Crazyflie w/ Double Motors

[absoloodle37]

5V step up powers the camera great (used VCOM and GND, pin 16 & 18), but I still lose signal when throttling up, or when moving 2m away from the TX. I used this one: http://www.pololu.com/product/798/

Also tested without the camera and I STILL have reception problems, so I don't think the camera/TX is a factor. I used to fly this double-motor CF without any reception issues, but now I can't push the throttle all the way up without losing signal. I also lose signal once the CF moves about 2m away from the USB TX. BTW, I also have a second CF (single motors) that flies normally on the same channel/bitrate and battery, so I know it's not a reception issue or a battery issue.

It's pretty strange, considering my double-motor CF didn't have this problem before I started messing with a camera/tx. Do you think the PCB or power supply is damaged somehow? How can I troubleshoot further?

Thanks for your help!

[absoloodle37]

After more testing, it appears the battery is related to the link reception problem. I've been using several different 25C-35C 3.7v batteries that have a larger capacity (400-600mah) than the stock 170mah Fullriver battery.

When I use the Fullriver battery that came with my CF, the reception issue goes away and I can fly normally, albeit only a couple minutes due to having double motors. I think the other batteries I've been using aren't providing the current/discharge needed (strange) or perhaps they aren't shielded well enough and are causing some type of RF interference. Wish I had more electronics experience to figure this out...

I'll continue testing.

[omwdunkley]

If you compare your two flies, are the LEDs equally bright?
I had the same symptom (along with a few more) when i damaged the voltage regulator, some details are here: http://forum.bitcraze.se/viewtopic.php?f=5&t=516
Maybe that helps!

[absoloodle37]

Thanks omwdunkley. One flie is completely dead (no lights except for when charging; can't even turn on when connected to battery) and my one with double motors drops it's link once the power is pushed up above idle or when moved 2m away. The LED's are bright though, but they get dim after a few seconds. Tried troubleshooting (different batteries, RF interference, etc.) but I think it's a bad regulator.

Will try to replace the VREG like you/tobias did in the other thread. Did that solve the problem for you?

[Bumbolt]

What is the total payload that you guys can handle with this? And wht is your flight time with full load and standard battery.

It's seems to me that you guys are aiming for more weight to lift heavier batteries. I'm looking for more payload to lift more sensors, so i can't really afford to swap the standard battery for a heavier battery. Still waiting for my shipment (i did order spare motors and blades). I would need about 21.3g payload in ideal cases but i think this is an illusion. I could propably live with something in the 12.9-17.2g range.

The specs say you can lift 5-10g with a default flie and you say you added 5-10g extra. So that would mean i can lift 10-20g extra. Am i correct?

[absoloodle37]

I extended the second set of motors outside of the original motors so they would be out from under the prop wash of the first.

In the modified double motor configuration, I'm carrying 10g of total battery weight (240mah for the CF, 70mah for an FPV camera), plus 5g for the camera & tx. This gives me about 10 mins total flying time, which is plenty for the short clips I'm filming flying around the rooms in my house. The vibration of the motors on the tx degrades the image quality, so I'm working on damping solutions.

When I get some time, I'll refine these numbers for you, but this should get you started. 20 total grams of payload should work, but you'll have to factor in the 5g for the 170mah OEM battery (15g left), and then you'll only have a few minutes of flight time.

What kind of payload are you considering?

[Bumbolt]

I want to lift some (HR)LV-MaxSonar®-EZ™ sensors for a mapping bot. It's a college project. In an ideal case we should lift 5 sensors, each 4.3g but this is to much. Doing it within the margins of the crazyflie's lifting possibilities is the main goal of the project.

In the mean time i've recieved my crazyflie and i'm experimenting with making my own pc API to fly it. So no sensors yet. I did order 4 extra motors, mounts and blades. So i've got plenty of spares.

[Csulok]

Why not just use 4 15W motors if the controller can handle them?