Wanting to see if anyone could look over my log and tell me what they think I should change or leave it.
I see a little output oscilliation that I am trying to figure out where it is coming from.
To my taste, yaw is way too sloppy (± 2 degrees almost, peaking to 5 sometimes - the feel and FPV feed, if any, should probably be disastrous). This may also be a contributing cause to few-degree pitch and roll deviations especially at maneuvre extremes.
Well, actually yaw is completely at defaults, which may explain this. Obviously, it’s 2025 and for a 3-inch quad you want some YawD tuning as well.
By the way, what are the ESCs? Surely something running Bluejay, but seem to be reasonably powerful to supply an EDT2 stream that does seem to actually show something. If I read the subsystem right, you may benefit from increasing the timing a bit, as various stress bits seem to correlate with aggressive maneuvres, which kind of says that the grip of the ESCs on the motors is not as tight as one may want.
1 Like
Thank you for taking time to look at my log.
I haven’t tuned the yaw yet, I was trying to get roll and pitch dialed in first.
Grateful for your time!!
It’s usually the advice to tune roll and pitch, then tune yaw, then re-tune roll and pitch again. I expect much better handling of roll and pitch after yaw stops feeding roll into pitch and vice versa. ATC_ACCEL_Y_MAX should ideally go up to some 150k…200k for reasonable FPV experience on a machine of this size. Expect some 10-20% of accel increase in other axes after you re-tune them after yaw is dialed in.
You may also check how position handling works if you plan to use loiter or similar modes. I have seen that the defaults are noticeably suboptimal for agile machines. This is to be tuned manually, but not too hard. My non-quad video of trial-and-error tuning for the position subsystem is linked below.
1 Like
Hi Kevin,
Can you tell me the AP hardware you are using in your 3in quad? I was thinking about making one soon.
@Quadzilla I really like this AIO, kinda limited for processing power but seems to work great for me. Price is a plus.
I’ve heard good things about Micoair aio’s but havent tried them…
Thank you so much I will look at them.
1 Like
I’d be happy to share the full build list for my 3.5" Arducopter beater.
The build goals were:
- Arducopter firmware
- Sub 250g AUW
- Sub £200 (excluding battery)
- High performance
I used the ImpulseRC Micro Alien 4" frame with 1604 motors and 3.5" props. Performance is very good and autotune gave a tight tune. The biggest limitation is that the GPS and compass performance is compromised by proximity to the VTX antenna, battery lead and capacitor. It can loiter well and do high speed auto missions, but I’ve yet to refine the WPNAV parameters for smooth fast-ish auto missions.
The advantage of the Micro Alien frame is that it’s light (~35g) and compact, but it is a tight build and only really suited to a 20x20 stack and analogue VTX. Weight is 152g dry, 233g with a 4S 650mah LiPo.
I imagine the 3" variant with 1404 motors would also perform well.
2 Likes
Very cool! I hope to package up the Hex frame for you soon!