Bitcraze Forums

hello yall

im just looking for some confirmation on changing the crazyflie2.0 motors to bigger hubsan ones.....exactly the 8.5x 20mm ones.here

example>
http://ru.aliexpress.com/item/Hubsan-X4 ... 59701.html

i have read and followed these links already and understand the process but as im a bit worried to break my crazyflie id like to confirm some things.....
viewtopic.php?f=6&t=871&start=10
https://github.com/fpiesik/pCraze
http://frankpiesik.org/2014/06/01/crazy-experiments/


im just asking for confirmation on some notes that im a bit unsure......

so in one of the posts there is a reply from tobias that said


There are some factors that limit the current.

1. The battery. The 170mAh battery for the Crazyflie has a protection circuit (PCM) to cut it off at over 4A continuous. Switch to a bigger and better battery.
???so i plan like in the links to use this battery https://www.ebay.co.uk/itm/Nanotech-750 ... 1830335705 because of the high c rating (discharge rate) i can get the required amps i belive?

2. The battery connector. Can be worked around by switching to a better connector or soldering the battery directly.
???whats wrong with the connector?it cant handle the amps?

3. The board traces. These can probably handle 10A but has not been tested or calculated. External wires could be soldered to increase current capability.
???can someone explain a bit more for me?

4. MOSFETs. These should be able to handle at least 3A per motor.
??? thats ok then.

5. The noise the increased current generate. This is probably the most difficult factor to handle but could be helped by putting decoupling capacitors between ground and the battery connected motor terminal.
???ok so thats a cap 470uf between vcc and gnd of the battery ?vcc being the bat input plus (red-wire)and gnd being the bat input ground(black-wire)?

he used 3 470u(10V) capacitors, one of them connected to the battery terminals and the other two connected to vcom and ground.

??? where is vcom and which ground the bat ground or anyground on the crazyflie?

i also noted just after he wrote this
"
It shouldn't be too hard to put an external +BAT wire. Or even easier, you can solder all positive motor wires directly to the battery connector (if they are long enough)

???can i do that..would that be better than the two caps in parrelel?

. Then that wont be an issue. Then you can also easily solder a capacitor, try maybe 100uF, between + and - on the battery connector.
"

???so can i solder all (red-wire) + wires to the plus (again-red-wire) of the battery terminal ?

??? put an external +BAT wire???whats that??

anyway thats all...

i uploaded a photo of shematic and a drawing its maybe allot to ask but so the idiots like me find it easy for the future if osmone could draw the mod in a shematic like below and add there configuration it would be nice...

thanks again

Hi,

Most of those factors are for the Crazyflie 1.0. For the Crazyflie 2.0 I would say creating new motor mounts might be the biggest hurdle. Else the rest of the system should be able to handle the 8.5mm motors just fine. A bigger battery with higher C rating and more capacity would be preferred as well.

ok so no need for the caps on the crazyflie 2.0 .using 3.7v 750mah 30c rating should be fine then.

i have already printed a frame so will upload somewhere when tested...thanks

You can definitely try without a cap but if you get a detectable voltage drop during thrusting you might have to add one.