I have been building for a couple of years and initally I had a lot of trouble with failures of ESC's and motors. When I finally switched to Hobbywing Xrotor ESC's and T-motor I never had a problem again. I am dubious of high priced items these days because so much is just the same junk with high priced lipstick on it.
But in the case of T-Motor they are noticeably smoother. They use larger bearings and shafts. The windings are clean and uniform. But I am still a cheapskate and I take advantage of surplus like the 2213-950kv from 3DR. I bought 10 when they were dumping their stock at $5 per motor. But even at $10 from Multirotor Mania, who did the same thing, they are a good buy. I also get them surplus when someone is not doing a build or for some reasoning getting rid of new motors.
I kind feel bad about intruding over here because the Solo was always designed as a tool for cinematographers but now that the Open Solo project has brought it back from the dead it is a target for the DIY crowd. It offers features that are just not cheaply available to the DIY community. My Holy Grail is to have HD Video, RC Control and telemetry over one transceiver radio, which the Solo offers, but it is very hard to find in the DIY arena. Usually we have to have three radios on an aircraft to do the same thing, which poses problems.
So I am using another donor Solo to build a 680mm quad with Solo guts which should have 25m of flight time, at least that is what I am shooting for.
Thought I would pass on some learnings (and almost-learnings) from my attempts to upgrade stock 3DR motor pods. (I'll leave out my attempts to change bearings, since I have not invested in an appropriate bearing installation tool, and so far the results have not been good.) After soldering in four motors as were used on the 3DR Iris, I was impressed with the relatively quiet sound. Of course the pitch of the sound was higher because they are spinning at a higher speed, all other things being equal when compared to the stock motors/bearings. This may be relevant to a later comment.
As someone else noted,
if you can find a source of adapters (only two mounting screws) to match these special motors, you will find that the color of the adapters is
opposite of the colors used on the Solo (see photo). And if you do enough of these mods, you may rediscover that the Solo motor pods are hardware-keyed (see image) to prevent users from inserting a "silver" pod into a Solo body arm designed to hold a "black" pod. And of course you must pay attention to the direction that the motor is
supposed to be spinning, which is
opposite of the directional arrow on the pod. If the motor is spinning in the wrong direction, then reverse
any two of the three motor wires. By now you may wonder if all of the trouble is worth it. After all, once you've tampered with a manufactured product, there's a chance of introducing a new problem(s).
Now look at the attached image of four propellers. From left to right are: (a) stock 3DR Iris; (b) stock 3DR Solo; (c) stock APC; (d) stock Master Airscrew. Don't try to use stock Iris props because they won't fully seat on the adapter (shaft is too long). The other three props attach with no problems (CW and CCW).
On the bench using Mission Planner to test the motors, everything sounds great. Outside with props on, powered up and ready to launch, everything sounds great.
However after launch there is a noticeable, rhythmic, rotational shake in the Solo. Maybe not bad enough to overcome the gimbal, but not a good thing. The shake is most pronounced with the MA props, less so with the APC props, and even less with the stock Solo props. Twice I have swapped out the modified pods with new stock Solo pods (apparently with "good" bearings, at least for now), and both times the Solo looks and sounds great with the stock pods. Not so with the modified pods. So...
maybe one of the modified pods has a problem.
Maybe the whole set of 950 Kv motors introduces a problem.
Maybe there's a parameter value(s) that could be carefully changed to reduce the shake.
Maybe someone has seen this problem before first-hand, and has found a solution!
Those IRIS motors do sound nice.
