocket_Quad_V1_1_Quadcopter_4pc_.html

The weight might answer my question as to "why no brushless with a MWC?". 3g apiece compared to 50g+ for brushless. Here I am already looking to increase thrust and payload weight. lol. My accelerometer and 328p boards are so small and light anyway. I do need to put a camera on it though, but for some really simple object detection. Super low resolution (Westworld-like pixelation) so a 328p can process. Fun stuff! Wow, I need a good digital scale! hehehe
 
This might work and it has a transmitter built in. Otherwise, you should be able to find a micro camera pretty easily.

http://www.hobbyking.com/hobbyking/...R_Ladybird_V2_FPV_Ultra_Micro_Quadcopter.html

If you're in the US, I use this scale and it works wonderfully, but I did have to buy a standard 500g weight to calibrate it:

http://www.harborfreight.com/1000-gram-digital-scale-60332.html

I got that on Amazon:

http://www.amazon.com/American-Weig...=1-1-catcorr&keywords=500g+calibration+weight

They also have a scale/weight combo on Amazon for $20, so that might be your best bet.
 
Great information MM thank you! Yeah, it is funny that the calibration weight is almost the same price as the scale itself. There are a few options on Amazon. .01g or .1g resolution in 100g and 1000g sizes. I might get both because I would think that component selection for a board could matter based on hundredths of a gram. Also, someone posted that a 'clean' nickel is exactly 5 grams, so 20 of those would be a good calibration weight (for the 100g scale that is). What do you think? If I order both, I could make a 100g weight and then use five of those to calibrate the larger scale. Hmm.

I have a few options for a camera. I have a few various CMOS camera modules on my embedded bench to play with, and a whole bunch of the 328p 16MHz 5v boards to support these little subsystems. I am going to order some 8MHz/3.3v versions today so I may test power consumption versus processing speed / performance. I am so jazzed about this, I had a hard time getting to sleep last night.

Since you are doing such a great job of answering all my mysteries, is there a digital caliper you would recommend?
 
I know - I bought the scale and then got home and read the instructions and realize it was no good unless calibrated! Keeping weight down is extremely important when working with regular sized quads, but when you're building a micro, that's amplified by a lot and every fraction of a gram likely matters. I've never built a micro, but I'd definitely get both just to have them if you're going to build one. I have no clue about the nickel thing, but it's probably close enough - except maybe if you're calibrating the scale that's doing .01 gram increments. But then even a calibration weight from Amazon would be no good. They're all pretty much made in China and I'm sure they have a decent size tolerance.

Hahaha - I'm glad you're excited! I love this hobby. Any time I'm working on a build, I usually lose sleep and then end up dreaming about the build while I'm sleeping. And I have a bunch of a-ha! moments in my dreams. But usually I wake up and realize they aren't realistic.

If you have a harbor freight near by or want to buy online, they have a bunch of digital calipers for cheap. That's what I use. They might not be the best quality, but they are very inexpensive. If you need a lot of certainty as far as accuracy goes, I'd just find one with good reviews on Amazon or something.
 
mm said:
Hahaha - I'm glad you're excited! I love this hobby. Any time I'm working on a build, I usually lose sleep and then end up dreaming about the build while I'm sleeping. And I have a bunch of a-ha! moments in my dreams. But usually I wake up and realize they aren't realistic.

If you have a harbor freight near by or want to buy online, they have a bunch of digital calipers for cheap. That's what I use. They might not be the best quality, but they are very inexpensive. If you need a lot of certainty as far as accuracy goes, I'd just find one with good reviews on Amazon or something.
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Ok, thank you for the advice!

I often dream of accessing and writing blocks of code that are floating out in the air around me. The routines often look familiar to me as objects, like an orange versus an apple for example. I stick my pointer finger in between lines of code and pull them apart and fill the space with my thoughts. Probably because I watched the Iron Man movie series too many times. lmao!

I plan to blog my project as I progress, and I would be happy to post about it here.

Hey, off topic but what do you think about the proposed FAA regulations concerning FPV flight? I'm depressed!!

Thanks again sir for all your info!!
 
I have a little dilemma... I found some brushless motors on HobbyKing that are really light. Although the specs show 3.1g total weight, the weight of the item is listed at 15g. I assume that is the shipping weight (I hope!) because 3.1g makes these almost as light as the brushed motors I was going to use.

I have some research to do, like what the Kv spec means, and thrust to weight ratio. I am looking for more thrust, but also something more durable and certainly quieter than brushed motors. Cost of course is an issue too. These brushless Turnigy motors are about $10-$18 which makes them quite an upgrade from brushed. I need to gather data on how the thrust and noise features will possibly outweigh added weight and power consumption.

Any thoughts are certainly appreciated. I of course will need to look for how to mount these on a 100mm integrated frame or if I have to look for a frame elsewhere. I have seen others, but nothing smaller than 200mm prop to prop diagonally.
 
Kv = thousand RPM's per volt applied (no load).

It's probably shipping weight, but it's weird that it's that much more.

What motors are they? Do you have a link?
 
The ones mentioned but smaller. Still shows 12g versus 2.3g including mount and wire.
http://www.hobbyking.com/hobbyking/...AP_02_7000kv_Brushless_Micro_Motor_2_3g_.html
The power (2a) is throwing me. 4 motors plus electronics would be 8-9 amps? That's a lot. Probably too much power for an insect emulating micro quad. I realize that is amperage for full-out operation, but I do not want to fly it through my ceiling. lol.

Looks like I have a lot of calculations to do.
 
mm said:
With the recommended prop, it only drew .9a and had 19g of thrust with a 1 cell lipo.
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I have to assume that is good. 3.6a and 76g of thrust, or less actually when you take into account the wake of each prop, or so I have read. How would one test this? I thought about equally tethering each extension to some sort of sensor that reports 'pull', with equal lengths of some sort of tether material. If I could do that accurately, I could sample thrust readings using different lengths of tether. Might help me to calibrate gyros, etc. I'm sure there is some sort of device that provides this. Any thoughts?
 
My 1000g/.1g and 100g/.01g digital scales arrived today! WOOHOO! Now it is time to plan and build the subsystems. :cool:
 
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