Newbie gets cocky and purchases incorrect stuff

D

dpp

Member
Hi,
Yep, I got cocky and tried to combine to builds into one. I followed a build video on ubemy for a drone that works with a Raspberry pie because I wanted to be able to code missions into it. This build is built on a larger frame with 10" props BUT I decided I wanted to use a smaller frame (5'' Lawson FPV Battle Axe Freestyle Frame 250mm 5 Inch Carbon Fiber Quadcopter Frame Kit) so I bought that and some DroneACC 12pcs 5045 3-Blade Propellers 5 Inch Tri Blade Props

But my motors are Emax MT2213-935KV 2212 CW CCW Brushless Motor For DJI F450 X525 Quadcopter Multirotor with LHI Brushless 30a ESC Speed Controller. These motors have 8mm shaft holes so the props do not fit. I have searched for 5" props with 8mm shaft holes but can not find any. My guess is that there is a reason for this. :)

My question for the experts here is, are any of these parts salvageable? or do I need to start from scratch?

Any help would be greatly appreciated.

Regards
app
 
Hello dpp,

Welcome to the forum!

It's all good, making mistakes and learning from them is a big part of this hobby so better to get started early right ;)

Regarding the pi based copter I would hold off on that till you have some things flying with betaflight or iNav or some other more stable flight controller software than the straight DIY solution. I think for the most part you'll want a Flight Controller (FC) and just have the Pi doing some higher level coordination but honestly not sure what you can't do with iNav that you might accomplish with a Pi. Also Betaflight and iNav and OpenTX are all open source projects so you can just fork and add on your own code if you want to be able to tinker around with the internals of things.

Everything you listed so far will work fine except for those motors. I think for the appropriate RPM on the prop that you want for 5" quads you'd need very high voltage batteries to make that work and likely the ESCs only support up to 4S or around 16.8V fully charged and at rest.

I'd say return the motors, get some 2450kv or so motors with 2206 dimensions (or thereabouts, 2208 or a bit bigger would be fine) and will be in good shape. The kv tells you how many RPM per volt you get, with 4S you want to use somewhere between 2300-2600kv, and 2450kv seems fairly popular as an option when using 3S or 4S batteries. If using 6S batteries you'd use 1800kv or so motors so with 900kv motors you scooped would need like 12S which is kind of absurd for a small quad (some people have done it, see NurkFPV and others) but 12S ESCs are expensive generally as are chargers etc. etc. so using that higher voltage pack comes with a lot of extra costs (with some gain in electrical efficiency at higher voltage, less energy lost as heat due to higher amperage that you would get in motors if you were on lower voltage).

TLDR, return motors, get 2450kv ones, buy a Betaflight and/or iNav compatible FC and 4 individual ESCs (my 2 cents, if you are messing around type you are likely to blow ESC and then individual is easier to deal with than a 4 in 1 board.... ie stick with what you chose already)

---

Also you'll need to get a receiver of some sort and transmitter, suggest getting a T16 variant of some sort there are a few out now, I have a regular Jumper T16 and happy with it, binds to everything I can find laying around so far, has module for the TX antenna(s) so can swap out if it somehow doesn't support something you're using (probably TBS only, it includes Spektrum/DSMX/DSM2 and FrSky). Also, also need a charger and batteries. After that should have enough parts to build a Line of Sight flyable quad, can get a little used to that at first in terms of just hovering and "walking the dog" watch some getting started vids. If you want to fly FPV then get camera/goggles/display setup to transmit/receive video, if you want to go GPS controlled get GPS module like Beitian 880 or the M8N ones (watch out for fakes a lot out there)
www.u-blox.com

Counterfeit products and u-blox brand misuse

Counterfeit products and u-blox brand misuse
www.u-blox.com www.u-blox.com
 
Last edited:
HI Again.

I got some Crazepony DX2205 KV 2300 brushless motors and set them up with my 30a ESCs, Matek PDB-xt60 and Li-poly 14.8v 30c 300mAH RC Battery. But when i power up the motors they start to smoke and do not seem to spin very fast. Any idea what i am doing wrong?
 
If motors are smoking it usually means something shorted out the wires inside the motor. Unfortunately most of these bldc motors don't have a "stop" for the mounting screws so if the screws you used to mount the motors are too long they can get up into the windings and scrape the enamel off and cause a short in the winding (current is meant to go all the way around the loop). Another issue though not as big a problem is the battery size you'll probably want 1300mAh or 1500mAh batteries (for at least like 5 min flight time) I like the ones from ovionic. For the motors check the screws going into the base of the motor backing them out and using shorter screws may help but if already smoked then at least part of the coil is toasted so probably needs to be replaced. This is one of those crappy gotchas when doing your first build.
 
One other way motors can get smoked is if they are stuck on a branch or the like and you throttle up hard and the ESCs deliver enough current to cook the motor (usually in this scenario I've just cooked the esc but have seen it smoke plenty of motors for others)
 
Hi and thanks for the response.

So based on what you said about the screw length, i detached a motor from the frame and tested it and it worked perfectly. But i checked and the screws are not touching the coils. The motors come with 2 sizes of screw and i am using the shorter ones and they barely go inside the motor base but something is causing the issue when the screws are in. I re-attached the motor and got the same issue. Any idea why the screws would be effecting the motor if they are not touching the coils?
 
Sorry yah really not sure could maybe post video or close ups of the motor mounted but honestly not sure, make sure the esc is well insulated from the carbon fiber frame too if using one since it is conductive to some degree.
 
You nailed it. Good call. I put a strip of insulation tape between the ESC cables (which strangely are already insulated) and the frame/motor screws and that did the trick. See pic attached. Thanks for all the help. Onto the next issue :)
 

Attachments

  • Screen-Shot-2020-06-10-at-5.35.46-PM.jpg
    Screen-Shot-2020-06-10-at-5.35.46-PM.jpg
    566.2 KB · Views: 0
Back
Top