That's a thought - I was leaning towards black (because aesthetics matter) 2205's - they're about AUD6/set more expensive than the 2403's
It's not really left overs it's the proceeds of grabbing bargains over the past few months. I was intending to build a kind of big camera bus to lift my nice Feiyu brushless Gimbal and GoPro with it all but instead I bought this for reasons unknown.
I suppose I could build a servo-Gimbal into the front of it in the TBS discovery style?
The Spedix arrived from Hobbykings Australian warehouse and at my front door on the Tuesday after my weekend purchase so I was very quickly able to see just what a great deal I scored.
Hobbyking had been selling an S250Q and a S250AQ, and in my enthusiasm to buy something I didn't need I couldn't work out the difference. So I bought the S250Q.
As it turns out theres a different in the upper and lower plates that sweeps the "rear" motors back a bit more. Apparently this makes the AQ more agile. In hindsight with my flying I bought the right frame!
The frame came well packed in a simple cardboard box with the complete kit of arms, carbon plates, rubber ball camera mount, PDB, ESCs and a few stickers. The single sheet of "instructions" are a few clear diagrams covering what goes where.
The PDB and ESCs are set up to plug and play. While normally I'd be hesitant to rely upon 2mm banana plugs for connecting the power to the ESCs this is one of the built-in features of the frame and I'm hoping the wire lengths with make this a neat idea. The PDB will accomodate 6 motors and had the Hex version frame kit (with PDB and ESCs) been available at the same discount price I suspect I'd have that instead.
The plastics look to be we moulded and carefully designed. The arms for example have alloy spacers integrated for mounting, this should make the frame quite durable. I'm confident I'll be breaking the landing legs though - that seems to be my flying talent.
The S250 was my first 250 quad, and I'd been flying variations of it for the past couple years. I've also kept up on the RCG forums for it, and here are my thoughts. It's excellent for introducing beginners to the 250 class, especially given it's cost and ease of assembly. But it's not very durable. The first thing to break is usually the (green) landing gear. They are very brittle, and if you snag/hit them on the ground, they tend to snap. Modifying them by shortening/cutting them in half, makes them more stout and much less prone to breakage. But if you mount your battery on the bottom, they will not be long enough to provide ground clearance for it. But this hasn't caused any problem for me. The next part I started breaking was the bottom plate, and I've gone thru 8 of them! At only 2mm thick, it can't withstand much of an impact. Mine always broke near the arms, due to an impact to one of the (plastic) arms. To prevent this, I stacked a second plate, but then the weak link became the arms themselves, and I started breaking them. I also had several failures involving the board-mounted bullet connectors on the PDB. The shock of impact was breaking the solder joint. Over time, I had to resolder most of them. Not sure if this (cold solder joint) was a common defect, but I've read of a couple other reports. I'm not a racer, but like to fly proximity around my trees and dabble in freestyle. And as my flying got faster and more aggressive, this frame became too much of a hassle to maintain. At HK's sale price, I still recommend it to beginners. But I don't feel it is adequate for anyone flying at a more spirited level.
I’ve cleared off the bench and started to organise myself to get this build happening.
I have two motivations; 1. The Trifecta is doing my head in and adding in learning iNavs foibles plus the flight dynamics of Tricopters means I’m just chasing my tail too much. I’ve ordered ESCs for it and will rebuild it over time. So this will be my iNav Test bed.
2. I have a desire to build another super tidy version of a simple quad.
I’ve also been looking at the F3 EVO FC that I “broke” with the great Trifecta Fail. I’m going to do a board level replacement of the burnt Schottky Diode and clean it all up and go from there. The EVO will support all the iNav features I want, including the Sonar. I will then have 3 quads running F3 EVOs and a “spare” F3 Deluxe for a future build.
If I can’t arrive at a point where I can make either iNav or Cleanflight work for what I want I think I’ll switch back to Pix or just drop the cash on a Xiaomi/Phantom/Mavic for my Camera Bus wants.
First we clean up all the through-holes on the PCB:
This is the 5th or 6th time I'm soldered/desoldered most of this borrd so it's got a lot of flux on it. I'll grab some cleaner and bring it back to "new" once the replacement BAT54C is installed.
BAT54C?
When I realised I had a burnt part on the PCB I started searching, I ended up finding this thread (plus I had another two EVO's to read component numbers off). https://www.rcgroups.com/forums/showthre...ing-f3-evo
As it turns out RS Components sells BAT54C in small batches of 10 components. At a mere AUD0.35 each delivered! (There's a cheaper version than this but I'm ordering "Brand Name"). They should arrive during the week.
The Flight Stack: SO Although the Speedix frame came with a huge and heavy PDB I've decided to use one of the nice Matek units like the UAVFutures build I put together. It's much lighter, adds current sensing and is much neater.
The GPS module is tiny so hopefully it's still effective!
ESC's: Speedix produces round! ESCs and they're included in this bundle. Supposedly they're BLHeli friendly. We will see!
It will be interesting to see what kind of performance you get from that tiny GPS. The ceramic antenna is super tiny, so unless you keep it well away from sources of interference, it will probably have a hard time keeping a lock on enough satellites, especially as it's based on a clone of the older UBlox 7 design.
Does it have a magnetometer built in or will you be using the one that's included in the F3 Evo's IMU? You will need to use one for autonomy on a quad. Fixed wing craft don't need a magnetometer as heading can be deduced from several position readings over time. Quads can change heading too quickly for inferred heading to be useful.
Hopefully you'll be able to get compass readings that are stable enough to be useful. This can be a challenge on a small quad as it's hard to get the magnetometer out of the interference generated by the PDB, motors and ESC power wires.
21-Oct-2017, 01:15 PM (This post was last modified: 22-Oct-2017, 07:37 AM by Aaron. Edit Reason: Stoopid Autocorrect )
GPS gets a 5-6 satellite lock in my study when on the bench near the window. It’s not as good as my M7 on the Trifecta but definitely works. I do have a larger M8N kicking about but the tiny one intrigued me enough to buy when it was on sale.
I’ve had no issues using FC magnetometers with the APM boards, and the EVO clones seem pretty stable too.
Racerstar 2205 2300kv have been ordered for it, they’re the most expensive bit at about AUD40 for the set delivered. Everything else has been closer to AUD15 each.
Was looking at Cheap250 again and actually flying it in the front garden (you can interchange "flying in the front garden" with "weed whacking the front garden") and thoughts for a while at least I should really throw some cheap plastic prop guards onto the Spedix AND the UAVFutures build.
My flying is moderately lousy and given I have some much configuration to chase with the latter two that the additional safety is probably a good idea.
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